Strain tolerance of the Vv. Cerebri sup. (Bridging Veins) calculated from head-on collision tests with cadavers

1974 ◽  
Vol 75 (2) ◽  
pp. 131-144 ◽  
Author(s):  
Peter Löwenhielm
Keyword(s):  
Strain Tolerance ◽  
Bridging Veins

Pterional Approach for Surgical Treatment of Olfactory Groove Meningiomas

Neurosurgery ◽  
1989 ◽  
Vol 25 (6) ◽  
pp. 942-947 ◽  
Author(s):  
W. Hassler ◽  
J. Zentner
Keyword(s):  
Surgical Treatment ◽  
Superior Sagittal Sinus ◽  
Cerebrospinal Fluid Fistula ◽  
Pterional Approach ◽  
Olfactory Groove ◽  
Sagittal Sinus ◽  
Frontal Brain ◽  
Bridging Veins ◽  
Frontal Sinuses ◽  
Fluid Fistula

Abstract We present our experience with the surgical treatment of olfactory groove meningiomas using a pterional approach. This approach provides the advantages of previous techniques, such as preserving the frontal brain and superior sagittal sinus, early devascularization of the tumor, and late dissection of tumor borders. Moreover, it also compensates for the shortcomings of other techniques, e.g., compression of frontal bridging veins, late dissection of dorsal tumor aspects involving vessels and optic nerves as well as facultative infection and cerebrospinal fluid fistula-related complications caused by opening of frontal sinuses. To date, 11 patients were treated in this way. As we encountered no surgical complications in our series we are encouraged to present our procedure.

scholarly journals Ceramic Thermal Barrier Coatings for Turbine Engine Components

1982 ◽  
Author(s):  
D. S. Duvall ◽  
D. L. Ruckle
Keyword(s):  
Thermal Barrier Coatings ◽  
Ceramic Coatings ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Turbine Engine ◽  
Thermal Environments ◽  
Strain Tolerance ◽  
Endurance Testing ◽  
Plasma Sprayed ◽  
Cooling Air

The durability of plasma sprayed ceramic thermal barrier coatings subjected to cyclic thermal environments has been improved substantially by improving the strain tolerance of the ceramic structure and also by controlling the substrate temperature during the application of the coating. Improved strain tolerance was achieved by using ceramic structures with increased porosity, microcracking or segmentation. Plasma spraying on a controlled-temperature substrate also has been shown to improve durability by reducing harmful residual stresses. The most promising of the strain tolerant ceramic coatings have survived up to 6000 cycles of engine endurance testing with no coating or vane platform damage. In side-by-side engine tests, thermal barrier coatings have shown that they greatly reduce platform distress compared to conventionally coated vanes in addition to permitting reductions in cooling air and attendant increases in engine efficiency.

scholarly journals The effects of cardiac rehabilitation on haemodynamic parameters measured by impedance cardiography in patients with coronary artery disease

2020 ◽  
pp. 126-126
Author(s):  
Milovan Stojanovic ◽  
Marina Deljanin-Ilic ◽  
Stevan Ilic ◽  
Dejan Petrovic ◽  
Bojan Ilic
Keyword(s):  
Coronary Artery Disease ◽  
Negative Correlation ◽  
Impedance Cardiography ◽  
Exercise Stress ◽  
Strong Positive Correlation ◽  
Physical Strain ◽  
Strong Negative Correlation ◽  
Positive Correlation ◽  
Strain Tolerance ◽  
Artery Disease

Background / Aim. Well-organized cardiovascular rehabilitation (CVR) reduces cardiovascular burden by influencing cardiovascular risk factors, improving the quality of life and reducing mortality and hospital readmission. However, its effects on hemodynamic status are largely unknown. The aim of our study was to evaluate the influence of three-week CVR program on hemodynamic status and to investigate if there is a correlation between physical strain tolerance and hemodynamic parameters measured by impedance cardiography (ICG) before and after CVR program in patients with coronary artery disease. Methods. Fifty-two patients attended a three-week CVR program. At the beginning and at the end of rehabilitation program laboratory tests, exercise stress tests (EST) and ICG measurements were taken. Results. Patients showed better strain tolerance on the second exercise stress test (EST2) by achieving higher strain level (Z=2,315; p=0,021) and longer duration of test (Z=2,305; p=0,021). There was a strong positive correlation between the level of EST2 and cardiac output (CO) (r=0,538; p<0,001) and stroke volume (SV) (r=0,380; p=0,017) on the second ICG (ICG2). Also, there was a strong negative correlation between EST2 level and systemic vascular resistance (SVR) (r=-0,472; p=0,002) and SVR index (SSVRI) (r=-0,407; p=0,010) on ICG2. There was a strong positive correlation between EST2 duration and CO (r=0.517; p=0.001) as well as between EST2 duration and SV (r=0.340; p=0.034), and a strong negative correlation between EST2 duration and SVR (r=-0.504; p=0.001) as well as between EST2 duration and SVRI (r=-0.448; p=0.004), according to ICG2. Conclusion. Our study showed that a well-designed CVR program can lead to better physical strain tolerance. Furthermore, CVR led to a significant positive correlation between EST and cardiac output as well as between EST and stroke volume measured by ICG. On the other hand, there was a significant negative correlation between EST and vascular related parameters according to ICG at the end of the CVR program.

Measurements on Critical Current and Bending Strain Tolerance for Ex Situ ${{\rm MgB}_{2}}$ Wires and Tapes Under High Field up to 8 T

2018 ◽  
Vol 28 (3) ◽  
pp. 1-5 ◽  
Author(s):  
Julien Avronsart ◽  
Christophe Berriaud ◽  
Xavier Chaud ◽  
Clement Hilaire ◽  
Mario Kazazi ◽  
...  
Keyword(s):  
Critical Current ◽  
High Field ◽  
Ex Situ ◽  
Bending Strain ◽  
Strain Tolerance ◽  
Bending Strain Tolerance

Strain Tolerance and Microstructure of Thermal Barrier Coatings Produced by Electron Beam Physical Vapor Deposition Process

2006 ◽  
Vol 522-523 ◽  
pp. 267-276 ◽  
Author(s):  
Kunihiko Wada ◽  
Yutaka Ishiwata ◽  
Norio Yamaguchi ◽  
Hideaki Matsubara
Keyword(s):  
Electron Beam ◽  
High Temperature ◽  
Thermal Barrier Coatings ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Aging Treatment ◽  
Nanoindentation Test ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Strain Tolerance

Several kinds of thermal barrier coatings (TBCs) deposited by electron beam physical vapor deposition (EB-PVD) were produced as a function of electron beam power in order to evaluate their strain tolerance. The deposition temperatures were changed from 1210 K to 1303 K depending on EB power. In order to evaluate strain tolerances of the EB-PVD/TBCs, a uniaxial compressive spallation test was newly proposed in this study. In addition, the microstructures of the layers were observed with SEM and Young’s moduli were measured by a nanoindentation test. The strain tolerance in as-deposited samples decreased with an increase in deposition temperature. In the sample deposited at 1210 and 1268 K, high-temperature aging treatment at 1273 K for 10 h remarkably promoted the reduction of the strain tolerance. The growth of thermally grown oxide (TGO) layer generated at the interface between topcoat and bondcoat layers was the principal reason for this strain tolerance reduction. We observed TGO-layer growth even in the as-deposited sample. Although the thickness of the initial TGO layer in the sample deposited at high temperature was thicker, the growth rate during aging treatment was smaller than those of the other specimens. This result suggests that we can improve the oxidation resistance of TBC systems by controlling the processing parameters in the EB-PVD process.

Rotating squares auxetic metamaterials with improved strain tolerance

2021 ◽  
Vol 30 (3) ◽  
pp. 035015
Author(s):  
A Sorrentino ◽  
D Castagnetti ◽  
L Mizzi ◽  
A Spaggiari
Keyword(s):  
Strain Tolerance ◽  
Improved Strain

The So-Called Cranial Dural Channels and Their Relationship with the Bridging Veins

2021 ◽  
Author(s):  
Gerasimos Baltsavias ◽  
Vincenzo Paterno ◽  
Heinrich Lanfermann
Keyword(s):  
Bridging Veins

Spontaneous chronic subdural hematomas in young adults with a deficiency of coagulation factor XIII

2005 ◽  
Vol 102 (6) ◽  
pp. 1130-1132 ◽  
Author(s):  
Alessio Albanese ◽  
Antonio Tuttolomondo ◽  
Carmelo Anile ◽  
Giovanni Sabatino ◽  
Angelo Pompucci ◽  
...  
Keyword(s):  
Young Adults ◽  
Factor Xiii ◽  
Coagulation Factor ◽  
Content Type ◽  
Coagulation Factor Xiii ◽  
Subdural Hematomas ◽  
History Of ◽  
Bridging Veins ◽  
Fine Print

✓ Chronic subdural hematomas (SDHs) generally occur in elderly patients. Its pathogenesis is usually related to head trauma with tearing and rupture of the bridging veins, although in some cases a history of trauma is not recognizable. There are many reports regarding the association between spontaneous chronic SDHs and an alteration in coagulative parameters. A coagulative disorder should be suspected when an unexplained hemorrhage occurs, especially in a young patient. The authors report on three young men with a deficiency in coagulation factor XIII (FXIII) who underwent surgery for chronic SDHs. The role of FXIII in the pathogenesis of chronic SDH is emphasized. In patients with unexplained chronic SDH all coagulation parameters and factors should be screened to identify an eventual coagulative disorder.

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