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.

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

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.

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

Experimental techniques for the determination of thermophysical properties to enhance chemical processes

2009 ◽  
Vol 81 (10) ◽  
pp. 1769-1782 ◽  
Author(s):  
Dominique Richon
Keyword(s):  
Chemical Processes ◽  
Basic Principles ◽  
Analysis Techniques ◽  
Fundamental Research ◽  
Scientists And Engineers ◽  
Work Up ◽  
Accurate Experimental Data

It is of utmost importance to have accurate experimental data available in order to develop accurate modeling for scientific and engineering purposes as it is emphasized through several herein-reported discussions with reknown scientists and engineers. Many methods are used to determine phase equilibria. Classification of the methods is not straightforward as several basic principles can be mixed in several different ways. In this paper, we have selected some techniques, developed in our laboratory, to illustrate one type of classification. Several apparatuses are described. The techniques where all phases are analyzed are very often preferred to those relying on partial determinations requiring data treatment through models. The internal analyses by means of spectroscopic or other in situ analysis techniques are not applicable every time. Then, sampling devices are necessary. Sampling devices must be reliable and lead to extract sample amounts small enough not to disturb the equilibrium under study. The ROLSI™ sampler developed at MINES ParisTech is a very powerful device allowing one to work up to 100 MPa, 850 K, with corrosive components and with samples from 1 μg to some mg. Applications of this sampler are described for fundamental research (phase equilibrium measurements) and industrial purposes (process control and monitoring).

STUDIES ON THE AROMATISATION OF NEUTRAL STEROIDS IN PREGNANT WOMEN

1964 ◽  
Vol 45 (4) ◽  
pp. 535-559 ◽  
Author(s):  
E. Bolté ◽  
S. Mancuso ◽  
G. Eriksson ◽  
N. Wiqvist ◽  
E. Diczfalusy
Keyword(s):  
Pregnant Women ◽  
Comparative Studies ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Radioactive Material ◽  
Placental Barrier ◽  
Therapeutic Abortion ◽  
Limited Ability ◽  
Better Than

ABSTRACT In 15 cases of therapeutic abortion by laparotomy the placenta was disconnected from the foetus and perfused in situ with tracer amounts of radioactive dehydroepiandrosterone (DHA), dehydroepiandrosterone sulphate (DHAS), androst-4-ene-3,17-dione (A), testosterone (T) and 17β-oestradiol (OE2). Analysis of the placentas, perfusates and urine samples revealed an extensive aromatisation of DHA, A and T; more than 70% of the radioactive material recovered was phenolic, and at least 80 % of this phenolic material was identified as oestrone (OE1), 17β-oestradiol (OE2) and oestriol (OE3), the latter being detected only in the urine. Comparative studies indicated that A and T were aromatised somewhat better than DHA and that all three unconjugated steroids were aromatised to a much greater extent than DHAS. Radioactive OE1 and OE2 were isolated and identified in the placentas and perfusates, but no OE3, epimeric oestriols, or ring D ketols could be detected in these sources, not even when human chorionic gonadotrophin (HCG) was added to the blood prior to perfusion. Lack of placental 16-hydroxylation was also apparent when OE2 was perfused. Regardless of the precursor perfused, there was three times more OE2 than OE1 in the placenta and three times more OE1 than OE2 in the perfusate. This was also the case following perfusion with OE2. The results are interpreted as suggesting the existence in the pregnant human of a placental »barrier« limiting the passage of circulating androgen. The barrier consists of a) limited ability to transfer directly DHAS and b) an enzymic mechanism resulting in the rapid and extensive aromatisation of the important androgens DHA, A and T.

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.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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