Dayakar Penumadu - US grants

9452059 Penumadu An automated electro-pneumatic controlled true triaxial testing device with flexible boundaries enables students to investigate the importance of stress path and drainage conditions on the strength of soils. Two types of laboratory experiments that use this device have been developed. The first familiarizes students with concepts related to static transducer calibration, analog to digital conversion, signal conditioning, software and hardware gain and problems of aliasing. The second type deals with the isotropic and anisotropic consolidation and testing of soil samples using a predefined stress path. Stress and strain controlled static shear tests can be performed and essentially any stress path can be simulated through the data acquisition and control software. This laboratory capability shows the relevance of the various laboratory strength tests with actual field conditions using the same testing device, and illustrates the concepts related to electronic data acquisition and control. An important benefit is that the same device can be used to illustrate the drained and undrained stress-strain characteristics of both isotropic and Ko consolidated soil samples. The samples can be sheared under a predefined stress path and the observed pore pressure behavior (for undrained testing) can be compared. Soil testing programs are developed to examine the issues related to type of consolidation, stress path and the rate of loading.

9512140 Penumadu This Academic Research Infrastructure (Acquisition) Award is made to partially fund the purchase of a combined axial force-torsion closed loop loading frame with appropriate electronic control interfaces. This testing apparatus will produce biaxial states of stress and will be used in four ongoing research projects involving clay soils, polycrystalline metals, electrical conduction in reinforced cement composites and cold region research. Graduate and undergraduate research students will be able to tremendously improve their research training with this equipment. ***

This award provides funding for a three year project at Clarkson University for a Combined Research-Curriculum Development program entitled, "Geotechnical Test Simulator," under the direction of Dr. Dayakar Penumadu. This project is a collaborative effort between Clarkson University and Georgia Institute of Technology. The objective of the proposal is to develop virtual laboratory experiments and use computer simulations (in addition to the existing limited laboratory exposure), to complement and extend conventional components of the education process. This laboratory simulator will have an immediate nationwide impact on the course(s) related to geotechnical engineering which are usually required for all graduating Civil and Environmental Engineering (CEE) majors and can be easily extended and implemented in different related branches of engineering education (e.g. Geology, Structural Engineering, Hydraulics Engineering, Environmental Engineering etc.).

This award from the Division Researv in the Division of Materials Research provides partial support to the Imaging and Neutrons (IAN2006) Workshop at Oak Ridge, TN in October 23-25, 2006. The goals of the workshop are three-fold: (1) identify the current needs and potential contributions of imaging with neutrons in a wide range of science and areas of applications; (2) recognize new imaging techniques that may be made possible by advanced next generation sources that go beyond established techniques of radiography and tomography; (3) produce a report identifying both potentially valuable imaging techniques and directions for additional research and investment to realize this potential worldwide.
The workshop is sponsored by a range of Federal and international agencies and it covers a broad range of topics in "Imaging and Neutrons", such as neutron radiography and tomography, imaging of dynamic systems, phase contrast enhancements, microscopy with neutron optics, imaging with spin-polarized neutrons. New methods for whole human body imaging followed by gamma ray imaging will also be presented. These will have application in water distribution in sedimentary formations, oil flow in operating internal combustion engines, water plugs in hydrogen-oxygen fuel cells, swords and helmets in archeological studies, and structures of explosive devices. Funds from the National Science Foundation will support participation of young scientists and engineers particularly from underrepresented groups.

ARI-MA: Transformational Scintillation Materials for Neutron and Gamma Detectors and Educational Integration

The objective of this research is to develop transformative scintillation materials for use in neutron and gamma radiation detectors that will notably advance the technology for detecting nuclear threats. The approach is to utilize a diverse team with expertise in scintillation materials, chemistry, physics, imaging, radiation metrology and transport, and nuclear engineering. The senior investigators have unique access to neutron and reactor facilities at Oak Ridge and around the world to facilitate the development of next generation scintillation materials for advanced radiation detection.
The intellectual merit will include the development of polymeric nano-composites for neutron and photon detection with high efficiency and energy resolution. In addition, new materials and methods for the fabrication of crystalline based neutron and gamma ray detectors will be developed. Neutron detectors with capabilities for rejection of photon counts will be developed through the use of suitable geometric, composition, and pulse shape characteristics. This type of research is essential for developing the basic science and novel materials required for next generation radiation detection.
Broader impacts will include the development of technology to manufacture large volumes of inexpensive neutron scintillation materials using structural composite techniques. Trained students and personnel from this project will contribute to advancing future nuclear threat detection technology. New course materials and laboratory exercise modules will be developed and incorporated into distance learning programs to impact large numbers of students from nuclear engineering and related programs throughout the United States.

The planned University of Tennessee, Knoxville site of the I/UCRC for Integrative Materials Joining for Energy Applications has the potential to allow accelerated development and deployment of hybrid material systems for energy applications and will be focused on the scale-up of proven laboratory developments relevant to automotive, aerospace, and energy applications. The research has the potential to enable scientific discoveries related to the thermo-mechanical-chemical properties of interfaces between these constituent materials to be achieved. Advanced in-situ and ex-situ characterization techniques will be applied to understand issues such as cyclic thermal and stress loading, residual stress development, and microstructural evolution. This new site plans to produce fundamental research at the crossroads of joining and additive manufacturing.

The focus of the planned site on joining and additive manufacturing of advanced materials is of central importance to the competitiveness of the automotive, aerospace, and energy sectors. The planned new site plans to work with Hardin Valley Elementary School (HVES) to recruit students for forming and mentoring independent FIRST LEGOfi League (FLL) team(s) as they tackle real-world engineering challenges. This interaction with elementary school children might be their first towards introducing and encouraging them to consider STEM choices in their future academic careers. Additionally, the proposed site of CIMJSEA will collaborate with non-profit organizations in Tennessee and the College of Engineering Office of Diversity Programs in order to foster interaction with underrepresented groups over a wide range of ages.

The University of Tennessee, Knoxville (UTK) site of the Center for Integrative Materials Joining Science for Energy Applications (CIMJSEA) seeks to close the gap between material development and weldability and to develop scientifically based methodologies for assessing material weldability and joinability that span from the nanometer to millimeter length scales over a wide variety of materials, while educating and developing a new generation of materials joining engineers and scientists. The program seeks to identify
 critical joining-related challenges to ensure alignment of research projects and to explore
the development of materials specifically tailored for manufacturing. Research will be relevant 
to the future and existing manufacturing. The UTK site specialties include materials development, crosscutting capabilities that include multi-scale characterization
and modeling, as well as a new thrust area in additive manufacturing. The latter has the potential to benefit society in a multitude of ways including reducing scarce and dwindling raw materials. Proficient new engineers will design by building layer-by-layer instead of by subtraction, allowing for unlimited possibilities in design complexity. The program will reach out to a large age span of students, from elementary school onwards, by organizing and coaching younger students through LEGO league competitions, establishing and maintaining open 3D printing laboratories on campus, and by supporting Senior Capstone Design activities.
Technical efforts of the UTK site will foster innovations in welding, materials joining and
additive manufacturing technologies through interdisciplinary research, bringing together design, robotics and automation, process control, materials science, advanced characterization and high-performance computational modeling. The research at the UTK site includes large-scale additive manufacturing and joining polymer matrix composites
to metals. In combination with existing joining technologies the efforts of the UTK site will create an environment where the development of hybrid material systems is accelerated and will be focused
on the scale-up of proven laboratory developments relevant to automotive, aerospace, and energy applications. The research will promote scientific discoveries related to the thermo-mechanical-chemical properties of interfaces between these constituent materials and advanced in situ and ex situ characterization techniques will be applied to understand issues such as cyclic thermal and
stress loading, residual stress development, and microstructural evolution. The end result will be a steady flow of fundamental research at the crossroads of joining and additive manufacturing.

This Major Research Instrumentation award will fund the acquisition of a modern X-ray scattering instrument to support soft materials research in the Tennessee Valley and surrounding region. The instrument will be installed at the University of Tennessee in the Polymers Characterization Lab, an established user facility for academic and industrial researchers. This acquisition will enable measurements of hierarchical structure in soft materials under controlled environmental conditions, thereby informing the design of new materials for strong and lightweight composites, safe batteries, gas and water purification, oil spill remediation, drug delivery, and 3D printing. The proposed instrument is extremely flexible, easy to use, and well-suited to a large user base with a diverse and continuously evolving research portfolio. The team is highly experienced with the design, implementation, and analysis of X-ray scattering measurements, so students will receive training in advanced materials characterization, which is critical to maintaining US technological competitiveness in the global market.

This award will fund the acquisition of a multimode X-ray scattering system to support soft materials characterization in targeted or extreme environments. The system will be installed at the University of Tennessee in the Polymers Characterization Lab, an established, sustainable, and centrally-supported user facility. The proposed acquisition will enable four workhorse techniques for characterization of hierarchical structure in soft and hybrid materials: transmission small angle X-ray scattering (SAXS), transmission wide angle X-ray scattering (WAXS), grazing-incidence small angle X-ray scattering (GISAXS), and grazing-incidence wide angle X-ray scattering (GIWAXS). The instrument can accommodate samples in a variety of states, including bulk powders, liquids, and films, and is equipped with integrated environmental controls to examine material responses to temperature, humidity, gases, applied tension, and applied shear. X-ray scattering measurements will inform fundamental studies of structure-property-processing relations in soft and hybrid materials, providing immediate support to a variety of federally funded research programs in nanocomposites, energy storage, separations, renewable materials, and biomaterials. The team will leverage the acquisition of the X-ray scattering instrument for the design of new course modules and a regional immersion workshop, thereby elevating the educational experience of undergraduate and graduate students through training in advanced materials characterization.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

The Manufacturing and Materials Joining Innovation Center (Ma2JIC) research aims to close the gap between materials development and weldability by developing scientifically based methodologies for assessing weldability and joinability that span length scales over a wide variety of materials. The University of Tennessee, Knoxville (UTK) site strengths include materials development, crosscutting capabilities including multi-scale characterization and modeling, and metal additive manufacturing (AM). AM technologies have the potential to benefit society in a multitude of ways including reducing scarce and dwindling raw materials and producing unique parts for variety of applications associated with aerospace, infrastructure, energy, and automotive industries. Equally important is educating and developing a new generation of materials joining engineers and scientists. Engineers will design by building layer-by-layer and parts can feature unlimited possibilities in design complexity. During Phase I the UTK site of Ma2JIC established collaborative research with small-, medium- and large-scale industries and national laboratories and began shaping and refining a research agenda based on industrial needs. During Phase II the Ma2JIC UTK site seeks to continue to grow these collaborations along with research relevant to future and existing manufacturing industries, establishing new collaborations, and initiating projects that will strengthen collaborations with the other Ma2JIC sites.

Technical efforts of the Ma2JIC UTK site promote innovations in welding, materials joining, and additive manufacturing technologies through interdisciplinary research bringing together design, robotics and automation, process innovation/control, materials science, advanced characterization and high-performance computational modeling. The research portfolio of the UTK site brings capabilities in the area of large-scale additive metal manufacturing and characterization techniques, especially using radiation based scattering and imaging using neutrons and X-rays. The end results of the projects will be focused on promoting higher yields and scale-up of proven laboratory developments relevant to aerospace, infrastructure, energy, and automotive applications. The research promotes scientific discoveries related to the thermo-mechanical-chemical properties of new and existing materials consolidated and joined using traditional and new techniques. Complementary computational and experimental characterization techniques, including in situ and ex situ conditions, will be applied to understand issues such as cyclic thermal and stress loading, residual stress development, and microstructural evolution. The UTK site will produce fundamental research techniques and students versed in these techniques at the crossroads of joining and additive manufacturing.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.