A Method for Measuring Tension in Small Ligaments: An Application to the Ligaments of the Wrist Carpus

1993 ◽  
Vol 115 (3) ◽  
pp. 218-224 ◽  
Author(s):  
P. Kristal ◽  
A. F. Tencer ◽  
T. E. Trumble ◽  
E. North ◽  
D. Parvin
Keyword(s):  
Lateral Load ◽  
Ulnar Deviation ◽  
The Core ◽  
Axial Tension ◽  
Rigid Frame ◽  
Core Rod ◽  
A New Technique ◽  
Nylon Line

A new technique has been devised for measuring the in situ tension in small ligaments. It is based on measuring the tension in an axially loaded flexible cable with pinned endpoints by deflecting the cable laterally and measuring its lateral load and deformation. Studies were performed in which nylon line and bone ligament bone preparations were placed in a materials tester and loaded in axial tension. Axial load as measured by lateral load and deformation was found to agree with the known load to within 8 percent. The method was sensitive to error in determination of ligament length, nonperpendicularity of the laterally applied load to the long axis of the ligament, and when used in situ, impingement of the ligament on a third bone causing bending. A device, consisting of an LVDT mounted to a rigid frame with its core rod connected to a load cell, was developed. The position of the core rod was controlled by a manual screw drive, and a hook on the other end of the core rod was used to deflect the ligament laterally. This device was applied to the study of tensions in five ligaments of the palmar wrist carpus, in seven cadaver specimens. Results showed that the radioscaphocapitate (RSC) and radiolunate (RL) ligaments had significantly greater tensions than the lunotriquetral (LT), the triquetrocapitate (TC), and scaphocapitate (SC) ligaments. For the four positions of the hand tested, neutral, 14 deg radial and 14 deg ulnar deviation, and 28 deg of extension, ligament tensions were found to be unaffected by position. In all positions tested, all ligaments had measurable tension, demonstrating the importance of ligaments in maintaining the integrity of the wrist carpus.

Web-Stiffened Sandwich Structures

1971 ◽  
Vol 38 (4) ◽  
pp. 964-970 ◽  
Author(s):  
Y. N. Chen ◽  
D. Ranlet ◽  
J. Kempner
Keyword(s):  
Eigenfunction Expansion ◽  
Sandwich Beam ◽  
Continuum Theory ◽  
Free Vibrations ◽  
The Core ◽  
Rigid Frame ◽  
Discrete Nature ◽  
Comparison Of The Results ◽  
Energy Principles

A model representation of a web-cored sandwich structure, which is based upon the energy principles of continuum theory while retaining the discrete nature of the webs, is studied. The determination of a second-order shear modulus, which measures local bending effects, accounts for the transverse shear deformation of the core. This notion is exemplified through consideration of the flexure and buckling of a web-stiffened sandwich beam, and by comparison of the results calculated from rigid frame analysis with those based on the sandwich solution. Additionally, the technique for employing classical Bernoulli-Euler modes in the eigenfunction expansion of displacement functions is extended and applied to the problems of free vibrations of a free-free web-stiffened sandwich beam.

scholarly journals Cover Feature: A New Technique for In Situ Determination of the Active Surface Area Changes of Li–Ion Battery Electrodes (Batteries & Supercaps 10/2020)

2020 ◽  
Vol 3 (10) ◽  
pp. 962-962
Author(s):  
Maciej Ratynski ◽  
Bartosz Hamankiewicz ◽  
Dominika A. Buchberger ◽  
Maciej Boczar ◽  
Michał Krajewski ◽  
...  
Keyword(s):  
Surface Area ◽  
Active Surface ◽  
New Technique ◽  
Active Surface Area ◽  
Li Ion Battery ◽  
Li Ion ◽  
A New Technique

An investigation into the causes of small scale variation in sediment community oxygen consumption in the Rockall Trough

1986 ◽  
Vol 88 ◽  
pp. 281-290
Author(s):  
J. W. Patching ◽  
R. C. T. Raine ◽  
P. R. O. Barnett
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Small Scale ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Core ◽  
Rockall Trough ◽  
Small Cross Sectional Area

An attempt was made to interpret the core to core variation in oxygen uptake observed during anin situdetermination of sediment community oxygen consumption (SCOC) at a station in the Rockall Trough using the “suspended core” technique. No direct relationships between macrofaunal abundance or biomass and SCOC were observed. The results obtained suggested that the use of experimental chambers of small cross-sectional area (26.2cm2) allow for greater influence on SCOC of the activity of individual organisms which would otherwise be averaged out by larger, grab-type enclosures. The possible significance of other components of the benthos is discussed.

A New Technique for In Situ Determination of the Active Surface Area Changes of Li–Ion Battery Electrodes

2020 ◽  
Vol 3 (10) ◽  
pp. 1028-1039 ◽  
Author(s):  
Maciej Ratynski ◽  
Bartosz Hamankiewicz ◽  
Dominika A. Buchberger ◽  
Maciej Boczar ◽  
Michał Krajewski ◽  
...  
Keyword(s):  
Surface Area ◽  
Active Surface ◽  
New Technique ◽  
Active Surface Area ◽  
Li Ion Battery ◽  
Li Ion ◽  
A New Technique

A Novel Dynamic Measurement of Permeability

1981 ◽  
Vol 21 (06) ◽  
pp. 670-678
Author(s):  
J.H. Moran ◽  
C.M. Papaconstantinou
Keyword(s):  
Zeta Potential ◽  
Water Movement ◽  
Fluid Velocity ◽  
Well Logging ◽  
Transient Pressure ◽  
Laboratory Procedure ◽  
The Core ◽  
Slight Generalization

Abstract A method is proposed for the laboratory determination of permeability; a water-saturated core is shaken and the electrokinetic electromotive forces (emf's) generated thereby are measured as an indication of water movement within the core. This method also can provide a determination of the zeta potential. It is of special interest because of its possible extension to use as a well logging measurement. Introduction Permeability commonly is determined by applying a constant pressure differential lengthwise across a core and measuring the resultant flow through it. Permeability measurements also can be made in situ in boreholes by monitoring transient pressure variations resulting from flow disturbances. In the latter method, fluid and pore compressibilities generally must be taken into account. This paper considers a new laboratory procedure for permeability measurement wherein fluid compressibility again plays a role. The core to be measured is saturated with water, and electrodes are attached to its end faces. It is sealed so that no water can enter or leave. The core then is shaken parallel to its axis with a sinusoidal acceleration. Because the water is compressible, the core acceleration (acting like a synthetic gravity field) will cause some motion of the water relative to the rock frame. The water movement results in the generation of electrokinetic emf's that are monitored in amplitude and phase along with the acceleration. The upper part of Fig. 1 schematically indicates the arrangement of the core. The lower part of Fig. 1 indicates the measurement and interpretation. It is possible to determine k (permeability) and (zeta potential) by measuring a* (complex acceleration). V* (complex electrokinetic emf), and theta (phase angle between V* and a*). Measurements of this kind are described. These measurements, and others not reported here, have met with good success. The technique is of interest because of its good simulation of in-situ measurements and its possible use as a well logging measurement. Also, it can yield gas a by-product. There is the further possibility that it can be extended to measurements of relative permeability by controlling and the conductivity of the fluid. Theory The equations used to described fluid flow, which are a slight generalization of those used in pressure-testing analysis, are (1a) and (1b) in these equations, v is the pore/fluid velocity relative to the rock frame; a is the acceleration of the rock frame; mu and p are the viscosity and the density of the saturating fluid, respectively: K is the bulk modulus of the fluid, which can be corrected for pore compressibility in the usual way; phi and k are the rock porosity and permeability, respectively; and p is the excess pressure resulting from fluid compression. In Eqs. 1a and 1b, it is assumed that the rock frame itself is accelerated as a unit. Thus, a will not depend on the coordinate x along the core. The two terms on the left side of Eq. 1a correspond to flow and compression of the fluid resulting from the driving body force produced by a. SPEJ P. 670^

Rapid determination of the original boron isotopic composition from altered basaltic glass by in situ secondary ion mass spectrometry

2020 ◽  
Vol 35 (2) ◽  
pp. 238-245 ◽  
Author(s):  
Miaohong He ◽  
Xiaoping Xia ◽  
Xiaolong Huang ◽  
Jinlong Ma ◽  
Jieqiong Zou ◽  
...  
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Profile Analysis ◽  
Rapid Determination ◽  
Basaltic Glass ◽  
The Core ◽  
Secondary Ion ◽  
Isotopic Profile ◽  
Boron Isotopic Composition

Rapid determination of the original boron composition from altered basaltic glass by SIMS boron isotopic profile analysis from the core to rim.

scholarly journals LABORATORY APPLICATIONS OF RADIOISOTOPIC TRACERS TO FOLLOW BEACH SEDIMENTS

2011 ◽  
Vol 1 (8) ◽  
pp. 17
Author(s):  
Norman E. Taney
Keyword(s):  
Pulse Height ◽  
Radioactive Tracer ◽  
Beach Erosion ◽  
Radioactive Material ◽  
Beach Sediments ◽  
Scientists And Engineers ◽  
A New Technique ◽  
Thames River

For many years coastal scientists and engineers have attempted to label sedimentary particles in order that their movement paths might be determined. Several attempts have been made at the Beach Erosion Board, none of which met with any measure of success. Furthermore, inherent in this system is an extensive sampling program and arduous identification of the labeled particles. Recently, however, the labeling of natural sediments or simulated sediments with radioisotopes as tracers has proved successful and a long sought goal has been achieved. The utilization of radioactive material as sediment tracers has increased during the approximately 10 years since its inception. Since the initial test in the Thames River^1' in England, the utilization of this technique has spread until it is practically worldwide!2""8^ In the main, the objectives of these tests have been qualitative, the determination of movement path and of sedimentation areas of the tracer material, and thus of the sediments, which are being followed. Labeling techniques have varied widely and involve plating or precipitating a thin film of radioactive material on the natural sediments, the utilization of glass containing a radioactive tracer to simulate the natural sediments, the incorporation of radioactive material within the natural sediments or within simulated sediments, and ion exchange between the natural sediments and tracer material. The means of detection have also varied broadly: Geiger-Mueller systems with one or several GM tubes in gangs, scintillation systems making use of pulse-height spectrometry, and autoradiographic techniques have all been used. The monitoring has varied also as sediment and tracer materials have been monitored in situ or samples have been taken and the monitoring accomplished in the laboratory. The staff of the Beach Erosion Board has been interested in this new application of radioisotopes since 1955. A literature survey was initiated at that time and is continuing at present. A feasibility study was completed in 1958 which indicated that radioisotopic tracers presented a new technique with which to study sediment transport. The report strongly recommended that studies be planned and executed utilizing this technique. In the Annual Bulletin of the Beach Erosion Board, 1960,^9'several test objectives and procedures were outlined.

Imaging of ribosomal RNA-protein interactions by dark-field STEM

1989 ◽  
Vol 47 ◽  
pp. 250-251
Author(s):  
M. Boublik ◽  
V. Mandiyan ◽  
S. Tumminia ◽  
J.F. Hainfeld ◽  
J.S. Wall
Keyword(s):  
Nucleic Acid ◽  
16S Rrna ◽  
Dark Field ◽  
Radius Of Gyration ◽  
Central Domain ◽  
The Core ◽  
16S Rna ◽  
30S Subunit ◽  
Core Particles

Success in protein-free deposition of native nucleic acid molecules from solutions of selected ionic conditions prompted attempts for high resolution imaging of nucleic acid interactions with proteins, not attainable by conventional EM. Since the nucleic acid molecules can be visualized in the dark-field STEM mode without contrasting by heavy atoms, the established linearity between scattering cross-section and molecular weight can be applied to the determination of their molecular mass (M) linear density (M/L), mass distribution and radius of gyration (RG). Determination of these parameters promotes electron microscopic imaging of biological macromolecules by STEM to a quantitative analytical level. This technique is applied to study the mechanism of 16S rRNA folding during the assembly process of the 30S ribosomal subunit of E. coli. The sequential addition of protein S4 which binds to the 5'end of the 16S rRNA and S8 and S15 which bind to the central domain of the molecule leads to a corresponding increase of mass and increased coiling of the 16S rRNA in the core particles. This increased compactness is evident from the decrease in RG values from 114Å to 91Å (in “ribosomal” buffer consisting of 10 mM Hepes pH 7.6, 60 mM KCl, 2 m Mg(OAc)2, 1 mM DTT). The binding of S20, S17 and S7 which interact with the 5'domain, the central domain and the 3'domain, respectively, continues the trend of mass increase. However, the RG values of the core particles exhibit a reverse trend, an increase to 108Å. In addition, the binding of S7 leads to the formation of a globular mass cluster with a diameter of about 115Å and a mass of ∽300 kDa. The rest of the mass, about 330 kDa, remains loosely coiled giving the particle a “medusa-like” appearance. These results provide direct evidence that 16S RNA undergoes significant structural reorganization during the 30S subunit assembly and show that its interactions with the six primary binding proteins are not sufficient for 16S rRNA coiling into particles resembling the native 30S subunit, contrary to what has been reported in the literature.

INDIREKTE PAPIERCHROMATOGRAPHISCHE METHODE ZUR BESTIMMUNG DER HARNOESTROGENE

1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Granulosa Cell ◽  
Iron Content ◽  
List Type ◽  
Granulosa Cell Tumour ◽  
Hydrolysis Of ◽  
Phenol Fraction ◽  
Qualitative Determination

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.

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