scholarly journals Plasma Electrolytic Polishing of Nitinol: Investigation of Functional Properties

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6450
Author(s):  
Kristina Navickaitė ◽  
Lucia Ianniciello ◽  
Jaka Tušek ◽  
Kurt Engelbrecht ◽  
Christian R. H. Bahl ◽  
...  
Keyword(s):  
Shape Memory ◽  
Negative Impact ◽  
High Surface ◽  
Phase Transformation Temperature ◽  
Chemical Contamination ◽  
Polishing Process ◽  
Electrolytic Polishing ◽  
Shape Memory Properties ◽  
Before And After ◽  
Plasma Electrolytic

A novel, environmentally friendly, fast, and flexible polishing process for Nitinol parts is presented in this study. Nitinol samples with both superelastic and shape memory properties at room temperature were investigated. The chemical contamination and surface roughness of superelastic Nitinol plates were examined before and after plasma electrolytic polishing. The shift in phase transformation temperature and tensile strength before and after the polishing process were analysed using Nitinol wire with shape memory properties. The obtained experimental results were compared to the data obtained on reference samples examined in the as-received condition. It was found that plasma electrolytic polishing, when the right process parameters are applied, is capable of delivering Nitinol parts with extremely high surface quality. Moreover, it was experimentally proven that plasma electrolytic polishing does not have a negative impact on functionality or mechanical properties of polished parts.

Shape Memory Behavior of Ti-50.9at%Ni Alloy after ECAE Processes

2007 ◽  
Vol 561-565 ◽  
pp. 2313-2316 ◽  
Author(s):  
Zhi Guo Fan ◽  
Chao Ying Xie
Keyword(s):  
Phase Transformation ◽  
Shape Memory ◽  
Initial Solution ◽  
Transformation Behavior ◽  
Shape Memory Behavior ◽  
Solution Treated ◽  
Ni Alloy ◽  
Coarse Grains ◽  
Shape Memory Properties ◽  
Before And After

The initial coarse grains of Ti-50.9at%Ni were obviously refined after eight ECAE processes. Effects of pressing number on the transformation behavior have been investigated in detail. Comparing with the initial solution-treated Ti-50.9at%Ni, the R-phase transformation was stimulated and the martensitic temperature Ms decreased with ECAE processes at 773K. The shape memory properties of Ti-50.9at%Ni alloy before and after ECAE processes at 773K have been measured. Good one way shape memory and superelasticity were obtained for the submicron-grained Ti-50.9at%Ni alloy.

scholarly journals Investigation of the Finishing Technology of SLM Implants

2021 ◽  
Vol 346 ◽  
pp. 01039
Author(s):  
Timur Ablyaz ◽  
Karim Muratov ◽  
Evgenii Shlykov ◽  
Ilia Osinnikov ◽  
Luiza Konogorova
Keyword(s):  
Processing Time ◽  
Geometric Parameters ◽  
Cobalt Chromium ◽  
Chromium Powder ◽  
Electrolytic Polishing ◽  
Chromium Alloys ◽  
Before And After ◽  
Plasma Electrolytic ◽  
Stent Surface

In this research, the use of plasma electrolytic polishing (PEP) as a finishing treatment of materials obtained by the SLM method from CoCr30 cobalt-chromium powder is proposed. To assess the possibility of using this method, a simulator sample was used. The imitation sample was polished for 60 seconds. The roughness and the size of the removal material were measured. Based on the results obtained for the simulator sample, a conclusion was made about the possibility of using PEP technology for finishing the treatment stent. The stent simulator was also polished. The processing time was 30s and 60s. The geometric parameters were measured, and the removal material was calculated. Images of the stent surface were taken before and after PEP. It was found that with an increase in the processing time from 30 to 60 seconds, the allowance removed from all surfaces increases almost twice. The possibility of using the PEP technology as a finishing operation for the manufacture of stents from cobalt-chromium alloys is shown.

Indentation Recovery of Shape Memory Foams Produced by Solid State Foaming

2014 ◽  
Vol 611-612 ◽  
pp. 656-663 ◽  
Author(s):  
Denise Bellisario ◽  
Fabrizio Quadrini ◽  
Loredana Santo
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Shape Memory ◽  
Room Temperature ◽  
Thermal Recovery ◽  
Compaction Process ◽  
Initial Shape ◽  
Epoxy Foam ◽  
Shape Memory Properties ◽  
Before And After

In this study, solid state foaming was used to produce epoxy foam samples with shape memory properties. Foams were indented at room and high temperature by using flat pins with diameter from 1 to 5 mm. Micro-indentations were performed as well only at room temperature. The indentation marks were measured before and after thermal recovery to evaluate the ability of the material to reach the initial shape. For a better understanding of the overall process, a study was made also to predict the initial precursor density as a function of the compaction parameters. This way, it was also evaluated that the effect of the compaction process is covered by the effect of the foaming step.

Migration Patterns and Labor Market Outcomes

2018 ◽  
Author(s):  
Anda David ◽  
Mohamed Ali Marouani
Keyword(s):  
Labor Market ◽  
Negative Impact ◽  
Labor Market Outcomes ◽  
Wealth Index ◽  
Transition Matrices ◽  
Market Outcomes ◽  
Migration Patterns ◽  
Depth Analysis ◽  
Before And After ◽  
Spatial Composition

This chapter focuses on the external effects of emigration on non-migrants, and particularly on the interactions with labor market outcomes in Tunisia before and after the revolution. Using the new Tunisia Labor Market Panel Survey (TLMPS), we conduct an in-depth analysis of the structure and dynamics of migration, including the profile of migrants and their origin households, mainly in terms of skills and spatial composition. We investigate transition matrices, employment status, income for current migrants and returnees, and the evolution of remittances. Our analysis confirms the role of emigration as a safety valve for the Tunisian labor market. Moreover, origin households of migrants have a significantly higher wealth index. Our analysis also tends to confirm the effects of remittances on labor supply of non-migrants, which can have a negative impact on Tunisia’s unemployment rate when a crisis in destination countries affects the remittance rate negatively.

scholarly journals Chemical Contamination Pathways and the Food Safety Implications along the Various Stages of Food Production: A Review

2021 ◽  
Vol 18 (11) ◽  
pp. 5795
Author(s):  
Kgomotso Lebelo ◽  
Ntsoaki Malebo ◽  
Mokgaotsa Jonas Mochane ◽  
Muthoni Masinde
Keyword(s):  
Food Safety ◽  
Food Production ◽  
Food Industry ◽  
Food Packaging ◽  
Agricultural Sector ◽  
Negative Impact ◽  
Anthropogenic Factors ◽  
Chemical Contamination ◽  
Chemical Toxicity ◽  
Chemical Substances

Historically, chemicals exceeding maximum allowable exposure levels have been disastrous to underdeveloped countries. The global food industry is primarily affected by toxic chemical substances because of natural and anthropogenic factors. Food safety is therefore threatened due to contamination by chemicals throughout the various stages of food production. Persistent Organic Pollutants (POPs) in the form of pesticides and other chemical substances such as Polychlorinated Biphenyls (PCBs) have a widely documented negative impact due to their long-lasting effect on the environment. This present review focuses on the chemical contamination pathways along the various stages of food production until the food reaches the consumer. The contamination of food can stem from various sources such as the agricultural sector and pollution from industrialized regions through the air, water, and soil. Therefore, it is imperative to control the application of chemicals during food packaging, the application of pesticides, and antibiotics in the food industry to prevent undesired residues on foodstuffs. Ultimately, the protection of consumers from food-related chemical toxicity depends on stringent efforts from regulatory authorities both in developed and underdeveloped nations.

Thermo‐responsive shape memory properties based on polylactic acid and styrene‐butadiene‐styrene block copolymer

2021 ◽  
pp. 51000
Author(s):  
Fathin Hani Azizul Rahim ◽  
Abdul Aziz Saleh ◽  
Raa Khimi Shuib ◽  
Ku Marsilla Ku Ishak ◽  
Zuratul Ain Abdul Hamid ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Shape Memory ◽  
Polylactic Acid ◽  
Shape Memory Properties ◽  
Styrene Butadiene Styrene ◽  
Styrene Butadiene ◽  
Butadiene Styrene

Impact of Dividend Tax Change on the Payout Policy of Indian Companies

2019 ◽  
Vol 20 (5) ◽  
pp. 1282-1291
Author(s):  
Sanjay Dhamija ◽  
Ravinder Kumar Arora
Keyword(s):  
Negative Impact ◽  
Payout Policy ◽  
Tax Law ◽  
Dividend Payout ◽  
Inside Ownership ◽  
Regulatory Changes ◽  
Before And After ◽  
The Government ◽  
The Impact ◽  
Dividend Tax

The article examines the impact of regulatory changes in the tax on dividends on the payout policy of Indian companies. The tax law was recently amended to levy tax on dividends received by large shareholders. As the promoters group is the largest shareholder, this is expected to have a negative impact on the payout policy of companies. Furthermore, companies with larger promoter holdings have a higher motivation to reduce their payout. The study covers 370 companies present in the BSE 500 Index and compares the dividend payout of the companies before and after the introduction of tax levy. The study finds that the newly introduced tax indeed caused a shift in the dividend policy of companies, particularly those companies which have high levels of inside ownership. The findings have significant implications for companies, investors and the government.

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