scholarly journals Pull-Out Capability of a 3D Printed Threadless Suture Anchor with Rectangular Cross-Section: A Biomechanical Study

2021 ◽  
Vol 11 (24) ◽  
pp. 12128
Author(s):  
Yueh-Ying Hsieh ◽  
Lien-Chen Wu ◽  
Fon-Yih Tsuang ◽  
Chia-Hsien Chen ◽  
Chang-Jung Chiang
Keyword(s):  
Cross Section ◽  
Cyclic Load ◽  
Suture Anchor ◽  
Rectangular Cross Section ◽  
The Body ◽  
Load Test ◽  
The Novel ◽  
Pullout Strength ◽  
Pull Out ◽  
3D Printed

Suture anchor fixation is a common method for securing bone and soft tissue in the body, with proven applications in the hip, elbow, hand, knee and foot. A critical limiting factor of suture anchors is the pull-out strength, particularly in suboptimal bone. This study introduces a novel 3D printed threadless suture anchor with a rectangular cross-section. The titanium anchor was designed with surface fenestration and a porous central core to improve bone ingrowth. The aim of this study was to compare the pull-out properties of the novel threadless anchor with a traditional circular threaded suture anchor. The anchors were inserted into a 0.24 g/cm3 synthetic cancellous bone block at angles of 90° and 135° to the surface. The sutures were pulled at 180° (parallel) to the surface under a static pull test (anchor pullout) and cyclic load test using a tensile testing machine. Under the static load, the greatest pullout strength was seen with the novel threadless anchor inserted at 90° (mean, 105.6 N; standard deviation [SD], 3.5 N). The weakest pullout strength was seen with the threaded anchor inserted at 90° (mean, 87.9 N; SD, 4.1 N). In the cyclic load test, all six of the threaded anchors with a 90° insertion angle pulled out after 18 cycles (70 N). All of the threadless anchors inserted at 90° survived the cyclic test (90 N). In conclusion, the novel threadless suture anchor with rectangular cross-section and traditional threaded suture anchor had similar pullout survivorship when inserted at either 90° or 135°. In addition, the 3D printed threadless anchor has the potential for good bone integration to improve long-term stabilization.

Experimental Analysis of Vortex Induced Vibration in the Bladeless Small Wind Turbine

2019 ◽  
Author(s):  
Micha Premkumar Thomai ◽  
Lasoodawanki Kharsati ◽  
Nakandhrakumar Rama Samy ◽  
Seralathan Sivamani ◽  
Hariram Venkatesan
Keyword(s):  
Energy Conversion ◽  
Wind Turbine ◽  
Natural Frequency ◽  
Cross Section ◽  
Vortex Shedding ◽  
Rectangular Cross Section ◽  
The Body ◽  
Test Facility ◽  
Vortex Induced Vibration ◽  
Small Wind Turbine

Abstract Vortex-induced vibration is one of the predominant fundamental concepts for forced oscillation which attracts considerable practical engineering application for energy conversion. In this work, an oscillation of a mast arising as a result of wind force is utilized for energy conversion. The paradigm for energy conversion from vortex-induced vibration in the mast is the bladeless wind turbine. It consists of a rigid mass known as a mast, fixed in the spring of stiffness (k) and allowed to oscillate along the direction of the flow. In this work, four different types of mast have been fabricated and tested. The first is uniform tapered hollow conical mast (MAST1), the cross-section of the second is uniform tapered plus symbol (MAST2), the third is uniform tapered inversed plus symbol (MAST3) and the fourth is uniform tapered simple rectangular cross-section (MAST4). All the masts were fabricated using fiber carbon. The experiments were conducted in a versatile small wind turbine testing facility of Hindustan Institute of Technology and Science, Chennai. This test facility contained an open jet wind tunnel with variable frequency drive and other measuring instruments. The vibration sensor was located in the mast where it experienced a large oscillation in a free stream. In this experiment, an increase in wind velocity led to a terrible change in the amplitude of vibration. A vigorous oscillation was experienced in this mast at this critical frequency, when the natural frequency of the mast was synchronized with the frequency of the vortex shedding and the frequency of the oscillation of the mast. The total force in this oscillation was a summation of the body force due to the mass of the mast and vorticity force that is mainly which was the result of the shedding of the vortices. In this work, extensive studies have been carried out for Reynolds number ranging from 2.5 × 105 to 5.0 × 105. The mast length to diameter ratio of 13 was exposed to various speeds of wind and response was measured. The occurrence of the maximum oscillation in a simple rectangular mast was seen where vortex shedding due to the bluff body was large for constant mass and spring stiffness. The frequency of the oscillation at maximum amplitude of the rectangular cross-section mast was equal to the natural frequency, due to vortices shedding at critical velocity. This demonstrated the appropriateness of the simple rectangular cross-section for harnessing the low rated wind energy and its suitability for renewable energy conversion in the small bladeless wind turbine.

Refractory equipment for firing aluminum nitride substrates

2020 ◽  
pp. 7-9
Author(s):  
Yu. K. Nepochatov ◽  
P. M. Pletnev ◽  
A. A. Denisova
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
The Body ◽  
Special Design ◽  
High Quality ◽  
Reducing Environment ◽  
Recovery Medium

The features of firing aluminitride substrates, characterized by a high temperature of more than 1800 0С and the presence of a reducing environment, are described. It is shown that the high quality of substrates in parallelism, thermal conductivity, and other properties can be achieved, along with the establishment of optimal firing modes, using a special design of a capsule based on boron nitride, which is a container that consists of a body - a box of rectangular cross section, bottom and plane-parallel dividing plates with supports. To create a local (inside the capsule) clean recovery medium, thorn-groove interlocks between the body and the bottom are provided, filled with a heat-resistant inert powder.

Generation and Investigation of Embedded Micro-Channels Network Using Three Dimensional Printing Technology

2017 ◽  
Author(s):  
Austin Smith ◽  
Hamzeh Bardaweel
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Hydrodynamic Characteristics ◽  
Shear Stresses ◽  
Printing Technology ◽  
Micro Channels ◽  
3D Printed ◽  
Printing Direction

The work presented here is motivated by the recent growing interest in using additive manufacturing to fabricate micro-channels networks. Distorted shapes and rough geometries influence hydrodynamic characteristics of micro-channels by increasing their flow resistance and pressure drop or altering wall shear stresses inside them. Since geometric conformity and shape fidelity of micro-channels networks are greatly influenced by manufacturing process, this work is focused on dimensional characterization of micro-channels fabricated using additive manufacturing. In this work, circular and rectangular cross-section micro-channels are 3D printed. Shapes and dimensions of 3D printed micro-channels are examined using Scanning Electron Microscope (SEM) imaging. In this work, 500 μm diameter and 200 μm square transparent PolyLactic Acid (PLA) micro-channels are 3D printed with average errors 0.25% and 1.65%, respectively. SEM images confirmed geometric conformity and shape fidelity of the 3D printed circular and rectangular cross-section micro-channels. Statistical analysis is performed on multiple prints to verify reproducibility and shape conformity. Results show that factors such as printing direction play essential role in the shape conformity and geometric fidelity of the micro-channels. Although 3D printing is a promising route for attaining micro-channels there are still significant improvements that can be made to the precision of the printer in the XY plane for printing small geometric figures. This improvement will likely come as the printing technology and software both improve to allow the operator more control over the outcome of the print. Additionally, new 3D printing materials may open the gate for new applications in different fields such as thermal management and microfluidics.

scholarly journals Scalable continuous flow hydrogenations using Pd/Al2O3-coated rectangular cross-section 3D-printed static mixers

2020 ◽  
Author(s):  
René Lebl ◽  
Yutong Zhu ◽  
Derrick Ng ◽  
Christian H. Hornung ◽  
David Cantillo ◽  
...  
Keyword(s):  
Cross Section ◽  
Continuous Flow ◽  
Rectangular Cross Section ◽  
Static Mixers ◽  
3D Printed

Experimental Tensile Tests on Bone Cement: Effect of Test Sample Shape

2015 ◽  
Vol 665 ◽  
pp. 29-32
Author(s):  
Cristian Sorin Nes ◽  
Lucian Bogdan ◽  
Jenel Marian Patrascu
Keyword(s):  
Bone Cement ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Circular Cross Section ◽  
Tensile Tests ◽  
The Body ◽  
Sample Shape ◽  
Cross Section Area ◽  
Section Area ◽  
Shape And Size

Objectives: The mechanical characteristics of bone cement depend on the chemical composition, mixing technique, polymerization period and temperature. Additionally, the shape of the cement mantle can also lead to variations in the mechanical properties of the material, as thicker walls are significantly more non-homogeneous and less permeable for the body fluids. This paper presents experimental tensile tests on bone cement focused on the study of the influence of the test specimen shape on the obtained results.Methods: High viscosity bone cement, produced and supplied as polymer powder and monomer liquid portions was used. The mixed cement was inserted during the working time into two types of silicon molds: one with the shape and size according to ISO 527 (“dogbone” shape with rectangular cross section area) and other with the shape and size according to ASTM F 2118 (“dogbone” shape with circular cross section area). Both types of test specimens have approximately the same value of the cross sectional gauge area. All samples were polished with grit abrasive paper in the longitudinal direction and soaked in phosphate buffered saline (PBS) solution. The specimens were subjected to a tensile test on a hydraulic machine. To avoid the occurrence of critical stress areas on the specimen, special fixing devices were manufactured.Results and conclusions: The stress–strain curves of all specimens tested exhibited similar linear elastic regime followed by brittle fracture. However, different values of the ultimate tensile strength and elastic modulus of tested samples were recorded.

On Dynamics of Bar of Rectangular Cross Section

2000 ◽  
Vol 68 (4) ◽  
pp. 662-666 ◽  
Author(s):  
N. B. Rassoulova
Keyword(s):  
Fourier Transform ◽  
Closed Form ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Original Method ◽  
The Body ◽  
Closed Form Solutions ◽  
Nonstationary Waves ◽  
Parameters Inversion ◽  
Laplace And Fourier Transform

The propagation of nonstationary waves in semi-infinite elastic rectangular bars is studied. It is assumed that two opposite lateral surfaces of the body are free of forces, while the two others are subjects to cross conditions. By introducing three new potential functions, the author succeeded in getting closed-form solutions in Laplace and Fourier transform parameters. Inversion of the transform solutions, carried out by an original method of inversion, is suggested herein.

Diaghilev and British Writing

2009 ◽  
Vol 27 (1) ◽  
pp. 65-92
Author(s):  
Susan Jones
Keyword(s):  
Visual Arts ◽  
The Body ◽  
The Novel ◽  
Literary Responses ◽  
Literary Aesthetics ◽  
Ballets Russes ◽  
The Arts ◽  
The Subject ◽  
And Gender ◽  
Opening Up

This article explores the diversity of British literary responses to Diaghilev's project, emphasising the way in which the subject matter and methodologies of Diaghilev's modernism were sometimes unexpectedly echoed in expressions of contemporary British writing. These discussions emerge both in writing about Diaghilev's work, and, more discretely, when references to the Russian Ballet find their way into the creative writing of the period, serving to anchor the texts in a particular cultural milieu or to suggest contemporary aesthetic problems in the domain of literary aesthetics developing in the period. Figures from disparate fields, including literature, music and the visual arts, brought to their criticism of the Ballets Russes their individual perspectives on its aesthetics, helping to consolidate the sense of its importance in contributing to the inter-disciplinary flavour of modernism across the arts. In the field of literature, not only did British writers evaluate the Ballets Russes in terms of their own poetics, their relationship to experimentation in the novel and in drama, they developed an increasing sense of the company's place in dance history, its choreographic innovations offering material for wider discussions, opening up the potential for literary modernism's interest in impersonality and in the ‘unsayable’, discussions of the body, primitivism and gender.

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