scholarly journals Investigation of Applicability of an Embedded EM Sensor to Measure the Tension of a PSC Girder

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Junkyeong Kim ◽  
Ju-Won Kim ◽  
Seunghee Park
Keyword(s):  
Tensile Force ◽  
Magnetic Hysteresis ◽  
Experimental Studies ◽  
Measured Data ◽  
Area Ratio ◽  
Test Results ◽  
Sectional Area ◽  
Initial Value ◽  
Initial State ◽  
Cross Sectional

This study investigates the applicability of an embedded EM sensor using a series of experimental studies. To verify the embedded EM sensor, the magnetic hysteresis of various types of PS tendons is measured. After that, the embedded EM sensor is embedded into the concrete and the possibility of obtaining measurements is verified. Finally, the downscaled PSC girder specimen having a sheath with a different curvature is fabricated and the influence of the sheath curvature is investigated. The magnetic hysteresis was changed constantly even though the type of PS tendon was changed, and the embedded EM sensor can measure the magnetic hysteresis, even in the concrete and curved sheath. The area of magnetic hysteresis was decreased according to the increase in the tension force, but the actual values were different according to the number and cross-sectional area of tendons and the initial state of sensors. To compensate for the measured data, the tensile force was converted to the tensile stress and the area ratio was used to compensate for the initial value of the EM sensor. According to the test results, the embedded EM sensor could be applied to the actual PS girder and it can measure the actual tension, which includes the friction loss.

scholarly journals Atrophy patterns in isolated subscapularis lesions

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gernot Seppel ◽  
Andreas Voss ◽  
Daniel J. H. Henderson ◽  
Simone Waldt ◽  
Bernhard Haller ◽  
...  
Keyword(s):  
Muscle Atrophy ◽  
Area Ratio ◽  
Cross Sectional Area ◽  
Control Group ◽  
Sectional Area ◽  
Cross Sectional ◽  
Subscapularis Muscle ◽  
Mri Scans ◽  
The Mean ◽  
The Cross

Abstract Background While supraspinatus atrophy can be described according to the system of Zanetti or Thomazeau there is still a lack of characterization of isolated subscapularis muscle atrophy. The aim of this study was to describe patterns of muscle atrophy following repair of isolated subscapularis (SSC) tendon. Methods Forty-nine control shoulder MRI scans, without rotator cuff pathology, atrophy or fatty infiltration, were prospectively evaluated and subscapularis diameters as well as cross sectional areas (complete and upper half) were assessed in a standardized oblique sagittal plane. Calculation of the ratio between the upper half of the cross sectional area (CSA) and the total CSA was performed. Eleven MRI scans of patients with subscapularis atrophy following isolated subscapularis tendon tears were analysed and cross sectional area ratio (upper half /total) determined. To guarantee reliable measurement of the CSA and its ratio, bony landmarks were also defined. All parameters were statistically compared for inter-rater reliability, reproducibility and capacity to quantify subscapularis atrophy. Results The mean age in the control group was 49.7 years (± 15.0). The mean cross sectional area (CSA) was 2367.0 mm2 (± 741.4) for the complete subscapularis muscle and 1048.2 mm2 (± 313.3) for the upper half, giving a mean ratio of 0.446 (± 0.046). In the subscapularis repair group the mean age was 56.7 years (± 9.3). With a mean cross sectional area of 1554.7 mm2 (± 419.9) for the complete and of 422.9 mm2 (± 173.6) for the upper half of the subscapularis muscle, giving a mean CSA ratio of 0.269 (± 0.065) which was seen to be significantly lower than that of the control group (p < 0.05). Conclusion Analysis of typical atrophy patterns of the subscapularis muscle demonstrates that the CSA ratio represents a reliable and reproducible assessment tool in quantifying subscapularis atrophy. We propose the classification of subscapularis atrophy as Stage I (mild atrophy) in case of reduction of the cross sectional area ratio < 0.4, Stage II (moderate atrophy) in case of < 0.35 and Stage III (severe atrophy) if < 0.3.

Use of Cardiac Magnetic Resonance Imaging Based Measurements of Inferior Vena Cava Cross-Sectional Area in the Diagnosis of Pericardial Constriction

2015 ◽  
Vol 66 (3) ◽  
pp. 231-237 ◽  
Author(s):  
Kate Hanneman ◽  
Paaladinesh Thavendiranathan ◽  
Elsie T. Nguyen ◽  
Hadas Moshonov ◽  
Rachel Wald ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cardiac Magnetic Resonance ◽  
Inferior Vena ◽  
Vena Cava ◽  
Area Ratio ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Resonance Imaging ◽  
Cross Sectional ◽  
Aortic Area

Purpose To evaluate the value of cardiac magnetic resonance imaging (MRI)–based measurements of inferior vena cava (IVC) cross-sectional area in the diagnosis of pericardial constriction. Methods Patients who had undergone cardiac MRI for evaluation of clinically suspected pericardial constriction were identified retrospectively. The diagnosis of pericardial constriction was established by clinical history, echocardiography, cardiac catheterization, intraoperative findings, and/or histopathology. Cross-sectional areas of the suprahepatic IVC and descending aorta were measured on a single axial steady-state free-precession (SSFP) image at the level of the esophageal hiatus in end-systole. Logistic regression and receiver-operating curve (ROC) analyses were performed. Results Thirty-six patients were included; 50% (n = 18) had pericardial constriction. Mean age was 53.9 ± 15.3 years, and 72% (n = 26) were male. IVC area, ratio of IVC to aortic area, pericardial thickness, and presence of respirophasic septal shift were all significantly different between patients with constriction and those without ( P < .001 for all). IVC to aortic area ratio had the highest odds ratio for the prediction of constriction (1070, 95% confidence interval [8.0-143051], P = .005). ROC analysis illustrated that IVC to aortic area ratio discriminated between those with and without constriction with an area under the curve of 0.96 (95% confidence interval [0.91-1.00]). Conclusions In patients referred for cardiac MRI assessment of suspected pericardial constriction, measurement of suprahepatic IVC cross-sectional area may be useful in confirming the diagnosis of constriction when used in combination with other imaging findings, including pericardial thickness and respirophasic septal shift.

Assessment of sand stabilization potential of a plant-derived biomass

2016 ◽  
Vol 23 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Dunja Perić ◽  
Paul A. Bartley ◽  
Lawrence Davis ◽  
Ali Ulvi Uzer ◽  
Cahit Gürer
Keyword(s):  
Area Ratio ◽  
Cross Sectional Area ◽  
Experimental Program ◽  
Early Age ◽  
Shear Stresses ◽  
Sectional Area ◽  
Cross Sectional ◽  
Near Surface ◽  
Total Cross Sectional Area ◽  
Dry Sand

AbstractLignin is a coproduct of biofuel and paper industries, which exhibits binding qualities when mixed with water. Lignin is an ideal candidate for a sustainable stabilization of unpaved roads. To this end, an experimental program was devised and carried out to quantify effects of lignin on compaction and early age shear strength behaviors of sand. Samples were prepared by mixing a particular type of coproduct called calcium lignosulfonate (CaL) with sand and water. Based on the extensive analyses of six series of strength tests, it was found that a normalized cohesion increased with an increasing normalized areas ratio. Normalizations were carried out by dividing the cohesion and area ratio by gravimetric CaL content whereby the area ratio was obtained by dividing the portion of the cross-sectional area occupied with lignosulfonate-water (CaL-W) paste by the total cross-sectional area. While the increase in the normalized cohesion eventually leveled out, the cohesion peaked at 6% of CaL. Thus, sand-CaL-water (S-CaL-W) mixes sustained larger shear stresses than dry sand for a range of normal stresses below the limiting normal stress. Consequently, the early age behavior indicates that adding CaL-W to sand is clearly beneficial in the near-surface applications in dry sand.

Fabrication and Mechanical Properties of Dense/Porous β-Tricalcium Phosphate Bioceramics

2007 ◽  
Vol 330-332 ◽  
pp. 907-910
Author(s):  
Fa Ming Zhang ◽  
Jiang Chang ◽  
Jian Xi Lu ◽  
Kai Li Lin
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Exponential Growth ◽  
Weight Bearing ◽  
Area Ratio ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Matrix ◽  
Porous Bioceramics

Attempt to increase the mechanical properties of porous bioceramics, a dense/porous structured β-TCP bioceramics that mimic the characteristics of nature bone were fabricated. Experimental results show that the dense/porous structured β-TCP bioceramics demonstrated excellent mechanical properties with compressive strength up to 74 MPa and elastic modulus up to 960 MPa, which could be tailored by the dense/porous cross-sectional area ratio obeying the rule of exponential growth. The interface between the dense and porous bioceramics is connected compactly and tightly with some micropores distributed in the matrix of both porous and dense counterparts. The dense/porous structure of β-TCP bioceramics may provide an effective way to increase the mechanical properties of porous bioceramics for bone regeneration at weight bearing sites.

scholarly journals Morphological study of the vastus medialis oblique in recurrent patellar dislocation based on magnetic resonance images

2020 ◽  
Author(s):  
Lei Shu ◽  
Xu Yang ◽  
Hangyuan He ◽  
Biao Chen ◽  
Liaobin Chen ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Muscle Fibre ◽  
Tilt Angle ◽  
Area Ratio ◽  
Control Group ◽  
Vastus Medialis ◽  
Morphological Parameters ◽  
Sectional Area ◽  
Cross Sectional ◽  
Patella Tilt

Abstract Background: To investigate the morphological parameters of the vastus medialis obliquus (VMO) muscle and delineate its importance in the maintenance of patellofemoral joint stability.Methods: The magnetic resonance imaging (MRI) data of seventy-five knees (fifty-four patients) with recurrent lateral patella dislocation (LPD) and seventy-five knees (seventy patients) without recurrent LPD were retrospectively analysed. Five morphological parameters related to the VMO (elevation in the sagittal plane and coronal plane, craniocaudal extent, muscle-fibre angulation, cross-sectional area ratio) and two patella tilt parameters (patella tilt angle, bisect offset ratio) were measured in MR images. The independent-samples t test or chi-square test was used for statistical comparisons.Results: The mean ages of the patients in the recurrent LPD group and control group were 22.1 ± 9.9 years and 24.0 ± 6.5 years, respectively. Eighteen out of seventy-five (24%) patients MRI showed VMO injuries. Compared with the control group, the patients with recurrent LPD showed significantly higher sagittal VMO elevation (10.4 ± 2.3 mm vs 4.1 ± 1.9 mm), coronal VMO elevation (15.9 ± 5.7 mm vs 3.9 ± 3.7 mm), muscle-fibre angulation (35.4 ± 8.0° vs 27.9 ± 6.3°), patella tilt angle (25.9 ± 10.7° vs 9.1 ± 5.2°), and bisect offset ratio values (0.9 ± 0.3 vs 0.5 ± 0.1) and significantly lower craniocaudal extent (13.7 ± 5.3 mm vs 16.7 ± 5.1 mm) and cross-sectional area ratio values (0.05 ± 0.02 vs 0.07 ± 0.02).Conclusions: The results showed that abnormalities in the VMO and patella tilt were clearly present in recurrent LPD patients compared with normal people.

Plasticity and Viscoplasticity

1989 ◽  
Author(s):  
Shiro Kobayashi ◽  
Soo-Ik Oh ◽  
Taylan Altan
Keyword(s):  
Uniaxial Tension ◽  
Metal Forming ◽  
Experimental Studies ◽  
Plasticity Theory ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Stress Strain ◽  
Cross Sectional ◽  
Theory Of Plasticity ◽  
Classical Plasticity

The theory of plasticity describes the mechanics of deformation in plastically deforming solids, and, as applied to metals and alloys, it is based on experimental studies of the relations between stresses and strains under simple loading conditions. The theory described here assumes the ideal plastic body for which the Bauschinger effect and size effects are neglected. The theory also is valid only at temperatures for which recovery, creep, and thermal phenomena can be neglected. The basic theory of classical plasticity is described by Hill, and also in References, in addition to the books listed in Chap. 1. A concise description of the general plasticity theory necessary for metal forming is given in the book by Johnson et al.. In this chapter, certain important aspects of the theory are presented in order to elucidate the developments of the finite-element solutions of metal-forming problems discussed in this book. First, various measures of stress and strain are introduced. Then, the governing equations for plastic deformation and principles that are the foundations for the analysis are described. The extension of the theory of plasticity to time-dependent theory of viscoplasticity is outlined in Section 4.8. Particular references are made, in Sections 4.3 through 4.7, to the books by Hill and by Johnson and Mellor, and to the section on general plasticity theory in the book by Johnson et al.. The basic quantities that may be used to describe the mechanics of deformation when a body deforms from one configuration to another under an external load are the stress, strain, and strain-rate. Various measures of these quantities are defined, depending upon how closely formulations represent actual situations. Although it is not possible to provide the complete mathematical formulations in one-dimensional deformation, these measures are introduced for the case of simple uniaxial tension. Consider the uniaxial tension test of a round specimen whose initial length is l0 and cross-sectional area is A0. The specimen is stretched in the axial direction by the force P to the length l and the cross-sectional area A at time t, as shown in Fig. 4.1. The response of the material is recorded as the load-displacement curve, and converted to the stress-strain curve as shown in the figure. The deformation is assumed to be homogeneous until necking begins.

scholarly journals Numerical Investigation of a two-inlet PVT air collector

2019 ◽  
Vol 136 ◽  
pp. 05014
Author(s):  
Zhangyang Kang ◽  
Zhaoyang Lu ◽  
Xin Deng ◽  
Qiongqiong Yao
Keyword(s):  
Heat Transfer ◽  
Single Channel ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Thermal Characteristics ◽  
Area Ratio ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Maximum Heat

A numerical study of heat and mass transfer characteristics of a two-inlet PV/T air collector is performed. The influence of thermal characteristics and efficiency is investigated as the area ratios of inlet and outlet of the single channel with two inlets are changed. The design of the two-inlet PV/T air collector can avoid the poor heat transfer conditions of the single inlet PV/T air collector and improve the total photo-thermal efficiency. When the inlet/outlet cross-sectional area ratio is reduced, the inlet air from the second inlet enhances the convection heat transfer in the second duct and the temperature distribution is more uniform. As the cross-sectional area of the second inlet increase, the maximum heat exchange amount of the two-inlet PV/T air collector occurs between the inlet and outlet cross-sectional area ratio L=0.645 and L=0.562.

Strength Performance of T-Headed Rebar in Concrete

2013 ◽  
Vol 284-287 ◽  
pp. 1401-1408
Author(s):  
Chien Kuo Chiu ◽  
Kai Ning Chi ◽  
Ker Chun Lin
Keyword(s):  
Strength Properties ◽  
Normal Weight ◽  
Concrete Cover ◽  
Building Structures ◽  
Test Results ◽  
Sectional Area ◽  
Cross Sectional ◽  
Strength Performance ◽  
Practical Engineering ◽  
Cover Thickness

In recent years, the T-Headed bar has been gradually applied to bridge and building structures. However, until Year 2008, a debut of the headed bar in the ACI 318 Design Code was found. There were six limitations on materials’ strength properties, bearing area of head and concrete-cover thickness and spacing of the reinforcement with the head to be made in the Section 12.6 of the ACI 318-08 Code. This paper concerns some issues that were difficult application for the practical engineering or had potential to be improved. They include the clear spacing of the headed bars not less than 4 times the diameter of the bars, the bearing area of head of the headed bar not less than 4 times cross-sectional area of the bars and concrete limit on normal-weight and its effective compression strength not more than 42 MPa. In this study, a total of 43 specimens with a CCT node (Compression-Compression-Tension Node) experimental model were conducted to evaluate anchored performance of the headed bars. Study parameters in this work included strength of concrete, size of reinforcement, bearing area of T head, spacing of bars and confinement condition provided by horizontal reinforcement. Additionally, some benchmark specimens those placed straight bars, and standard 90º and 180º hook bars were carried out for comparison. Test results showed that for anchorage performance, the T-headed bars could provide better than the standard 90º and 180º hook bars. Test results also indicated that the headed bars with head bearing area of three times sectional area of the bar were able to perform as well anchored behavior as their head bearing area with four times sectional area of the bar. In addition, comparing the test results of specimens their spacing having 1.5 and 4 times diameter of the bar, it was found that their anchored strength capacities were similar.

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