scholarly journals On Attempting to Create a Virtual Laboratory for Application-Oriented Microstructural Optimization of Multi-Phase Materials

2021 ◽  
Vol 11 (4) ◽  
pp. 1506
Author(s):  
Faisal Qayyum ◽  
Sergey Guk ◽  
Rudolf Kawalla ◽  
Ulrich Prahl

Physics-based and phenomenological crystal plasticity numerical simulations provide an opportunity to develop microstructurally informed models for multi-phase material. The Düsseldorf Advanced Material Simulation Kit (DAMASK) has been developed as a flexible tool for modeling and studying the several deformation mechanisms of such materials at the microscopic and macroscopic scales. In the recent past, several methodologies and techniques were developed for obtaining or constructing microstructural details and calibrating the physics-based model parameters for single-phase and multi-phase materials. Combining and standardizing the devised methods with an appropriate database can help establish a virtual laboratory to analyze the effect of microstructural attributes on the mechanical behavior of multi-phase materials. This article deals with the comprehensive background of the developed techniques and methods for the multi-phase materials class by the current research group. The combinations of different experimental and numerical techniques to validate results are explained along with the advantages and limitations. The ideas of combining the different available tools and the associated challenges are discussed. The article presents some recent work related to the phase parameters identification of the multi-phase materials and detailed insight into the obtained results.

2019 ◽  
Author(s):  
Joseph John Pyne Simons ◽  
Ilya Farber

Not all transit users have the same preferences when making route decisions. Understanding the factors driving this heterogeneity enables better tailoring of policies, interventions, and messaging. However, existing methods for assessing these factors require extensive data collection. Here we present an alternative approach - an easily-administered single item measure of overall preference for speed versus comfort. Scores on the self-report item predict decisions in a choice task and account for a proportion of the differences in model parameters between people (n=298). This single item can easily be included on existing travel surveys, and provides an efficient method to both anticipate the choices of users and gain more general insight into their preferences.


Sexualities ◽  
2020 ◽  
pp. 136346072098169
Author(s):  
Aidan McKearney

This article focuses on the experiences of gay men in the rural west and northwest region of Ireland, during a period of transformational social and political change in Irish society. These changes have helped facilitate new forms of LGBTQI visibility, and local radicalism in the region. Same-sex weddings, establishment of rural LGBT groups and marching under an LGBT banner at St Patricks Day parades would have been unthinkable in the recent past; but they are now becoming a reality. The men report continuing challenges in their lives as gay men in the nonmetropolitan space, but the emergence of new visibility, voice and cultural acceptance of LGBT people is helping change their lived experiences. The study demonstrates the impact of local activist LGBT citizens. Through their testimonies we can gain an insight into the many, varied and interwoven factors that have interplayed to create the conditions necessary for the men to: increasingly define themselves as gay to greater numbers of people in their localities; to embrace greater visibility and eschew strategies of silence; and aspire to a host of legal, political, cultural and social rights including same-sex marriage. Organic forms of visibility and local radicalism have emerged in the region and through an analysis of their testimonies we can see how the men continue to be transformed by an ever-changing landscape.


2006 ◽  
Vol 519-521 ◽  
pp. 71-78 ◽  
Author(s):  
J. David Embury ◽  
Warren J. Poole ◽  
David J. Lloyd

The process of work hardening in aluminum alloys is important from the viewpoint of formability and the prediction of the properties of highly deformed products. However the complexity of the strengthening mechanisms in these materials means that one must carefully consider the interaction of dislocations with the detailed elements of the microstructure and the related influence of the elements on dislocation accumulation and dynamic recovery. In addition, it is necessary to consider the influence of the work hardening process at various levels of plastic strain. This permits the possibility of designing microstructure for tailored plastic response, e.g. not simply designed for yield strength but also considering uniform elongation, spring-back, ductility etc. This presentation will explore the concept of identifying the various interactions which govern the evolution of the work hardening and their possible role in alloy design.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Abdulaziz Al Sultan ◽  
Ericka Teleg ◽  
MacKenzie Horn ◽  
Piyush Ojha ◽  
Linda Kasickova ◽  
...  

Background: CTA spot sign is a predictor of intracerebral hemorrhage (ICH) expansion. This sign can fluctuate in appearance, volume, and timing. Multiphase CTA (mCTA) can identify spot sign through 3 time-resolved images. We sought to identify a novel predictor of follow up total hematoma expansion using mCTA. Methods: This cohort study included patients with ICH between 2012-2019. Quantomo software was used to measure total hematoma volume (ml) from baseline CT & follow-up CT/MRI blinded to spot sign in 3 mCTA phases. Spot sign expansion was calculated by subtracting 1 st phase spot sign volume from 2 nd phase spot sign volume measured in microliters. Results: 199 patients [63% male, mean age 69 years, median NIHSS 11, IQR 6-20] were included. Median baseline ICH volume was 16.1 ml (IQR 5-29.9 ml). Amongst all three mCTA phases, spot sign was best detected on the 2nd phase (23% vs 17.5% 1 st phase vs 22% 3 rd phase). In multivariable regression, spot sign expansion was significantly associated with follow up total hematoma expansion (OR: 1.03 per microliter of spot sign expansion, p=0.01). Figure 1 shows the predicted total hematoma expansion by spot sign expansion. mCTA spot sign had a higher sensitivity for predicting total hematoma volume expansion than single-phase CTA (reported in meta-analysis of 14 studies), 86% vs 53%, respectively, while both having similar specificity, 87% vs 88%, respectively. Conclusion: Spot sign expansion on mCTA is a novel predictor of total hematoma expansion and could be used to select patients for immediate therapeutic intervention in future clinical trials. Using mCTA improves sensitivity while preserving specificity over single-phase CTA.


2018 ◽  
Vol 20 (3) ◽  
pp. 362-372 ◽  
Author(s):  
Katharina Schregel ◽  
Ioannis Tsogkas ◽  
Carolin Peter ◽  
Antonia Zapf ◽  
Daniel Behme ◽  
...  

Author(s):  
Hafiz Muhammad Yasir Naeem ◽  
Aamer Iqbal Bhatti ◽  
Yasir Awais Butt ◽  
Qadeer Ahmed

Limited capacity and short life cycle of a battery are the major impediments in development of practical Electric Vehicles (EVs). Eco-driving is an optimization technique through which a velocity trajectory that consumes minimum energy is advised to the driver. However, presence of traffic signals to control large traffic network degrades the performance of eco-driving; as applying brakes to stop and then maximum re-acceleration to restart a trip consumes lot of energy. Eco-driving problem with multiple traffic signals and static model of battery has been proposed as Two Point Boundary Value Problem (TPBVP). TPBVP fails to solve multi-phase problem as a single phase due to discontinuity of the co-states at the junction, that is, start of a new phase. This paper investigates an optimal solution with both EV and battery dynamics in the presence of multiple traffic signals as Multi Point Boundary Value Problem (MPBVP) using multiple shooting technique. Traffic signals come at some intermediate points of a trip. MPBVP ensures continuity at the junction to solve the multi-phase problem as a single phase through inter dependencies between each phases. Goal of this work is not only to solve constrained eco-driving problem with traffic signals but also include charging and discharging limits on battery that indirectly improves battery’s life cycle. Results indicate that EV has crossed all the traffic signals during their green duration without applying brakes with also satisfying all the other constraints and continuity condition. Moreover, it can be seen that energy consumption using MPBVP is also marginally lesser as compared to TPBVP.


Fractals ◽  
2021 ◽  
Author(s):  
Wenhui Song ◽  
Masa Prodanovic ◽  
Jun Yao ◽  
Kai Zhang ◽  
Qiqi Wang

2021 ◽  
Author(s):  
Michael R Konopczynski ◽  
Mojtaba Moradi

Abstract The design and method of operation of Autonomous Inflow Control Devices are reviewed, including single-phase and multi-phase flow performance. Next, the multi-phase flow of fluids in the annular space between circular conduits is examined based on published information and flow pattern maps. This information is brought together in a thought experiment describing how AICDs and well performance will react to the segregation of fluids upstream of the flow control device, and the potential impact that the degree of restrictiveness on unwanted effluents can affect the flow performance of the reservoir and well. Finally, the impact on well flow performance is quantified by computer modelling of the reservoir inflow performance, annular flow performance, and AICD performance. The sensitivity of well productivity is assessed for multiple flow scenarios adjusting several model parameters, including type and number of AICDs per zone, GOR, water cut, flow rate, and well completion size. Although the concept of an AICD that completely shuts off gas and/or water production sounds appealing to those wishing to eliminate the production of unwanted effluents, a full understanding of the dynamics of inflow from the reservoir and phase segregation in the wellbore is necessary to evaluate the impact of highly restrictive AICDs on well productivity. With annular separation, even small water cuts or limited amounts of free gas flowing into the wellbore can cause most of the highly restrictive AICDs in a multiple device zone to shut, greatly impacting the oil productivity of the zone and the well. Using AICDs that are not as restrictive of the unwanted effluents allows the operator to continue to produce oil at significant rates when associated with low water cuts or reduced free-gas GORs. A workflow for determining the optimum degree of restrictiveness is proposed and demonstrated.


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