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- Adl-Zarrabi, Bijan, 1959, et al.
(författare)
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Sustainability Assessment of Infrastructure Elements with Integrated Energy Harvesting Technologies
- 2016
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Ingår i: Energy and Environment. - : Wiley. - 9781119307761 ; , s. 221-234
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The possibility of integrating energy harvesting devices into the bridge/tunnel structures along Coastal Highway Route E39 has been investigated in a feasibility study by the Norwegian Public Roads Administration (NPRA). The main advantage of integrating energy conversion devices in a structural element is the reduction of costs compared to stand-alone devices. The construction could be used as a foundation, a mooring point and provide a dry environment for electrical devices. Easy access to the production site could also reduce the cost for installation, operation and maintenance. Two important challenges related to harvesting renewable energy by infrastructure elements, without concerning about the energy source, are to store it or feed the energy to the grid. In the second case, tailoring generation to demand is of critical importance. Tasks such as supply and demand management, for instance, peak hour management, what kind of storage should be used - electrical or thermal - need be solved. Furthermore, integrating energy production devices in a structure might cause negative environmental impacts and affect the life expectancy and maintenance costs of such structures. The potential environmental impacts associated with renewable technologies are the consequences for bird life or marine fauna at the fjord crossing locations, as well as noise and visual impact. Thus, a sustainability assessment should be performed in order to quantify the ecological, economical and societal impacts of the suggested alternatives.
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- Burstein, R., et al.
(författare)
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Mapping 123 million neonatal, infant and child deaths between 2000 and 2017
- 2019
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 574:7778, s. 353-358
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Tidskriftsartikel (refereegranskat)abstract
- Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations. © 2019, The Author(s).
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| 5. |
- Ghomi, Erfan Rezvani, et al.
(författare)
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A collection of the novel coronavirus (COVID-19) detection assays, issues, and challenges
- 2021
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Ingår i: Heliyon. - : Elsevier BV. - 2405-8440. ; 7:6
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Forskningsöversikt (refereegranskat)abstract
- The global pandemic of COVID-19 has rapidly increased the number of infected cases as well as asymptomatic individuals in many, if not all the societies around the world. This issue increases the demand for accurate and rapid detection of SARS-CoV-2. While accurate and rapid detection is critical for diagnosing SARS-CoV-2, the appropriate course of treatment must be chosen to help patients and prevent its further spread. Testing platform accuracy with high sensitivity and specificity for SARS-CoV-2 is equally important for clinical, regional, and global arenas to mitigate secondary transmission rounds. The objective of this article is to compare the current detection technology and introduce the most accurate and rapid ones that are suitable for pandemic circumstances. Hence, the importance of rapid detection in societies is discussed initially. Following this, the current technology for rapid detection of SARS-CoV-2 is explained and classified into three different categories: nucleic acid-based, protein-based, and point of care (PoC) detection testing. Then, the current issues for diagnostic procedures in laboratories are discussed. Finally, the role of new technologies in countering COVID-19 is also introduced to assist researchers in the development of accurate and timely detection of coronaviruses. As coronavirus continues to affect human lives in a detrimental manner, the development of rapid and accurate virus detection methods could promote COVID-19 diagnosis accessible to both individuals and the mass population at patient care. In this regard, rRT-PCR and multiplex RT-PCR detection techniques hold promise.
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- Heshmati, Nader, et al.
(författare)
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Microstructural influences on simultaneous strength and fatigue crack resistance in advanced high-strength steels
- 2024
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Ingår i: International Journal of Fatigue. - : Elsevier BV. - 0142-1123 .- 1879-3452. ; 184
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we investigate the relation between microstructure and fatigue crack propagation mechanisms in three commercial hot-rolled thick-plate advanced high-strength steels (AHSSs), namely 800CP, 700MC, and 700MCPlus, and compare them with a conventional high-strength low-alloy (HSLA) steel, 500MC, commonly used in heavy-duty vehicle chassis production. Tensile testing, and fatigue crack growth rate (FCGR) assessments have been conducted, and mechanisms controlling the performance of these steels are comprehensively examined through microstructure characterization before and after fatigue testing. Notably, FCGR results reveal that, despite having the highest yield strength among the investigated steels, 700MCPlus exhibits the slowest FCGR in both near-threshold and stable crack growth regimes. This improved fatigue crack propagation resistance of 700MCPlus in terms of its threshold stress intensity factor range (Delta Kth) is attributed to its unique texture, which restricts slip activity, and the presence of martensite at grain boundaries, contributing to fatigue crack deflection. This martensite-induced crack deflection becomes more significant in the stable crack growth regime, where fatigue crack primarily propagates intergranularly as the stress intensity factor range (Delta K) increases. These mechanistic findings offer new design possibilities for AHSSs, combining excellent strength and fatigue performance.
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| 7. |
- Hoseini-Athar, Mohammad Mehdi, et al.
(författare)
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Microstructure and superplasticity of Mg-2Gd-xZn alloys processed by equal channel angular pressing
- 2021
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Ingår i: Materials Science & Engineering. - : Elsevier. - 0921-5093 .- 1873-4936. ; 808
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Tidskriftsartikel (refereegranskat)abstract
- Microstructure, mechanical properties and superplastic behavior of Mg-2Gd-xZn (x = 0, 1, 2 and 3 wt%) alloys were investigated after extrusion and equal channel angular pressing (ECAP). After only 2 passes of ECAP, a homogenous fine-grained microstructure with a grain size of 2.33 mu m and a high fraction of high-angle grain boundaries of 84% were formed in the Mg-2Gd-3Zn (GZ23) alloy, while 4 ECAP passes were necessary to create such a structure in the other alloys. This was attributed to the higher solute drag effect in the other alloys, retarding dynamic recrystallization (DRX). Although DRX occurred more easily in the GZ23 alloy, the final DRX grain size was slightly coarser compared to the other alloys. Shear punch testing (SPT) showed that grain refinement during ECAP leads to a slight increase in the shear yield strength of all studied materials after 2 ECAP passes, which was mostly balanced by texture softening caused by the shear texture component and grain growth after 4 ECAP passes. Contrary to the other alloys, the GZ23 alloy exhibited superplastic behavior after a lower number of ECAP passes. In addition, the superplastic temperature for GZ23 was 648 K, which was lower than the 673 K observed for the other alloys. The m-values of similar to 0.45-0.5 and activation energies of 98-114 kJ/mol suggested grain boundary sliding (GBS) controlled by grain boundary diffusion as the dominant deformation mechanism in the superplastic regime. This was confirmed by microstructural observations.
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| 8. |
- Hoseini-Athar, Mohammad Mehdi, et al.
(författare)
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Tailoring the texture of an extruded Mg sheet through constrained groove pressing for achieving low mechanical anisotropy and high yield strength
- 2020
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Ingår i: Scripta Materialia. - : Elsevier BV. - 1359-6462 .- 1872-8456. ; 186, s. 253-258
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Tidskriftsartikel (refereegranskat)abstract
- Constrained groove pressing (CGP) was utilized to modify the texture and mechanical properties of extruded Mg-2Gd-3Zn sheet with typical TD (transverse direction)-split texture and pronounced mechanical anisotropy. The texture evolution sequence during CGP was studied and it was observed that a new (1211) component with basal poles rotated 15-30 toward the extrusion direction (ED) is introduced during CGP, as a result of simultaneous activation of basal and prismatic slip and shear deformation. Finally, a non-basal ED-TD double split texture was obtained after the CGP process, resulting in significantly reduced mechanical anisotropy.
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| 10. |
- Hoseini-Athar, Mohammad Mehdi, et al.
(författare)
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Towards implementation of alloy-specific thermo-fluid modelling for laser powder-bed fusion of Mg alloys
- 2024
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Ingår i: JOURNAL OF MAGNESIUM AND ALLOYS. - : Elsevier BV. - 2213-9567. ; 12:6, s. 2327-2344
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Tidskriftsartikel (refereegranskat)abstract
- Multi-physics thermo-fluid modeling has been extensively used as an approach to understand melt pool dynamics and defect formation as well as optimizing the process-related parameters of laser powder-bed fusion (L-PBF). However, its capabilities for being implemented as a reliable tool for material design, where minor changes in material-related parameters must be accurately captured, is still in question. In the present research, first, a thermo-fluid computational fluid dynamics (CFD) model is developed and validated against experimental data. Considering the predicted material properties of the pure Mg and commercial ZK60 and WE43 Mg alloys, parametric studies are done attempting to elucidate how the difference in some of the material properties, i.e., saturated vapor pressure, viscosity, and solidification range, can influence the melt pool dynamics. It is found that a higher saturated vapor pressure, associated with the ZK60 alloy, leads to a deeper unstable keyhole, increasing the keyhole-induced porosity and evaporation mass loss. Higher viscosity and wider solidification range can increase the non-uniformity of temperature and velocity distribution on the keyhole walls, resulting in increased keyhole instability and formation of defects. Finally, the WE43 alloy showed the best behavior in terms of defect formation and evaporation mass loss, providing theoretical support to the extensive use of this alloy in L-PBF. In summary, this study suggests an approach to investigate the effect of materials-related parameters on L-PBF melting and solidification, which can be extremely helpful for future design of new alloys suitable for L-PBF.
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