19 research outputs found

    A Comparative Study of AHP and Fuzzy AHP Method for Inconsistent Data

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    In various cases of decision analysis we use two popular methods – Analytical Hierarchical Process (AHP) and Fuzzy based AHP or Fuzzy AHP. Both the methods deal with stochastic data and can determine decision result through Multi Criteria Decision Making (MCDM) process. Obviously resulting values of the two methods are not same though same set of data is fed into them. In this research work, we have tried to observe similarities and dissimilarities between two methods’ outputs. Almost same trend or fluctuations in outputs have been seen for both methods’ for same set of input data which are not consistent. Both method outputs’ ups and down fluctuations are same for fifty percent cases

    NGOs' strategies and the challenge of development and democracy in Bangladesh

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    Recent research Bangladesh has come to embody an interesting paradox. On the one hand, it has experienced rising rates of growth, a slow but steady decline in poverty and impressive progress in terms of social development, outperforming some of its richer neighbours on a number of Millennium Development Goals. On the other hand, it has an abysmal record on governance and was ranked as the world’s most corrupt country for five consecutive years by Transparency International. There is an emerging view that the country’s extremely active development NGO sector has contributed to some of the more positive achievements. The question that this paper sets out to address is why these organisations have not made an equivalent contribution on the governance front. The paper argues that while Bangladesh is reported to have more NGOs per capita than other developing countries, those organisations have gradually abandoned social mobilising and collective action strategies for a narrower focus on service delivery and microcredit provision. Our research with the members of six organisations that straddle the continuum between microfinance and social mobilisation suggests that the specific developmental strategies of these membership-based groups do indeed have consequences for both development and democracy in the country

    Vision, challenges and opportunities for a Plant Cell Atlas

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    With growing populations and pressing environmental problems, future economies will be increasingly plant-based. Now is the time to reimagine plant science as a critical component of fundamental science, agriculture, environmental stewardship, energy, technology and healthcare. This effort requires a conceptual and technological framework to identify and map all cell types, and to comprehensively annotate the localization and organization of molecules at cellular and tissue levels. This framework, called the Plant Cell Atlas (PCA), will be critical for understanding and engineering plant development, physiology and environmental responses. A workshop was convened to discuss the purpose and utility of such an initiative, resulting in a roadmap that acknowledges the current knowledge gaps and technical challenges, and underscores how the PCA initiative can help to overcome them.</jats:p

    Tradeoff in interfacial shear strength and elastic properties in functionalized graphene oxide nanocomposites

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    Graphene oxide (GO) nanoplatelets can be used to reinforce neat resin or the matrix phase of fiber composites for improved mechanical properties. Although the oxygen content levels in GO and reduced graphene oxide (rGO) strongly influence the interface with the polymer, experimental-based optimization of the oxygen content for enhanced composite properties is difficult and time-consuming. Fortunately, molecular dynamics (MD) simulation can be used to efficiently predict the interfacial properties of composite on the molecular level and provide physical insight into the effect of the oxygen content of rGO. In this study, MD is used to predict the elastic properties of rGO/epoxy interfaces and the corresponding interfacial shear strength (IFSS) for different oxygen content levels. The results indicate that increasing levels of oxygen in rGO results in interfaces with a reduced in-plane elastic modulus but a substantially higher IFSS. These results are important for the design of rGO/epoxy composites for specific engineering applications

    Effect of moisture stress on morphological and yield attributes of four sorghum varieties

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    Drought adversely affects growth and yield of crops to various extents. Growing of drought tolerant crops is a good option to obtain economical yields from water stress areas for which quick method to screen drought tolerant plants, particularly in early stages of their growth is important. For this reason, a field experiment was conducted to evaluate the genetical potential to drought tolerance of four sorghum varieties viz Hybrid Sorgo, Safal, BD 731, BD 740. The experiment was laid out in a split plot design with three replications. The plants were grown under three drought levels viz. 100% FC (control), 70% FC and 40% FC. Growth and yield of the Sorghum varieties were found to be decreased gradually with gradual increase in drought levels as compared to the control. This reduction was associated with decreased yield components. Water stress also decreased protein and starch content. The variety BD 740 followed by BD 731 showed the better performance in respect of no. of grains panicle-1, panicle dry weight, 1000-grain weight, grain yield hill-1, protein content and starch content than Hybrid Sorgo and Safal at same water stress condition. Therefore Bangladeshi varieties were found more tolerant than Hybrid Sorgo variety to water stress. Findings of this research will be helpful for the farmers about the beneficial use of resource in terms of managing limited water as well as increasing crop productivity. Finally these research findings would certainly contribute food security in Bangladesh

    Probing the Influence of Surface Chemical Functionalization on Graphene Nanoplatelets-Epoxy Interfacial Shear Strength Using Molecular Dynamics

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    In this work, a characterization study of the interfacial interaction between different types of graphene nanoplatelets and an epoxy matrix is computationally performed. To quantify the discrete mutual graphene–epoxy “interfacial interaction energy” (IIE) within the nanocomposite, molecular dynamics simulations with a reactive force field are performed on a localized model of the suggested nanocomposite. Pull-out molecular dynamics simulations are also performed to predict the interfacial shear strength between the two constituents. The results indicate a significant increase in interfacial adhesion of functionalized nanoplatelets with the hosting epoxy matrix relative to virgin graphene nanoplatelets. The obtained results also demonstrate a dramatic increase in the interfacial interaction energy (IIE) (up to 570.0%) of the functionalized graphene/epoxy nanocomposites relative to the unmodified graphene/epoxy nanocomposites. In the same context, the surface functionalization of graphene nanoplatelets with the polymer matrix leads to a significant increase in the interfacial shear strength (ISS) (up to 750 times). The reported findings in this paper are essential and critical to producing the next generation of lightweight and ultra-strong polymer-based nanocomposite structural materials

    Multiscale modeling for virtual manufacturing of thermoset composites

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    A novel multi-scale Integrated Computational Material Engineering (ICME) approach to predict the evolution of residual stress during curing of thermoset composites is presented. Molecular Dynamics (MD) simulations and Finite Element Analysis (FEA) are used at their respective length scales to determine the cure induced effect on thermoset fiber-reinforced composites. First, curing is simulated at the molecular level to predict the density (shrinkage), Young’s modulus, and yield strength as a function of the degree of cure. Second, the correlation between polymer properties and tensile transverse strength is obtained by modeling the residual stress build-up at the micro-scale. Preliminary results are presented for EPON 862 and EPON 828 epoxy systems at the nano-scale. A theoretical framework for future work is outlined

    Multiscale Process Modeling of Semicrystalline PEEK for Tailored Thermomechanical Properties

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    Polyether ether ketone (PEEK) is a semicrystalline thermoplastic that is used in high-performance composites for a wide range of applications. Because the crystalline phase has a higher mass density than that of the amorphous phase, the evolution of the crystalline phase during high-temperature annealing processing steps results in the formation of residual stresses and laminate deformations, which can adversely affect the composite laminate performance. Multiscale process modeling, utilizing molecular dynamics, micromechanics, and phenomenological PEEK crystal kinetic laws, is used to predict the evolution of volumetric shrinkage, elastic properties, and thermal properties, as a function of crystalline phase evolution, and thus annealing time, in the 306-328 °C temperature range. The results indicate that lower annealing temperatures in this range result in a faster evolution of thermomechanical properties and shrinkage toward the pure crystalline values. Therefore, from the perspective of composite processing, it may be more advantageous to choose the higher annealing rates in this range to slow the volumetric shrinkage and allow PEEK stress relaxation mechanisms more time to relax internal residual stresses in PEEK composite laminates and structures

    Interfacial characteristics between flattened CNT stacks and polyimides: A molecular dynamics study

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    New fabrication methods for carbon nanotube (CNT) networks have been reported, producing self-assembled stacks of flattened CNTs (flCNTs), which could potentially be infiltrated with polymers for enhanced load transfer. In this work, Molecular Dynamics simulation is used to model flCNT/polyimide nano-composites to characterize the interfacial characteristics. Two polyimides, fluorinated and non-fluorinated, are simulated and compared on the basis of interfacial interaction energy, friction force, and transverse strength. The results indicate that the fluorinated polyimide exhibits a lower interaction energy, higher frictional force, and higher peak strength in transverse tension relative to the non-fluorinated polyimide, which is likely due to the steric hindrance and interlocking of the fluorine atoms. The presence of polyimide significantly enhances the interfacial friction over bare incommensurate flCNTs. This study is intended to drive the design of new light-weight, high-strength materials involving flCNTs for aerospace structural applications

    Grid-Vehicle-Grid (G2V2G) Efficient Power Transmission: An Overview of Concept, Operations, Benefits, Concerns, and Future Challenges

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    Electric vehicles (EVs) are proportionally increasing day-by-day with the inclusion of upgraded technology toward considered zero carbon emission efforts. To mitigate greenhouse gas emissions from the transportation sector, grid-to-vehicle (G2V) and vehicle-to-grid (V2G) technologies are getting significant attention nowadays. EVs equipped with modern technology can help to stabilize the power grids through load-balancing topology during peak hours. The improvement in EVs can support the surroundings in numerous ways, such as power grid voltage and frequency regulations, harmonics distortions, accessible solar energy implemented to the grids, and peak load stabilizations. This literature review analyzes G2V and V2G impacts in more depth, namely opportunities, improvements in strategies, operation, control, issues, and new technology adoptions. This paper emphasizes the possibilities of bringing advancements in EV technology, smooth operations between grids and EVs, fast bidirectional charging and discharging scopes, control of grids and EVs structures, issues, benefits, pitfalls, challenges, and recommendations
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