Andrea Zocca, Cynthia Gomes, Ulf Linow, Heidi Marx, Jörg Melcher, Paolo Colombo and Jens Günster
This paper aims to present an additive manufacturing-based approach in which a new strategy for a thermally activated local melting and material flow, which results in…
Abstract
Purpose
This paper aims to present an additive manufacturing-based approach in which a new strategy for a thermally activated local melting and material flow, which results in densification of printed structures, is introduced.
Design/methodology/approach
For enabling this self-organized relaxation of printed objects by the viscous flow of material, two interconnected structures are printed simultaneously in one printing process, namely, Structure A actually representing the three dimensional object to be built and Structure B acting as a material reservoir for infiltrating Structure A. In an additional process step, subsequent to the printing job, an increase in the objects’ temperature results in the melting of the material reservoir B and infiltration of structure A.
Findings
A thermally activated local melting of the polymethylsilsesquioxane results in densification of the printed structures and the local formation of structures with minimum surface area.
Originality/value
The present work introduces an approach for the local relaxation of printed three-dimensional structures by the viscous flow of the printed material, without the loss of structural integrity of the structure itself. This approach is not restricted only to the materials used, but also offers a more general strategy for printing dense structures with a surface finish far beyond the volumetric resolution of the 3D printing process.
Cynthia Gomes, Nahum Travitzky, Peter Greil, Wilson Acchar, Hansu Birol, Antonio Pedro Novaes de Oliveira and Dachamir Hotza
This paper seeks to detail the fabrication of a glass‐ceramic substrate, based on the LiO2‐ZrO2‐SiO2‐Al2O3 (LZSA) system, by laminated object manufacturing (LOM) using water‐based…
Abstract
Purpose
This paper seeks to detail the fabrication of a glass‐ceramic substrate, based on the LiO2‐ZrO2‐SiO2‐Al2O3 (LZSA) system, by laminated object manufacturing (LOM) using water‐based cast tapes.
Design/methodology/approach
Small amounts of ZrSiO4 were added to control the thermal expansion coefficient (TEC) of the original glass‐ceramic (LZSA5Zr: LZSA+5 wt% ZrSiO4). In order to verify the influence of the amount and nature of crystalline phases on the thermal and dielectric behavior of the material, LZSA and LZSA5Zr laminates were sintered at 700°C for 30 min and crystallized at either 800 or 850°C for 30 min.
Findings
LZSA laminates (sintered and crystallized at 700 and 800°C, respectively) exhibited a relative density of ∼90 percent, a dielectric constant of 8.39, a dielectric loss tangent of 0.031 and TEC of 5.5×10−6 K−1 (25‐550°C). The addition of 5 wt% ZrSiO4 to original LZSA glass‐ceramics led to a nearly constant TEC value of 6×10−6 K−1 throughout the whole temperature interval (25‐800°C). Dielectric properties of LZSA5Zr did not show any remarkable change when compared to original LZSA.
Originality/value
The thermal, mechanical and electrical properties of LZSA glass‐ceramic laminates fabricated by LOM makes them potential candidates for substrate applications.
Details
Keywords
Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some…
Abstract
Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some legal aspects concerning MNEs, cyberspace and e‐commerce as the means of expression of the digital economy. The whole effort of the author is focused on the examination of various aspects of MNEs and their impact upon globalisation and vice versa and how and if we are moving towards a global digital economy.
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The argument for the damaging effects of capitalist modes of production on traditional or indigenous communities is convincing, and has been upheld by scholars interested in…
Abstract
The argument for the damaging effects of capitalist modes of production on traditional or indigenous communities is convincing, and has been upheld by scholars interested in development issues. Recent research, however, has called for a closer look at the problem. In this paper, a Japanese village that was created by the government for collective rice farming under a state-controlled distribution system is examined in an attempt to discern how a sudden shift to capitalist modes of production and largely uncontrolled marketing changed the social structure of the community. It is argued that the effects of such a shift may actually promote new unions and different kinds of solidarity, even when the overall impression indicates a decline in solidarity.
Félix Orlando Martínez-Ríos, José Antonio Marmolejo-Saucedo and Gonzalo Abascal-Olascoaga
This chapter proposes a protocol based on blockchain technology applied to corporate social responsibility (CSR). The first part discusses the characteristics associated with CSR…
Abstract
This chapter proposes a protocol based on blockchain technology applied to corporate social responsibility (CSR). The first part discusses the characteristics associated with CSR actions and the main difficulties its development faces, such as transparency, security, fault tolerance, among others. Subsequently, the authors describe the characteristics and concepts related to blockchain-based developments to later describe our framework for the control and development of CSR actions based on blockchain. Herein, the authors also describe how to publicly and privately identify the participating elements of CSR and the operations and resources necessary for the implementation and operation of the proposed protocol.