Modelling and Optimization of a Non-Constrained Multi-objective Problem having Multiple Utility Functions using Bayesian Theory

One of the multi-objective optimization methods makes use of the utility function for the objective functions. Utility function creating the most satisfaction answers for decision makers (DMs) by considering the priorities of the DMs; in an available studies; there are only one utility function for each objective function. But due to practical situation in different decision making environments in an industry or trade lead each goal has multiple utility functions. This paper presents a model of multi- objective problem in which each of the objective function has multiple utility function applying Bayesian theory. This model allows DMs to calculate the probability of these utilities using conditional probability in conditions of uncertainty. In addition, examples are given to illustrate the usefulness of this model

Solution-processed multiferroic thin-films with large magnetoelectric coupling at room-temperature

Experimental realization of thin films with a significant room-temperature magnetoelectric coupling coefficient, αME, in the absence of an external DC magnetic field, has been thus far elusive. Here, a large coupling coefficient of 750 ± 30 mV Oe-1 cm-1 is reported for multiferroic polymer nanocomposites (MPCs) thin-films in the absence of an external DC magnetic field. The MPCs are based on PMMA-grafted cobalt-ferrite nanoparticles uniformly dispersed in the piezoelectric polymer poly(vinylidene fluoride-co-trifluoroethylene, P(VDF-TrFE). It is shown that nanoparticle agglomeration plays a detrimental role and significantly reduces αME. Surface functionalization of the nanoparticles by grafting a layer of poly(methyl methacrylate) (PMMA) via atom transfer radical polymerization (ATRP) renders the nanoparticle miscible with P(VDF-TRFE) matrix, thus enabling their uniform dispersion in the matrix even in submicrometer thin films. Uniform dispersion yields maximized interfacial interactions between the ferromagnetic nanoparticles and the piezoelectric polymer matrix leading to the experimental demonstration of large αME values in solution-processed thin films, which can be exploited in flexible and printable multiferroic electronic devices for sensing and memory applications.</p

Magnetoelectric coupling coefficient in multiferroic capacitors:Fact vs Artifacts

Multiferroic materials are characterized by their magnetoelectric coupling coefficient, which can be obtained using a lock-in amplifier by measuring the voltage developed across a multiferroic capacitor in a time-variable magnetic field, Hac cos(ωt), where Hac and ω are the amplitude and frequency of the applied magnetic field. The measurement method, despite its simplicity, is subject to various parasitic effects, such as magnetic induction, which leads to significant over-estimation of the actual magnetoelectric response. This article outlines the measurement theory for a multiferroic capacitor using the lock-in technique. It is demonstrated that the inductive contribution has linear proportionality with Hac, ω, and Hacω. It is shown that the true magnetoelectric coupling response is retrieved from the real component of the lock-in signal. Using a polymer-nanoparticle multiferroic composite, the internal consistency of the proposed measurement method is experimentally demonstrated, and it is shown that the actual multiferroic signal can be retrieved using the lock-in technique by removing the magnetic induction contribution from the signal. It is observed that the magnetoelectric voltage shows only a linear dependence with Hac, a saturating behavior with ω, and Hacω. Furthermore, a measurement protocol for reliable reporting of magnetoelectric coupling coefficient has been provided.</p

Solution-processed multiferroic thin-films with large magnetoelectric coupling at room-temperature

Experimental realization of thin films with a significant room-temperature magnetoelectric coupling coefficient, αME, in the absence of an external DC magnetic field, has been thus far elusive. Here, a large coupling coefficient of 750 ± 30 mV Oe-1 cm-1 is reported for multiferroic polymer nanocomposites (MPCs) thin-films in the absence of an external DC magnetic field. The MPCs are based on PMMA-grafted cobalt-ferrite nanoparticles uniformly dispersed in the piezoelectric polymer poly(vinylidene fluoride-co-trifluoroethylene, P(VDF-TrFE). It is shown that nanoparticle agglomeration plays a detrimental role and significantly reduces αME. Surface functionalization of the nanoparticles by grafting a layer of poly(methyl methacrylate) (PMMA) via atom transfer radical polymerization (ATRP) renders the nanoparticle miscible with P(VDF-TRFE) matrix, thus enabling their uniform dispersion in the matrix even in submicrometer thin films. Uniform dispersion yields maximized interfacial interactions between the ferromagnetic nanoparticles and the piezoelectric polymer matrix leading to the experimental demonstration of large αME values in solution-processed thin films, which can be exploited in flexible and printable multiferroic electronic devices for sensing and memory applications.</p

Comparison and application of top and bottom air decks to improve blasting operations

The blasting operation is an integral part of mines, and it is still being used as the most economical tool to fragment and displace rock mass. Appropriate blast optimization alleviates undesirable side effects, such as ground vibration, air blasts and flyrock, and it and enhances rock fragmentation. Blast optimization can also be effective in reducing the overall mining cost. One way of reducing blasting side effects is to use deck charges instead of continuous ones. The location of the deck(s) is still considered an unanswered question for many researchers. In this study, an investigation was carried out to find an appropriate air deck position(s) within the blast hole. For this, air decks were placed at three different positions (top, middle and bottom) within a blast hole at Cheshmeh-Parvar gypsum and Chah-Gaz iron ore mines to understand and evaluate air deck location impact on blast fragmentation and blast nuisances. The results were compared based on the existing blasting practices at both mines, as well as the air-deck blasting results. The results obtained from the blasting were very satisfactory; it was found that charging with a top air deck, as compared to current blasting practices, causes a decrement in the specific charge, as well as a decrement of 38% in the back break and 50% in flyrock; the average size of fragments obtained from blasting was increased by 26%. Thus, it can be said that the top air deck is more advantageous than the bottom air deck in terms of reducing undesired blasting consequences

Interacting Cosmic Fluids in Brans-Dicke Cosmology

We provide a detailed description for power-law scaling FRW cosmological models in Brans-Dicke theory dominated by two interacting fluid components during the expansion of the universe.Comment: 13 pages, 8 figure

Analysis of the Geopolitics of the Eastern Mediterranean Strategy of Islamic Republic of Iran with Emphasis on Sacred Defense

Geopolitical developments and events are always among the factors that create geopolitical opportunities and challenges for political actors, and political actors seek to make the most of geopolitical opportunities and eliminate or reduce challenges. The iraq war against iran was one of those events that, while creating geopolitical challenges for iran, also provided geopolitical opportunities for it, especially in the eastern mediterranean. As the eastern mediterranean region is considered to be iran's most important sphere of influence today, this article seeks to examine how iraq's imposed war on iran made iran's geopolitical foundations in the region meaningful and how geopolitical opportunities used it.In this article, information has been collected by library and documentary methods and analyzed descriptively-analytically. The results show that the holy defense created geopolitical opportunities for iran in the eastern mediterranean and iran was able to strengthen the foundations of expanding its strategic depth in the eastern mediterranean based on the definition of the geopolitical code of the axis of resistance by using the geopolitical foundations of the eastern mediterranean in the period of the holy defense and become its most important geostrategic region to date

STRUCTURAL INVESTIGATION OF HEIGHT - IRREGULAR- STEEL BRACED STRUCTURES AGAINST PROGRESSIVE COLLAPSE

Considering failure scenarios caused by a progressive collapse of structural systems subjected to special loadings such as explosion, impact, fire, design error and excessive unexpected loads is one of the main challenges that nowadays structural engineers encounter. Progressive collapse is defined as propagation of local failure of a structural member to other members that ultimately leads to failure of the whole structure or a portion of it. The effect of irregularities and the use of viscous damper in structural behavior of steel braced buildings against progressive collapse is the spotlight of this study. Three different steel buildings (5, 9 and 13 stories) with vertical irregularities are considered and analyzed with PERFORM 3D software. In the first part of this study, different scenarios for a sudden elimination of columns are modeled and the effect of irregularities on the pattern of collapse is studied. Then viscous dampers are used in the model to study whether they are able to prevent or mitigate the dynamic effects caused by the progressive collapse. The results show that the corner columns of the buildings are more sensitive than side columns. In addition, installing viscous dampers in the structure can improve its dynamic behavior to some extent