Development Of Additive Technologies Research Articles

Decomposition strategies in the problems of simulation of additive laser technology processes

The development of additive technologies and their application in industry is associated with the possibility of predicting the final properties of a crystallized added material. This paper describes the problem characterized by a dynamic and spatially nonuniform computational complexity, which, in the case of uniform decomposition of a computational domain, leads to an unbalanced load on computational cores. The strategy of partitioning of the computational domain is used, which minimizes the CPU time losses in the serial computations of the additive technological process. The chosen strategy is optimal from the standpoint of a priori unknown dynamic computational load distribution. The scaling of the computational problem on the cluster of the Institute on Laser and Information Technologies (RAS) that uses the InfiniBand interconnect is determined. The use of the parallel code with optimal decomposition made it possible to significantly reduce the computational time (down to several hours), which is important in the context of development of the software package for support of engineering activity in the field of additive technology.

On the actual tasks of metrology in the field of additive technologies

Metrology and scientific and technological progress are inextricably linked, since, on the one hand, without the precise measurements it is impossible to develop science, and on the other hand, the very achievements of science and technology stimulate the development of measuring techniques, the emergence of new methods and means for determining various physical quantities . Due to this interconnection, the urgent tasks of modern metrology necessarily have to be tasks, the solution of which ensures progress in all spheres of human activity, including science, technology and technology, ecology, social relations, etc. The report discusses the current problems of metrology due to the transition to the third stage of the industrial revolution, the development of additive and information technology, nanotechnology. The approaches of countries with developed scientific and technical and economic potential to solve these problems are analyzed.

International Seminar on Interdisciplinary Problems in Additive Technologies

Additive manufacturing is an extremely wide term and covers many conventional technologies. They include the creation of semiconductor heterostructures by methods of molecular beam epitaxy and methods of coating deposition from gas phase, offset lithography and application of multilayer coatings on products using different techniques, etc. Additive manufacturing is the process of making objects from a 3D-model through layer-by-layer binding of materials, as opposed to subtractive manufacturing methods such as traditional machining. These are fast developing technologies in various sectors, from space to medicine.Modern additive manufacturing is rooted in stereolithography, which expanded from the idea of Otto John Munz in 1951 and advanced further due to the development of model scanning methods, techniques for forming layers from various materials, projection of images and curing technologies. Laminated object manufacturing was developed in 1985, and fused deposition modeling in 1986. Beginning from the 1990s, additive technologies have been used to produce metallic objects through controlled heating by laser or electron beams.From 1995, a short term method for creating three-dimensional objects was born—3D printing. The surge in the development of additive technologies (AT) was in 2009. However, as usual, the energetic start was replaced by particular disappointment and the manifestation of unsuspecting drawbacks of additive technologies. Significant problems are connected with materials science: materials and products produced by AT usually do not possess the required properties and often have a limited lifetime. AT theoretically allow the production of parts of any shape and complexity. However, the products from polymers made by stereolithography do not exhibit long-term stability. The quality of the surface of a product made by the layer-by-layer cladding method is far behind that obtained by molding. Products made by jet printing are very brittle. The technologies of laser melting hardly allow complete melting of all powder particles in a layer, especially in the case of alloyed powder. So the discussion of problems in materials science, typical for various types of additive manufacturing, is an important stage in the progress of the field.

Distant rehabilitation: the sources, current state-of-the-art, and further prospects

Medical rehabilitation is now a priority of the Russian Healthcare [Skvortsova V.I., 2012]. Rehabilitation centers are usually located in big cities and are not available for most patients. Therefore, one of the modern trends in the development of rehabilitation is a distantly controlled rehabilitation. We have developed a program of distant rehabilitation in Russia, based on our own achievements and experience of foreign colleagues. The article provides an overview of methods according to world literature studies. The survey shows that the problem of distant rehabilitation is relevant in our time, and requires additional clinical research and technological development.

Development of novel additive manufacturing technology: an investigation of a selective composite formation process

Purpose– The purpose of this study is to present a novel additive manufacturing (AM) technology which is based on selective formation of cellulose-acrylate composite. Besides proposing a process that combines the benefits of fibres and photopolymers, this paper reports the development of material, characterisation of a straight line composite formation, adherence between layers and functional feasibility of the proposed concept.Design/methodology/approach– For the preliminary evaluation of the proposed process, a composite material based on cellulose-photopolymer was developed, while a multi-objective optimisation study indicated the formulation which results in the maximum values of layer adherence, tensile strength of composite and the effect of the water on the mechanical strength of material. For the characterisation of the process, three main subjects were analysed: the characterisation of straight line composite formation, the effect of composite formation process on previous layers and the functional feasibility of technology.Findings– In the material development, the tensile strength of dry composite was identified between 20 and 30 MPa, while the tensile strength of wet composite was between 5 and 12 MPa. It is important to note that the dry and wet cellulose presented tensile strength, respectively, equal to 15 and 1 MPa, indicating the possibility of residual material removal only with the use of water or other soft solvent. The values of adherence between layers (peeling test) were found to be between 0.12 and 0.15 kgf, and the photopolymer formulation which resulted in the maximum adherence has monomer/oligomer ratio equal to 1.5 and 2 per cent wt of photoinitiator percentual. As result of the optimisation study, the material formulation was compounded by monomer – 10 ml, oligomer – 4.5 ml and photoinitiator – 2 per cent, being found suitable to characterise and evaluate the proposed process. The study of composite formation along a straight line showed values of line width between 1,400 and 3,500 μm in accordance with light power, laser velocity and laser beam diameter. On the other hand, the number of previous layers affected by the composite formation varied from 0 to 4, indicating a potential process limit. In the functional feasibility study, a feasible process window which resulted in the maximum dimensional deviation equal to 0.5 mm was identified. In addition, the mean mechanical tensile strength was found to be around 30 MPa for longitudinal laser trajectory (90°) and 15 MPa for transversal laser trajectory (0°), highlighting the anisotropic behaviour of final parts according to the manufacturing strategy.Originality/value– This paper proposed a novel AM technology and also described studies related to the characterisation of this concept. This work might also be useful to the development of other AM processes and applications.

Status and prospects of development of additive technology in the titanic products manufacture

The article deals with the prospects of additive technology development in the manufacture of titanium products. Their advantages compared withr traditional products production and processing methods and problems associated with their use are studied The problems can be solved on the basis of a cluster approach. A promising example of the practical use of additive technologies in the industry of Russia is to organize the titanium research and application in a cluster. It was found that for the economic evaluation of the application of additive technologies in the production of titanium products it is necessary to develop methodological provisions, reflecting the specificity of their application

PROSTHETIC EAR RECONSTRUCTION APPLYING COMPUTER TOMOGRAPHIC (CT) DATA AND ADDITIVE MANUFACTURING TECHNOLOGIES

The treatment of auricle defect can be by surgical or prosthetic ear rehabilitation depending on the condition. Current practice by surgeon for prosthetic ear rehabilitation require patient to go for osseointegrated craniofacial implant surgery for retention of the prosthetic ear. Impression technique play a vital role in accurate reproduction of affected and unaffected ears, orientation of the ear during wax try in and fabrication of ear prostheses. Traditionally, the wax pattern was created from the impression taken from patient and the final prosthesis is processed with silicone material. This conventional method has always been time consuming, massive work and caused discomfort to patient. Moreover the accuracy of the final prosthetic sometimes was not satisfied. Improvement in medical imaging technology whereby data from computerized tomography (CT) in 2D format can be converting to 3 dimensional images gave tremendous view for surgeon to visualize the result. A new and impressive advance in the development of additive manufacturing technology is now being able to be applied in medical field. The widespread use of computer-aided design (CAD) combine with computer aided manufacturing (CAM) produced the momentum and desire to translate the 3-D images into physical models. Studies and research have indicated the viability of using medical imaging technology, computer aided design (CAD) and additive manufacturing techniques in prosthetics. This paper proposed a novel method of fabricating the prosthetic ear applying mirror image technique to reconstruct the missing ear, and then fabricate the 3D model of the prosthetic ear using Stereolitography (SLA) technology that will become the master mold to produce the final prosthetic ear. This method eliminates the traditional wax pattern procedure. A clinical study is done onto a patient in HUSM and comparison is made between traditional method vs new approach using computer aided technology. Result showed that there is significant different between traditional and new approach design. The new method also shows time reduction during design and fabrication stage.

Высокоэнергетическая компьютерная томография в аддитивных технологиях ответственных металлических изделий

The current state of digital additive technologies and areas of their application is analyzed in the paper. 
 The main sources and sizes of geometry errors as well as porosity of additive metal products are estimated. It is shown that post-processing of matching surfaces is necessary at assembling critical mechanical units containing additive parts. 
 Non-destructive testing of critical additive metal articles with complex internal structure does not conform to capabilities of traditional NDT methods; new NDT problems of additive parts are formulated.
 A unique role of high-energy computed tomography is substantiated and experimentally confirmed; CT can become an important factor in further development of additive technologies by providing a feedback between a technology, an internal structure and performance abilities of the products.

高性能金属构件的激光增材制造

Laser additive manufacturing is an integrated manufacturing technology that takes precision forming and high performance into consideration. Laser additive manufacturing includes the laser solid forming technique, which is characterized by synchronized powder feeding, and selective laser melting, which is characterized by powder bed fusion. The microstructure of metal components produced by laser additive manufacturing technology consists of columnar dendrite that is epitaxially grown from the substrate. The grains in the metal components are coarse; however, the microstructure in the grains is fine, without the macro segregation. As a result, the mechanical properties of the components produced by laser additive manufacturing technology are equivalent to the forging standard. Laser additive manufacturing technology can also be combined with traditional processing technology to achieve combination manufacturing for the production of complex and high-precision components. In the present paper, recent developments in laser additive manufacturing technology have been reviewed in the following aspects: technical principles, microstructure characteristics, mechanical properties, and application status. On this basis, this paper discusses the development trends in the field and the key scienti c issues to be solved. It is noted that the optimized structural design of metal components based on functional priority has become possible.

Modeling California policy impacts on greenhouse gas emissions

This paper examines policy and technology scenarios in California, emphasizing greenhouse gas (GHG) emissions in 2020 and 2030. Using CALGAPS, a new, validated model simulating GHG and criteria pollutant emissions in California from 2010 to 2050, four scenarios were developed: Committed Policies (S1), Uncommitted Policies (S2), Potential Policy and Technology Futures (S3), and Counterfactual (S0), which omits all GHG policies. Forty-nine individual policies were represented. For S1–S3, GHG emissions fall below the AB 32 policy 2020 target [427 million metric tons CO2 equivalent (MtCO2e)yr−1], indicating that committed policies may be sufficient to meet mandated reductions. In 2030, emissions span 211–428MtCO2eyr−1, suggesting that policy choices made today can strongly affect outcomes over the next two decades. Long-term (2050) emissions were all well above the target set by Executive Order S-3-05 (85MtCO2eyr−1); additional policies or technology development (beyond the study scope) are likely needed to achieve this objective. Cumulative emissions suggest a different outcome, however: due to early emissions reductions, S3 achieves lower cumulative emissions in 2050 than a pathway that linearly reduces emissions between 2020 and 2050 policy targets. Sensitivity analysis provided quantification of individual policy GHG emissions reduction benefits.

Fusarium wilts of ornamental crops and their management

The production of ornamental plants continues to be a thriving and expanding industry in the United States, Canada, South America, Australia, and Europe, supported by plant industries in many developing countries. Fusarium wilt diseases, however, continue to plague the industry due to imperfections in clean stock propagation systems, latency of disease development, irrigation systems that allow propagule spread, and a low priority placed on breeding efforts towards Fusarium-resistant cultivars of ornamentals. Management requires a multifaceted approach employing cultivar resistance as well as cultural, biological, and chemical strategies. Ignorance of the sources of inoculum and how it is spread has allowed many missed opportunities for preventing Fusarium wilt diseases. When the disease has become established in a production system, many approaches for achieving suppression have been explored, but most have not met the high standard for a zero disease threshold demanded by the industry. The following review was designed to highlight management studies that have advanced our knowledge of how to minimize Fusarium diseases and to indicate areas where additional research and technological development are needed.

Preliminary Development of 3D-Printed Custom Substrata for Benthic Algal Biofilms

Abstract Due to their fast rates of growth and regeneration, algae are a promising source of biomass for biofuels, aquatic pollution recovery, and a source of protein nutrients, among others. Cultivation of benthic algal biofilm communities, in particular, shows promise for these functions, yet control of quality and yield are strongly dependent on substrata characteristics that affect algal attachment and growth. No previous research efforts have taken advantage of the recent developments in additive technology to support algal biofilm development. Additive manufacturing allows for the design and control of surface features and provides a platform for developing substrata with surface topographies customized for algal colonization. This article seeks to establish the feasibility of colonizing 3D-printed custom substrata with algal biomass. Three exploratory experiments on algal biofilm colonization of printed surfaces were conducted under a variety of laboratory and natural environments, and all printed ...

The future for design education: preparing the design workforce for additive manufacturing

The role of the designer is changing. This is in response to the development of integrated digital technologies that have recently matured. The future role of the designer is unlikely to be an evolution of past practice, but rather be characterised as a step-change in practice. This is because the basic premise of the designer has remained relatively unchanged since the industrial revolution even with advances in technology, until now. Rather than providing additional manufacturing tools, the recent development of additive manufacturing technologies for direct manufacturing is proving to be a catalyst for the renegotiation of relationships between designers and consumers, and adoption of new approaches to design and supply enabled by digital communication. This article considers the implications for product design education with examples of changing student practice and curriculum in the development of a workforce to meet the opportunities and challenges of additive manufacturing and associated digital technologies.

Laser additive manufacturing of high-performance metal compo- nents

Laser additive manufacturing is an integrated manufacturing technology that takes precision forming and high performance into consideration. Laser additive manufacturing includes the laser solid forming technique, which is characterized by synchronized powder feeding, and selective laser melting, which is characterized by powder bed fusion. The microstructure of metal components produced by laser additive manufacturing technology consists of columnar dendrite that is epitaxially grown from the substrate. The grains in the metal components are coarse; however, the microstructure in the grains is fine, without the macro segregation. As a result, the mechanical properties of the components produced by laser additive manufacturing technology are equivalent to the forging standard. Laser additive manufacturing technology can also be combined with traditional processing technology to achieve combination manufacturing for the production of complex and high-precision components. In the present paper, recent developments in laser additive manufacturing technology have been reviewed in the following aspects: technical principles, microstructure characteristics, mechanical properties, and application status. On this basis, this paper discusses the development trends in the field and the key scienti c issues to be solved. It is noted that the optimized structural design of metal components based on functional priority has become possible.

Use of a high-throughput in vitro microfluidic system to develop oral multi-species biofilms.

There are few high-throughput in vitro systems which facilitate the development of multi-species biofilms that contain numerous species commonly detected within in vivo oral biofilms. Furthermore, a system that uses natural human saliva as the nutrient source, instead of artificial media, is particularly desirable in order to support the expression of cellular and biofilm-specific properties that mimic the in vivo communities. We describe a method for the development of multi-species oral biofilms that are comparable, with respect to species composition, to supragingival dental plaque, under conditions similar to the human oral cavity. Specifically, this methods article will describe how a commercially available microfluidic system can be adapted to facilitate the development of multi-species oral biofilms derived from and grown within pooled saliva. Furthermore, a description of how the system can be used in conjunction with a confocal laser scanning microscope to generate 3-D biofilm reconstructions for architectural and viability analyses will be presented. Given the broad diversity of microorganisms that grow within biofilms in the microfluidic system (including Streptococcus, Neisseria, Veillonella, Gemella, and Porphyromonas), a protocol will also be presented describing how to harvest the biofilm cells for further subcultureor DNA extraction and analysis. The limits of both the microfluidic biofilm system and the current state-of-the-art data analyses will be addressed. Ultimately, it is envisioned that this article will provide a baseline technique that will improve the study of oral biofilms and aid in the development of additional technologies that can be integrated with the microfluidic platform.

Use of a High-throughput <em>In Vitro</em> Microfluidic System to Develop Oral Multi-species Biofilms

There are few high-throughput in vitro systems which facilitate the development of multi-species biofilms that contain numerous species commonly detected within in vivo oral biofilms. Furthermore, a system that uses natural human saliva as the nutrient source, instead of artificial media, is particularly desirable in order to support the expression of cellular and biofilm-specific properties that mimic the in vivo communities. We describe a method for the development of multi-species oral biofilms that are comparable, with respect to species composition, to supragingival dental plaque, under conditions similar to the human oral cavity. Specifically, this methods article will describe how a commercially available microfluidic system can be adapted to facilitate the development of multi-species oral biofilms derived from and grown within pooled saliva. Furthermore, a description of how the system can be used in conjunction with a confocal laser scanning microscope to generate 3-D biofilm reconstructions for architectural and viability analyses will be presented. Given the broad diversity of microorganisms that grow within biofilms in the microfluidic system (including Streptococcus, Neisseria, Veillonella, Gemella, and Porphyromonas), a protocol will also be presented describing how to harvest the biofilm cells for further subculture or DNA extraction and analysis. The limits of both the microfluidic biofilm system and the current state-of-the-art data analyses will be addressed. Ultimately, it is envisioned that this article will provide a baseline technique that will improve the study of oral biofilms and aid in the development of additional technologies that can be integrated with the microfluidic platform.

Midwest vision for sustainable fuel production

This article charts the progress of CenUSA Bioenergy, a USDA-NIFA-AFRI coordinated agricultural project focused on the North Central region of the US. CenUSA’s vision is to develop a regional system for producing fuels and other products from perennial grass crops grown on marginally productive land or land that is otherwise unsuitable for annual cropping. This article focuses on contributions CenUSA has made to nine primary systems needed to make this vision a reality: feedstock improvement; feedstock production on marginal land; feedstock logistics; modeling system performance; feedstock conversion into biofuels and other products; marketing; health and safety; education, and outreach. The final section, Future Perspectives, sets forth a roadmap of additional research, technology development and education required to realize commercialization.

Directly Manufacturing Mouse Mold by Plasma Deposition Manufacturing

Direct fabrication of end-use parts made of metal material has become one of the most interesting fields relevant to research and development of additive manufacturing technologies. This paper presents an effort of trial manufacture of a metal mouse mold with good performances of dimensional precision and fine surface roughness using direct manufacturing technology. The PDM (Plasma Deposition Manufacturing) process is adopted to couple with the milling process, which synthesizes plasma deposition as an additive technique, and milling as a subtractive technique during the processing. Plasma deposition manufacturing is demonstrated to allow rapidly fabricating the metal mouse mold directly from its CAD model without mold or tooling-based intermediary processes. The PDM method provides a new access to directly manufacture the metal parts and mold with short-process and high quality.

Analyzing Offshore Wind Power Patent Portfolios by Using Data Clustering

Offshore wind power has been extremely popular in recent years, and in the energy technology field, relevant research has been increasingly conducted. However, research regarding patent portfolios is still insufficient. The purpose of this research is to study the status of mainstream offshore wind power technology and patent portfolios and to investigate major assignees and countries to obtain a thorough understanding of the developmental trends of offshore wind power technology. The findings may be used by the government and industry for designing additional strategic development proposals. Data mining methods, such as multiple correspondence analyses and k-means clustering, were implemented to explore the competing technological and strategic-group relationships within the offshore wind power industry. The results indicate that the technological positions and patent portfolios of the countries and manufacturers are different. Additional technological development strategy recommendations were proposed for the offshore wind power industry.

Rare earths supply chains: Current status, constraints and opportunities

The unique properties of rare earth elements (REEs) and lack of alternatives for their application in modern technologies, especially electronics and fast growing green technologies such as renewable energy generation and storage, energy efficient lights, electric cars, and auto catalysts, as well as specific military and aerospace applications, underpin their strategic status.The absolute domination of China in the production of REEs, aggravated by a significant reduction in export quotas since 2010, raised severe concerns of securing REE supply in the USA, Japan, European Union and other countries. In 2010–2012 it resulted in skyrocketing prices and supply deficit for most REEs, leading to numerous new REE start-up companies around the world, with allocation of large investments in additional geological explorations and technology development. At the same time, the supply difficulties enforced the downstream users of REEs to invest in the development of recycling technologies and reuse options for these elements.The main focus of this paper is to overview existing and emerging REE supply chains outside of China up to date (end of 2013), define their environmental constraints and opportunities, as well as reflect on a broader range of technical, economic, and social challenges for both primary production and recycling of REEs. A better understanding of these factors could help to optimize the supply chain of virgin and recycled rare earths, minimise the environmental impacts arising from their processing, and be used as a prototype for a broader range of critical metals and commodities.