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Technologies, Volume 4, Issue 4 (December 2016) – 9 articles

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200 KiB  
Technical Note
Deriving an Indoor Environmental Index for Portuguese Office Buildings
by João F. P. Gomes and Hélder M. S. Esteves
Technologies 2016, 4(4), 40; https://doi.org/10.3390/technologies4040040 - 16 Dec 2016
Cited by 2 | Viewed by 3522
Abstract
In 2002, the European Commission (EU) issued a Directive aiming to reduce the energy consumption of buildings, which was adopted by the EU member states and came into force in 2006. Portugal adopted it by issuing law decrees in 2006 which considered not [...] Read more.
In 2002, the European Commission (EU) issued a Directive aiming to reduce the energy consumption of buildings, which was adopted by the EU member states and came into force in 2006. Portugal adopted it by issuing law decrees in 2006 which considered not only the energy saving aspects but also additional specific measures aiming to protect indoor air quality (IAQ). This new legislation is now being enforced, and it will be necessary to define compliance acceptance levels for the prescribed indoor air limits. The use of comfort or environmental indexes could be of considerable help to ameliorate the evaluation of IAQ. This paper presents a proposal of an index regarding IAQ which considers both the aspects of thermal comfort and non-toxicity. The proposed index was calculated for offices of several European countries, available from previous studies and for Portugal as well. Bearing in mind there is few existing data, this study is consistent with the proposed index, as the obtained values are similar to Greece, which has several similarities with the Portuguese situation. Full article
618 KiB  
Article
The Physics of Turbulence-Free Ghost Imaging
by Yanhua Shih
Technologies 2016, 4(4), 39; https://doi.org/10.3390/technologies4040039 - 08 Dec 2016
Cited by 12 | Viewed by 5653
Abstract
Since its first experimental demonstration, ghost imaging has attracted a great deal of attention due to interests in its fundamental nature and its potential applications. In terms of applications, the most interesting and useful feature, perhaps, is the turbulence insensitivity of thermal light [...] Read more.
Since its first experimental demonstration, ghost imaging has attracted a great deal of attention due to interests in its fundamental nature and its potential applications. In terms of applications, the most interesting and useful feature, perhaps, is the turbulence insensitivity of thermal light ghost imaging, i.e., atmospheric turbulence would not have any influence on the ghost images of sunlight. Inspired by ghost imaging, a new type of camera is ready for turbulence-free imaging applications. This turbulence-free camera would be especially useful for long distance imaging, such as satellite imaging. How could fluctuations of thermal light produce an image? Why is it turbulence-free? This article addresses these questions. Full article
(This article belongs to the Special Issue Quantum Imaging)
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2575 KiB  
Article
Tensile Properties of Al-12Si Fabricated via Selective Laser Melting (SLM) at Different Temperatures
by Konda Gokuldoss Prashanth, Sergio Scudino and Jürgen Eckert
Technologies 2016, 4(4), 38; https://doi.org/10.3390/technologies4040038 - 02 Dec 2016
Cited by 41 | Viewed by 7246
Abstract
Additive manufacturing processes such as selective laser melting (SLM) are attracting increasing attention and are regarded as the manufacturing technology of the future, because of their ability to produce near net shaped components of theoretically any shape with added functionality. Various properties, including [...] Read more.
Additive manufacturing processes such as selective laser melting (SLM) are attracting increasing attention and are regarded as the manufacturing technology of the future, because of their ability to produce near net shaped components of theoretically any shape with added functionality. Various properties, including mechanical, tribological, welding, and corrosion properties, of Al-12Si alloys fabricated via SLM have been extensively studied. However, all of these studies were carried out at ambient conditions. Nevertheless, under working conditions, these alloys experience service temperatures ranging between 373 and 473 K. The present study focuses on the evaluation of the mechanical properties of SLM-fabricated Al-12Si alloys in this temperature range. For this, Al-12Si alloy specimens were annealed at 573 K, a temperature well beyond the test temperature in order to provide a stable microstructure during tensile testing. The plasticity of these materials increases along with the size of the dimples on the fracture surface with increasing tensile test temperature. Moreover, the annealed Al-12Si alloy exhibits appreciable tensile properties when tested between 373 K and 473 K. The results suggest that Al-12Si samples fabricated via SLM may be ideal candidates for automotive applications such as pistons and cylinder heads. Full article
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3807 KiB  
Article
Effect of Particle Size on Microstructure and Mechanical Properties of Al-Based Composite Reinforced with 10 Vol.% Mechanically Alloyed Mg-7.4%Al Particles
by Anil K. Chaubey, Prashanth Konda Gokuldoss, Zhi Wang, Sergio Scudino, Nilay K. Mukhopadhyay and Jürgen Eckert
Technologies 2016, 4(4), 37; https://doi.org/10.3390/technologies4040037 - 19 Nov 2016
Cited by 35 | Viewed by 6212
Abstract
The effect of Mg-7.4%Al reinforcement particle size on the microstructure and mechanical properties in pure Al matrix composites was investigated. The samples were prepared by hot consolidation using 10 vol.% reinforcement in different size ranges, D, 0 < D < 20 µm (0–20 [...] Read more.
The effect of Mg-7.4%Al reinforcement particle size on the microstructure and mechanical properties in pure Al matrix composites was investigated. The samples were prepared by hot consolidation using 10 vol.% reinforcement in different size ranges, D, 0 < D < 20 µm (0–20 µm), 20 ≤ D < 40 µm (20–40 µm), 40 ≤ D < 80 µm (40–80 µm) and 80 ≤ D < 100 µm (80–100 µm). The result reveals that particle size has a strong influence on the yield strength, ultimate tensile strength and percentage elongation. As the particle size decreases from 80 ≤ D < 100 µm to 0 < D < 20 µm, both tensile strength and ductility increases from 195 MPa to 295 MPa and 3% to 4% respectively, due to the reduced ligament size and particle fracturing. Wear test results also corroborate the size effect, where accelerated wear is observed in the composite samples reinforced with coarse particles. Full article
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1381 KiB  
Article
Mass Proportion, Bioactive Compounds and Antioxidant Capacity of Carrot Peel as Affected by Various Solvents
by Van Tang Nguyen and Christopher J. Scarlett
Technologies 2016, 4(4), 36; https://doi.org/10.3390/technologies4040036 - 17 Nov 2016
Cited by 18 | Viewed by 5158
Abstract
The aim of this study was to determine the mass proportion of carrot root and the effects of four various solvents (methanol, water, ethanol and hexane) on the contents of total phenolics and saponins as well as antioxidant capacity of carrot peel to [...] Read more.
The aim of this study was to determine the mass proportion of carrot root and the effects of four various solvents (methanol, water, ethanol and hexane) on the contents of total phenolics and saponins as well as antioxidant capacity of carrot peel to identify an optimal solvent for effective extraction of bioactive compounds from carrot peel for further investigation. The results showed that carrot root consisted of body, heads and peel with their mass proportion of 83.19%, 5.01% and 14.19% by fresh weight, respectively. Among four solvents tested, methanol obtained the highest levels of extraction yield (54.02% by dry weight), total phenolic content (9.02 mg GAE/g dry weight) and antioxidant capacity (DPPH radical scavenging capacity, cupric ion reducing antioxidant capacity, and ferric reducing antioxidant power) from carrot peel, while water extracted the highest content of saponins (272.9 mg EE/g dry weight) and possessed the maximum ABTS radical scavenging capacity. Therefore, methanol and water are considered for effective extraction of phenolics and saponins from carrot peel, respectively. The phenolic/saponin-enriched extracts are potential sources for further applications in the healthy food and/or pharmaceutical industries. Full article
(This article belongs to the Section Innovations in Materials Processing)
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452 KiB  
Article
Capturing the True Value of Assistive Technologies to Consumers in Routine Outcome Measurement
by Desleigh De Jonge and Wendy Stevens
Technologies 2016, 4(4), 35; https://doi.org/10.3390/technologies4040035 - 14 Oct 2016
Cited by 28 | Viewed by 4590
Abstract
(1) Background: Recent reforms in Australia, providing people with disability and older people with choice and control over allocated funding, have altered consumer expectations and transformed the landscape of assistive technology (AT) service provision. The purpose of this study is to report on [...] Read more.
(1) Background: Recent reforms in Australia, providing people with disability and older people with choice and control over allocated funding, have altered consumer expectations and transformed the landscape of assistive technology (AT) service provision. The purpose of this study is to report on the routine AT outcomes of people who accessed an AT consultation service and examine how well these capture the impact of AT on their lives; (2) Methods: This study, which uses mixed methods for concurrent triangulation of the data, reports on the outcomes for 127 people who acquired a range of assistive technology in 2015 and examines the adequacy of an existing service outcome framework in capturing the true value of these technologies to AT users. Outcome data was routinely collected by a community service 2–4 months following an AT consultation. A telephone or face-to-face interview gathered demographic information as well as AT outcomes, using two standardized tools, the Individualized Prioritised Problem Assessment (IPPA) and the EATS 6D. Qualitative comments relating to the impact of the AT on the person’s life were also documented; (3) Results: The acquired AT generally met or exceeded expectations of the person using the AT and the attending health professional. Overall, people experienced decreased difficulty and increased feelings of autonomy, with most of the reported improvements identified in mobility and usual activities; (4) Conclusion: Routine outcome data provide some evidence of the value of AT in addressing concerns as identified by clients. Qualitative data, which captured the impact of AT on people’s lives, suggest that the empowering and transformative aspects of AT are not currently being captured by existing measures. Full article
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8395 KiB  
Article
Characterization of 316L Steel Cellular Dodecahedron Structures Produced by Selective Laser Melting
by Konda Gokuldoss Prashanth, Lukas Löber, Hans-Jörg Klauss, Uta Kühn and Jürgen Eckert
Technologies 2016, 4(4), 34; https://doi.org/10.3390/technologies4040034 - 08 Oct 2016
Cited by 64 | Viewed by 7252
Abstract
The compression behavior of different 316L steel cellular dodecahedron structures with different density values were studied. The 316L steel structures produced using the selective laser melting process has four different geometries: single unit cells with and without the addition of base plates beneath [...] Read more.
The compression behavior of different 316L steel cellular dodecahedron structures with different density values were studied. The 316L steel structures produced using the selective laser melting process has four different geometries: single unit cells with and without the addition of base plates beneath and on top, and sandwich structures with multiple unit cells with different unit cell sizes. The relation between the relative compressive strength and the relative density was compared using different Gibson-Ashby models and with other published reports. The different aspects of the deformation and the mechanical properties were evaluated and the deformation at distinct loading levels was recorded. Finite element method (FEM) simulations were carried out with the defined structures and the mechanical testing results were compared. The calculated theory, simulation estimation, and the observed experimental results are in good agreement. Full article
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1806 KiB  
Article
Mechanical and Corrosion Behavior of New Generation Ti-45Nb Porous Alloys Implant Devices
by Konda Gokuldoss Prashanth, Ksenia Zhuravleva, Ilya Okulov, Mariana Calin, Jürgen Eckert and Annett Gebert
Technologies 2016, 4(4), 33; https://doi.org/10.3390/technologies4040033 - 30 Sep 2016
Cited by 25 | Viewed by 5728
Abstract
Strategies to improve the mechanical compatibility of Ti-based materials for hard tissue implant applications are directed towards significant stiffness reduction by means of the adjustment of suitable β-phases and porous device architectures. In the present study, the effect of different compaction routes of [...] Read more.
Strategies to improve the mechanical compatibility of Ti-based materials for hard tissue implant applications are directed towards significant stiffness reduction by means of the adjustment of suitable β-phases and porous device architectures. In the present study, the effect of different compaction routes of the gas-atomized β-Ti-45Nb powder on the sample architecture, porosity, and on resulting mechanical properties in compression was investigated. Green powder compacted and sintered at 1000 °C had a porosity varying between 8% and 12%, strength between 260 and 310 MPa, and Young’s modulus ranging between 18 and 21 GPa. Hot pressing of the powder without or with subsequent sintering resulted in microporosity varying between 1% and 3%, ultimate strength varying between 635 and 735 MPa, and Young’s modulus between 55 and 69 GPa. Samples produced with NaCl space-holder by hot-pressing resulted in a macroporosity of 45% and a high strength of ˃200 MPa, which is higher than the strength of a human cortical bone. Finally, the corrosion tests were carried out to prove that the presence of residual NaCl traces will not influence the performance of the porous implant in the human body. Full article
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3057 KiB  
Article
Interactions between the Ionic Liquid and the ZrO2 Support in Supported Ionic Liquid Membranes for CO2 Separation
by Cinthia E. Sánchez-Fuentes, Sibele B. Pergher, Mirella Gutiérrez-Arzaluz, Violeta Mugica-Álvarez, Eduardo Terrés and Miguel Torres-Rodríguez
Technologies 2016, 4(4), 32; https://doi.org/10.3390/technologies4040032 - 28 Sep 2016
Cited by 2 | Viewed by 4774
Abstract
This work reports the interaction study of two supported ionic liquid membranes (SILMs) based on 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]), which were impregnated into porous zirconia supports with 20 nm average pore diameters. [...] Read more.
This work reports the interaction study of two supported ionic liquid membranes (SILMs) based on 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]), which were impregnated into porous zirconia supports with 20 nm average pore diameters. The interaction of ionic liquid-support observed from diffuse reflectance (DR), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS) is reported. The IR spectrum in the 600 to 4000 cm−1 range showed a specific interaction of the ionic liquid with the support. The N2 and CO2 permeances in the SILMs with [C4mim][BF4] were 8.7 × 10−8 mol·s−1·m−2·Pa−1 and 9.6 × 10−7 mol·s−1·m−2·Pa−1, respectively. The separation factor through the ionic liquid in the membrane as a function of temperature showed that the SILMs studied here can be used for CO2 separation at low temperatures. Full article
(This article belongs to the Special Issue Carbon Capture and Storage (CCS) Technologies)
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