Differences in the Compressive Stress-Strain Response of Infiltrating Ductal Carcinomas with and without Lobular Features — Implications for Mammography and Elastography

2003 ◽  
Vol 25 (3) ◽  
pp. 109-121 ◽  
Author(s):  
Thomas A. Krouskop ◽  
Pamela S. Younes ◽  
Seshadri Srinivasan ◽  
Thomas Wheeler ◽  
Jonathan Ophir
Keyword(s):  
Critical Strain ◽  
Tumor Tissue ◽  
Testing Machine ◽  
Strain Response ◽  
Irreversible Change ◽  
Tissue Stiffness ◽  
Instron Testing Machine ◽  
Additional Testing ◽  
Ductal Carcinomas ◽  
Strain Threshold

In a previous study, it was noted that in some cases when compressive strains greater than about 5% were applied to tumors removed from the breast, there was an abrupt and irreversible change in the tissue stiffness. The data from that study were further analyzed and infiltrating ductal carcinomas with and without lobular features were selected for additional testing to explore their behavior under compressive strains from 0–10%. Fresh tumor samples were tested using a servo-hydraulic Instron testing machine to apply ramp type displacement loads to the samples. The results show that when strains greater than 5% are applied to the tumor tissue without lobular features, there is an irreversible decrease in the stiffness of the tissue while no such change is noted in the other tumor tissue. The implications for this behavior in making mammographic and elastographic images of the breast were then explored using finite element simulations to determine under what compression conditions could the critical strain threshold be reached in the tumor tissue.

Differences in the Compressive Stress-Strain Response of Infiltrating Ductal Carcinomas with and without Lobular Features — Implications for Mammography and Elastography

2003 ◽  
Vol 25 (3) ◽  
pp. 162-170 ◽  
Author(s):  
Thomas A. Krouskop ◽  
Pamela S. Younes ◽  
Seshadri Srinivasan ◽  
Thomas Wheeler ◽  
Jonathan Ophir
Keyword(s):  
Critical Strain ◽  
Tumor Tissue ◽  
Testing Machine ◽  
Strain Response ◽  
Irreversible Change ◽  
Tissue Stiffness ◽  
Instron Testing Machine ◽  
Additional Testing ◽  
Ductal Carcinomas ◽  
Strain Threshold

In a previous study, it was noted that in some cases when compressive strains greater than about 5% were applied to tumors removed from the breast, there was an abrupt and irreversible change in the tissue stiffness. The data from that study were further analyzed and infiltrating ductal carcinomas with and without lobular features were selected for additional testing to explore their behavior under compressive strains from 0–10%. Fresh tumor samples were tested using a servo-hydraulic Instron testing machine to apply ramp type displacement loads to the samples. The results show that when strains greater than 5% are applied to the tumor tissue without lobular features, there is an irreversible decrease in the stiffness of the tissue while no such change is noted in the other tumor tissue. The implications for this behavior in making mammographic and elastographic images of the breast were then explored using finite element simulations to determine under what compression conditions could the critical strain threshold be reached in the tumor tissue.

Study of Bismuth Telluride Crystal Strength

2019 ◽  
pp. 1-8
Author(s):  
A. A. Gorbatovskiy
Keyword(s):  
Tensile Strength ◽  
Bismuth Telluride ◽  
Elasticity Modulus ◽  
Testing Machine ◽  
Bend Testing ◽  
Instron Testing Machine ◽  
Measurement Results ◽  
Strength Tests ◽  
Semiconductor Properties

The article presents results of strength tests of bismuth telluride prismatic samples obtained by growing crystals. These crystals have semiconductor properties and are used in the heat machines, the run-ability of which largely depends on the strength of crystals. Data available in the literature are significantly different from each other. It has been shown that, the most consistent strength tests results are obtained in case of bend testing. The measurement results of the elasticity modulus and tensile strength are given. For tests, an INSTRON testing machine with maximum direct stress of the 1000 H was used.

scholarly journals In Vitro Frictional Forces Generated by Three Different Ligation Methods

2008 ◽  
Vol 78 (5) ◽  
pp. 917-921 ◽  
Author(s):  
Paola Gandini ◽  
Linda Orsi ◽  
Chiara Bertoncini ◽  
Sarah Massironi ◽  
Lorenzo Franchi
Keyword(s):  
Steel Wire ◽  
Testing Machine ◽  
Low Friction ◽  
Instron Testing Machine ◽  
Resistance To Sliding ◽  
Titanium Wire ◽  
Frictional Forces ◽  
Conventional Bracket ◽  
Wire Resistance

Abstract Objective: To test the hypothesis that there is no difference between the frictional forces produced by a passive self-ligating bracket (SLB) in vitro and a conventional bracket (CB) used with two types of elastomeric ligatures. Materials and Method: The brackets, wires and ligation methods used in vitro were a passive SLB and a CB used with two types of elastomeric ligatures (conventional elastomeric ligature [CEL] and unconventional elastomeric ligatures [UEL]). The bracket ligation systems were tested with two types of wires (0.014″ super elastic nickel titanium wire and 0.019″ × 0.025″ stainless steel wire). Resistance to sliding of the bracket/wire/ligature systems was measured with an experimental model mounted on the crosshead of an Instron testing machine with a 10 N load cell. Each sample was tested 10 consecutive times under a dry state. Results: Frictional forces close to 0 g were recorded in all tests with SLB and in all tests with UEL on CB with both wire types. Resistance to sliding increased significantly (87–177 g) (P < .05) when CEL on CB was used with both wires. Conclusion: UELs may represent a valid alternative to passive SLBs for low-friction biomechanics.

scholarly journals Material properties of Velcro fastenings

1982 ◽  
Vol 6 (2) ◽  
pp. 93-96
Author(s):  
D. L. Bader ◽  
M. J. Pearcy
Keyword(s):  
Cyclic Loading ◽  
Material Properties ◽  
Testing Machine ◽  
Force Extension ◽  
Instron Testing Machine ◽  
Attachment Strength

An assessment of the material properties of three types of touch and close fasteners (Velcro) in general orthopaedic usage is presented. The materials were tested under various loading regimes using an Instron testing machine. The force-extension curves were analyzed and values determined for both the stiffness and strength of the various attachments. Particular reference was made to the alteration in attachment strength after cyclic loading. The strength of the standard Velcro was found to be least affected after cyclic loading to simulate continuous usage. A recommendation is made on the specific application of each type of Velcro based on their material properties.

scholarly journals Effects of physical and morphological properties of roots on fracture resistance

2014 ◽  
Vol 08 (02) ◽  
pp. 261-264 ◽  
Author(s):  
Huseyin Ertas ◽  
Burak Sagsen ◽  
Hakan Arslan ◽  
Ozgur Er ◽  
Elif Tarim Ertas
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Fracture Resistance ◽  
Linear Regression Analysis ◽  
Testing Machine ◽  
Morphological Properties ◽  
Root Fracture ◽  
Volume Weight ◽  
Instron Testing Machine ◽  
Root Fracture Resistance

ABSTRACT Objective: The aim of this study was to determine how physical and morphological properties affect the fracture resistance of roots, and which criteria are important for root specimen standardization in fracture resistance studies. Materials and Methods: Seventy-five freshly extracted human canine teeth were selected. Crowns were sectioned from the cement–enamel junction and the root lengths were set at 16 mm. Then they were prepared up to ProTaper F3 file. Each root was numbered and data were obtained by measuring mesiodistal and buccolingual dimensions, volume, weight, and density. Tests for fracture strength were performed using an Instron Testing Machine (Instron Corp. MA, USA). The force was applied axially, angled at 45 degrees with a constant speed of 1 mm/min. For each sample, the force at the time of fracture was recorded in Newtons. Results were evaluated statistically using linear regression analysis. Results: Volume and weight of the roots had more effect than mesiodistal or buccolingual dimensions on root fracture resistance. Conclusions: In root fracture resistance studies, volume or weight of the roots must be standardized when distributing roots to groups.

scholarly journals High Strain-Rate Compressive Properties of Carbon/Epoxy Laminated Composites – Effects of loading direction and temperature

2018 ◽  
Vol 183 ◽  
pp. 02011
Author(s):  
Kenji Nakai ◽  
Tsubasa Fukushima ◽  
Takashi Yokoyama ◽  
Kazuo Arakawa
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Elevated Temperatures ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Slenderness Ratio ◽  
Testing Machine ◽  
Negative Temperature ◽  
Hopkinson Pressure Bar ◽  
Instron Testing Machine

The high strain-rate compressive characteristics of a cross-ply carbon/epoxy laminated composite in the three principal material directions or fibre (1-), in-plane transverse (2-) and throughthickness (3-) directions are investigated on the conventional split Hopkinson pressure bar (SHPB) over a range of temperatures between 20 and 80 °C. A nearly 10 mm thick cross-ply carbon/epoxy composite laminate fabricated using vacuum assisted resin transfer molding (VaRTM) was tested. Cylindrical specimens with a slenderness ratio (= length/diameter) of 0.5 are used in high strain-rate tests, and those with the slenderness ratios of 1.0 and 1.5 are used in low and intermediate strain-rate tests. The uniaxial compressive stress-strain curves up to failure at quasi-static and intermediate strain rates are measured on an Instron testing machine at elevated temperatures. A pair of steel rings is attached to both ends of the cylindrical specimens to prevent premature end crushing in the 1-and 2-direction tests on the Instron testing machine. It is shown that the ultimate compressive strength (or failure stress) exhibits positive strainrate effects and negative temperature ones over a strain-rate range of 10–3 to 103/s and a temperature range of 20 to 80 °C in the three principal material directions.

scholarly journals Dynamic Recrystallization Behavior and Processing Map of the 6082 Aluminum Alloy

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1042 ◽  
Author(s):  
Dao-chun Hu ◽  
Lei Wang ◽  
Hong-jun Wang
Keyword(s):  
Dynamic Recrystallization ◽  
Critical Strain ◽  
High Efficiency ◽  
Processing Map ◽  
Testing Machine ◽  
Hot Compression ◽  
Hot Working ◽  
Al Alloy ◽  
Strain Rates ◽  
6082 Al Alloy

Multiple hot-compression tests were carried out on the 6082 aluminum (Al) alloy using a Gleeble-1500 thermal simulation testing machine. Data on flow stresses of the 6082 Al alloy at deformation temperatures of 623 to 773 K and strain rates from 0.01 to 5 s−1 were attained. Utilizing electron backscatter diffraction (EBSD) and a transmission electron microscope (TEM), the dynamic recrystallization behaviors of the 6082 Al alloy during hot compression in isothermal conditions were explored. With the test data, a hot-working processing map for the 6082 Al alloy (based on dynamic material modeling (DMM)) was drawn. Using the work-hardening rate, the initial critical strain causing dynamic recrystallization was determined, and an equation for the critical strain was constructed. A dynamic model for the dynamic recrystallization of the 6082 Al alloy was established using analyses and test results from the EBSD. The results showed that the safe processing zone (with a high efficiency of power dissipation) mainly corresponded to a zone with deformation temperatures of 703 to 763 K and strain rates of 0.1 to 0.3 s−1. The alloy was mainly subjected to continuous dynamic recrystallization in the formation of the zone. According to the hot-working processing map and an analysis of the microstructures, it is advised that the following technological parameters be selected for the 6082 Al alloy during hot-forming: a range of temperatures between 713 and 753 K and strain rates between 0.1 and 0.2 s−1.

Evaluation of Shear Bond Strength and SEM Observation of All-in-one Self-etching Primer Used for Bonding of Fissure Sealants

2006 ◽  
Vol 7 (2) ◽  
pp. 9-16 ◽  
Author(s):  
Maha Abdulla Al-Sarheed
Keyword(s):  
Phosphoric Acid ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
Fissure Sealants ◽  
Fissure Sealant ◽  
Sem Observation ◽  
Instron Testing Machine ◽  
Acid Etch ◽  
The Mean

Abstract Objectives To evaluate and compare enamel shear bond strength of an all-in-one self-etching primer (Prompt™ L-Pop™) to regular acid etch material when bonded to two-fissure sealant systems (Concise and Dyract Seal). Method and Materials Forty newly extracted non-carious first permanent molars were embedded in a Teflon mold. The teeth were divided into four groups and each consisted of ten specimens. The bonding surfaces were treated with either Prompt L-Pop as recommended by the manufacturer or etched with phosphoric acid. After 24 hours of water storage, the specimens were evaluated for shear bond strength using an Instron testing machine. Scanning electron microscope (SEM) examinations were carried out to evaluate the failure sites of the sealants. Results The mean shear bond strengths using Prompt L-Pop were Concise: 23.46 MPa and Dyract Seal: 20.34 MPa. These values were higher than and statistically different from those of Dyract Seal (9.99 MPa) and Concise (8.85 MPa) when phosphoric acid was used. The failure was predominantly of the adhesive type. The SEM examination showed the failure of debonding was predominantly related to the type of etching systems used rather than the type of fissure sealants. Conclusion The use of the all-in-one self-etching adhesive Prompt L-Pop improves the mean enamel shear bond strength of fissure sealants. Citation Al-Sarheed MA. Evaluation of Shear Bond Strength and SEM Observation of All-in-one Self-etching Primer Used for Bonding of Fissure Sealants. J Contemp Dent Pract 2006 May;(7)2:009-016.

scholarly journals Inelastic Behavior in Repeated Shearing of Bovine White Matter

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Taylor S. Cohen ◽  
Andrew W. Smith ◽  
Panagiotis G. Massouros ◽  
Philip V. Bayly ◽  
Amy Q. Shen ◽  
...  
Keyword(s):  
White Matter ◽  
Strain Rate ◽  
Critical Strain ◽  
Mechanical Response ◽  
Tissue Mechanics ◽  
Strain Rates ◽  
Inelastic Behavior ◽  
Fiber Breakage ◽  
Rate Dependent ◽  
Strain Threshold

Understanding the brain’s response to multiple loadings requires knowledge of how straining changes the mechanical response of brain tissue. We studied the inelastic behavior of bovine white matter and found that when this tissue is stretched beyond a critical strain threshold, its reloading stiffness drops. An upper bound for this strain threshold was characterized, and was found to be strain rate dependent at low strain rates and strain rate independent at higher strain rates. Results suggest that permanent changes to tissue mechanics can occur at strains below those believed to cause physiological disruption or rupture of axons. Such behavior is characteristic of disentanglement in fibrous-networked solids, in which strain-induced mechanical changes may result from fiber realignment rather than fiber breakage.

scholarly journals Abstract 1915:In vivoprostate tumor tissue stiffness differs by tumor region and can be recapitulated in bioengineered prostate tumor tissues

2019 ◽  
Author(s):  
Nicole L. Habbit ◽  
Benjamin Anbiah ◽  
Luke S. Anderson ◽  
Joshita Suresh ◽  
Iman Hassani ◽  
...  
Keyword(s):  
Tumor Tissue ◽  
Prostate Tumor ◽  
Tissue Stiffness ◽  
Tumor Tissues ◽  
Tumor Region
Sign in / Sign up

Export Citation Format

Share Document