scholarly journals Mechanically Strong and Tailorable Polyimide Aerogels Prepared with Novel Silicone Polymer Crosslinkers

Gels ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 57
Author(s):  
Zhongxin Zhang ◽  
Yurui Deng ◽  
Zhiyi Lun ◽  
Xiao Zhang ◽  
Mingyuan Yan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Small Molecule ◽  
Low Cost ◽  
Chain Structure ◽  
Degree Of Polymerization ◽  
Silane Coupling Agents ◽  
Surface Areas ◽  
Silicone Polymers ◽  
The Cost ◽  
Silicone Polymer

Polyimide (PI) aerogels were prepared using self-designed silicone polymer cross-linkers with multi-amino from low-cost silane coupling agents to replace conventional small-molecule cross-linkers. The long-chain structure of silicone polymers provides more crosslinking points than small-molecule cross-linkers, thus improving the mechanical properties of polyimide. To investigate the effects of amino content and degree of polymerization on the properties of silicone polymers, the different silicone polymers and their cross-linked PI aerogels were prepared. The obtained PI aerogels exhibit densities as low as 0.106 g/cm3 and specific surface areas as high as 314 m2/g, and the maximum Young’s modulus of aerogel is up to 20.9 MPa when using (T-20) as cross-linkers. The cross-linkers were an alternative to expensive small molecule cross-linkers, which can improve the mechanical properties and reduce the cost of PI aerogels.

scholarly journals The Effect of Heat Treatment on the Microstructure and Mechanical Properties of the Novel Low-Cost Ti-3Al-5Mo-4Cr-2Zr-1Fe Alloy

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3798
Author(s):  
Meng Sun ◽  
Dong Li ◽  
Yanhua Guo ◽  
Ying Wang ◽  
Yuecheng Dong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aging Time ◽  
Volume Fraction ◽  
Low Cost ◽  
Solution Treatment ◽  
Solution Temperature ◽  
The Novel ◽  
Α Phase ◽  
The Cost

In order to reduce the cost of titanium alloys, a novel low-cost Ti-3Al-5Mo-4Cr-2Zr-1Fe (Ti-35421) titanium alloy was developed. The influence of heat treatment on the microstructure characteristics and mechanical properties of the new alloy was investigated. The results showed that the microstructure of Ti-35421 alloy consists of a lamina primary α phase and a β phase after the solution treatment at the α + β region. After aging treatment, the secondary α phase precipitates in the β matrix. The precipitation of the secondary α phase is closely related to heat treatment parameters—the volume fraction and size of the secondary α phase increase when increasing the solution temperature or aging time. At the same solution temperature and aging time, the secondary α phase became coarser, and the fraction decreased with increasing aging temperature. When Ti-35421 alloy was solution-treated at the α + β region for 1 h with aging surpassing 8 h, the tensile strength, yield strength, elongation and reduction of the area were achieved in a range of 1172.7–1459.0 MPa, 1135.1–1355.5 MPa, 5.2–11.8%, and 7.5–32.5%, respectively. The novel low-cost Ti-35421 alloy maintains mechanical properties and reduces the cost of materials compared with Ti-3Al-5Mo-5V-4Cr-2Zr (Ti-B19) alloy.

Mechanical Properties of ABS Embedded with Basalt Fiber Fillers

2016 ◽  
Vol 16 (2) ◽  
pp. 69-74 ◽  
Author(s):  
Ayman M. M. Abdelhaleem ◽  
Mohammed Y. Abdellah ◽  
Hesham I. Fathi ◽  
Montasser Dewidar
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Low Cost ◽  
Basalt Fiber ◽  
Acrylonitrile Butadiene Styrene ◽  
Hardness Test ◽  
Basalt Fibers ◽  
Notched Strength ◽  
The Cost ◽  
Plastic Injection

AbstractAcrylonitrile-butadiene-styrene (ABS) has great verity applications in aerospace and automobiles industries. Mechanical strength of the ABS is superior to even that of impact resistant polystyrene. In addition metallic coatings can be applied to the surface of ABS moldings. The main aim of the present work is to investigate the mechanical properties of additives of basalt fibers (BF) to ABS with (5, 10, and 15) wt% embedded into the polymer matrix by using plastic injection molding technique. This new perceptions has been done on basalt fibers that have a potential low cost with its good mechanical performance. The ultimate tensile strength that obtained from the composite with 15 wt% is 56.67 MPa with 40.52 % increase value than neat ABS, Young’s modulus gradually increases with increasing the amount of additives. Impact un-notched strength decreases with a reported increment of 24.617 KJ.m–2. A Rockwell hardness test is also used and with the increases of additives the amount of hardness of the composite increases. A scan electron microscopy (SEM) on the fracture surface is captured to check the morphologies structure of the composite comparable with a neat ABS. and it is showed a very good distribution and bonding of the B.F. with the pure ABS. As well as the cost of the ABS and BF is reduced by a percentage of 15 %.

There is Low Cost Titanium Componentry Today

2013 ◽  
Vol 551 ◽  
pp. 11-15 ◽  
Author(s):  
J.C. Withers ◽  
V. Shapovalov ◽  
R. Storm ◽  
R.O. Loutfy
Keyword(s):  
Mechanical Properties ◽  
Low Cost ◽  
Cost Component ◽  
Automotive Components ◽  
One Step ◽  
Near Net Shape ◽  
Mechanical Properties And Corrosion ◽  
The Cost ◽  
Processing Steps ◽  
Better Than

In spite of titanium’s excellent combinations of lightweight, mechanical properties, and corrosion resistance it has been excluded from many applications because of its high cost in fabricated componentry. The major cost to produce a titanium alloy component is the processing of the sponge into alloy plus the several processing steps for fabricating the final finished component. If low cost titanium is to become a reality, the cost of post sponge processing to final finished components must be dramatically reduced. Processing to convert sponge directly in one step to an alloyed near net shape low cost component has been demonstrated. The mechanical properties are equivalent to better than standard processed wrought titanium. Example, automotive components and other applications that confirm titanium componentry at substantially lower cost than standard processing will be provided.

Validation of a low-cost selective powder deposition process through the characterization of tin bronze specimens

2021 ◽  
pp. 146442072110319
Author(s):  
Samuel Magalhães ◽  
Manuel Sardinha ◽  
Carlos Vicente ◽  
Marco Leite ◽  
Relógio Ribeiro ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Low Cost ◽  
Deposition Process ◽  
Metal Powders ◽  
Tin Bronze ◽  
Powder Deposition ◽  
Manufacturing Technologies ◽  
The Cost

Additive manufacturing technologies are becoming increasingly popular due to their advantages over traditional subtracting manufacturing technologies. Despite advances in this field, fixed and maintenance costs for additive manufacturing with metals remain high. The introduction of low-cost metal machines in the additive manufacturing market considerably reduces the cost of acquiring and maintaining this type of equipment. This work aims to establish the process requirements for a low-cost selective powder deposition process, and validate it through the production of specimens in the laboratory and evaluate their mechanical properties. Tin bronze specimens were produced under different manufacturing conditions, namely powder dimensions, type of crucible and coke, firing segments and casting strategy. The morphology and chemical composition of the specimens were carried out combining the scanning electron microscopy and energy dispersive X-Ray spectroscopy techniques, respectively. It was observed that crucibles and coke with impurities that react with the metal powders and infill in a reducing atmosphere have influence in the final quality of parts. Tested samples displayed high variability of results which can be correlated with different manufacturing conditions. The selection of the appropriate print parameters led to the manufacture of tin bronze specimens with mechanical properties comparable to those reported in the literature. Overall, low-cost selective powder deposition is a promising technology, if identified manufacturing issues are addressed.

scholarly journals Effect of Carbon Nanotube Loading on Electrical Properties of Electrospun Polyvinylidene Fluoride (PVDF) Fiber

2021 ◽  
Vol 2080 (1) ◽  
pp. 012015
Author(s):  
Jia Wei Lee ◽  
S.B Sharifah Shahnaz ◽  
A.Z Nur Hidayah ◽  
S. Yahud ◽  
Noorasikin Samat
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Polyvinylidene Fluoride ◽  
Low Cost ◽  
Peak Shift ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Surface Areas ◽  
Β Phase ◽  
Graphite Sheets

Abstract Polyvinylidene fluoride (PVDF) is a high purity thermoplastic fluropolymer that use in the aircraft, electronics, and chemical industry. Carbon nanotube (CNTs) is made up of rolled up of graphite sheets, exhibits excellent chemical, thermal, mechanical properties, and large surface areas. PVDF fibers blended with CNTs were able to enhance the β-phase which contributes to piezoelectric properties. Electrospinning is the simplest and low-cost method to produce PVDF/CNT fibers by dissolving PVDF in solvent N, N-Dimethylformamide (DMF). 15wt% PVDF solution was used. CNT loading were varied at 0.0wt%, 0.35wt%, 0.80wt% and 1.00wt% with parameters of 20kV, tip-to-collector distance (TCD) 15cm and flow rate 1.0mLh-1. Scanning Electron Microscope (SEM), four-point probe and X-ray Diffraction (XRD) were used to determine the morphology and crystallinity of electrospun PVDF/CNT fibers. The SEM analysis concluded all fibers showed beaded structure due to low concentration of PVDF solution with insufficient ultrasonification and stirring, cause electrospraying and agglomeration. XRD and four-point probe analysis concluded PVDF/0.35wt%CNT showed the highest β-phase content with intense XRD peak and highest electrical conductivity. However, shift peak is observed among all fibres due to short electrospinning time leads to insufficient thickness of electrospun mat, which affects the mechanical properties of fibres and causes peak shift.

Microstructure and Mechanical Properties of Si3N4/hBN Composites Prepared by Hot-Pressing Using Nitrided Si3N4 Powders

2007 ◽  
Vol 544-545 ◽  
pp. 415-418 ◽  
Author(s):  
Ki Ju Lee ◽  
Chang Hyun Jin ◽  
Woon Suk Hwang ◽  
Won Seung Cho
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
Low Cost ◽  
Ceramic Composites ◽  
Pull Out ◽  
Microstructure And Mechanical Properties ◽  
N2 Atmosphere ◽  
The Cost ◽  
The Relationship ◽  
Crack Paths

In order to produce Si3N4/hBN composite with low cost, it seems necessary to use nitrided Si3N4 powders since the cost of Si powder is much cheaper than that of Si3N4 powder. The purpose of the present work is to investigate the nitride conditions, and in particular, we focused on the relationship between microstructures and mechanical properties of hot-pressed Si3N4/hBN ceramic composite using nitrided Si3N4 powders. The mixed powders of Si3N4 and hBN were prepared by nitriding Si powders at 1380oC for 24 h, and subsequently sintered by hot-pressing at 1800oC for 2 h in N2 atmosphere. The microstructure and mechanical properties of the Si3N4/hBN composites were investigated. Flexural strength, Young’s modulus, and hardness decreased by the addition of 20 vol% hBN. The addition of BN resulted in a decrease in the modulus as well as an increase in the size of fracture source, both contribute to the observed decrease in mechanical properties. The Si3N4/BN based ceramic composites revealed enhanced crack deflection. The Vickers indentation crack paths in specimens are sinusoidal due to pull-out of grains during crack propagation.

Advance Protection for Three Phase Induction Motor using Microcontroller Atmega32

2018 ◽  
Vol 8 (1) ◽  
pp. 172
Author(s):  
Karan S Belsare ◽  
Gajanan D Patil
Keyword(s):  
Induction Motor ◽  
Low Cost ◽  
Short Circuit ◽  
Cost Factor ◽  
Protection Scheme ◽  
Three Phase ◽  
The Cost

A low cost and reliable protection scheme has been designed for a three phase induction motor against unbalance voltages, under voltage, over voltage, short circuit and overheating protection. Taking the cost factor into consideration the design has been proposed using microcontroller Atmega32, MOSFETs, relays, small CTs and PTs. However the sensitivity of the protection scheme has been not compromised. The design has been tested online in the laboratory for small motors and the same can be implemented for larger motors by replacing the i-v converters and relays of suitable ratings.

Janus – A New Approach to Air Combat Pilot Training

2019 ◽  
Vol 2019 (4) ◽  
pp. 7-22
Author(s):  
Georges Bridel ◽  
Zdobyslaw Goraj ◽  
Lukasz Kiszkowiak ◽  
Jean-Georges Brévot ◽  
Jean-Pierre Devaux ◽  
...  
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
High Energy ◽  
Training System ◽  
Embedded Sensors ◽  
Pilot Training ◽  
New Approach ◽  
Combat Aircraft ◽  
Air Combat ◽  
The Cost

Abstract Advanced jet training still relies on old concepts and solutions that are no longer efficient when considering the current and forthcoming changes in air combat. The cost of those old solutions to develop and maintain combat pilot skills are important, adding even more constraints to the training limitations. The requirement of having a trainer aircraft able to perform also light combat aircraft operational mission is adding unnecessary complexity and cost without any real operational advantages to air combat mission training. Thanks to emerging technologies, the JANUS project will study the feasibility of a brand-new concept of agile manoeuvrable training aircraft and an integrated training system, able to provide a live, virtual and constructive environment. The JANUS concept is based on a lightweight, low-cost, high energy aircraft associated to a ground based Integrated Training System providing simulated and emulated signals, simulated and real opponents, combined with real-time feedback on pilot’s physiological characteristics: traditionally embedded sensors are replaced with emulated signals, simulated opponents are proposed to the pilot, enabling out of sight engagement. JANUS is also providing new cost effective and more realistic solutions for “Red air aircraft” missions, organised in so-called “Aggressor Squadrons”.

Cellulose Nanofibrils-based Hydrogels for Biomedical Applications: Progresses and Challenges

2020 ◽  
Vol 27 (28) ◽  
pp. 4622-4646 ◽  
Author(s):  
Huayu Liu ◽  
Kun Liu ◽  
Xiao Han ◽  
Hongxiang Xie ◽  
Chuanling Si ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Metal Ion ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Cellulose Nanofibrils ◽  
Wound Dressings ◽  
Preparation Methods ◽  
Tissue Scaffold ◽  
Surface Areas ◽  
Mechanical Methods

Background: Cellulose Nanofibrils (CNFs) are natural nanomaterials with nanometer dimensions. Compared with ordinary cellulose, CNFs own good mechanical properties, large specific surface areas, high Young's modulus, strong hydrophilicity and other distinguishing characteristics, which make them widely used in many fields. This review aims to introduce the preparation of CNFs-based hydrogels and their recent biomedical application advances. Methods: By searching the recent literatures, we have summarized the preparation methods of CNFs, including mechanical methods and chemical mechanical methods, and also introduced the fabrication methods of CNFs-based hydrogels, including CNFs cross-linked with metal ion and with polymers. In addition, we have summarized the biomedical applications of CNFs-based hydrogels, including scaffold materials and wound dressings. Results: CNFs-based hydrogels are new types of materials that are non-toxic and display a certain mechanical strength. In the tissue scaffold application, they can provide a micro-environment for the damaged tissue to repair and regenerate it. In wound dressing applications, it can fit the wound surface and protect the wound from the external environment, thereby effectively promoting the healing of skin tissue. Conclusion: By summarizing the preparation and application of CNFs-based hydrogels, we have analyzed and forecasted their development trends. At present, the research of CNFs-based hydrogels is still in the laboratory stage. It needs further exploration to be applied in practice. The development of medical hydrogels with high mechanical properties and biocompatibility still poses significant challenges.

scholarly journals A low-cost wireless endoscope camera: a preliminary report

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
J. M. Lazarus ◽  
M. Ncube
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Video Transmission ◽  
Low Cost ◽  
Battery Life ◽  
Resource Constrained ◽  
High Definition ◽  
Industry Standard ◽  
Constrained Environments ◽  
The Cost

Abstract Background Technology currently used for surgical endoscopy was developed and is manufactured in high-income economies. The cost of this equipment makes technology transfer to resource constrained environments difficult. We aimed to design an affordable wireless endoscope to aid visualisation during rigid endoscopy and minimally invasive surgery (MIS). The initial prototype aimed to replicate a 4-mm lens used in rigid cystoscopy. Methods Focus was placed on using open-source resources to develop the wireless endoscope to significantly lower the cost and make the device accessible for resource-constrained settings. An off the shelf miniature single-board computer module was used because of its low cost (US$10) and its ability to handle high-definition (720p) video. Open-source Linux software made monitor mode (“hotspot”) wireless video transmission possible. A 1280 × 720 pixel high-definition tube camera was used to generate the video signal. Video is transmitted to a standard laptop computer for display. Bench testing included latency of wireless digital video transmission. Comparison to industry standard wired cameras was made including weight and cost. The battery life was also assessed. Results In comparison with industry standard cystoscope lens, wired camera, video processing unit and light source, the prototype costs substantially less. (US$ 230 vs 28 000). The prototype is light weight (184 g), has no cables tethering and has acceptable battery life (of over 2 h, using a 1200 mAh battery). The camera transmits video wirelessly in near real time with only imperceptible latency of < 200 ms. Image quality is high definition at 30 frames per second. Colour rendering is good, and white balancing is possible. Limitations include the lack of a zoom. Conclusion The novel wireless endoscope camera described here offers equivalent high-definition video at a markedly reduced cost to contemporary industry wired units and could contribute to making minimally invasive surgery possible in resource-constrained environments.

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