scholarly journals Fundamentals of Force-Controlled Friction Riveting: Part II—Joint Global Mechanical Performance and Energy Efficiency

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2489 ◽  
Author(s):  
Gonçalo Pina Cipriano ◽  
Lucian Blaga ◽  
Jorge dos Santos ◽  
Pedro Vilaça ◽  
Sergio Amancio-Filho
Keyword(s):  
Energy Efficiency ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
Tensile Force ◽  
Optimization Approach ◽  
Additional Energy ◽  
Efficient Manner ◽  
Control Optimization ◽  
Friction Parameters ◽  
And Control

The present work investigates the correlation between energy efficiency and global mechanical performance of hybrid aluminum alloy AA2024 (polyetherimide joints), produced by force-controlled friction riveting. The combinations of parameters followed a central composite design of experiments. Joint formation was correlated with mechanical performance via a volumetric ratio (0.28–0.66 a.u.), with a proposed improvement yielding higher accuracy. Global mechanical performance and ultimate tensile force varied considerably across the range of parameters (1096–9668 N). An energy efficiency threshold was established at 90 J, until which, energy input displayed good linear correlations with volumetric ratio and mechanical performance (R-sq of 0.87 and 0.86, respectively). Additional energy did not significantly contribute toward increasing mechanical performance. Friction parameters (i.e., force and time) displayed the most significant contributions to mechanical performance (32.0% and 21.4%, respectively), given their effects on heat development. For the investigated ranges, forging parameters did not have a significant contribution. A correlation between friction parameters was established to maximize mechanical response while minimizing energy usage. The knowledge from Parts I and II of this investigation allows the production of friction riveted connections in an energy efficient manner and control optimization approach, introduced for the first time in friction riveting.

scholarly journals Chemical and physical interactions of regenerated cellulose yarns and isocyanate-based matrix systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bernhard Ungerer ◽  
Ulrich Müller ◽  
Antje Potthast ◽  
Enrique Herrero Acero ◽  
Stefan Veigel
Keyword(s):  
Mechanical Performance ◽  
Tensile Force ◽  
Tensile Modulus ◽  
Tensile Tests ◽  
Size Exclusion ◽  
Regenerated Cellulose ◽  
Hydrolytic Cleavage ◽  
Yarn Twist ◽  
Exclusion Chromatography ◽  
Physical And Chemical

AbstractIn the development of structural composites based on regenerated cellulose filaments, the physical and chemical interactions at the fibre-matrix interphase need to be fully understood. In the present study, continuous yarns and filaments of viscose (rayon) were treated with either polymeric diphenylmethane diisocyanate (pMDI) or a pMDI-based hardener for polyurethane resins. The effect of isocyanate treatment on mechanical yarn properties was evaluated in tensile tests. A significant decrease in tensile modulus, tensile force and elongation at break was found for treated samples. As revealed by size exclusion chromatography, isocyanate treatment resulted in a significantly reduced molecular weight of cellulose, presumably owing to hydrolytic cleavage caused by hydrochloric acid occurring as an impurity in pMDI. Yarn twist, fibre moisture content and, most significantly, the chemical composition of the isocyanate matrix were identified as critical process parameters strongly affecting the extent of reduction in mechanical performance. To cope with the problem of degradative reactions an additional step using calcium carbonate to trap hydrogen ions is proposed.

scholarly journals Fuel metering and control optimization based on combustion state diagnosis

2020 ◽  
Vol 594 ◽  
pp. 012013
Author(s):  
X H Wang ◽  
H T Chen ◽  
X X Zhu ◽  
J L Zhang ◽  
W L Liu ◽  
...  
Keyword(s):  
Control Optimization ◽  
And Control ◽  
State Diagnosis

scholarly journals Real-World Implementation of an ICT-Based Platform to Promote Energy Efficiency

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2416
Author(s):  
Marina Dorokhova ◽  
Fernando Ribeiro ◽  
António Barbosa ◽  
João Viana ◽  
Filipe Soares ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Real World ◽  
Energy Savings ◽  
Quality Parameters ◽  
Horizon 2020 ◽  
Flexible Devices ◽  
Information And Communication ◽  
Energy Consuming ◽  
And Behavior ◽  
And Control

The energy efficiency requirements of most energy-consuming sectors have increased recently in response to climate change. For buildings, this means targeting both facility managers and building users with the aim of identifying potential energy savings and encouraging more energy-responsible behaviors. The Information and Communication Technology (ICT) platform developed in Horizon 2020 FEEdBACk project intends to fulfill these goals by enabling the optimization of energy consumption, generation, and storage and control of flexible devices without compromising comfort levels and indoor air quality parameters. This work aims to demonstrate the real-world implementation and functionality of the ICT platform composed of Load Disaggregation, Net Load Forecast, Occupancy Forecast, Automation Manager, and Behavior Predictor applications. Particularly, the results obtained by individual applications during the test phase are presented alongside the specific metrics used to evaluate their performance.

scholarly journals Improving Energy Efficiency Fairness of Wireless Networks: A Deep Learning Approach

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4300 ◽  
Author(s):  
Hoon Lee ◽  
Han Seung Jang ◽  
Bang Chul Jung
Keyword(s):  
Energy Efficiency ◽  
Wireless Networks ◽  
Deep Learning ◽  
Power Control ◽  
Control Method ◽  
Optimal Solution ◽  
Control Policy ◽  
Maximization Problem ◽  
Optimization Approach ◽  
Conventional Optimization

Achieving energy efficiency (EE) fairness among heterogeneous mobile devices will become a crucial issue in future wireless networks. This paper investigates a deep learning (DL) approach for improving EE fairness performance in interference channels (IFCs) where multiple transmitters simultaneously convey data to their corresponding receivers. To improve the EE fairness, we aim to maximize the minimum EE among multiple transmitter–receiver pairs by optimizing the transmit power levels. Due to fractional and max-min formulation, the problem is shown to be non-convex, and, thus, it is difficult to identify the optimal power control policy. Although the EE fairness maximization problem has been recently addressed by the successive convex approximation framework, it requires intensive computations for iterative optimizations and suffers from the sub-optimality incurred by the non-convexity. To tackle these issues, we propose a deep neural network (DNN) where the procedure of optimal solution calculation, which is unknown in general, is accurately approximated by well-designed DNNs. The target of the DNN is to yield an efficient power control solution for the EE fairness maximization problem by accepting the channel state information as an input feature. An unsupervised training algorithm is presented where the DNN learns an effective mapping from the channel to the EE maximizing power control strategy by itself. Numerical results demonstrate that the proposed DNN-based power control method performs better than a conventional optimization approach with much-reduced execution time. This work opens a new possibility of using DL as an alternative optimization tool for the EE maximizing design of the next-generation wireless networks.

Daylighting Strategies in Iranian Vernacular Residential Buildings in Hot and Dry Climate

2015 ◽  
Vol 747 ◽  
pp. 329-332
Author(s):  
Elham Maghsoudi Nia ◽  
Titi Hajihasani ◽  
Mohd Yazid Mohd Yunos ◽  
Nordin Abdul Rahman
Keyword(s):  
Energy Efficiency ◽  
Significant Role ◽  
Residential Buildings ◽  
Design Phase ◽  
Review Of Literature ◽  
Shading Devices ◽  
And Control

Daylighting strategies and control of it, plays a significant role in energy efficiency and provision of visual comforts in buildings. This study conducted a review of literature and observation in a hot and dry region of Iran in order to investigate daylighting strategies and control of it by shading devices in the vernacular residential buildings. The results show thatdaylight in vernacular rooms was provided through door, window, Rozan, Moshabak, and Goljam. These components were equipped with thevertical and horizontalshading devices such as Orsi, Sarsayeh, Tabeshband and Kharakpoushto control the sunlight. The vernacular lighting strategy was in response to the energy efficiency and provided visual comfort.The vernacular concepts and schemes still can be adopted and reused by architects and developers. The study recommends appropriate daylight schemes and shading devices in design phase to achieve energy efficiency in new residential buildings.

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