The increasing application of additive manufacturing (AM) technology across various sectors has sparked significant interest in characterizing 3D-printed components. An essential aspect of achieving fracture-resistant designs is gaining a comprehensive understanding of the fracture behavior exhibited by these components. While most studies have focused on linear-elastic fracture mechanics (LEFM), there is a lack of comprehensive studies on the post-yield fracture behavior (PYFM) of 3D-printed components. As a result, this study aims to fill this gap by investigating the impact of raster angle, a critical parameter influencing fracture properties and often leading to premature failures, on the fracture properties of fused deposition modeling (FDM) 3D printed acrylonitrile butadiene styrene (ABS) using essential work of fracture (EWF). Outcomes showed that by changing lay-ups from [90]5 to [0]5, the value of we or elastic work increased by nearly 306%. Further, the maximum and minimum values of the plastic work (βwp) were for [45/−45/45/−45/45] and [90]5 lay-ups, in order. By changing lay-ups from [90]5 to [45/−45/45/−45/45], the value of βwp increased by approximately 216%. In addition, the fractured surfaces of tested samples are also analyzed to provide insights into the dominant failure mechanisms for different raster angles. 相似文献
The aim of this numerical investigation is to evaluate the laminar forced convection of biologically synthesized water-silver nanofluid through a heat sink (HS) filled with porous foam (PHS) using first and second laws of thermodynamics. The impacts of inlet velocity (V = 0.5–3 m·s−1) and volume fraction of nanofluid (φ = 0–1%) on the performance metrics of HS are assessed and the outcomes are compared with those of the non-porous HS (NHS). The outcomes revealed that for both the PHS and NHS, the increase of V causes an intensification in convection coefficient, pumping power, and entropy generation due to fluid friction, while the maximum CPU temperature, thermal resistance, and entropy generation due to the heat transfer reduces by boosting V. Also, it was found that the augmentation of V results in intensification in convection coefficient, pumping power, overall hydrothermal performance, and frictional entropy generation, while the opposite is true for maximum CPU temperature, thermal resistance, and thermal entropy generation. Furthermore, it was reported that, except for φ = 0.5%, the overall hydrothermal performance of NHS is better than that of PHS, while PHS has better second-law performance than NHS in all the studied cases. Also, it can be concluded that the best hydrothermal performance for PHS belongs to φ = 1% and V = 0.5 m·s−1, while for NHS, these values are 1% and 2 m·s−1. 相似文献
Due to the current fossil fuel crisis and associated adverse environmental impacts, renewable energy sources (RES) have drawn interest as alternatives to fossil fuels for powering water desalination systems. Over the last few decades the utility of renewable energy sources such as solar, geothermal, and wind to run desalination processes has been explored. However, the expansion of these technologies to larger scales is hampered by techno-economic and thermo-economic challenges. This paper reviews the state-of-the-art in the field of renewable energy-powered thermal desalination systems (RE-PTD) to compare their productivity and efficiency through thermodynamic, economic, and environmental analyses. We performed a comparative study using published data to classify RE-PTD systems technologies on the basis of the energy collection systems that they use. Among RE-PTD systems, solar energy powered-thermal desalination systems demonstrate high thermo-environ-economic efficiency to produce fresh water to meet various scales of demand. 相似文献
The Kouh-e Zar mining area is located in the central part of the “Khaf–Bardaskan” volcanic-plutonic zone, NE Iran. Mining activity has resulted in pollution of soil and water resources by potentially toxic elements including arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), antimony (Sb), nickel (Ni) and zinc (Zn). In this study, the major source of heavy metal pollution and elucidating the probable environmental risks associated with this area were determined by quantifying pollution in soils and water resources. Concentrations of Cd, Cr, Cu, Pb and Zn in the Kouh-e Zar mining area varied in the range of 5–470, 33–442, 25–5125, 81.15–12,096.27 and 55–4210 mg/kg, respectively. The geo-accumulation index for Cd in all samples was extremely high (Igeo > 5) and the enrichment factor also shows an extremely high amount (EF > 40), both representing evidence for highly polluted soil in the area. However, the coefficients of aqueous migration (Kx) of Cd, Cr, Cu, Pb and Zn were Kx < 0.1, so they are classified as “least mobile and inert” grade. Also, the heavy metals tend to remain in soil (solid environment). Cluster analysis (CA) determined the lithogenic origin for Zn, Cu, Cr and Cd, and the anthropogenic origin (mining activity) for Pb in the soils of the mining area. The concentrations of Cd, Cu, Pb and Zn in water are controlled by free Fe and Mn oxy-hydroxide content in the soils. Both water–rock interaction and mining activity have contributed to pollution in the area.
The continuous evolution of sliding rock masses activated by rainfall combined with snowmelt will be discussed in this paper. The effects of precipitation on slip velocities during the periods separating failure events have already been studied in the literature by means of either pure statistical approaches or sophisticated numerical codes. A simple schematic model will be presented in this paper based on a crude physical and geometrical simplification of the rock mass hydromechanical system. This model enables simulating the correlations between rainfall/snowmelt data and slip velocities with relative efficiency. This model may be considered as an intermediate tool between purely statistical and more sophisticated numerical models; moreover, it is potentially useful for assessing the stability of civil engineering and open-pit mining slopes. 相似文献
A modified mixed oxide method which is based on a two step reaction sintering process was designed to obtain single phase
PMN ceramics. In this regard, pyrochlore phase formation during calcination process at different calcination temperatures
was studied to determine the best soaking temperature for the first step in the specified method. In other words, the calcination
temperature in which the least pyrochlore phase produced was chosen as the first step soaking temperature. The results showed
that by utilizing this new method, single phase PMN ceramics with a high relative density of 98% can be synthesized successfully
using conventional mixed oxide starting materials. 相似文献
According to the concept of an intrinsic hybrid composite, adhesive bonding is designed for generating the connection between the applied fiber reinforced polymer and a metallic insert. To induce adhesive bonding, a metallic insert, made of aluminum, is coated. This contribution focusses on the development of a suitable coating system. To this end, the coating system must meet certain requirements. On one hand, demands on the coating like ductility can be deduced from analyzing the manufacturing process. On the other hand, requirements like corrosion protection as well as high static and dynamic strength arise from specific applications under considerations. The utilized coating system is based on organically modified silicate layers (Ormosil) applied using a sol–gel process. To prove that this coating system fulfils the requirements, the corrosion protection is analysed by impedance spectroscopy. Furthermore, different mechanical experimental investigations are performed to verify the ductility of the coating as well as the strength of the resulting interface. Hence, it is shown that the considered coating system can be applied for the analysed intrinsic hybrid composite manufactured in series. 相似文献
ABSTRACT Reactive power is one of the main characteristics that play a major role in power systems. When reactive flow is inadequate, the power system is confronted with voltage collapse and more than enough reactive power production follows the circulation in the network and consequently the occupation of power lines. On the other hand, power market evolves from centralised and vertically integrated structure to a competitive environment. The reactive power market is different from energy market and like others such as spinning reserve, frequency control and power system stabiliser is taken in the category of the ancillary service market. This paper reviews various mechanisms for pricing of reactive power in both levels of transmission and distribution (T&D) system. Additionally, the cost paid for reactive power service in the presence of distributed energy resources is analysed because of their high penetration in the power system, especially in distribution level. 相似文献