Long-term seawater anti-corrosion properties of Al alloy triggered by femtosecond laser structuring with phase change

2021 ◽  
pp. 151612
Author(s):  
Rahul A. Rajan ◽  
Srinivasa Rao Konda ◽  
Chaudry Sajed Saraj ◽  
Yu Hang Lai ◽  
Gopal Verma ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Phase Change ◽  
Al Alloy ◽  
Corrosion Properties ◽  
Laser Structuring

scholarly journals Femtosecond laser‐assisted excision of conjunctival melanocytic lesions: Cosmetic and long‐term outcomes

2021 ◽  
Author(s):  
Victoria Grace Dimacali ◽  
Yu‐Chi Liu ◽  
Hon Shing Ong ◽  
Darren S. J. Ting ◽  
Jodhbir S. Mehta
Keyword(s):  
Femtosecond Laser ◽  
Long Term Outcomes ◽  
Melanocytic Lesions

Methods for Separation of Copper Oxide Nanoparticles From Colloidal Suspension in Dodecane

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohammed H. Sheikh ◽  
Muhammad A. R. Sharif
Keyword(s):  
Energy Storage ◽  
Copper Oxide ◽  
Phase Change ◽  
Phase Change Materials ◽  
Research Work ◽  
Cuo Nanoparticles ◽  
Health Hazards ◽  
Suspension Stability ◽  
Reduced Pressure

Phase change materials (PCM) are used in many energy storage applications. Energy is stored (latent heat of fusion) by melting the PCM and is released during resolidification. Dispersing highly conductive nanoparticles into the PCM enhances the effective thermal conductivity of the PCM, which in turn significantly improves the energy storage capability of the PCM. The resulting colloidal mixture with the nanoparticles in suspension is referred to as nanostructure enhanced phase change materials (NEPCM). A commonly used PCM for energy storage application is the family of paraffin (CnH2n+2). Mixing copper oxide (CuO) nanoparticles in the paraffin produces an effective and highly efficient NEPCM for energy storage. However, after long term application cycles, the efficiency of the NEPCM may deteriorate and it may need replacement with fresh supply. Disposal of the used NEPCM containing the nanoparticles is a matter of concern. Used NEPCM containing nanoparticles cannot be discarded directly into the environment because of various short term health hazards for humans and all living beings and unidentified long term environmental and health hazards due to nanoparticles. This problem will be considerable when widespread use of NEPCM will be practiced. It is thus important to develop technologies to separate the nanoparticles before the disposal of the NEPCM. The primary objective of this research work is to develop methods for the separation and reclamation of the nanoparticles from the NEPCM before its disposal. The goal is to find, design, test, and evaluate separation methods which are simple, safe, and economical. The specific NEPCM considered in this study is a colloidal mixture of dodecane (C12H26) and CuO nanoparticles (1–5% mass fraction and 5–15 nm size distribution). The nanoparticles are coated with a surfactant or stabilizing ligands for suspension stability in the mixture for a long period of time. Various methods for separating the nanoparticles from the NEPCM are explored. The identified methods include: (i) distillation under atmospheric and reduced pressure, (ii) mixing with alcohol mixture solvent, and (iii) high speed centrifugation. These different nanoparticle separation methods have been pursued and tested, and the results are analyzed and presented in this article.

Femtosecond laser structuring of permeable and resorbable biomaterial

2021 ◽  
Vol 7 (2) ◽  
pp. 713-716
Author(s):  
Swen Grossmann ◽  
Sabine Illner ◽  
Robert Ott ◽  
Grit Rhinow ◽  
Carsten Tautorat ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Biomedical Applications ◽  
Mechanical Characteristics ◽  
Membrane Properties ◽  
Fiber Network ◽  
Laser Technology ◽  
Laser Structuring ◽  
Wide Range ◽  
Nanofiber Membranes ◽  
Post Production

Abstract Bioresorbable nanofiber nonwovens with their fascinating properties provide a wide range of potential biomedical applications. Modification of the material enables the adjustment of mechanical and biological characteristics depending on the desired application. Due to the nanosized fiber network, post-production structuring is very challenging. Within this study, we use femtosecond laser technology for structuring permeable and resorbable electrospun poly-L-lactide (PLLA) membranes. We show that this post-production process can be used without disturbing the fiber network near the structured areas. Furthermore, the modification of the water permeability and mechanical characteristics due to the laser structuring was investigated. The results prove femtosecond laser technology to be a promising method for the adjustment of the membrane properties and which in consequence can help to optimize cell adhesion, enable revascularization and open up applications of nanofiber membranes in personalized medicine.

Long-term intraocular pressure changes after femtosecond laser–assisted cataract surgery in healthy eyes and glaucomatous eyes

2019 ◽  
Vol 45 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Avni A. Shah ◽  
Jeanie Ling ◽  
Niraj R. Nathan ◽  
Ashton J. Kalhorn ◽  
Qingxia Chen ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Femtosecond Laser ◽  
Cataract Surgery ◽  
Pressure Changes ◽  
Healthy Eyes

scholarly journals Effect of Structural Modification on Corrosion Behavior of Hypo Eutectic Al-Si Alloy

2018 ◽  
Vol 778 ◽  
pp. 16-21
Author(s):  
Muhammad Mansoor ◽  
Muhammad Kamran Yaseen ◽  
Shaheed Khan
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Earth Metal ◽  
Alloy System ◽  
Eutectic Phase ◽  
Al Alloy ◽  
General Corrosion ◽  
Corrosion Properties ◽  
Unmodified Alloy ◽  
Cast Alloys

Al-Si eutectic cast alloys are widely used in aeronautical and automobile industries where significantly high strength, toughness and wear resistance are required. This class of cast alloys exhibit relatively low corrosion resistance in brine environments. The mechanical properties of the alloy system mainly depend upon the shape of Si rich eutectic phase, which mainly has acicular geometry. In present research, the effect of modified microstructure of 12 wt. % Si-Al alloy on corrosion behavior was studied. The needle like Si rich eutectic phase was modified to disperse spherical structure using rare earth metal halides. The corrosion rate and pitting behavior of modified and unmodified alloy were evaluated in 3.5% NaCl solution by general corrosion for calculated time. It was observed that the corrosion rate and pitting tendency of modified alloy had been appreciably reduced as compare to unmodified alloy. The improvement of corrosion properties were the attributes of changed morphology and distribution of Si rich eutectic phase.

scholarly journals Comparative Analysis of the Intrastromal MyoRing Implantation performed with the Femtosecond Laser

2017 ◽  
Vol 6 (2) ◽  
pp. 49-57
Author(s):  
Maksim V Sinitsyn ◽  
Nadezhda A Pozdeyeva ◽  
Nikolai P Pashtayev
Keyword(s):  
Comparative Analysis ◽  
Femtosecond Laser ◽  
Corneal Thickness ◽  
Functional Results ◽  
Standard Group ◽  
Pronounced Increase ◽  
Group I ◽  
Biomechanical Parameters ◽  
Group Ii

ABSTRACT Purpose To comparatively analyze the intrastromal MyoRing implantation with femtosecond laser (FL) using the standard and optimized technologies in the experiment and based on the long-term clinical-functional results of the patients with keratoconus (KC) at stages II and III. Materials and methods The experimental work was performed on 24 eyes of rabbits. All eyes were divided into six groups according to the method of operation. In the clinical part of the research, the surgical treatment of 70 patients (76 eyes) with KC at stages II and III was done. Depending on the technology of the operation, all patients were divided into two groups. Group I consisted of 29 patients (32 eyes) with KC, in which MyoRing implantation was performed according to the standard, group II consisted of 31 patients (32 eyes) with KC, in which MyoRing implantation was performed according to the optimized technology. Results Higher voltage was required for stretching samples of the second group in comparison with the third and the sixth group in comparison with the fifth group. In group I, during the period of 6 to 36 months the surgery reverses keratometry, corneal thickness above the MyoRing, and posterior corneal elevation. In group II, 12 months after surgery the clinical and functional parameters remained stable throughout the period of observation. Conclusion Greater reduction in corneal biomechanical stability was observed after formation of the intrastromal pocket in comparison with an intrastromal tunnel; a more pronounced increase in the strength characteristics of the cornea was observed after implantation of the ring in intrastromal pocket, compared with implantation intracorneal segments in intrastromal tunnel, and with increasing depth of intrastromal ring implantation. Application of optimized MyoRing implantation technology compared with standard allows more biomechanical parameters of the cornea to improve and reduce the risk of the ring protrusion. How to cite this article Sinitsyn MV, Pozdeyeva NA, Pashtayev NP. Comparative Analysis of the Intrastromal MyoRing Implantation performed with the Femtosecond Laser. Int J Kerat Ect Cor Dis 2017;6(2):49-57.

Structural Characterization and Corrosion Properties of BTESPT Silane Films on Surface of 2024-T6 Aluminium Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 1111-1116 ◽  
Author(s):  
Ming An Chen ◽  
Xuan Xie ◽  
Guo Fu Xu ◽  
Hui Zhong Li ◽  
Xin Ming Zhang
Keyword(s):  
Structural Characterization ◽  
Water Solution ◽  
Corrosion Current ◽  
Immersion Test ◽  
Alloy Sheet ◽  
Al Alloy ◽  
Entire Surface ◽  
Corrosion Properties ◽  
The Matrix

2024-T6 Al alloy sheet s were modified by bis-[triethoxysilylpropyl] tetrasulfide (BTESPT) silane film to improve the corrosion resistance. Fourier-Transform Reflection Absorption (FTIR-RA) spectroscopy was used for structural characterization of BTESPT silane film formed on surface of the sheet. Potentiodynamic polarization and immersion test in 3.5% NaCl solution were used for evaluating the corrosion performances of the silane film. The results showed that the film formed after curing at 120 °C for 40 min was cross-linked through Si-O-Si and that it was covered on the entire surface of the sheet. The content of elements S and Si on the Al2CuMg particles is a little higher that of on the matrix. The strong peak at 1032 cm-1 indicated that the film was linked to the sheet by Si-O-Al. Compared to the untreated case, the corrosion current density of the sheet treated with the silane film was reduced by close to 2 orders. Treatment of BTESPT silane can provide about 670 h protection of corrosion for the sheet in 3.5% NaCl water solution.

Laboratory and Field Investigations of the Performance of HPCC Coatings

2004 ◽  
Author(s):  
Fraser King ◽  
Jenny Been ◽  
Robert Worthingham ◽  
Grant Rubie
Keyword(s):  
Laboratory Testing ◽  
High Performance ◽  
Impact Damage ◽  
Mechanical Damage ◽  
Degradation Process ◽  
Field Trials ◽  
Hot Water ◽  
Corrosion Properties ◽  
Field Exposure

Three-layer FBE-polyolefin coatings offer the promise of good adhesive and corrosion properties from the FBE layer coupled with resistance to mechanical damage from the outer polyolefin layer. TransCanada Pipelines have been investigating the long-term behaviour of High Performance Composite Coating (HPCC) using a combination of laboratory testing and field trials. In the laboratory, panels of HPCC were subjected to standard CD disbondment testing following a two-stage degradation process. The degradation process, designed to simulate field exposure, involved impact damage followed by exposure to either a hot-water soak (60°C), or to microbiologically active soil with and without the application of CP. Following exposure, the duplicate panels were subject to 28-day CD disbondment tests to determine the extent of damage caused by the combination of impact and soil/hot water exposure. In the field, a section of HPCC coating was excavated and examined after 11 years service. In addition to visual inspection, the coating was examined in situ using a newly developed impedance technique EISPlus. This technique is a development of earlier EIS techniques and allows the dielectric properties of the coating to be determined in addition to the impedance of the solution-filled pores. EISPlus provides an improved sensitivity for high-impedance coatings, such as FBE, HPCC, and polyolefin tape. Furthermore, since it is a dry technique, rapid measurements can be made on coatings exposed to field conditions allowing the in-service performance to be determined. Results of both the laboratory testing and field EISPlus measurements are presented and the long-term performance of the coating discussed.

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