Microstructure features and the prediction of longitudinal elastic modulus of small-diameter-original Bamboo (Phyllostachys glauca McClure)

2016 ◽  
Vol 35 (10) ◽  
pp. 824-833 ◽  
Author(s):  
Jun Jiang
Keyword(s):  
Elastic Modulus ◽  
Small Diameter ◽  
Longitudinal Elastic Modulus

scholarly journals Elastic Modulus and Elasticity Ratio of Malignant Breast Lesions with Shear Wave Ultrasound Elastography: Variations with Different Region of Interest and Lesion Size

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1015
Author(s):  
Antonio Bulum ◽  
Gordana Ivanac ◽  
Eugen Divjak ◽  
Iva Biondić Špoljar ◽  
Martina Džoić Dominković ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Shear Wave ◽  
Large Diameter ◽  
Small Diameter ◽  
Shear Wave Elastography ◽  
Lesion Size ◽  
Ultrasound Elastography ◽  
Breast Lesions ◽  
Malignant Breast ◽  
The Impact

Shear wave elastography (SWE) is a type of ultrasound elastography with which the elastic properties of breast tissues can be quantitatively assessed. The purpose of this study was to determine the impact of different regions of interest (ROI) and lesion size on the performance of SWE in differentiating malignant breast lesions. The study included 150 female patients with histopathologically confirmed malignant breast lesions. Minimal (Emin), mean (Emean), maximal (Emax) elastic modulus and elasticity ratio (e-ratio) values were measured using a circular ROI size of 2, 4 and 6 mm diameters and the lesions were divided into large (diameter ≥ 15 mm) and small (diameter < 15 mm). Highest Emin, Emean and e-ratio values and lowest variability were observed when using the 2 mm ROI. Emax values did not differ between different ROI sizes. Larger lesions had significantly higher Emean and Emax values, but there was no difference in e-ratio values between lesions of different sizes. In conclusion, when measuring the Emin, Emean and e-ratio of malignant breast lesions using SWE the smallest possible ROI size should be used regardless of lesion size. ROI size has no impact on Emax values while lesion size has no impact on e-ratio values.

scholarly journals Tissue ingrowth markedly reduces mechanical anisotropy and stiffness in fibre direction of highly aligned electrospun polyurethane scaffolds

2019 ◽  
Author(s):  
Hugo Krynauw ◽  
Jannik Buescher ◽  
Josepha Koehne ◽  
Loes Verrijt ◽  
Georges Limbert ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Vascular Graft ◽  
Small Diameter ◽  
Mechanical Anisotropy ◽  
Fibre Direction ◽  
Tissue Ingrowth ◽  
Fibre Alignment ◽  
Random Fibre ◽  
Directed Research

AbstractPurposeThe lack of long-term patency of synthetic vascular grafts currently available on the market has directed research towards improving the performance of small diameter grafts. Improved radial compliance matching and tissue ingrowth into the graft scaffold are amongst the main goals for an ideal vascular graft.MethodsBiostable polyurethane scaffolds were manufactured by electrospinning and implanted in subcutaneous and circulatory positions in the rat for 7, 14 and 28 days. Scaffold morphology, tissue ingrowth, and mechanical properties of the scaffolds were assessed before implantation and after retrieval.ResultsTissue ingrowth after 24 days was 96.5 ± 2.3% in the subcutaneous implants and 77.8 ± 5.4% in the circulatory implants. Over the 24 days implantation, the elastic modulus at 12% strain decreased by 59% in direction of the fibre alignment whereas it increased by 1379% transverse to the fibre alignment of the highly aligned scaffold of the subcutaneous implants. The lesser aligned scaffold of the circulatory graft implants exhibited an increase of the elastic modulus at 12% strain by 77% in circumferential direction.ConclusionBased on the observations, it is proposed that the mechanism underlying the softening of the highly aligned scaffold in the predominant fibre direction is associated with scaffold compaction and local displacement of fibres by the newly formed tissue. The stiffening of the scaffold, observed transverse to highly aligned fibres and for more a random fibre distribution, represents the actual mechanical contribution of the tissue that developed in the scaffold.

scholarly journals An Upper Bound of Longitudinal Elastic Modulus for Unidirectional Fibrous Composites as Obtained from Strength of Materials Approach

2018 ◽  
Author(s):  
John Venetis ◽  
Emilio Sideridis
Keyword(s):  
Elastic Modulus ◽  
Upper Bound ◽  
Theoretical Models ◽  
The Novel ◽  
Fibrous Composites ◽  
Strength Of Materials ◽  
Fiber Concentration ◽  
Longitudinal Elastic Modulus ◽  
The Matrix ◽  
Specific Variation

In this paper, an upper bound of the longitudinal elastic modulus of &nbsp;unidirectional&nbsp;&nbsp; fibrous composites is proposed according to strength of materials approach, on the premise that the fiber is much stiffer than the matrix. In the mathematical derivations, the concept of boundary interphase between fiber and matrix was also taken into account and the main objective of this work is the attainment of an upper bound for the interphase stiffness with respect to fiber concentration by volume. The novel element here is that the authors have not taken into consideration any specific variation law to approximate the interphase modulus. The theoretical results arising from the proposed formula were compared with those obtained from some reliable theoretical models as well as with experimental data found in the literature, and a satisfactory agreement was observed.

Out-of-Plane Longitudinal Elastic Modulus of Supported Polymer Thin Films

2009 ◽  
Vol 42 (18) ◽  
pp. 7164-7167 ◽  
Author(s):  
N. Gomopoulos ◽  
W. Cheng ◽  
M. Efremov ◽  
P. F. Nealey ◽  
G. Fytas
Keyword(s):  
Thin Films ◽  
Elastic Modulus ◽  
Polymer Thin Films ◽  
Longitudinal Elastic Modulus ◽  
Out Of Plane

scholarly journals Assessment of the arterial stiffness in patients with acute ischemic stroke using longitudinal elasticity modulus measurements obtained with Shear Wave Elastography.

2016 ◽  
Vol 18 (2) ◽  
pp. 182 ◽  
Author(s):  
Zhaojun Li ◽  
Lianfang Du ◽  
Feng Wang ◽  
Xianghong Luo
Keyword(s):  
Ischemic Stroke ◽  
Elastic Modulus ◽  
Arterial Stiffness ◽  
Shear Wave ◽  
Arterial Wall ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Shear Wave Elastography ◽  
Bilateral Carotid ◽  
Longitudinal Elastic Modulus

Aim: Arterial wall elasticity including the circumferential and longitudinal modulus is a measure of sub-clinical cardiovascular disease; the circumferential modulus is increased in acute ischemic stroke (AIS). There are still no reports of non-invasive measurement of longitudinal elastic modulus of arterial wall and its prospect of clinical application. In this study, the longitudinal elastic modulus of the arterial wall was assessed using real-time shear wave elastography in patients with AIS. The technique’s feasibility and its related factors were studied initially. Materials and methods: In this study 179 patients with AIS and 168 age- and sex-matched controls were examined. The pulse wave velocity (PWV) of the bilateral carotid arteries was measured using radio frequency ultrasound technology. The 20 areas of superficial walls of bilateral carotid artery were analyzed by real-time shear wave elastography (SWE), and the average values of longitudinal average elastic modulus (MEmean), maximum elastic modulus (MEmax), minimum elastic modulus (MEmin), and elastic modulus standard deviation (MESD) were measured. Results: The PWV, MEmean, MEmax and MESD of the carotid artery in patients with AIS were greater than those in the control group. Age, systolic blood pressure, PWV, and low-density lipoprotein were positively related to MEmean and MEmax (r=0.221and r=0.248, r=0.174 and r=0.176, r=0.776 and r=0.716, r=0.173 and r=0.200, p<0.05) and were independent risk factors for MEmean and MEmax。ROC curves for detection of ischemic stroke as decided by PWV, MEmean and MEmax. The area under the curves were 0.55±0.03 (p≤0.05), 0.59±0.03 (p≤0.05) and 0.60±0.03 (p=0.023), respectively. The optimal PWV, MEmean and MEmax cutoff values for the detection of ischemic stroke were 9.66 m/s, 55.4 kPa and 65.4 kPa, with 69%, 73% and 73% sensitivity and 89%, 53% and 51% specificity, respectively. Conclusions: SWE could measure non-invasively the longitudinal elastic modulus of the arterial wall and evaluate the arterial stiffness. It was equivalent to the PWV which showed circular elastic modulus of arterial wall on evaluating AIS. Age, systolic blood pressure, pulse wave velocity, and low-density lipoprotein were independent risk factors for longitudinal elastic modulus. SWE may be effective in the assessment of arterial stiffness and offer a potential clinical benefit.

Power Transmission by Belting

1940 ◽  
Vol 143 (1) ◽  
pp. 318-327 ◽  
Author(s):  
J. G. Jagger ◽  
F. Sykes
Keyword(s):  
Elastic Modulus ◽  
Isotropic Material ◽  
Power Transmission ◽  
Small Diameter ◽  
Compression Modulus ◽  
Transverse Compression ◽  
Linear Elastic ◽  
Compressive Stresses ◽  
The Mean ◽  
Surface Compression

During experimental work on flexible belts running on pulleys of small diameter, the loss of speed of the follower arising from the elasticity of the belt was observed to be considerably greater than would be normally expected. It was also noticed that this loss of speed depended on the mean tension of the belt and the diameter of the pulley. The usual type of belt material does not follow a linear elastic law for strains in the direction of its length, the elastic modulus being relatively low at low tensions and when in compression. On the assumption that compressive stresses can be neglected, the resulting stress distribution is found to account partly for the experimental results. In addition the material has a relatively low transverse compression modulus, and the surface compression causes an additional slip loss which would be negligible with an isotropic material in all practical cases. The examination is applicable to V-belts when the effects producing radial movements are of greater importance because of the amplification by the groove angle. For both kinds of drive the relative influences of the component losses on efficiency are discussed, and conclusions can be drawn on the suitability of materials for small pulley drives.

scholarly journals Mechanical Properties of the Sarcolemma and Myoplasm in Frog Muscle as a Function of Sarcomere Length

1972 ◽  
Vol 59 (5) ◽  
pp. 559-585 ◽  
Author(s):  
Stanley I. Rapoport
Keyword(s):  
Elastic Modulus ◽  
Fiber Length ◽  
Elastic Moduli ◽  
Sarcomere Length ◽  
Fiber Surface ◽  
Frog Muscle ◽  
Fiber Tension ◽  
Resistance To Deformation ◽  
Longitudinal Elastic Modulus ◽  
Tension Curve

The elastimeter method was applied to the single muscle fiber of the frog semitendinosus to obtain the elastic moduli of the sarcolemma and myoplasm, as well as their relative contributions to resting fiber tension at different extensions. A bleb which was sucked into a flat-mouthed pipette at the fiber surface separated into an external sarcolemmal membrane and a thick inner myoplasmic region. Measurements showed that the sarcolemma does not contribute to intact fiber tension at sarcomere lengths below 3 µ. It was estimated that the sarcolemma contributed on the order of 10% to intact fiber tension at sarcomere lengths between 3 and 3.75 µ, and more so with further extension. Between these sarcomere lengths, the sarcolemma can be linearly extended and has a longitudinal elastic modulus of 5 x 106 dyne/cm2 (assuming a thickness of 0.1 µ). Resistance to deformation of the inner bleb region is due to myoplasmic elasticity. The myoplasmic elastic modulus was estimated by use of a model and was used to predict a fiber length-tension curve which agreed approximately with observations.

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