99 research outputs found
A‎ ‎solution ‎procedure ‎to ‎solve‎ multi-objective linear fractional programming problem in neutrosophic fuzzy environment
In this paper, an attempt has been taken to develop a method to solve the neutrosophic multiobjective linear fractional programming (NMOLFPP) problem. In the first step of our method, the problem is linearized based on some transformations. Then, the linearized model is reduced to a crisp multi-objective programming problem with the help of the accuracy function for each objective. In the following, we extended Zimmerman’s approach to maximize the truth membership and minimize the indeterminacy and falsity membership functions in the solution procedure. Finally, to illustrate the proposed approach, a numerical example is included
A weighted goal programming approach to fuzzy linear regression with quasi type-2 fuzzy input-output data
This study attempts to develop a regression model when both input data and output data are quasi type-2 fuzzy numbers. To estimate the crisp parameters of the regression model, a linear programming model is proposed based on goal programming. To handle the outlier problem, an omission approach is proposed. This approach examines the behavior of value changes in the objective function of proposed model when observations are omitted. In order to illustrate the proposed model, some numerical examples are presented. The applicability of the proposed method is tested on a real data set on soil science. The predictive performance of the model is examined by cross-validation.Publisher's Versio
Numerical analysis of fourth-order boundary value problems in fluid mechanics and mathematics
Unballanced performance of parallel connected large format lithium ion batteries for electric vehicle application
The integration of cells that exhibit differing electrical characteristics, such as variations in energy capacity and internal resistance can degrade the overall performance of the energy storage system (ESS) when those cells are aggregated into single battery pack. When cells are connected electrically in parallel, such variations can lead to significant individual differences in battery load current, state of charge (SOC) and heat generation. Further, if consideration is given to small variations in cell interconnection resistance, the detrimental effect on load imbalance is amplified. Given that cell resistance is known to be a function of both SOC and temperature, the impact of the imbalance is compounded as the performance of cells further diverge under load. During extended periods of excitation, variations in cell depth of discharge (DOD) and the occurrence of temperature gradients across the parallel connection will accelerate cell ageing and, if unmanaged, may present safety concerns such as the onset of thermal runaway. In this paper the impact of varied SOC and temperature on the overall performance of the ESS with parallel connected cells has been investigated. The results highlight that 8% variation in the initial SOC can result in a current difference of 62% among the cells, while a temperature variation of 8℃ results in a current deviation of 14%. Moreover, it was found that the interconnection resistance can significantly increase the inhomogeneity
Battery cycle life test development for high-performance electric vehicle applications
High Performance (HP) battery electric vehicle (BEV) and racing applications represent significantly different use cases than those associated with conventional consumer vehicles and road driving. The differences between HP use cases and the duty-cycles embodied within established battery test standards will lead to unrepresentative estimates for battery life and performance within a HP application. A strategic requirement exists to define a methodology that may be used to create a representative HP duty-cycle. Within this paper two methods HP duty-cycle design are evaluated and validated. Extensive simulation results into the electrical performance and heat generation within the battery highlight that the new HP duty-cycles provide a more representative duty-cycle compared to traditional battery test standards. The ability to more accurately predict the performance requirements for the battery system within this emerging and strategically important BEV sector will support a range of engineering functions. In addition, the ability to more accurately define the use-case for a HP-BEV will underpin ongoing experimentation and mathematical modelling to quantify the associated cell ageing and degradation that may occur within HP vehicle applications
A comparative study on different cooling strategies for lithium-ion battery cells
In this study a 1D electrochemical-thermal model is coupled with a 3D thermal model in order to predict the heat generation and corresponding temperature distribution in a battery cell. The developed model is verified
against experimental data for a 20 Ah lithium iron phosphate (LFP) which is operating at 20 °C ambient
temperature. The model is then adjusted to accommodate for 10Ah and 40 Ah cells by decreasing and
increasing the surface area of each cell as well as the tab dimensions. The temperature distribution of the
different cells are studied employing fin cooling as well as indirect liquid cooling system. Simulation results
highlight that the temperature gradient within the surface of the 40 Ah cell is almost 1.9 and 1.3 times that
of the 10 Ah and 20 Ah cells, respectively. Moreover, it is found that the fin cooling method by employing
aluminium plates between the cells is not a good choice when applied to large format batteries. Whereas, by
employing the indirect liquid cooling, a very uniform temperature along with low temperature gradient is
achieved even under high discharge rate. When the two cooling units have the same volume, the obtained
volumetric temperature gradient with fin cooling is equal to 20.5, 27.5 and 34.7 °C for the 10 Ah, 20 Ah and
40Ah respectively, whereas the corresponding value in case of the indirect cooling is 4.7, 5.2 and 6.2 °C
respectivel
Effect of insulin and cinnamon extract on spatial memory and gene expression of GLUT1, 3, and 4 in streptozotocin-induced Alzheimer’s model in rats
Objective(s): Since diminished hippocampal insulin signaling leads to memory impairment, insulin resistance and hyperinsulinemia are probably associated with Alzheimer’s disease (AD). The effect of intracerebroventricular injection of insulin (Ins) and oral cinnamon extract (Cinn) on glucose transporter (GLUT) 1, 3, and 4 gene expressions in the hippocampus and spatial memory in a streptozotocin (STZ)-induced AD rat model was investigated in the present study.Materials and Methods: Fifty-six adult male Sprague-Dawley rats (280±20 g) were allocated into eight distinct groups (n=7) of five controls (negative, Ins, Cinn, Ins+Cinn, and STZs) and three treatments (STZ+ Ins, STZ+ Cinn, and STZ+ Ins + Cinn). Single dose STZ 4  mg/kg (icv), Cinn at a dose of 200 mg/ kg (orally for 14 days), and Ins 5 mIU/5 µl (icv for 14 days) were administered in the defined groups. To evaluate the behavioral performance the animals were subjected to the Morris Water Maze (MWM) test. The level of mRNA expression of GLUTs was evaluated by the Real time-PCR method. Results: In the STZ+Cinn+Ins group, the performance of animals in the MWM test was improved and the over-expression of GLUTs genes in hippocampal tissue was observed. The results of Ins and Cinn synergist treatment groups revealed improvement in the behavioral tests and gene expression compared with Ins and Cinn treatment groups (P<0.001).Conclusion: Administration of Ins and Cinn has a positive effect on the function of the AD rat model. To clarify the effect of Ins and Cinn extract on the GLUTs investigated in this study, it is essential to evaluate their influence on the protein levels
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