scholarly journals Equal-Channel Angular Extrusion (ECAE): From a Laboratory Curiosity to an Industrial Technology

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 244 ◽  
Author(s):  
Vladimir Segal
Keyword(s):  
Large Scale ◽  
Equal Channel Angular Extrusion ◽  
Scale Validation ◽  
State Of The Art ◽  
Cost Effective ◽  
Industrial Applications ◽  
Industrial Technology ◽  
Structure Modification ◽  
Retrospective View ◽  
Angular Extrusion

This paper presents a state-of-the-art and a retrospective view of the critical stages in the evolution of equal-channel angular extrusion (ECAE) from the original idea to a cost-effective industrial technology. These stages include optimization of the structure modification and material processing, development of the special tools, process commercialization, and a large-scale validation of the semi-continuous ECAE at the industrial floor. All aspects are extensively summarized, based on the author’s experience in the field, which spans almost half of a century. Special attention is paid to the processing of large batch billets. Practical examples illustrate industrial applications of ECAE. The scope for future development is also discussed.

scholarly journals Using plants to remediate or manage metal-polluted soils: an overview on the current state of phytotechnologies

2021 ◽  
Vol 43 ◽  
pp. e58283
Author(s):  
Clístenes Williams Araújo do Nascimento ◽  
Caroline Miranda Biondi ◽  
Fernando Bruno Vieira da Silva ◽  
Luiz Henrique Vieira Lima
Keyword(s):  
Large Scale ◽  
State Of The Art ◽  
Cost Effective ◽  
Time Frame ◽  
Contaminated Site ◽  
Polluted Soils ◽  
Mining Sites ◽  
Current State ◽  
Remedial Actions ◽  
The Tropics

Soil contamination by metals threatens both the environment and human health and hence requires remedial actions. The conventional approach of removing polluted soils and replacing them with clean soils (excavation) is very costly for low-value sites and not feasible on a large scale. In this scenario, phytoremediation emerged as a promising cost-effective and environmentally-friendly technology to render metals less bioavailable (phytostabilization) or clean up metal-polluted soils (phytoextraction). Phytostabilization has demonstrable successes in mining sites and brownfields. On the other hand, phytoextraction still has few examples of successful applications. Either by using hyperaccumulating plants or high biomass plants induced to accumulate metals through chelator addition to the soil, major phytoextraction bottlenecks remain, mainly the extended time frame to remediation and lack of revenue from the land during the process. Due to these drawbacks, phytomanagement has been proposed to provide economic, environmental, and social benefits until the contaminated site returns to productive usage. Here, we review the evolution, promises, and limitations of these phytotechnologies. Despite the lack of commercial phytoextraction operations, there have been significant advances in understanding phytotechnologies' main constraints. Further investigation on new plant species, especially in the tropics, and soil amendments can potentially provide the basis to transform phytoextraction into an operational metal clean-up technology in the future. However, at the current state of the art, phytotechnology is moving the focus from remediation technologies to pollution attenuation and palliative cares.

scholarly journals A New Method of Manufacturing Thin-Walled Tube Made of AZ61 Magnesium Alloy Including Direct Extrusion And Corrugated Equal Channel Angular Extrusion

2021 ◽  
Author(s):  
H-J Hu ◽  
Ou Zhang ◽  
Gang Hu ◽  
Hui Zhao ◽  
Zhongwen OU
Keyword(s):  
Plastic Deformation ◽  
Magnesium Alloy ◽  
Large Scale ◽  
Equal Channel Angular Extrusion ◽  
Process Conditions ◽  
Workpiece Material ◽  
Plastic Deformation Behavior ◽  
Angular Extrusion ◽  
Thin Walled Tube ◽  
Thin Walled

Abstract Due to demand of strong toughness of thin walled tube, and good secondary forming properties and high-precision dimension, New plastic forming method should be researched to achieve a complete filling, uniform deformation and microstructure evolution during forming process.To obtain the deformation mechanisms of a new composite extrusion for thin walled tube fabricated by tube corrugated equal channel angular extrusion has been researched which is shorten as “TC-ECAE” in this paper. Finite element DEFORMTM-3D software to investigate the plastic deformation behavior of magnesium billet during TC-ECAE process has been employed. Computed parameters including workpiece material characteristics and process conditions have been taken into consideration. The pridictions of strains distributions and damage distributions and effective stress distributions and flow velocities distributions and microstructures evolutions have been explored. The results proved that the TC-ECAE process is a forming method for magnesium alloy tube which is suitable for large scale industrial application. The TC-ECAE process would cause serve plastic deformation and improve the dynamic recrystallization of magnesium alloy during TC-ECAE process.

scholarly journals Semi-Continuous Equal-Channel Angular Extrusion and Rolling of AA5083 and AZ31 Alloys

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1035 ◽  
Author(s):  
Vladimir Segal ◽  
Svetlana V. Reznikov ◽  
Nagendra Murching ◽  
Vincent H. Hammond ◽  
Laszlo J. Kecskes
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Large Scale ◽  
Equal Channel Angular Extrusion ◽  
Solution Treatment ◽  
Structure And Properties ◽  
Structural Refinement ◽  
Angular Extrusion ◽  
Lightweight Alloys ◽  
Technical Basis

This paper describes a new modification of equal-channel angular extrusion for the “pass-by-pass” semi-continuous (sc-ECAE) processing of lightweight alloys. Sc-ECAE leads to a multifold increase in productivity and decrease in costs, providing a technical basis for the commercialization of severe plastic deformation (SPD) on a large scale with massive volume production. The evolution of the structure and properties are analyzed for an aluminum alloy (AA) 5083 and a magnesium alloy AZ31 as model materials representing, respectively, the structural refinement under severe plastic deformation (SPD) via strain-induced formation of new grain boundaries and via dynamic recrystallization. For the first alloy, the microstructure after sc-ECAE is formed via ultrafine sub-grains, which are further transformed into sub-micrometer grains during post-ECAE rolling. The preliminary solution treatment of AA5083 is an important stabilizing factor for the achievement of high mechanical properties. For the second alloy, optimized sc-ECAE results in a remarkable structural refinement, and a good balance of properties is obtained with a low number of passes. However, additional rolling in the latter case leads to a degradation of the structure and properties.

scholarly journals Membrane transporters in the bioproduction of organic acids: state of the art and future perspectives for industrial applications

2020 ◽  
Vol 367 (15) ◽  
Author(s):  
I Soares-Silva ◽  
D Ribas ◽  
M Sousa-Silva ◽  
J Azevedo-Silva ◽  
T Rendulić ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Organic Acids ◽  
State Of The Art ◽  
Biomass Conversion ◽  
Current Trend ◽  
Dicarboxylic Acids ◽  
Cost Effective ◽  
Industrial Applications ◽  
Industrial Biotechnology ◽  
Extracellular Medium

ABSTRACT Organic acids such as monocarboxylic acids, dicarboxylic acids or even more complex molecules such as sugar acids, have displayed great applicability in the industry as these compounds are used as platform chemicals for polymer, food, agricultural and pharmaceutical sectors. Chemical synthesis of these compounds from petroleum derivatives is currently their major source of production. However, increasing environmental concerns have prompted the production of organic acids by microorganisms. The current trend is the exploitation of industrial biowastes to sustain microbial cell growth and valorize biomass conversion into organic acids. One of the major bottlenecks for the efficient and cost-effective bioproduction is the export of organic acids through the microbial plasma membrane. Membrane transporter proteins are crucial elements for the optimization of substrate import and final product export. Several transporters have been expressed in organic acid-producing species, resulting in increased final product titers in the extracellular medium and higher productivity levels. In this review, the state of the art of plasma membrane transport of organic acids is presented, along with the implications for industrial biotechnology.

scholarly journals Biotechnological Valorization of Pectinolytics and Their Industrial Applications: A Review

2014 ◽  
Vol 9 (11) ◽  
pp. 1934578X1400901 ◽  
Author(s):  
Muhammad Irshad ◽  
Muhammad Asgher ◽  
Zahid Anwar ◽  
Aftab Ahmad
Keyword(s):  
Large Scale ◽  
Value Added ◽  
Cost Effective ◽  
Industrial Applications ◽  
Green Biotechnology ◽  
A Value ◽  
Physico Chemical ◽  
Target Yield ◽  
High Yields ◽  
Agricultural Materials

In the last several years, in serious consideration of the worldwide economic and environmental issues there has been an increasing research interest in the value of naturally occurring bio-sourced materials. Agro-industrial based biomass comprised of pectin is an inexpensive, renewable, abundant natural resource that could be utilized for large-scale and cost-effective production of natural products i.e., pectinolytics. Pectinolytics are one of the most widely distributed enzymes in bacteria, fungi and plants. From ancient times to date, many methods have been introduced to improve the optimization of pectinolytics to obtain high yields of maximal purity. To expand the range of natural bio-resources the rapidly evolving tools of biotechnology can lower the conversion costs and also enhance target yield of the product of interest. This green biotechnology presents a promising approach to convert most of the agricultural materials into a value-added product with multiple applications. Major advances have already been achieved in recent years in order to obtain high levels of purity with optimal yields. The present review begins with an overview of pectinolytics and their physico-chemical features, and their specific role with classification based on pectic materials. Information is also given on the culture influences and potential sources of pectinolytics, followed by a brief summary of various industrial and biotechnological applications and future considerations.

A Short Review on Recent Development of Laccase Immobilization on Different Support Materials

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
Norsyafiqah Amalina Ahmad Jafri ◽  
◽  
Roshanida A. Rahman ◽  
Noorhalieza Ali ◽  
◽  
...  
Keyword(s):  
Large Scale ◽  
Cost Effective ◽  
Short Review ◽  
Industrial Applications ◽  
Innovative Strategies ◽  
Support Materials ◽  
High Production ◽  
Efficient Recovery ◽  
High Production Cost ◽  
Laccase Immobilization

Laccase is a bio catalytic agent and multi-copper enzyme containing oxidases that are potentially great for oxidizing large number of phenolic and non-phenolic compounds. However, drawbacks do arise when laccase use in large scale; low in stability, high production cost, non-reusability, sensitive towards denaturing and poor storage ability of free enzymes. These problems lead to the progress in laccase immobilization in order to facilitate the efficient recovery and re-use of the enzyme, thus enabling cost-effective in continuous processes. Apart from discussing on different methods in laccase immobilization such as entrapment, encapsulation and cross-linking in general, we have reviewed a recent development in laccase immobilization on different supports or carriers binding (natural and synthetic). Future works are recommended to focus on innovative strategies on the modified supports to improve the enzyme immobilization as well as sensible entrapment techniques for industrial applications.

scholarly journals Generation of compressed air by cascaded thermocompressors – project status

2021 ◽  
Vol 313 ◽  
pp. 04003
Author(s):  
Fabian Fischer ◽  
Hans-Detlev Kühl
Keyword(s):  
Large Scale ◽  
Waste Heat ◽  
Cost Effective ◽  
Industrial Applications ◽  
Compressed Air ◽  
Dead Volume ◽  
Design Parameters ◽  
Annular Gap ◽  
Industrial Energy ◽  
Constructive Simplicity

Compressed air is one of the most widely used industrial energy sources, and its production by mechanical compressors is extremely expensive and, in addition, inefficient. Therefore, the utilization of waste heat, which accrues on a large scale in many industrial applications, by means of a thermocompressor is an obvious alternative. This contribution presents a design approach to experimentally investigate a reciprocating thermocompressor with a self-actuated overdriven free displacer. These experiments shall be the basis for the design and realization of a cascade of identical stages, which has so far only been investigated by means of analytical modelling and theoretical similarity considerations. The main advantage of this approach is its extreme constructive simplicity and the expected self-regulating effect, which both facilitate a cost-effective production and operation. As the minimization of dead volume and fluid friction losses is essential, the heat exchangers and the regenerator are plainly realized by an annular gap around the displacer in the proposed design, thus further increasing its simplicity. The design parameters are determined by an optimization based on an analytical model extended by various losses and heat transfer limitations.

scholarly journals Governing REDD+: a state of the art review

2019 ◽  
Vol 12 (1) ◽  
pp. 182
Author(s):  
Vanessa Cuzziol Pinsky ◽  
Isak Kruglianskas
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
State Of The Art ◽  
Ghg Emissions ◽  
Cost Effective ◽  
Forest Degradation ◽  
Global Response ◽  
Systematic Analysis ◽  
Scale Experiment ◽  
Global Systems

Climate change is a daunting problem that results in actions-interactions from a number of actors in complex global systems, which require multi-level governance and a myriad of international and national policies. Deforestation is the second largest source of greenhouse gas (GHG) emissions. Success in this area can have a large impact on mitigation. We focus on the governance of ‘Reducing Emissions from Deforestation and Forest Degradation’ (REDD+), a large scale experiment in climate finance and a promising cost-effective mitigation mechanism to motivate developing countries to implement policy approaches to reduce forest-related GHG emissions. REDD+, in the context of strengthening the global response to the threat of climate change, is considered a breakthrough mechanism in international cooperation under the United Nations Framework Convention on Climate Change (UNFCCC) regime, as it was designed to be performance-based. In this paper we analyze a state of the art review on governing REDD+ based on a systematic analysis of peer-reviewed articles in the field. Ours results present a historical perspective of REDD+, literature review, and indicate the most relevant works and scholars in the field.

Service Computing for Industry 4.0: State of the Art, Challenges, and Research Opportunities

2022 ◽  
Vol 54 (9) ◽  
pp. 1-38
Author(s):  
Frank Siqueira ◽  
Joseph G. Davis
Keyword(s):  
Information And Communication Technologies ◽  
Industry 4.0 ◽  
Large Scale ◽  
State Of The Art ◽  
Manufacturing Sector ◽  
Industrial Applications ◽  
Smart Manufacturing ◽  
Software Infrastructure ◽  
Research Opportunities ◽  
Service Computing

Recent advances in the large-scale adoption of information and communication technologies in manufacturing processes, known as Industry 4.0 or Smart Manufacturing, provide us a window into how the manufacturing sector will evolve in the coming decades. As a result of these initiatives, manufacturing firms have started to integrate a series of emerging technologies into their processes that will change the way products are designed, manufactured, and consumed. This article provides a comprehensive review of how service-oriented computing is being employed to develop the required software infrastructure for Industry 4.0 and identifies the major challenges and research opportunities that ensue. Particular attention is paid to the microservices architecture, which is increasingly recognized as offering a promising approach for developing innovative industrial applications. This literature review is based on the current state of the art on service computing for Industry 4.0 as described in a large corpus of recently published research papers, which helped us to identify and explore a series of challenges and opportunities for the development of this emerging technology frontier, with the goal of facilitating its widespread adoption.

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