scholarly journals Effect of Strain Hardening and Rate Sensitivity on the Dynamic Growth of a Void in a Plastic Material

1992 ◽  
Vol 59 (1) ◽  
pp. 48-53 ◽  
Author(s):  
M. Ortiz ◽  
A. Molinari
Keyword(s):  
Strain Hardening ◽  
Plastic Material ◽  
Rate Sensitivity ◽  
Spherical Void ◽  
Hydrostatic Tension ◽  
The Matrix ◽  
Short And Long Term ◽  
Dynamic Growth ◽  
Long Term Behavior

The problem studied in this paper concerns the dynamic expansion of a spherical void in an unbounded solid under the action of remote hydrostatic tension. The void is assumed to remain spherical throughout the deformation and the matrix to be incompressible. The effects of inertia, strain hardening, and rate sensitivity on the short and long-term behavior of the void, as well as on its response to ramp loading, are investigated in detail.

Dissolution of spent nuclear fuel fragments at high alkaline conditions under H2 overpressure

MRS Advances ◽  
2016 ◽  
Vol 1 (62) ◽  
pp. 4163-4168
Author(s):  
E. González-Robles ◽  
M. Herm ◽  
V. Montoya ◽  
N. Müller ◽  
B. Kienzler ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Partial Pressure ◽  
Nuclear Fuel ◽  
Alkaline Solution ◽  
Spent Nuclear Fuel ◽  
Dissolution Tests ◽  
The Matrix ◽  
Alkaline Conditions ◽  
Long Term Behavior

ABSTRACTThe long-term behavior of the UO2 fuel matrix under conditions of the Belgian “Supercontainer design” was investigated by dissolution tests of high burn-up spent nuclear fuel (SNF) in high alkaline solution under 40 bar of (Ar + 8%H2) atmosphere. Four fragments of SNF, obtained from a pellet previously leached during two years, were exposed to young cement water with Ca (YCWCa) under 3.2 bar H2 partial pressure in four single/independent autoclave experiments for a period of 59, 182, 252 and 341 days, respectively. After a decrease of the concentration of dissolved 238U, which is associated with a reduction of U(VI) to U(IV), the concentration of 238U in solution is constant in the experiments running for 252 and 341 days. These observations indicate an inhibition of the matrix dissolution due to the presence of H2. A slight increase in the concentration of 90Sr and 137Cs in the aqueous solution indicates that there is still dissolution of the grain boundaries. These findings are similar to those reported for spent nuclear fuel corrosion in synthetic near neutral pH solutions.

scholarly journals Ubiquitous C IV 1550 Variability in B and Be Stars

1987 ◽  
Vol 92 ◽  
pp. 286-288 ◽  
Author(s):  
G. Sonneborn ◽  
M.P. Garhart ◽  
C.A. Grady
Keyword(s):  
Time Scale ◽  
High Dispersion ◽  
Be Stars ◽  
Line Profiles ◽  
Standard Star ◽  
B Stars ◽  
Short And Long Term ◽  
Resonance Transitions ◽  
Long Term Behavior

Studies of line profile variability of the ultraviolet 1550 Angstrom resonance transitions of C IV in Be stars (Sonneborn et al. 1986; Grady, et al. 1986a,b) have prompted an investigation into the short- and long-term behavior of the C IV lines in other types of B stars. We present examples of two well-studied Be stars, Omega Orionis and 66 Ophiuchi, and two non-Be stars, Beta Cephei and the standard star Zeta Cassiopeiae. Zeta Cas is also known to be a 53 Per variable (see Cox 1983). The IUE SWP high-dispersion spectra of Beta Cep and Zeta Cas have been obtained from the IUE archives. It has been known for some years that the C IV line profiles in Beta Cep vary in a time scale of several days (Fishel and Sparks, 1980). However, it came as a surprise to discover C IV variability in Zeta Cas. Available data allow us to set an upper limit of several months for the time scale of Zeta Cas C IV variability. The principal difference between the C IV variability in Be and non-Be stars appears to be the magnitude and velocity range of the effect.

scholarly journals Short- and long-term effects of habitat fragmentation differ but are predicted by response to the matrix

Ecology ◽  
2017 ◽  
Vol 98 (3) ◽  
pp. 807-819 ◽  
Author(s):  
Maldwyn J. Evans ◽  
Sam C. Banks ◽  
Don A. Driscoll ◽  
Andrew J. Hicks ◽  
Brett A. Melbourne ◽  
...  
Keyword(s):  
Habitat Fragmentation ◽  
Long Term Effects ◽  
The Matrix ◽  
Short And Long Term

Failure of a Test Embankment On a Sensitive Champlain Clay Deposit

1974 ◽  
Vol 11 (1) ◽  
pp. 142-164 ◽  
Author(s):  
P. La Rochelle ◽  
B. Trak ◽  
F. Tavenas ◽  
M. Roy
Keyword(s):  
Research Program ◽  
Factor Of Safety ◽  
Soft Clay ◽  
New Approach ◽  
Short And Long Term ◽  
Undrained Strength ◽  
The Stability ◽  
Long Term Behavior ◽  
Test Embankment

The present paper reports on the failure of a test embankment built on a soft, sensitive, and cemented clay in Saint-Alban, Quebec. The embankment was built as a first stage of a research program aimed at studying the short and long term behavior of embankments on soft clay foundations.A complete description of the embankment, of the instrumentation, and of the failure is given, followed by the analysis of the failure performed on the basis of different assumptions of fill behavior and of vane strength values mobilized in the clay crust. The analyses show that the assumptions of full mobilization of friction in the fill seems to be the most representative of the fill behavior in the present case and that a suitable factor of safety is obtained only when a reduction of vane strength is assumed to act in the crust.A new approach based on the residual undrained strength is suggested and seems to offer some potential as a valuable means of analyzing the stability of embankments on clay foundations.

The effect of annealing on the short and long term behavior of PEEK

1990 ◽  
Vol 24 (6) ◽  
pp. 657-664 ◽  
Author(s):  
P. Y. Jar ◽  
H. H. Kausch ◽  
W. J. Cantwell ◽  
P. Davies ◽  
H. Richard
Keyword(s):  
Short And Long Term ◽  
Long Term Behavior

(Invited) Sulfur Poisoning of Ni-Based SOFC-Anodes – Short and Long Term Behavior

2017 ◽  
Vol 77 (10) ◽  
pp. 141-147 ◽  
Author(s):  
André Weber ◽  
Sebastian Dierickx ◽  
Niklas Russner ◽  
Ellen Ivers-Tiffée
Keyword(s):  
Sulfur Poisoning ◽  
Short And Long Term ◽  
Long Term Behavior

scholarly journals Sofosbuvir protects Zika virus-infected mice from mortality, preventing short- and long-term sequela

2017 ◽  
Author(s):  
André C. Ferreira ◽  
Camila Z. Valle ◽  
Patricia A. Reis ◽  
Giselle Barbosa-Lima ◽  
Yasmine Rangel Vieira ◽  
...  
Keyword(s):  
Zika Virus ◽  
Neurological Disorders ◽  
Health Concern ◽  
Virus Challenge ◽  
Significant Public Health Concern ◽  
Significant Public Health ◽  
Short And Long Term ◽  
Long Term Behavior

ABSTRACTZika virus (ZIKV) caused significant public health concern, because of its association with congenital malformations, neurological disorders in adults and, more recently, with deaths. Considering the necessity to mitigate the cases ZIKV-associated diseases, antiviral interventions against this virus are an urgent necessity. Sofosbuvir, a drug in clinical use against Hepatitis C Virus (HCV), is among the FDA-approved substances endowed with anti-ZIKV activity. In this work, we further investigated the in vivo activity of sofosbuvir against ZIKV. Neonatal Swiss mice were infected with ZIKV (2 x 107 PFU) and treated with sofosbuvir at 20 mg/kg/day, a concentration compatible with pre-clinical development of this drug. We found that sofosbuvir reduced acute levels of ZIKV from 60 to 90 % in different anatomical compartments, such as in blood plasma, spleen, kidney and brain. Early treatment with sofosbuvir doubled the percentage and time of survival of ZIKV-infected animals, despite the aggressive virus challenge assayed and also prevented the acute neuromotor impairment triggered by the virus. On the long-term behavior analysis of ZIKV-associated sequelae, sofosbuvir prevented loss of hippocampal- and amygdala-dependent memory. Our results point out that sofosbuvir inhibits ZIKV replication in vivo, which is consistent with the prospective necessity of antiviral drugs to treat ZIKV-infected individuals.

Articular Cartilage Repair

1998 ◽  
Vol 26 (2) ◽  
pp. 309-324 ◽  
Author(s):  
Alan P. Newman
Keyword(s):  
Articular Cartilage ◽  
Basic Science ◽  
Vascular System ◽  
Randomized Study ◽  
Noncollagenous Proteins ◽  
The Matrix ◽  
Tremendous Amount ◽  
Short And Long Term ◽  
Science Investigations

Articular cartilage can tolerate a tremendous amount of intensive and repetitive physical stress. However, it manifests a striking inability to heal even the most minor injury. Both the remarkable functional characteristics and the healing limitations reflect the intricacies of its structure and biology. Cartilage is composed of chondrocytes embedded within an extracellular matrix of collagens, proteoglycans, and noncollagenous proteins. Together, these substances maintain the proper amount of water within the matrix, which confers its unique mechanical properties. The structure and composition of articular cartilage varies three-dimensionally, according to its distance from the surface and in relation to the distance from the cells. The stringent structural and biological requirements imply that any tissue capable of successful repair or replacement of damaged articular cartilage should be similarly constituted. The response of cartilage to injury differs from that of other tissues because of its avascularity, the immobility of chondrocytes, and the limited ability of mature chondrocytes to proliferate and alter their synthetic patterns. Therapeutic efforts have focused on bringing in new cells capable of chondrogenesis, and facilitating access to the vascular system. This review presents the basic science background and clinical experience with many of these methods and information on synthetic implants and biological adhesives. Although there are many exciting avenues of study that warrant enthusiasm, many questions remain. These issues need to be addressed by careful basic science investigations and both short- and long-term clinical trials using controlled, prospective, randomized study design.

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