Tensile properties of synthetic, absorbable monofilament suture materials before and after incubation in phosphate‐buffered saline

2020 ◽  
Vol 49 (3) ◽  
pp. 550-560
Author(s):  
Karen M. Tobias ◽  
Calvin E. Kidd ◽  
Pierre‐Yves Mulon ◽  
Xiaojuan Zhu
Keyword(s):  
Tensile Properties ◽  
Suture Materials ◽  
Monofilament Suture ◽  
Before And After ◽  
Phosphate Buffered Saline

Experimental Investigation of Mechanical Behavior of a Polyamide before and after Constrained Groove Pressing Process

2018 ◽  
Vol 36 ◽  
pp. 25-36
Author(s):  
Mohammed Salah Bennouna ◽  
Benaoumeur Aour ◽  
Fatiha Bouaksa ◽  
Saad Hamzaoui
Keyword(s):  
Experimental Investigation ◽  
Mechanical Behavior ◽  
Tensile Properties ◽  
Material Properties ◽  
Hold Time ◽  
Thermoplastic Polymer ◽  
Processed Material ◽  
Before And After ◽  
Number Of Cycles ◽  
Number Of Passes

In this paper an experimental investigation of mechanical behavior of a thermoplastic polymer (polyamide PA 66) processed by constrained groove pressing (CGP) using several passes is presented. To this end, corrugating and straightening tools are designed and manufactured. The effects of the number of passes and the hold time on the mechanical behavior of the polyamide have been highlighted. The obtained results show that the material properties and the microstructure are significantly altered under CGP process. It has been found that the microhardness and the tensile properties have been progressed accordingly to the number of cycles, especially when the samples are processed using a hold time of five minutes. Hence, it can be concluded that this latter plays a very important role on the reorientation and stabilization of the microstructure when the processed material is a polymer.

Mechanical Comparison of 10 Suture Materials before and after in Vivo Incubation

1994 ◽  
Vol 56 (4) ◽  
pp. 372-377 ◽  
Author(s):  
Daniel Greenwald ◽  
Scott Shumway ◽  
Paul Albear ◽  
Lawrence Gottlieb
Keyword(s):  
Suture Materials ◽  
Before And After

Reduced erythrocyte deformability alters pulmonary hemodynamics

1989 ◽  
Vol 67 (6) ◽  
pp. 2593-2599 ◽  
Author(s):  
M. P. Doyle ◽  
W. R. Galey ◽  
B. R. Walker
Keyword(s):  
Filtration Time ◽  
Pulmonary Hemodynamics ◽  
Rat Lungs ◽  
Before And After ◽  
Pulmonary Arterial ◽  
Rapid Switching ◽  
Phosphate Buffered Saline ◽  
Isolated Rat ◽  
Rbc Deformability

Isolated rat lungs were perfused with suspensions containing normal and stiffened erythrocytes (RBCs) to assess the effect of altered RBC deformability on pulmonary hemodynamics. RBC suspensions were prepared using cells previously incubated in isosmolar phosphate-buffered saline with or without 0.0125 or 0.01875% glutaraldehyde. Washed RBCs were resuspended in isosmolar 4% albumin saline solution. Isolated rat lungs were perfused with control and stiffened cells by the use of a perfusion system that allowed rapid switching between suspensions. Pressure-flow (P/Q) curves were constructed by measuring pulmonary arterial pressure (Ppa) over a range of flow rates. In a second set of experiments, P/Q curves were generated for perfusion with control and stiffened cells (0.0125% glutaraldehyde) before and after vasoconstriction with a synthetic prostaglandin analogue (U 46619). RBC deformability was quantified in all experiments by determination of filtration time of a dilute cell suspension through a 4.7 microns Nuclepore filter. Incubation with 0.0125 or 0.01875% glutaraldehyde produced a 6 or 21% decrease in RBC deformability, respectively. These decreases in deformability were associated with significant increases in Ppa at each flow rate. The increases in Ppa correlated significantly with the degree of RBC stiffening. With 0.0125% glutaraldehyde, the P/Q curve was shifted upward without a change in slope, whereas incubation with 0.01875% glutaraldehyde resulted in a significant increase in slope. Vasoconstriction and perfusion with stiffened RBCs had additive effects on Ppa. These findings suggest that decreases in RBC deformability cause physiologically significant elevations in hemodynamic resistance in the pulmonary circuit independent of vasoactivity.

scholarly journals Microstructure and Tensile Properties of Diffusion Bonded Austenitic Fe-Base Alloys—Before and After Exposure to High Temperature Supercritical-CO2

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 480 ◽  
Author(s):  
Sung Hwan Kim ◽  
Ji-Hwan Cha ◽  
Changheui Jang ◽  
Injin Sah
Keyword(s):  
High Temperature ◽  
Tensile Properties ◽  
Heat Exchangers ◽  
Boundary Migration ◽  
Bond Line ◽  
Grain Boundary Migration ◽  
Compact Type ◽  
Before And After ◽  
Temperature Exposure ◽  
Co2 Environment

Austenitic Fe-base alloys, SS 316H and Alloy 800HT, were diffusion bonded for use in compact-type heat exchangers in supercritical-carbon dioxide (S-CO2) Brayton cycles. For diffusion bonded 316H, grain boundary migration across the bond-line was observed despite the formation of some Cr-rich carbide, and its tensile properties were similar to those of as-received 316H. However, diffusion bonded Alloy 800HT exhibited severely degraded elongation compared to as-received 800HT due to the formation of continuous Ti-rich carbides along the bond-line. Post-bond heat treatment (PBHT) was found to improve elongation at fracture for diffusion bonded alloys. However, a subsequent corrosion test in S-CO2 at 600 °C (20 MPa) for 1000 h resulted in a loss of elongation. This was much more severe for PBHT-ed 800HT due to the formation of Cr-rich carbides at the bond-line. Meanwhile, it was found that the effect of ageing on loss of elongation during high temperature exposure was greater than that of S-CO2 environment.

Studies on Tensile Properties of Compatibilized and Uncompatibilized Low-Density Polyethylene/Jackfruit Seed Flour (LDPE/JFSF) Blends at Different JFSF Content

2017 ◽  
Vol 264 ◽  
pp. 120-123 ◽  
Author(s):  
Sung Ting Sam ◽  
Omar Sabbar Dahham ◽  
Pei Gie Gan ◽  
N.Z. Noimam ◽  
Jingi Y. Kuan ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Adipic Acid ◽  
Morphological Properties ◽  
Screw Extruder ◽  
Direct Introduction ◽  
Elongation At Break ◽  
Seed Flour ◽  
Before And After ◽  
Twin Screw ◽  
Natural Fillers

Currently, natural fillers seem to be the suitable materials in polymer industry, which have emerged as a viable and abundant replacement for the relatively high-cost and non-renewable conventional fillers. However, the direct introduction of natural fillers into polymer matrix could effect negatively on some properties. Therefore, the aim of this work is to evaluate the influence of jackfruit seed flour (JFSF) (before and after compatibilization) on the tensile properties of (LDPE/JFSF) blends. Different JFSF content (5, 10, 15 and 20 wt.%) with (63-100 𝜇𝑚) particle size were prepared in this work. Twin-screw extruder at 150°C and 50rpm screw speed followed by hot-compress machine at 150°C and 10MPa pressure were used respectively to produce (LDPE/JFSF) blends. Adipic acid (AA) solution was added as a compatibilizer into all blends equally (25wt% AA into 75wt% JFSf). The changes of tensile and morphological properties were investigated. Results shown decreasing on tensile strength and elongation at break of LDPE/JFSF and LDPE/JFSF/AA as JFSF increased. In contrast, Young’s modulus increased up to 10 wt.% of JFSF and then decreased. However, the addition of Adipic acid, particularly for JFSF 5wt.% has improved the tensile properties of LDPE/JFSF blends. The SEM micrographs showed the agglomeration at high JFSF content (20 wt%) which in turn effected negatively on the tensile properties. However, the blends show homogeneous surfaces as AA added.

scholarly journals The Relationship Between Proteoglycan Loss, Overloading-Induced Collagen Damage, and Cyclic Loading in Articular Cartilage

Cartilage ◽  
2019 ◽  
pp. 194760351988500
Author(s):  
Lorenza Henao-Murillo ◽  
Maria-Ioana Pastrama ◽  
Keita Ito ◽  
Corrinus C. van Donkelaar
Keyword(s):  
Articular Cartilage ◽  
Cyclic Loading ◽  
Mechanical Loading ◽  
Mechanical Tests ◽  
Repeated Loading ◽  
Healthy Cartilage ◽  
Before And After ◽  
Damage Grades ◽  
The Relationship ◽  
Phosphate Buffered Saline

Objective The interaction between proteoglycan loss and collagen damage in articular cartilage and the effect of mechanical loading on this interaction remain unknown. The aim of this study was to answer the following questions: (1) Is proteoglycan loss dependent on the amount of collagen damage and does it depend on whether this collagen damage is superficial or internal? (2) Does repeated loading further increase the already enhanced proteoglycan loss in cartilage with collagen damage? Design Fifty-six bovine osteochondral plugs were equilibrated in phosphate-buffered saline for 24 hours, mechanically tested in compression for 8 hours, and kept in phosphate-buffered saline for another 48 hours. The mechanical tests included an overloading step to induce collagen damage, creep steps to determine tissue stiffness, and cyclic loading to induce convection. Proteoglycan release was measured before and after mechanical loading, as well as 48 hours post-loading. Collagen damage was scored histologically. Results Histology revealed different collagen damage grades after the application of mechanical overloading. After 48 hours in phosphate-buffered saline postloading, proteoglycan loss increased linearly with the amount of total collagen damage and was dependent on the presence but not the amount of internal collagen damage. In samples without collagen damage, repeated loading also resulted in increased proteoglycan loss. However, repeated loading did not further enhance the proteoglycan loss induced by damaged collagen. Conclusion Proteoglycan loss is enhanced by collagen damage and it depends on the presence of internal collagen damage. Cyclic loading stimulates proteoglycan loss in healthy cartilage but does not lead to additional loss in cartilage with damaged collagen.

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