ODEI Spotlight: Career Services' 2021 Engineering Career Day (Virtual Career Fair)
2021-09-14 11:00 - 16:00 (America/New_York) | PA
Calling all Penn Engineers, candidates in STEM fields and those interested in engineering and technology – you’re warmly invited to Engineering Career Day 2021!!
Organizations participating are seeking undergraduate and graduate degree candidates, postdoctoral fellows and young alumni for internships and full-time opportunities! When they register, they indicate the majors and academic levels of the candidates they’re hiring, as well as indicate the type of roles they have to offer and their status on sponsoring international candidates!
PLEASE NOTE: Student Registration begins Tuesday September 7, 2021 at 12:00 PM ET. Both large-group information sessions (30 minutes each) and 1-to-1 meetings between students and representatives from each organization (10 minutes each) will be available to attendees, but you MUST register in advance of the event (beginning at the above date/time), and select each group session and/or 1-to-1 session you’d like to attend. Space is limited based on how many individual representatives are offered by the organization (anywhere from 1 to 15 representatives per organization) It is to your advantage to be prepared in advance and register for your selected sessions as early as possible, for participation is first-come, first-served.
See these step-by-step details on managing your registration and signing up for sessions for additional information.
When you register for the event, update your Handshake profile completely as employers will be able to see it.
Be sure to complete all fields in your Handshake profile including job and industry interests.
To sign up for Group or 1:1 sessions, your profile privacy setting will need to be set to “Community” or “Employers”.
Because employers can set requirements on the following fields for eligibility to sign up for 1:1 meetings in the virtual career fairs, make sure that the basics are accurate: graduation date, school year, major, GPA and work authorization. Click on the pencil icon in your Handshake profile to make any necessary changes. Students who have not yet declared a major or concentration should feel free to add their intended choice. Since only one school automatically transfers into Handshake, dual degree students should manually add their second school. Note to transfer students, first-year graduate students, certain PhD students, and post-docs: If you don’t have a Penn GPA, put in the GPA from your previous institution or previous degree for the career fairs so that you are not screened out based on not having a GPA in the system.
Engineering Career Day is open to all Penn students served by the Career Services office. Please see the Career Services Policies page of our website for details.
For information directly from Handshake on how to best update your Handshake account and prepare for the event, including what you’ll want to understand about each step of the registration process, please see: https://support.joinhandshake.com/hc/en-us/articles/360049934274

CEMB Future Leaders Seminar: “Exchange of molecular and cellular information: A hybrid model connecting regulatory interactions with stem cell divisions in the root”
2021-09-15 11:00 - 12:00 | https://upenn.zoom.us/j/96715197752
Launched in May 2021, the Future Leaders in Mechanobiology is a monthly seminar series featuring up-and-coming leaders in mechanobiology–PhD students and postdocs from a wide range of fields, backgrounds, and institutions. By providing an international stage to share one’s work and opportunities to interact with researchers at all career stages, we aim to create an inclusive and valuable series for early-stage researchers and the mechanobiology community as a whole.
Register Here to access the Zoom Link and visit the CEMB website for more information.

CBE Seminar: "Design of Sequential Catalytic Solvolysis Process for Selectively Deconstructing Waste Plastics"
2021-09-15 15:30 - 16:30 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Abstract
Environmental plastic problems have recently arisen as a core subject of global debate and concern. Plastic products for multiple applications have risen from 1.7 million in 1950 to 368 million tons in 2019 and are projected to reach 1,800 million tons by 2050. Recycling plastics and enabling the circular economy are essential to mitigate the accumulation of plastic wastes. However, the grand challenge of recycling waste plastics is the heterogeneity of comingled plastic wastes, containing various incompatible polymers, such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyamide (PA), etc., and additives and contaminants. This lecture will discuss the catalytic solvolysis processes that convert various plastics, such as polyesters, polyamides, and polyolefins, to value-added products such as monomers or hydrocarbon fuels and lubricants. Furthermore, a sequential catalytic solvolysis process, in which an individual polymer or classes of polymers in a plastic mixture is selectively deconstructed stage-by-stage, is designed. This novel process may enable a cost-competitive chemical upcycling method for processing comingled plastic wastes without laborious physical sorting.

MSE Seminar: "From Conducting Polymers to Conducting Molecular Search A Materials Science Pathway to the Perkin Medal"
2021-09-16 12:30 - 13:30 | Auditorium, LRSM Building, 3231 Walnut Street, Philadelphia, PA, 19104, United States
The Perkin Medal that Dr. Frommer is receiving in September cites her lifetime scientific accomplishments in electronically conducting polymers and atomic force microscopy. The reality is these are but two points on a continuum of using chemistry to reveal the molecular underpinnings of material properties.
This talk will take a path through studies to explore the evolution of her studies of materials and in-situ measurements of molecular interactions that lead to the control of matter on the nanoscale.
The thread that runs through these studies is using chemical understanding to document and manipulate material properties in the era of nanotechnology.
Diverse fields will be on the itinerary, from macromolecular solvation to 3D nanoprinting to data curation of the molecular universe.

BE Seminar: "Regenerative Engineering: Enabling Regenerative Medicine" (Guillermo Ameer)
2021-09-16 15:30 - 16:30 | Moore 216, 200 S. 33rd Street, Philadelphia, PA, 19104, United States
This seminar will be held live and broadcast via zoom – check your email for link or contact ksas@seas.upenn.edu.
Regenerative engineering is the convergence of advances in materials science, physical sciences, stem cell and developmental biology, and translational medicine to develop tools that enable the regeneration and reconstruction of tissue and organ function. I will describe how materials can be engineered to play a critical role in treating tissue and organ defects and dysfunction by promoting cellular processes that are conducive to regeneration. Applications of these materials to address the complications of diabetes and orthopaedic injuries will be discussed.

Fall 2021 GRASP Seminar: GRASP Research Overview – Day 1
2021-09-17 10:30 - 11:45 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
GRASP Lab Faculty confirmed presentations (where appropriate their presenters)…
Mark Yim – Welcome & Introduction
Pratik Chaudhari
Kostas Daniilidis (presented by Kenneth Chaney)
Eric Eaton
Dinesh Jayaraman
Dr. Vijay Kumar (presented by Steven Chen)
Marc Miskin
Michael Posa (presented by Matt Halm)
CJ Taylor

CEMB: Academic Job Search During the Pandemic
2021-09-17 11:00 - 12:00 | https://upenn.zoom.us/j/96715197752
The Center for Engineering Mechanobiology Trainee Leadership Council (TLC) presents a professional development event for graduate students and postdocs considering an academic career. We will talk with three UPenn alumni who have successfully navigated the academic job search during the pandemic. Hear what the search process was like and learn tips for your own search.

PICS Colloquium: "Protein dynamics and energy landscape engineering"
2021-09-17 14:00 - 15:00 | Zoom – email kathom@seas.upenn.edu
Abstract: Experiments only reveal a few of a protein’s structures with the atomic detail required to rationally engineer mutations and drugs. However, a protein actually has a vast landscape of uncharted conformations that present untapped opportunities for manipulating its function. My lab is developing simulation methods, called Markov state models (MSMs), that provide unprecedented access to proteins’ energy landscapes. We are employing these methods to understand how proteins function, to identify “cryptic” drug binding sites, and to design new drugs and proteins. Importantly, we have also developed a suite of experimental techniques for testing our predictions. This highly general platform is enabling progress on numerous scientific fronts. This talk will focus on how we are using this platform to understand and combat viruses like SARS-CoV-2 and Ebola.

BE Doctoral Dissertation Defense: "Evaluating the Efficacy of Prone Position and Therapeutic Treatments in ARDS Lungs Using Computed Tomography" (Yi Xin)
2021-09-17 15:00 - 17:00 | Donner-Grice Auditorium
The Department of Bioengineering at the University of Pennsylvania and Dr. Rahim Rizi are pleased to announce the Doctoral Dissertation Defense of Yi Xin.
Title: Evaluating the Efficacy of Prone Position and Therapeutic Treatments in ARDS Lungs Using Computed Tomography
Date: September 17, 2021
Time: 3:00pm
Location: Donner-Grice Auditorium (HUP Dulles Building 2nd floor) and via
Zoom: https://pennmedicine.zoom.us/j/3123106143?pwd=[REDACTED]

PSOC@Penn Seminar: "Glycosaminoglycans Modulate Long-Range Mechanical Communication Between Cells in Collagen Networks" (Xingyu Chen)
2021-09-20 12:00 - 13:00 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
Room: Towne 225/Raisler Lounge
For zoom link, contact manu@seas.upenn.edu.

Treeswift and the Penn Journey: From Research to Startup
2021-09-20 14:00 - 15:00 | https://upenn.zoom.us/j/96715197752
Treeswift is building the next generation of forest monitoring systems, providing forest stakeholders with precision data and analyses that are easily accessible and flexible. Treeswift’s services are used in carbon capture estimation, timber value estimation, deforestation monitoring, advanced growth forecasting, and forest management.
Treeswift makes complex forests easier to manage using robotics and artificial intelligence. This event is a talk and discussion by Treeswift CEO (and Penn CIS PhD student) Steven Chen on his experience of bringing academic research out of the lab and into the world.

PSOC@Penn Seminar: "Harnessing Biochemistry and Engineering to Visualize Metabolism" (Kayvan R. Keshari)
2021-09-20 16:00 - 17:00 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Oncogenic transformation has been shown to have a dramatic impact on the metabolic state of the cell. Recent reports have demonstrated that specific alterations in oncogenes and signaling pathways results in increases in pathway flux as well as diversion of substrates. Moreover, there is an argument that changes in metabolism can directly affect cell fate and thus promote oncogenesis. Interrogation of these pathways in relevant systems has been hindered though by lack of technologies capable of monitoring metabolism. Hyperpolarized magnetic resonance addresses a fundamental limitation of MRI for interrogating metabolic substrates, sensitivity. Using this approach, endogenous metabolic substrates can be converted into imaging probes to follow metabolic reactions in living systems. Utilizing this imaging as well as a wide range of biochemical tools and engineering approaches, one can develop strategies to mechanistically interrogate metabolic flux. This talk will focus on the combination of such approaches, demonstrating the synergy of new probes and platforms, to reveal metabolic mechanisms as well as their translation to humans.

CBE Joint Seminar: "Harnessing Biochemistry and Engineering to Visualize Metabolism"
2021-09-20 16:00 - 17:00 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
ABSTRACT
Oncogenic transformation has been shown to have a dramatic impact on the metabolic state of the cell. Recent reports have demonstrated that specific alterations in oncogenes and signaling pathways results in increases in pathway flux as well as diversion of substrates. Moreover, there is an argument that changes in metabolism can directly affect cell fate and thus promote oncogenesis. Interrogation of these pathways in relevant systems has been hindered though by lack of technologies capable of monitoring metabolism. Hyperpolarized magnetic resonance addresses a fundamental limitation of MRI for interrogating metabolic substrates, sensitivity. Using this approach, endogenous metabolic substrates can be converted into imaging probes to follow metabolic reactions in living systems. Utilizing this imaging as well as a wide range of biochemical tools and engineering approaches, one can develop strategies to mechanistically interrogate metabolic flux. This talk will focus on the combination of such approaches, demonstrating the synergy of new probes and platforms, to reveal metabolic mechanisms as well as their translation to humans.

MEAM Seminar: "Active Colloids in Nematics for Micro-robotics and Reconfigurable Systems"
2021-09-21 10:00 - 11:30 | Zoom – Email MEAM for Link, peterlit@seas.upenn.edu
Active colloids in nematic liquid crystals are exciting vehicles for materials manipulation. Colloid shape, surface chemistry and dynamic displacement can be designed to introduce defects whose non-linear dynamics generate new modalities of motion and interaction. These effects rely on energy conversion mechanisms, in which active colloids with tailored surface functionalization and shape seed defects and distortions in the nematic liquid crystal domain. Once the colloid moves, e.g., under the action of an external field, these defects undergo complex, non-linear rearrangements with implications for colloid motion. Interactions emerge that differ strikingly in range and form from their static counterparts. I describe our current state of understanding of these systems, their application and our vision for future work in the domain. These interactions provide a rich toolkit for hybrid top-down, bottom-up assembly schemes in which microrobots based on active nematic colloids exploit these far-from-equilibrium topological structures as tools for micro-robotic tasks including building and reconfiguring structures.

VIPER Lightning Talks: Addressing Energy Challenges Through Undergraduate Research
2021-09-21 12:30 - 13:30 | https://upenn.zoom.us/j/96715197752
The Vagelos Integrated Program in Energy Research (VIPER) is a dual-degree undergraduate program at the University of Pennsylvania that prepares students to be the next generation of energy leaders. Join us to learn more about the work they are doing to address energy and sustainability challenges through their undergraduate research.
Graduates of the program gain an interdisciplinary perspective as they earn both a Bachelor of Arts from the School of Arts and Sciences as well as a Bachelor of Science in Engineering from the School of Engineering and Applied Science. VIPER students also participate in a dedicated on-ramp into research and conduct fully-funded, cutting-edge research experiences with renowned Penn faculty throughout their time in college. If you are interested in learning more about the program, visit http://viper.upenn.edu. VIPER accepts transfer applications from first-year Penn students.

Plastic Waste: Global Challenges and Opportunities
2021-09-21 15:00 - 16:00 | https://upenn.zoom.us/j/96715197752
This event will be a panel discussion on polymer waste as a global societal challenge; recent efforts on polymer upcycling will be discussed.

CBE Seminar: “Engineering the Crystallization of Water Using Molecular and Biomolecular Agents”
2021-09-22 15:30 - 16:30 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Abstract
The crystallization of water affects various processes, both globally and in our daily lives. Ice crystals cause freezing and death when they grow in the extracellular fluids of organisms living in sub-freezing conditions. Similarly, the formation of gas hydrates in flowlines transporting gas/oil causing safety and economic risks, and the release of methane from gas hydrates to the atmosphere contributing to global warming. Antifreeze proteins (AFPs) are evolution’s answer to the problem of freezing in organisms, and some synthetic inhibitors of gas hydrates are currently in use. However, the mechanisms by which these natural and synthetic inhibitors work remain largely unclear.
My lab is using a unique combination of cold-stages (millikelvin resolution), fluorescence microscopy and microfluidics to study the effects of molecular agents on the crystallization of water. In my talk, I will describe how AFPs: a) bind to ice and inhibit its growth, b) synergistically enhance their activity, and c) accelerate and inhibit ice growth. I will then present our work with a synthetic dye molecule that assembles in solution and forms supramolecular assemblies that inhibit both ice and clathrate hydrates.

Global Discovery Series: Climate Change and Cities
2021-09-23 12:00 - 13:00 | https://upenn.zoom.us/j/96715197752
Professor Michael Weisberg, Director of Post-Graduate Programs at the Perry World House, and Perry World House Visiting Fellow and Penn Alumna Lolita Jackson talk about the impacts of climate change at the municipal level. While vastly different in scale, New York City and the Galápagos Town of Puerto Baquerizo Moreno (population 8000), the towns in which they have worked for many years, face similar threats: sea level rise, increased flooding from storms, and population growth. They also face the challenge of having their needs prioritized in the national and international arena. Join us for a lively conversation about climate change and these two cities.
This event is sponsored by Penn Alumni and Penn Engineering.

MSE David P. Pope Distinguished Lecture: "Skin-Inspired Organic Electronics"
2021-09-23 12:30 - 13:30 | PA
Skin is the body’s largest organ, and is responsible for the transduction of a vast amount of information. This conformable, stretchable, self-healable and biodegradable material simultaneously collects signals from external stimuli that translate into information such as pressure, pain, and temperature. The development of electronic materials, inspired by the complexity of this organ is a tremendous, unrealized materials challenge. However, the advent of organic-based electronic materials may offer a potential solution to this longstanding problem. Over the past decade, we have developed materials design concepts to add skin-like functions to organic electronic materials without compromising their electronic properties. These new materials and new devices enabled arrange of new applications in medical devices, robotics and wearable electronics. In this talk, Dr. Bao will discuss basic material design concepts for realizing stretchable, self-healable and biodegradable conductive or semiconductive materials. She will show our methods for scalable fabrication of stretchable electronic circuit blocks. Finally, she will show a few examples of applications we are pursuing uniquely enabled by skin-like organic electronics when interfacing with biological systems, such as low-voltage electrical stimulation, high-resolution large area electrophysiology, “morphing electronics” that grows with biological system and genetically targeted chemical assembly – GTCA.

BE Seminar: "Material Design for Lymph Node Drug Delivery and Immunomodulation" (Susan Thomas)
2021-09-23 13:30 - 16:30 | Moore 216, 200 S. 33rd Street, Philadelphia, PA, 19104, United States
This event will be held live and broadcast on zoom – link coming soon.
Lymph nodes mediate the co-mingling of cells of the adaptive system to coordinate adaptive immune response. Drug delivery principles and technologies our group has developed to leverage the potential of lymph nodes as immunotherapeutic drug targets to augment anti-cancer therapeutic effects will be described.

ODEI Spotlight: GIC Open House, Welcome and Introduction to Native and Indigenous Community
2021-09-23 18:00 - 20:00 | PA
Welcome and Introduction to Native and Indigenous Community
Date: Thursday, September 23, 2021
Time: 6:00 p.m. – 8:00 p.m. EST
Location: Greenfield Intercultural Center, 3708 Chestnut Street

CBE Graduate Student Symposium (GSS)
2021-09-24 08:00 - 18:00 | Singh Center for Nanotechnology, 3205 Walnut Street, Philadelphia, PA, 19104, United States

Fall 2021 GRASP Seminar: GRASP Research Overview – Day 2
2021-09-24 10:30 - 11:45 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
GRASP Lab faculty confirmed presentations (where appropriate their presenters)…
Dr. Ani Hsieh – Welcome & Introduction
Dr. Michelle Johnson (presented by Frances Sowande)
Dr. Dan Koditschek (presented by Wei-Hsi Chen)
Dr. George Pappas (presented by Yiannis Kantaros)
Dr. Rahul Mangharam
Dr. Nikolai Matni
Dr. Robert Stuart-Smith
Dr. Cynthia Sung
Dr. James Pikul

Sustainability and the Building Environment: Building Materials and Cooling Strategies that Combat a Warming Planet
2021-09-24 12:00 - 13:00 | https://upenn.zoom.us/j/96715197752
Air conditioning today accounts for nearly 20% of the total electricity used in buildings around the world and over 10% of the total primary energy use in the US. Already a major contributor to climate change, cooling energy demand is predicted to significantly increase over the next decades with urbanization, population growth and global warming. Heat stress is a major environmental justice concern, dis-proportionally impacting disadvantaged communities. We must find sustainable and equitable cooling alternatives to replace current building practices which only exacerbate the environmental crisis.
The webinar will include an overview of research by Penn faculty members on alternative low-energy cooling strategies and innovative building materials inspired by nature. This will be followed by case-studies of built projects presented by industry leaders in the field.

Penn Electric Racing and the Future of EV Engineering
2021-09-24 14:00 - 15:00 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Penn Electric Racing is Penn’s award winning Formula SAE electric racing team. Every year, we design and manufacture an electric racecar and compete against schools from across the country. This experience gives our students invaluable skills, allowing us to jumpstart careers in the EV industry. In this event, we will discuss the role of EV’s in the climate crisis and how Penn Electric Racing uniquely prepares our students to contribute to this industry.

PICS Colloquium: "How reproducible is your research?"
2021-09-24 14:00 - 15:00 | Zoom – email kathom@seas.upenn.edu
Abstract: Each year vast international resources are wasted on irreproducible research. The scientific community has been slow to adopt standard software engineering practices, despite the increases in high-dimensional data, complexities of workflows, and computational environments. Here we show how scientific software applications can be created in a reproducible manner when simple design goals for reproducibility are met. We describe the implementation of a test server framework and 40 scientific benchmarks, covering numerous applications in Rosetta bio-macromolecular modeling. High performance computing cluster integration allows these benchmarks to run continuously and automatically. Detailed protocol captures are useful for developers and users of Rosetta and other macromolecular modeling tools. The framework and design concepts presented here are valuable for developers and users of any type of scientific software and for the scientific community to create reproducible methods. Specific examples highlight the utility of this framework, and the comprehensive documentation illustrates the ease of adding new tests in a matter of hours.

MEAM Seminar: "Kirigami: Programming Cutting and Folding from Microscale to Meter Scale"
2021-09-28 10:00 - 11:30 | Zoom – Email MEAM for Link, peterlit@seas.upenn.edu
Programmable shape-shifting materials can take different physical forms to achieve multifunctionality in a dynamic and controllable manner. By introducing holes and cuts in 2D sheets, we demonstrate dramatic color and shape change and super-conformability via collapsing or expanding of the hole arrays in the micro- and macroscales. When choosing the cuts and geometry correctly, we show folding into the third dimension, known as kirigami. By programming the geometry of cuts and folding angles, we explore their potential applications in water harvesting, super-stretchable and shape conformable medical devices.

CBE Seminar: "Shake It Off: Dynamics of Bacterial Adhesions at Interfaces"
2021-09-29 15:30 - 16:30 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Abstract
Control over adhesion of bacteria on solid and liquid interfaces underlies a spectrum of practical applications, ranging from preventing the formation of destructive biofilms on medical devices and on resource pipelines to removing pollutants from water. Because microscale bacteria are similar in size to colloidal particles, bacterial adhesion has long been studied using models for colloidal deposition. Many bacteria, however, are active and can move, swim, tumble, and rotate near interfaces. This activity, not captured in models for deposition of passive colloids, must affect how bacteria deposit onto surfaces. Here, I will describe work exploring effects of motility on adhesion to solid substrates and to liquid-liquid interfaces. On solid surfaces, we relate near-surface mobility and adhesion to surface properties using imaging; engineer bacteria to identify surface adhesions that control transient mobility; and apply insights from these studies to design responsive polymer brush surfaces that detach adherent bacteria. On liquid-liquid interfaces, we test the applicability of thermodynamic pictures for adhesion of non-motile bacteria on oil droplets; identify how bacterial swimming alters this adhesion; and show that motile adhered bacteria can drive droplet rotation.

ODEI Spotlight: Promoting LGBTQ+ Inclusivity
2021-09-30 12:00 - 13:30 | PA
Are you looking for a way to expand your understanding of what it means to be a member of LGBTQ+ communities? Do you feel uneducated in conversations surrounding LGBTQ+ language and preferred terms? Join us for this interactive session which provides participants with an overview of LGBTQ+ history, terms, and current issues. It is a chance to expand your understanding of what it means to be a member of LGBTQ+ communities and gain tangible tips on how you can check implicit biases and effectively engage with and support those who identify within the queer community. Lunch will be provided (gluten-free and vegan options available). Registration required.

MEAM PhD Thesis Defense: "A Differential Homogenization Framework for Precipitation-Strengthened Metals"
2021-09-30 14:00 - 15:00 | Zoom – Email MEAM for Link, peterlit@seas.upenn.edu
Composite materials, such as metal- and polymer-matrix composites, exhibit both elastic and dissipative effects when subjected to macroscopic loadings. Even when the phases of the composite are characterized by a simple Maxwell rheology, the complex viscoelastic interactions between the phases give rise to emergent behavior at the macroscopic scale. Incorporating these “long-memory” effects in the context of analytical homogenization is the subject of this thesis.
In particular, I will present a novel differential homogenization framework for particulate composites comprised of elasto-viscoplastic strain-hardening phases that incorporates first and second-moment information about the local hardening fields and improves upon existing formulations which only consider the corresponding first moments. The present framework is motivated by precipitation-strengthened alloys, which constitute a commercially important class of whose mechanical properties can be altered by introducing stiff precipitates into the bulk (matrix) through heat-treatment.
First, we’ll consider the simple case of linear viscoelasticity and show that by using differential equations instead of difference equations, the new formulation is more robust than earlier approaches and recovers exact results for certain classes of composites.
Next, we provide estimates for creeping single crystals with elastic particles and find that the long-memory effect manifests as a transient creep-rate which is strongly dependent on the elasticity of the phases as well as the morphology of the particles. We also find that the timescales associated with macroscopic creep are strongly dependent on crystal symmetry as well as the loading configuration.
Lastly, we examine the effect of microstructure on the effective behavior of precipitation-strengthened crystals. It is found that overall, stiff precipitates induce larger levels of slip-activity and work-hardening, relative to a corresponding homogeneous crystal. For FCC crystals, the precipitate stiffness plays a significant role in modulating the overall anisotropy, while for HCP crystals the overall anisotropy is mostly affected by the viscous and hardening anisotropies. Moreover, it is found that incorporating the second-moments of the local hardening fields is important for generating accurate predictions, particularly at large deformations.
