Self-Contained 3D Bioprinter for Cardiovascular and Cancer Research

2019 ◽  
Author(s):  
Prabhuti Kharel ◽  
Likitha Somasekhar ◽  
Kevin Fernando ◽  
Kunal Mitra
Keyword(s):  
Cancer Research ◽  
Structural Integrity ◽  
Environmental Parameters ◽  
Primary Objective ◽  
3D Bioprinting ◽  
Deposition Method ◽  
Fabrication Technology ◽  
Tissue Constructs ◽  
Living Tissues ◽  
Selection Of

Bioprinting is a 3D fabrication technology used to accurately dispense cell-laden biomaterials for the fabrication of complex 3D functional living tissues. A syringe-based extrusion (SBE) deposition method comprising of multiple nozzles is integrated into the system. This allows for a wider selection of biomaterials that can be used for the formation of the extracellular matrix (ECM). The 3D bioprinting system presented in this paper aims to facilitate the process of 3D bioprinting through its ability to control the environmental parameters within an enclosed printing chamber. The primary objective of this research is to print viable 3D tissue constructs seeded with cells with high structural integrity and high resolution.

Self-Contained Three-Dimensional Bioprinter for Applications in Cardiovascular Research

2019 ◽  
Vol 13 (3) ◽  
Author(s):  
Prabhuti Kharel ◽  
Likitha Somasekhar ◽  
Amy Vecheck ◽  
Kunal Mitra
Keyword(s):  
Functional Characterization ◽  
Three Dimensional ◽  
Environmental Parameters ◽  
3D Bioprinting ◽  
Cardiovascular Research ◽  
Form Complex ◽  
Tissue Constructs ◽  
Long Duration ◽  
Selection Of

Bioprinting is a technique of creating 3D cell-laden structures by accurately dispensing biomaterial to form complex synthetic tissue. The printed constructs aim to mimic the native tissue by preserving the cell functionality and viability within the printed structure. The 3D bioprinting system presented in this paper aims to facilitate the process of 3D bioprinting through its ability to control the environmental parameters within an enclosed printing chamber. This design of the bioprinter targets to eliminate the need for a laminar flow hood, by regulating the necessary environmental conditions important for cell survival, especially during long duration prints. A syringe-based extrusion (SBE) deposition method comprising multiple nozzles is integrated into the system. This allows for a wider selection of biomaterials that can be used for the formation of the extracellular matrix (ECM). Tissue constructs composed of alginate-gelatin hydrogels were mixed with fibrinogen and human endothelial cells which were then characterized and compared using two methodologies: casted and bioprinted. Furthermore, vasculature was incorporated in the bioprinted constructs using sacrificial printing. Structural and functional characterization of the constructs were performed by assessing rheological, mechanical properties, and analyzing live-dead assay measurements.

A 3D bioprinting system to produce human-scale tissue constructs with structural integrity

2016 ◽  
Vol 34 (3) ◽  
pp. 312-319 ◽  
Author(s):  
Hyun-Wook Kang ◽  
Sang Jin Lee ◽  
In Kap Ko ◽  
Carlos Kengla ◽  
James J Yoo ◽  
...  
Keyword(s):  
Structural Integrity ◽  
3D Bioprinting ◽  
Tissue Constructs ◽  
Human Scale

Identification of Possible High Integrity Containers for Low-Level Nuclear Waste Disposal

1981 ◽  
Vol 6 ◽  
Author(s):  
Jeffrey D. Williams
Keyword(s):  
South Carolina ◽  
Structural Integrity ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Economic Factors ◽  
Burial Site ◽  
Low Level ◽  
High Integrity ◽  
Low Level Radioactive Waste ◽  
Selection Of

ABSTRACTIncreased concern by the State of South Carolina over the condition and capacity of the low-level radioactive waste burial site at Barnwell has prompted them to promulgate new regulations on waste burial containers. As of September 30, 1981, ion exchange resin and filter media waste with an activity of 1 μCi/cc or greater and with isotopes with halflives greater than five years disposed at Barnwell shall be solidified or confined in a “high integrity container”. The materials and designs of these containers are required to provide waste isolation from the environment for a period of 300 years and provide the structural integrity specified in 49 CFR 173.398(b). HITTMAN has been active in the design and development of containers suitable for this purpose with this paper detailing the analyses involved. Material selections were limited to stainless steel, fiberglass, and polyethylenes. Structural concerns focused on overpressure requirements, drop-testing requirements, and lifting capabilities. With a lifetime dose of up to 108 rads, the possibilities of radiation damage were considered. Preliminary selection of polyethylene was based on satisfactory resolution of these issues and economic factors.

Design and topological optimization of rear pressure bulkhead for a typical aircraft

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Marshal Thakran ◽  
Meenakshi ◽  
Jitender Sharma ◽  
Charles Gilbert Martin
Keyword(s):  
Numerical Analysis ◽  
Significant Influence ◽  
Design Methodology ◽  
Structural Integrity ◽  
Topological Optimization ◽  
Content Type ◽  
Iterative Design ◽  
Practical Implications ◽  
Insight Into ◽  
Selection Of

Purpose The purpose of this paper is to evaluate the model of a rear pressure bulkhead with different design optimizations to meet the pressurized cabin requirements of an aircraft. Design/methodology/approach This paper presents the results of the static analysis of a dome-shaped rear pressure bulkhead model designed in Catia-v5. Numerical analysis of model meshed in hyper-mesh and solved using Opti-Struct for iterative design optimizations. Findings All the iterative models are analyzed at 9 Psi. Rear pressure bulkhead designed with L-section stringer shows better results than the model optimized with T-section stringer for the same thickness. The model optimized with L-shaped stinger also reduces the weight of the bulkhead without affecting the structural integrity. Practical implications It has been concluded in this paper that the selection of specific shapes of the stringers shows a significant influence on weight reduction. Originality/value This paper provides a topical, technical insight into the design and development of a rear pressure bulkhead. It also outlines the future development of dome-shaped rear pressure bulkhead.

scholarly journals Strength Increasing Additive Manufacturing Fused Filament Fabrication Technology, Based on Spiral Toolpath Material Deposition

Machines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 57 ◽  
Author(s):  
Artem Avdeev ◽  
Andrey Shvets ◽  
Ilya Gushchin ◽  
Ivan Torubarov ◽  
Aleksey Drobotov ◽  
...  
Keyword(s):  
Deposition Method ◽  
Compression Tests ◽  
Fabrication Technology ◽  
Standard Samples ◽  
Fused Filament Fabrication ◽  
Material Deposition ◽  
Layer Deposition ◽  
Point Bend ◽  
Five Axis ◽  
Printing Method

The paper provides an overview of ways to increase the strength of polymer products obtained by fused filament fabrication (FFF) technology. An algorithm for calculating the spiral toolpaths for the material deposition using multi-axis printing is proposed. The design of the five-axis device for spiral-shaped deposition of the material is shown. The description of the proposed printing method is given. The results of comparative three-point bend and compression tests are presented. The standard samples obtained in the usual way by FFF technology, as well as samples with 2, 4, 6, 8 and 10 reinforcing layers obtained by spiral deposition of the material were investigated. The description of the tests is given, the dependences of the strength of the products on the number of reinforcing layers are obtained. Conclusions about the influence of the layer deposition method on the strength of the products are formulated.

scholarly journals Preparation methods for Graphene, Metal and Polymer-based Composites for EMI Shielding Materials: A Review

2021 ◽  
Author(s):  
Saba Ayub ◽  
Beh Hoe Guan ◽  
Faiz Ahmad ◽  
Muhammad Faisal Javed ◽  
Amir Mosavi ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Deposition Method ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Preparation Methods ◽  
Shielding Material ◽  
Selection Of

The electromagnetic inference is an issue from decades, where working for a better shielding material is still on-going. The purpose of this study is to review the existing methods in the formation of graphene, metal and polymer-based composites. Study indicates that in graphene and metal-based composites, the utilization of alternating deposition method showed the highest shielding effectiveness, whereas, in polymer-based composite, the utilization of chemical vapor deposition method showed highest shielding effectiveness. However, this review reveals that still there is a gap in the literature in terms of the selection of the method. Although there are various available methods which researchers adopt as per their convenience, none of the studies makes a comparison of the methods to form a similar composite. Therefore, as a future gap researcher needs to adopt various methods to form a single composite and then make a comparison of shielding effectiveness. This act will be useful for future researchers to select the appropriate method.

Adaptive multiple tuned mass dampers based on modal parameters for earthquake response reduction in multi-story buildings

2016 ◽  
Vol 20 (9) ◽  
pp. 1375-1389 ◽  
Author(s):  
Mohammad Sabbir Rahman ◽  
Md Kamrul Hassan ◽  
Seongkyu Chang ◽  
Dookie Kim
Keyword(s):  
Tuned Mass Damper ◽  
Primary Objective ◽  
Modal Parameters ◽  
Earthquake Response ◽  
Tuned Mass Dampers ◽  
Mass Damper ◽  
Modal Mass ◽  
Story Building ◽  
Selection Of ◽  
Multiple Tuned Mass Dampers

The primary objective of this research is to find the effectiveness of an adaptive multiple tuned mass damper distributed along with the story height to control the seismic response of the structure. The seismic performance of a 10-story building was investigated, which proved the efficiency of the adaptive multiple tuned mass damper. Structures with single tuned mass damper and multiple tuned mass dampers were also modeled considering the location of the dampers at the top of the structure, whereas adaptive multiple tuned mass damper of the structure was modeled based on the story height. Selection of the location of the adaptive multiple tuned mass damper along with the story height was dominated by the modal parameters. Participation of modal mass directly controlled the number of the modes to be considered. To set the stage, a comparative study on the displacements and modal energies of the structures under the El-Centro, California, and North-Ridge earthquakes was conducted with and without various types of tuned mass dampers. The result shows a significant capability of the proposed adaptive multiple tuned mass damper as an alternative tool to reduce the earthquake responses of multi-story buildings.

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