scholarly journals Manufacturing process design of high-pressure graphite-blasting for mechanical production of turbostratic graphene

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Kamilia Aokal ◽  
Abdul Hai Alami ◽  
Ali Cheaitou ◽  
Mohammad Ali Abdelkareem
Keyword(s):  
Manufacturing Process ◽  
Target Surface ◽  
Fold Increase ◽  
Graphite Powder ◽  
Large Area ◽  
Manufacturing Method ◽  
Stability Performance ◽  
Final Layer ◽  
Number Of Passes ◽  
Pressure Nozzle

AbstractIn this paper a manufacturing process is introduced to treat the bulk surfaces of surfaces via graphite powder blasting to directly produce an adherent layer of graphene. Subsequently, the study aims to correlate optical, thermal and electrochemical modifications with treatment parameters such as blasting pressure, nozzle distance and number of passes. After the treatment, the target surface has enhanced spectral, thermal and electrochemical properties because of the graphene’s turbostratic nature to adhesion to its surface. The thermal stability performance showed a consistent 5% increase relative to a bare aluminum substrate. A two-fold increase in corrosion resistance is seen in the sample compared to bare aluminum while diffuse absorbance values enhancement is around three-fold. This proposed manufacturing method provides straightforward and effective treatment at various degrees of automation. Since the deposited graphene substrate can cover a large area, it can be applied as a final layer on thermal collectors, PV panels and for other applications. It is possible to adopt this process to other well-established treatment plants without requiring high investments in the overhead expenses.

scholarly journals Self-powered multifunctional sensing based on super-elastic fibers by soluble-core thermal drawing

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mengxiao Chen ◽  
Zhe Wang ◽  
Qichong Zhang ◽  
Zhixun Wang ◽  
Wei Liu ◽  
...  
Keyword(s):  
Polymer Fibers ◽  
Elastic Fibers ◽  
Triboelectric Nanogenerator ◽  
Large Area ◽  
Manufacturing Method ◽  
Low Viscosity ◽  
Ion Movements ◽  
Self Powered ◽  
Thermal Drawing ◽  
Viscosity Polymer

AbstractThe well-developed preform-to-fiber thermal drawing technique owns the benefit to maintain the cross-section architecture and obtain an individual micro-scale strand of fiber with the extended length up to thousand meters. In this work, we propose and demonstrate a two-step soluble-core fabrication method by combining such an inherently scalable manufacturing method with simple post-draw processing to explore the low viscosity polymer fibers and the potential of soft fiber electronics. As a result, an ultra-stretchable conductive fiber is achieved, which maintains excellent conductivity even under 1900% strain or 1.5 kg load/impact freefalling from 0.8-m height. Moreover, by combining with triboelectric nanogenerator technique, this fiber acts as a self-powered self-adapting multi-dimensional sensor attached on sports gears to monitor sports performance while bearing sudden impacts. Next, owing to its remarkable waterproof and easy packaging properties, this fiber detector can sense different ion movements in various solutions, revealing the promising applications for large-area undersea detection.

Highly uniform manufacturing method for large-area microlens arrays

2017 ◽  
Vol 95 (1-4) ◽  
pp. 99-108 ◽  
Author(s):  
Xiaodong Zhang ◽  
Lihua Li ◽  
Zexiao Li ◽  
Changyuen Chan ◽  
Linlin Zhu ◽  
...  
Keyword(s):  
Large Area ◽  
Microlens Arrays ◽  
Manufacturing Method ◽  
Highly Uniform

Rotary Engine Rotor Side Seals Using New Machining Processes

2021 ◽  
pp. 1-46
Author(s):  
Yu-yuan Hsieh ◽  
Ming-Yi Tsai ◽  
Zhi-Zhe Xu
Keyword(s):  
Manufacturing Process ◽  
Electrical Discharge Machining ◽  
Iron Alloy ◽  
Machining Process ◽  
Machining Processes ◽  
Manufacturing Method ◽  
Rotary Engine ◽  
Traditional Manufacturing ◽  
The Cost ◽  
Engine Rotor

Abstract The study has developed a new machining process for the side seal components of gray cast iron alloy of rotor engine, which is different from the traditional WEDM (wire electrical discharge machining) process. The new manufacturing process (milling + grinding process) will save 78% of the cost and 83% of the time for making each side seal component, and the accuracy of the average surface roughness of the component will be 2.1 times that of the traditional manufacturing method. If the components are polished with a self-made polishing rod, the accuracy will be increased by almost 20 times compared with the new manufacturing process.

scholarly journals Fabrication of Demineralized Bone Matrix/Polycaprolactone Composites Using Large Area Projection Sintering (LAPS)

2019 ◽  
Vol 3 (2) ◽  
pp. 30 ◽  
Author(s):  
Mohsen Ziaee ◽  
Rebecca Hershman ◽  
Ayesha Mahmood ◽  
Nathan B. Crane
Keyword(s):  
Additive Manufacturing ◽  
Cancellous Bone ◽  
Demineralized Bone Matrix ◽  
Bone Matrix ◽  
Bone Allograft ◽  
Layer By Layer ◽  
Large Area ◽  
Manufacturing Method ◽  
Synthetic Scaffolds ◽  
Demineralized Bone

Cadaveric decellularized bone tissue is utilized as an allograft in many musculoskeletal surgical procedures. Typically, the allograft acts as a scaffold to guide tissue regeneration with superior biocompatibility relative to synthetic scaffolds. Traditionally these scaffolds are machined into the required dimensions and shapes. However, the geometrical simplicity and, in some cases, limited dimensions of the donated tissue restrict the use of allograft scaffolds. This could be overcome by additive manufacturing using granulated bone that is both decellularized and demineralized. In this study, the large area projection sintering (LAPS) method is evaluated as a fabrication method to build porous structures composed of granulated cortical bone bound by polycaprolactone (PCL). This additive manufacturing method utilizes visible light to selectively cure the deposited material layer-by-layer to create 3D geometry. First, the spreading behavior of the composite mixtures is evaluated and the conditions to attain improved powder bed density to fabricate the test specimens are determined. The tensile strength of the LAPS fabricated samples in both dry and hydrated states are determined and compared to the demineralized cancellous bone allograft and the heat treated demineralized-bone/PCL mixture in mold. The results indicated that the projection sintered composites of 45–55 wt %. Demineralized bone matrix (DBM) particulates produced strength comparable to processed and demineralized cancellous bone.

HIGH QUALITY FULLY IN-SITU MgB2 THIN FILMS OBTAINED BY DC MAGNETRON SPUTTERING

2003 ◽  
Vol 17 (04n06) ◽  
pp. 779-784 ◽  
Author(s):  
M. G. MAGLIONE ◽  
F. CHIARELLA ◽  
R. DI CAPUA ◽  
R. VAGLIO ◽  
M. SALVATO ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Target Surface ◽  
Residual Resistivity ◽  
Precursor Film ◽  
Large Area ◽  
Residual Resistivity Ratio ◽  
Resistivity Ratio

MgB 2 thin films were grown in-situ at INFM- University of Naples by a magnetron sputtering technique in a UHV system (10-7 Pa) equipped with 3 focused 2′′ magnetron sources (a stoichiometric MgB 2 and metallic Mg and B targets by Superconducting Components Inc.). The substrates (sapphire or MgO) were placed "on axis" at 7 cm from the target surface on the surface of a molybdenum heater that could be operated up to 1000°C under vacuum. Best results were obtained codepositing MgB 2 and Mg at equal sputtering power (500W) for 10 min on cold substrates, resulting in a Mg rich Mg-B precursor film. The films were then annealed inhyphen;situ at 830°C for 10 min in a In sealed Nb box in presence of saturated Mg vapor. The process is highly reproducible and can be easily scaled to produce large area films. The resulting films were about 1μm thick, with 100nm surface roughness as measured by AFM Resistive transition showed a maximum T c of 35 K and a transition width lower than 0.5 K. The residual resistivity ratio was 1.6 for the best sample. Resistivity measurements in external magnetic field up to 8 T have been performed both in parallel and perpendicular configuration. The upper critical magnetic field vs. temperature behavior has been determined from the experimental data and the superconducting anisotropy has been calculated for samples with different T c .

scholarly journals Amorphous solid dispersions and the confounding effect of nanoparticles in in vitro dissolution and in vivo testing: Niclosamide as a case of study

2020 ◽  
Author(s):  
Miguel O Jara ◽  
Zachary N Warnken ◽  
Robert O Williams
Keyword(s):  
Amorphous Solid ◽  
Fold Increase ◽  
Water Soluble ◽  
In Vitro Dissolution ◽  
Amorphous Solid Dispersion ◽  
In Vitro Tests ◽  
Manufacturing Method ◽  
Poorly Water Soluble

We developed an amorphous solid dispersion (ASD) of the poorly water soluble molecule niclosamide that achieved more than a 2 fold increase in bioavailability. Notably, this niclosamide ASD formulation increased the apparent drug solubility about 60 fold relative to the crystalline material due to the generation of nanoparticles. Niclosamide is a weakly acidic drug, BCS class II, and a poor glass former with low bioavailability in vivo. Hot melt extrusion is a high throughput manufacturing method commonly used in the development of ASDs for increasing the apparent solubility and bioavailability of poorly water-soluble compounds. We utilized the polymer polyvinylpyrrolidone vinyl acetate (PVPVA) to manufacture niclosamide ASDs by extrusion. Samples were analyzed based on their microscopic and macroscopic behavior and their intermolecular interactions, using DSC, XRD, NMR, FTIR, and DLS. The niclosamide ASD generated nanoparticles with a mean particle size of about 100 nm in FaSSIF media. In a side by side diffusion test, these nanoparticles produced a 4 fold increase in niclosamide diffusion. We successfully manufactured amorphous extrudates of the poor glass former niclosamide that showed remarkable in vitro dissolution and diffusion performance. These in vitro tests were translated to a rat model that also showed an increase in oral bioavailability.

scholarly journals UOE Pipe Manufacturing Process Simulation: Equipment Designing and Construction

2017 ◽  
Vol 69 (1) ◽  
pp. 100-112
Author(s):  
Dmitri Delistoian ◽  
Mihael Chirchor
Keyword(s):  
Process Simulation ◽  
Manufacturing Process ◽  
Strain Level ◽  
Stress And Strain ◽  
Special Equipment ◽  
Stress Strain ◽  
Cold Forming ◽  
Manufacturing Method ◽  
Submerged Arc ◽  
Pipe Manufacturing

Abstract UOE pipe manufacturing process influence directly on pipeline resilience and operation capacity. At present most spreaded pipe manufacturing method is UOE. This method is based on cold forming. After each technological step appears a certain stress and strain level. For pipe stress strain study is designed and constructed special equipment that simulate entire technological process.UOE pipe equipment is dedicated for manufacturing of longitudinally submerged arc welded DN 400 (16 inch) steel pipe.

scholarly journals A New Microhardness Testing Method on Grating Films

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Haitao Ma ◽  
Yi Jin ◽  
Jirigalantu
Keyword(s):  
Manufacturing Process ◽  
Test Method ◽  
Contour Length ◽  
Maximum Deviation ◽  
Model Parameters ◽  
Large Area ◽  
Average Hardness ◽  
Tool Edge ◽  
Microhardness Testing ◽  
The Relationship

The manufacturing process of large-area, high-precision gratings is a very complicated and time-consuming process. The hardness testing of grating films is an important step in the entire process. In order to simplify the manufacturing process of gratings, we have proposed a new method for testing microhardness based on tool edge indentation. Also, it unified tool adjustment and microhardness testing steps in the grating manufacturing process. First, a mathematical model of the relationship between tool load and indentation contour length is established. The model parameters were then modified using tool indentation experiments with different loads. When measured with a nanoindenter, the average hardness of the grating film was 447 MPa. The hardness value of the grating film obtained by our proposed method is almost the same as that measured by the nanoindenter, and the maximum deviation is about 2.2% of the average hardness value. The experimental results show that our proposed method can replace the microhardness test method of using a nanoindenter. Therefore, the disadvantages of using a nanoindenter to test the hardness of a grating film are avoided, such as the limited sample size, the sensitivity of the indenter to the roughness of the film and the depth of the indentation, and the accuracy of film testing, and the efficiency of grating ruling can be improved.

Manufacturing of Biodegradable Intramedullary Nail With High Strength

2021 ◽  
Author(s):  
Huifeng Shao ◽  
Zhuoluo Jing ◽  
Rougang Zhou ◽  
Zhiheng Nian ◽  
Haiqiang Liu ◽  
...  
Keyword(s):  
Fracture Fixation ◽  
Manufacturing Process ◽  
Freeze Drying ◽  
Bending Strength ◽  
Stress Shielding ◽  
High Strength ◽  
Shielding Effect ◽  
Long Bone ◽  
Manufacturing Method ◽  
Wide Range

Abstract Intramedullary nails (INs) have significant advantages in rigid fracture fixation. Conventional metal INs for long bone fracture fixation often lead to delay union or even nonunion healing due to their stress shielding effect and lack of biological activity. Besides, undegradable metals require a second surgery to remove them, which will not only impose a potential risk to the patient but also cause additional costs. Manufacturing high-strength biodegradable INs (BINs) is still a challenge. Here, an entirely new type of high-strength bioactive magnesium-containing silicate (CSi-Mg) BIN is manufactured by using casting, freeze drying and sintering technique. It has extremely high bending strength (> 41 MPa) and stable internal and external structure. We have systematically studied the influence of parameters such as the paste component, freeze drying process, and sintering process on the mechanical strength involved in the manufacturing process. According to our manufacturing method, a wide range of inorganic ceramic implants and BINs with different sizes can also be fabricated. The CSi-Mg BIN also has good bioactivity and biodegradation property. This bioceramic BIN and manufacturing process are expected to be applied to a variety of orthopedic medical devices. This novel bioactive BIN is expected to replace the traditional metal IN and become a more effective way of treating fracture.

High Quality GaAs on Soi by MOCVD

1989 ◽  
Vol 160 ◽  
Author(s):  
N.H. Karam ◽  
V. Haven ◽  
S. Vernon ◽  
J. Ramdani ◽  
N. El-Masry ◽  
...  
Keyword(s):  
Thermal Cycle ◽  
Defect Density ◽  
Fold Increase ◽  
Gate Length ◽  
Photoluminescence Intensity ◽  
Large Area ◽  
High Quality ◽  
Cycle Growth ◽  
Gaas Films ◽  
Low Temperature Photoluminescence

AbstractEpitaxial GaAs films have been successfully deposited on three-inch Si wafers with a buried oxide by MOCVD. The SOI wafers were prepared using Separation by IMplantation of OXygen (SIMOX) process. High quality GaAs on SIMOX films, with dislocation density in the range of 2–6 × 106 cm-2, have been achieved using Thermal Cycle Growth (TCG) deposition technique. These films showed a 50-fold increase in the low temperature photoluminescence intensity over conventional deposition. We have also fabricated MESFET’s in GaAs on SIMOX with performance comparable to those fabricated in GaAs. The maximum measured transconductance was in the range of 175-180 ms/mm at a 1.5 µm gate length and a 5 µm source to drain separation. This is the first demonstration of large area, high quality and low defect density GaAs on SIMOX.

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