Mechanical Behavior of Graphene Quantum Dot Epoxy Nanocomposites: A Molecular Dynamics Study Authors: Özgür Keleş1, Prathamesh P. Deshpande1*1Department of Chemical and Materials Engineering, San Jose State University, One Washington Sq, San Jose, CA*Corresponding author: [email protected] Abstract Quantum dot fillers were reported to enhance stiffness, yield strength, and toughness of polymers. However, the underlying mechanisms for […]

Non-Technical Description:The acquisition of a tip-enhanced Raman spectroscope at San Jose State University (SJSU) can significantly improve our understanding of nanometer-scale materials and foster hands-on learning experiences for undergraduate and master’s student researchers. The team at SJSU utilizes this optical instrument to tackle scientific challenges on materials science, with the materials for potential applications in […]

Many thanks to my co-authors and Robert Bruce for making this happen! Experiential Learning of Engineering Concepts in Immersive Virtual Learning Environments (VLEs) Özgür KeleşSan Jose State UniversityVincent Brubaker-GianakosSan Jose State UniversityVimal ViswanathanSan Jose State UniversityFarshid MarboutiSan Jose State University Abstract This paper describes the application of new Virtual Learning Environments (VLEs) in engineering education. […]

Many thanks to my SJSU colleagues for nominating and selecting me for the 2023 College of Engineering Award for Excellence in Scholarship. Kudos to all the faculty who is doing excellent research at our minority serving university with the available resources.    Posted 15th March 2023 by Ozgur Keles

We got an NEA grant titled “Exploring San Jose Cultural Heritage and Sustainable Design through 3D Printing Technology.” Thanks to Prof. Yoon Chung Han for leading the efforts.  We bring sustainable design, recycled materials, and additive manufacturing together under the cultural heritage umbrella. Click to see our previous work Future Artifact on Data+AI+Design+3D printing.   […]

Dei Rossi, Joseph, Ozgur Keles, and Vimal Viswanathan. “Fused Deposition Modeling with Induced Vibrations: A Study on the Mechanical Characteristics of Printed Parts.” Applied Sciences 12.18 (2022): 9327.  https://www.mdpi.com/2076-3417/12/18/9327 Abstract: The recent development of RepRap style 3D printers has made additive manufacturing technology available to the public at a low cost. While these 3D printers […]

I will be working on the mechanics of quantum dot nanocomposites. Thanks for all the support from NSF, reviewers, and officers Dr. Nakhiah Goulbourne and Dr. Siddiq Qidwai.  More information coming soon. ABSTRACT This Faculty Early Career Development (CAREER) grant will support fundamental research on processing-structure-mechanics relationships in thermosetting nanocomposites containing ultrasmall two-dimensional quantum dot […]

Effect of raster angle on mechanical properties of 3D printed short carbon fiber reinforced acrylonitrile butadiene styrene Skhandesh Srinivasan Ganesh Iyer and OzgurKeles Abstract The most common additive manufacturing technique fused filament fabrication (FFF) suffers from inter-bead porosity that reduces mechanical properties. Inter-bead pores follow the raster angle, which causes anisotropic mechanical properties. Yet, the […]

My vision for the Silicon Valley goes beyond education, companies, public, and environment, that goes to a collective, sustainable, self-learning ecosystem. Towards this vision, College of Engineering faculty and other decision makers decided to give me the Kordestani Endowed Chair Position for the third time and for a longer period.  Many thanks to Omid Kordestani […]

Temperature dependence of field-response mechanisms in 0.4Ba(Zr0.2Ti0.8)O3–0.6(Ba0.7Ca0.3)TiO3 Authors: Chris M Fancher, Özgür Keleṣ, Matthias Ehmke, Keith J BowmanPublication date: 2021/7/12Journal: Applied Physics LettersVolume: 119Issue: 2Pages: 022904 DescriptionUnderstanding the temperature dependence of how ferroelectric materials respond to electric fields is critical for determining how best to use these materials in applications. Here, temperature dependent in situ x-ray diffraction […]

Effect of fiber content and fiber orientation on mechanical behavior of fused filament fabricated continuous-glass-fiber-reinforced nylon Lukea, D. Soaresa,b, J. Marshalla, J. Sheddenb, O. Kelesa*  aDepartment of Chemical and Materials Engineering, San José State University, 1 Washington Sq, San José, CA 95192, United States bTenCate Advanced Composites, 18410 Butterfield Blvd., Morgan Hill, CA 95037, United […]

Prediction of elastic stresses in porous materials using fully convolutional networks Ozgur Keles, Yinchuan He, Birsen Sirkeci-Mergen Chemical and Materials Engineering Department, San Jose State University, San Jose, CA 95192 USA Electrical Engineering Department, San Jose State University, San Jose, CA 95192 USA Abstract Machine learning (ML) models enable exploration of vast structural space faster […]

ASME Santa Clara Valley Section Tech Talk Title: Multi-scale additive manufacturing of reliable hierarchical composites Ozgur Keles, Ph.D.  Assistant ProfessorChemical and Materials Engineering DepartmentSan Jose State University, San Jose, CA 95192 Abstract: Economic growth demands better products; hence, better materials. Specifically, product space in biomedical, aerospace, and automotive industries requires materials that are multi-functional, lightweight, reliable, and tough. The […]

A. Bokare, D. Nordlund, C. Melendrez, R. Robinson, Ozgur Keles, A. Wolcott, and F. Erogbogbo, “Surface Functionality and Formation Mechanisms of Carbon and Graphene Quantum,” Diamond and Related Materials, (2020) Accepted. Posted 30th September 2020 by Ozgur Keles

I will be collaborating with Palo Alto Research Center (formerly Xerox PARC) on a Department of Energy (DOE) grant shooting for enhanced properties in lead-free piezoelectric materials.  We will apply high-throughput (HT) processing and characterization techniques on piezoceramics. This unique HT data will enable materials informatics approaches to guide our experiments towards higher performance systems.  Figure.  […]

Croom, Brendan P; Keles, Ozgur; Flores, Mark D, Prediction Of Crack Propagation Along Non-Uniform Raster Patterns In Am Composites, ASC 35th Technical (Virtual) Conference, 2020.https://asc2020.nyc/program Figure 9. Damage progression in specimens with different α. (a-d) Damage at four increasing load steps. Specimens with α=0°,5°,10°,15°,20° and 30° are stacked from front to back in each panel; matrix […]

Effect of recycling on the mechanical behavior and structure of additively manufactured acrylonitrile butadiene styrene (ABS) Alex K. Cress 1, Jimmy Huynh1, Eric H. Anderson1, Ryan O’neill1, Yanika Schneider2, Özgür Keleş 1*1Chemical and Materials Engineering Department, San Jose State University, San Jose, CA, 95192, USA2EAG Laboratories, 810 Kifer Rd Sunnyvale, CA 94086, USA AbstractFused deposition […]

A predictive failure framework for brittle porous materials via machine learning and geometric matching methods  Alp Karakoç1, Özgür Keleş2,* 1Aalto University, Department of Bioproducts and Biosystems, Vuorimiehentie 1, Espoo, Finland 2San Jose State University, Chemical and Materials Engineering Department, One Washington Square, San Jose, CA 95192, USA https://link.springer.com/article/10.1007/s10853-019-04339-1 ABSTRACT Brittle porous materials are used in […]

J.R. Seibert, O. Keles, J. Wang, F. Erogbogbo, Data on Thermal Conductivity and Dynamic Mechanical Properties of Graphene Quantum dots in epoxy, Data in Brief,  https://doi.org/10.1016/j.dib.2019.105008. Fig. 2. TEM images of bird charcoal at 2500x (A) and at 50000x (B), and GQDs at 50000x (C) and 500000x (D) GQDs are indicated by the red circles. […]

“Multi-Scale Structure Control for Advanced Functional Materials” Ozgur Keles, Ph.D.Assistant ProfessorChemical and Materials Engineering DepartmentSan Jose State University Thursday, December 5, 20194:00 PMTien Room, 6101 Etcheverry Hall  ABSTRACTEconomic growth demands better products; hence, better materials. Specifically, product space in energy, defense, aerospace, and automotive industries requires materials that are multi-functional, lightweight, reliable, and tough. In addition, environmental regulations […]

Joel R Seibert, Ozgur Keles, Jun Wang, and Folarin Erogbogbo, “Infusion of Graphene Quantum Dots to Modulate Thermal Conductivity and Dynamic Mechanical Properties of Polymers,” Polymer, Accepted.  https://www.sciencedirect.com/science/article/pii/S0032386119309954?via%3Dihub Abstract  Graphene quantum dots are small fragments of graphene that may be advantageous to transferring properties to polymers because of their small size, molecular like interactions, surface […]

We will be installing a new EOS M 100 metal additive manufacturing system. Our research is targeting unexplored hierarchical structural spaces that can be achieved using the unique capabilities of the selective laser melting system. I would like to thank my co-PIs, collaborators, NSF officials,  and reviewers, including Birsen Sirkeci, Feruza Amirkulova, Raymond K. Yee, […]

See our new work at the International Mechanical Engineering Congress and Exposition, IMECE2019 November 11-14, 2019. Joseph Dei Rossi, Ozgur Keles, and Vimal Viswanathan, Fused deposition modeling with added vibrations: a parametric study on the accuracy of the printed parts, Proceedings of the ASME 2019 International Mechanical Engineering Congress and Exposition, IMECE2019 November 11-14, 2019, Salt Lake City, […]