A Mechanical Analyzer for Computing Transient Stresses in Airplane Structures

1950 ◽  
Vol 17 (3) ◽  
pp. 310-314
Author(s):  
R. L. Bisplinghoff ◽  
T. H. H. Pian ◽  
L. I. Levy
Keyword(s):  
Normal Modes ◽  
Phase Relations ◽  
Elastic Structure ◽  
Mechanical Analogy ◽  
Proper Design ◽  
Torsional Pendulum ◽  
And Function

Abstract A mechanical-analogy-type analyzer is described which is used for computing the transient stresses in an undamped elastic structure. The two main functions of the analyzer are (a) to evaluate the stresses due to the deformations of an elastic structure in its various normal modes, and (b) to superpose the effects of the modes with proper regard taken of their phase relations. Function (a) is accomplished by the use of torsional-pendulum simulators, and function (b) by the proper design of the electronic pickup and recording circuit. The analyzer is particularly useful in the determination of dynamic landing stresses in airplane structures.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

Microscopy of porous ceramics

1989 ◽  
Vol 47 ◽  
pp. 438-439
Author(s):  
H. M. Kerch ◽  
R. A. Gerhardt
Keyword(s):  
Porous Ceramics ◽  
Specimen Preparation ◽  
High Porosity ◽  
Ion Milling ◽  
Forming Process ◽  
Preparation Methods ◽  
Pore Texture ◽  
Proper Design ◽  
And Function ◽  
Function Information

Highly porous ceramics are employed in a variety of engineering applications due to their unique mechanical, optical, and electrical characteristics. In order to achieve proper design and function, information about the pore structure must be obtained. Parameters of importance include pore size, pore volume, and size distribution, as well as pore texture and geometry. A quantitative determination of these features for high porosity materials by a microscopic technique is usually not done because artifacts introduced by either the sample preparation method or the image forming process of the microscope make interpretation difficult.Scanning electron microscopy for both fractured and polished surfaces has been utilized extensively for examining pore structures. However, there is uncertainty in distinguishing between topography and pores for the fractured specimen and sample pullout obscures the true morphology for samples that are polished. In addition, very small pores (nm range) cannot be resolved in the S.E.M. On the other hand, T.E.M. has better resolution but the specimen preparation methods involved such as powder dispersion, ion milling, and chemical etching may incur problems ranging from preferential widening of pores to partial or complete destruction of the pore network.

scholarly journals Experimental investigation to characterize simple versus multi scaling analysis of hydraulic conductivity at a mesoscale

2021 ◽  
Author(s):  
Guglielmo Federico Antonio Brunetti ◽  
Samuele De Bartolo ◽  
Carmine Fallico ◽  
Ferdinando Frega ◽  
Maria Fernanda Rivera Velásquez ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Spatial Variability ◽  
Hydraulic Properties ◽  
Scaling Laws ◽  
Scaling Analysis ◽  
Field Scale ◽  
Porous Formation ◽  
Proper Design ◽  
First Time

AbstractThe spatial variability of the aquifers' hydraulic properties can be satisfactorily described by means of scaling laws. The latter enable one to relate the small (typically laboratory) scale to the larger (typically formation/regional) ones, therefore leading de facto to an upscaling procedure. In the present study, we are concerned with the spatial variability of the hydraulic conductivity K into a strongly heterogeneous porous formation. A strategy, allowing one to identify correctly the single/multiple scaling of K, is applied for the first time to a large caisson, where the medium was packed. In particular, we show how to identify the various scaling ranges with special emphasis on the determination of the related cut-off limits. Finally, we illustrate how the heterogeneity enhances with the increasing scale of observation, by identifying the proper law accounting for the transition from the laboratory to the field scale. Results of the present study are of paramount utility for the proper design of pumping tests in formations where the degree of spatial variability of the hydraulic conductivity does not allow regarding them as “weakly heterogeneous”, as well as for the study of dispersion mechanisms.

Statistical determination of normal modes

1987 ◽  
Vol 64 (5) ◽  
pp. 425 ◽  
Author(s):  
John F. Geldard ◽  
Lawrence R. Pratt
Keyword(s):  
Normal Modes ◽  
Statistical Determination

Assessment of the impact of nanoparticles on the activity of biomimetic membrane

2021 ◽  
Vol XXXVII (1) ◽  
pp. 89-100
Author(s):  
Dorota Kondej
Keyword(s):  
Occupational Safety ◽  
Biological Membranes ◽  
Structure And Function ◽  
Lipid Monolayer ◽  
Biomimetic Membranes ◽  
Safety And Health ◽  
Biomimetic Membrane ◽  
And Function ◽  
The Impact

This paper presents basic information on a structure and function of biological membranes. Types of biomimetic membranes modelling properties of biological membranes were introduced. The method of testing surface properties of a lipid monolayer, which is the basic type of biomimetic membranes, was described. The presented method makes it possible to evaluate the effect of nanoparticles on the surface activity of biomimetic membranes based on the determination of the surface index MA. This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Erratum: Plasma‐Filled Waveguide with Axial Magnetization. I. Variational Determination of Normal Modes

1969 ◽  
Vol 40 (12) ◽  
pp. 4999-4999
Author(s):  
K. S. Champlin ◽  
G. H. Glover ◽  
D. E. O'Connor
Keyword(s):  
Normal Modes

scholarly journals The Impact of Arthroscopic Capsular Release in Patients with Primary Frozen Shoulder on Shoulder Muscular Strength

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Michał Waszczykowski ◽  
Michał Polguj ◽  
Jarosław Fabiś
Keyword(s):  
Muscular Strength ◽  
Frozen Shoulder ◽  
Active Motion ◽  
Capsular Release ◽  
Arthroscopic Capsular Release ◽  
Limited Function ◽  
And Function ◽  
The Impact

The aim of this study was to evaluate the impact of arthroscopic capsular release in patients with primary frozen shoulder on muscular strength of nonaffected and treated shoulder after at least two-year follow-up after the surgery. The assessment included twenty-seven patients, who underwent arthroscopic capsular release due to persistent limitation of range of passive and active motion, shoulder pain, and limited function of upper limb despite 6-month conservative treatment. All the patients underwent arthroscopic superior, anteroinferior, and posterior capsular release. After at least two-year follow-up, measurement of muscular strength of abductors, flexors, and external and internal rotators of the operated and nonaffected shoulder, as well as determination of range of motion (ROM) and function (ASES) in the operated and nonaffected shoulder, was performed. Measurement of muscular strength in the patient group did not reveal statistically significant differences between operated and nonaffected shoulder. The arthroscopic capsular release does not have significant impact on the decrease in the muscular strength of the operated shoulder.

scholarly journals Determination of the complex frequencies for the normal modes below 1mHz after the 2010 Maule and 2011 Tohoku earthquakes

2014 ◽  
Vol 56 (5) ◽  
Author(s):  
Hao Ding ◽  
Wen-Bin Shen
Keyword(s):  
Time Series ◽  
Normal Modes ◽  
Power Spectra ◽  
Tohoku Earthquake ◽  
Superconducting Gravimeter ◽  
Width Ratio ◽  
Maule Earthquake ◽  
Attenuation Models ◽  
First Time

<p>Based upon SG (superconducting gravimeter) records, the autoregressive method proposed by Chao and Gilbert [1980] is used to determine the frequencies of the singlets of seven spheroidal modes (<sub>0</sub>S<sub>2</sub>, <sub>2</sub>S<sub>1</sub>, <sub>0</sub>S<sub>3</sub>, <sub>0</sub>S<sub>4</sub>, <sub>1</sub>S<sub>2</sub>, <sub>0</sub>S<sub>0</sub>, and <sub>3</sub>S<sub>1</sub>) and the degenerate frequencies of three toroidal modes (<sub>0</sub>T<sub>2</sub>, <sub>0</sub>T<sub>3</sub>, and <sub>0</sub>T<sub>4</sub>) below 1 mHz after two recent huge earthquakes, the 2010 Mw8.8 Maule earthquake and the 2011 Mw9.1 Tohoku earthquake. The corresponding quality factor <em>Q</em>s are also determined for those modes, of which the <em>Q</em>s of the five singlets of <sub>1</sub>S<sub>2</sub> and the five singlets (<em>m</em>=0, <em>m</em>=±2, and <em>m</em>=±3) of <sub>0</sub>S<sub>4</sub> are estimated for the first time using the SG observations. The singlet <em>m</em>=0 of <sub>3</sub>S<sub>1</sub> is clearly observed from the power spectra of the SG time series without using other special spectral analysis methods or special time series from pole station records. In addition, the splitting width ratio <em>R</em> of <sub>3</sub>S<sub>1</sub> is 0.99, and consequently we conclude that <sub>3</sub>S<sub>1</sub> is normally split. The frequencies and <em>Q</em>s of the modes below 1mHz may contribute to refining the 3D density and attenuation models of the Earth.</p>

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