Preliminary Study of a Test Procedure for Obtaining Step Wave Loadings on Structures at Deep Submergence.

1979 ◽  
Author(s):  
J. P. Wright ◽  
M. L. Baron ◽  
F. L. DiMaggio
Keyword(s):  
Test Procedure ◽  
Preliminary Study

scholarly journals Static and Fatigue Tests on Cementitious Cantilever Beams Using Nanoindenter

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 630 ◽  
Author(s):  
Yidong Gan ◽  
Hongzhi Zhang ◽  
Branko Šavija ◽  
Erik Schlangen ◽  
Klaas van Breugel
Keyword(s):  
Cement Paste ◽  
Fracture Behaviour ◽  
Test Procedure ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Cantilever Beams ◽  
Fundamental Properties ◽  
Micromechanical Properties ◽  
Preliminary Study ◽  
Binding Component

Cement paste is the main binding component in concrete and thus its fundamental properties are of great significance for understanding the fracture behaviour as well as the ageing process of concrete. One major aim of this paper is to characterize the micromechanical properties of cement paste with the aid of a nanoindenter. Besides, this paper also presents a preliminary study on the fatigue behaviour of cement paste at the micrometer level. Miniaturized cantilever beams made of cement paste with different water/cement ratios were statically and cyclically loaded. The micromechanical properties of cement paste were determined based on the measured load-displacement curves. The evolution of fatigue damage was evaluated in terms of the residual displacement, strength, and elastic modulus. The results show that the developed test procedure in this work is able to produce reliable micromechanical properties of cement paste. In addition, little damage was observed in the cantilever beams under the applied stress level of 50% to 70% for 1000 loading cycles. This work may shed some light on studying the fatigue behaviour of concrete in a multiscale manner.

scholarly journals On the Use of Ultrasound Waves to Monitor the Local Dynamics of Friction Joints

2019 ◽  
Vol 60 (1) ◽  
pp. 129-141
Author(s):  
L. Pesaresi ◽  
A. Fantetti ◽  
F. Cegla ◽  
L. Salles ◽  
C.W. Schwingshackl
Keyword(s):  
Numerical Models ◽  
Test Procedure ◽  
Contact Interface ◽  
Stick Slip ◽  
Local Dynamics ◽  
Ultrasound Waves ◽  
Preliminary Study ◽  
Initial Results ◽  
Nonlinear Nature ◽  
Validation Experiments

Abstract Friction joints are one of the fundamental means used for the assembly of structural components in engineering applications. The structural dynamics of these components becomes nonlinear, due to the nonlinear nature of the forces arising at the contact interface characterised by stick-slip phenomena and separation. Advanced numerical models have been proposed in the last decades which have shown some promising capabilities in capturing these local nonlinearities. However, despite the research efforts in producing more advanced models over the years, a lack of validation experiments made it difficult to have fully validated models. For this reason, experimental techniques which can provide insights into the local dynamics of joints can be of great interest for the refinement of such models and for the optimisation of the joint design and local wear predictions. In this paper, a preliminary study is presented where ultrasound waves are used to characterise the local dynamics of friction contacts by observing changes of the ultrasound reflection/transmission at the friction interface. The experimental technique is applied to a dynamic friction rig, where two steel specimens are rubbed against each other under a harmonic tangential excitation. Initial results show that, with a controlled experimental test procedure, this technique can identify microslip effects at the contact interface.

Dynamic testing of water treatment coagulants

2001 ◽  
Vol 1 (4) ◽  
pp. 65-72 ◽  
Author(s):  
J. Gregory ◽  
L. Rossi
Keyword(s):  
Mode Of Action ◽  
Dynamic Testing ◽  
Test Procedure ◽  
Aluminium Sulphate ◽  
Jar Test ◽  
Iron Salts ◽  
Flow Through ◽  
Preliminary Study ◽  
Selection For ◽  
Empirical Approaches

Pre-polymerised inorganic coagulants, such as polyaluminium chloride (PAC) have several advantages over conventional aluminium and iron salts. However, their mode of action is not fully understood and progress in this area has been made largely by empirical approaches. In this preliminary study we have followed the dynamics of flocculation of model clay/humic acid suspensions following the addition of three different coagulants: aluminium sulphate and two commercial PAC products. Experiments were conducted using controlled stirring rates in a modified jar test procedure, in which the formation and break-up of flocs could be monitored continuously by a flow-through optical technique. The results show significant differences in the behaviour of the coagulants and one of the PAC samples gives much larger and stronger flocs. Further experiments along these lines should help to elucidate the mode of action of different forms of coagulant and to aid in their selection for specific applications.

A Study of Temperature Gradients Inside a Horizontal Cylinder With Heated and Recirculated Diving Gas Mixtures

1972 ◽  
Vol 94 (4) ◽  
pp. 1142-1148
Author(s):  
L. S. Linderoth ◽  
D. P. Werner ◽  
R. L. Bentz
Keyword(s):  
Heat Transfer ◽  
Test Data ◽  
Test Procedure ◽  
Horizontal Cylinder ◽  
Temperature Gradients ◽  
Temperature Profiles ◽  
Actual Behavior ◽  
Model Data ◽  
Model Chamber ◽  
Preliminary Study

There is little data available in the literature regarding temperature gradients and heat transfer in diving chambers (decompression chambers) with an environment of normal diving mixtures of helium and oxygen at pressures up to 33 atm. This paper reports on a preliminary study that was made to determine the actual behavior of the gas mix-tures in a model chamber as compared to predicted behavior. It was hypothesized that three distinct regions of flow are developed from the circulation of the environmental gas. Equations were developed for the temperature profiles and checked by the model data. Agreement between theory and test data was quite good. The test procedure and instrumentation are described in part. Full details and data are available in reference [18].

The Ultrastructure of Metastatic Human Mammary Carcinoma After Prolonged Estrogen Therapy

1967 ◽  
Vol 25 ◽  
pp. 180-181
Author(s):  
John H.L. Watson ◽  
John L. Swedo ◽  
R.W. Talley
Keyword(s):  
Mammary Carcinoma ◽  
Osmium Tetroxide ◽  
Estrogen Therapy ◽  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Human Mammary Carcinoma ◽  
Surgical Biopsy ◽  
Lead Hydroxide ◽  
Preliminary Study ◽  
Hormonal Therapies

A preliminary study of human mammary carcinoma on the ultrastructural level is reported for a metastatic, subcutaneous nodule, obtained as a surgical biopsy. The patient's tumor had responded favorably to a series of hormonal therapies, including androgens, estrogens, progestins, and corticoids for recurring nodules over eight years. The pertinent nodule was removed from the region of the gluteal maximus, two weeks following stilbestrol therapy. It was about 1.5 cms in diameter, and was located within the dermis. Pieces from it were fixed immediately in cold fixatives: phosphate buffered osmium tetroxide, glutaraldehyde, and paraformaldehyde. Embedment in each case was in Vestopal W. Contrasting was done with combinations of uranyl acetate and lead hydroxide.

Fine structure of early degenerating myofibers in the tibialis anterior of young ‘MDX’ mouse

1988 ◽  
Vol 46 ◽  
pp. 322-323
Author(s):  
H.D. Geissinger ◽  
C.K. McDonald-Taylor
Keyword(s):  
Fine Structure ◽  
Muscle Regeneration ◽  
Tibialis Anterior ◽  
Genetic Defect ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Histopathological Changes ◽  
Electron Microscopic ◽  
Dystrophic Mouse ◽  
Preliminary Study

A new strain of mice, which had arisen by mutation from a dystrophic mouse colony was designated ‘mdx’, because the genetic defect, which manifests itself in brief periods of muscle destruction followed by episodes of muscle regeneration appears to be X-linked. Further studies of histopathological changes in muscle from ‘mdx’ mice at the light microscopic or electron microscopic levels have been published, but only one preliminary study has been on the tibialis anterior (TA) of ‘mdx’ mice less than four weeks old. Lesions in the ‘mdx’ mice vary between different muscles, and centronucleation of fibers in all muscles studied so far appears to be especially prominent in older mice. Lesions in young ‘mdx’ mice have not been studied extensively, and the results appear to be at variance with one another. The degenerative and regenerative aspects of the lesions in the TA of 23 to 26-day-old ‘mdx’ mice appear to vary quantitatively.

Ultrastructural observations of the aorta of calves implanted with a mechanical left ventricular assist device

1990 ◽  
Vol 48 (3) ◽  
pp. 834-835
Author(s):  
J P Cassella ◽  
V Salih ◽  
T R Graham
Keyword(s):  
Left Ventricular Assist Device ◽  
Ventricular Assist Device ◽  
Left Ventricular ◽  
Aortic Tissue ◽  
Assist Device ◽  
Ventricular Assist ◽  
Transmission Electron ◽  
Left Ventricular Assist ◽  
Preliminary Study

Left ventricular assist systems are being developed for eventual long term or permanent implantation as an alternative to heart transplantation in patients unsuitable for or denied the transplant option. Evaluation of the effects of these devices upon normal physiology is required. A preliminary study was conducted to evaluate the morphology of aortic tissue from calves implanted with a pneumatic Left Ventricular Assist device-LVAD. Two 3 month old heifer calves (calf 1 and calf 2) were electively explanted after 128 days and 47 days respectively. Descending thoracic aortic tissue from both animals was removed immediately post mortem and placed into karnovsky’s fixative. The tissue was subsequently processed for transmission electron microscopy (TEM). Some aortic tissue was fixed in neutral buffered formalin and processed for routine light microscopy.

A preliminary study on the potential of front face fluorescence spectroscopy for the discrimination of Moroccan virgin olive oils and the prediction of their quality

2021 ◽  
Author(s):  
Hicham Zaroual ◽  
El Mestafa El Hadrami ◽  
Romdhane Karoui
Keyword(s):  
Fluorescence Spectroscopy ◽  
Olive Oil ◽  
Virgin Olive Oil ◽  
Front Face ◽  
Virgin Olive Oils ◽  
Olive Oils ◽  
Preliminary Study

This study examines the feasibility of using front face fluorescence spectroscopy (FFFS) to authenticate 41 virgin olive oil (VOO) samples collected from 5 regions in Morocco during 2 consecutive crop seasons.

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