Electrical Engineering

Indian Institute of Technology Bombay

People

People

Faculty

Pradeep R. Nair
Qualifications

• Ph. D. School of ECE, Purdue University, West Lafayette, IN, USA 2009.
• M. Tech. EE, Indian Institute of Technology (IIT), Bombay, India 2004.
• B. Tech. ECE, National Institute of Technology (NIT), Calicut, India 2002.

Research Interests

• Nanoscale devices for energy and healthcare applications.
• Semiconductor device physics and reliability.
• Microelectromechanical systems (MEMS)

Work Experience

• Post-doctoral research (School of ECE, Purdue University, 2009-2011).

Journal Papers
<hr style="height:2px;border-width:0;color:gray;background-color:gray"

  1. Sumanshu Agarwal and Pradeep R. Nair, "Device Engineering of Perovskite solar cells to achieve near ideal efficiency", Applied Physics Letters, vol. 107, pp. 123901, 2015.
  2. Raghu Chavali, Sanchit Khatavkar, C. V. Kannan, V. Kumar, Pradeep R. Nair, Jeff Gray, and Muhammad A. Alam, "Multi-Probe Characterization of Inversion Charge for Self-Consistent Parameterization of HIT Cells", IEEE Journal of Photovoltaics, vol. 5, pp. 725-735, 2015.
  3. Sumanshu Agarwal, M. Seetharaman, M. Kumawat, A. Subbiah, S. Sarkar, D. Kabra, M. A. G. Namboothiry , and Pradeep R. Nair, "On the Uniqueness of Ideality Factor and Voltage Exponent of Perovskite-Based Solar Cells", Journal of Physical Chemistry Letters, vol. 5, pp. 4115-4121, 2014.
  4. P. R. Nair and M. A. Alam, "Unified analytic model for current transients at nanostructured electrodes", --, 2012.
  5. J. Go, P. R. Nair, and M. A. Alam, "Theory of signal and noise in double-gated nanoscale electronic pH sensors", Journal of Applied Physics, 2012.
  6. J. Go, P. R. Nair, B. Reddy, B. Dorvel, R. Bashir, and M. A. Alam, "Coupled Heterogeneous Nanowire–Nanoplate Planar Transistor Sensors for Giant (>10 V/pH) Nernst Response", ACS Nano, 2012.
  7. A. Jain, P. R. Nair, and M. A. Alam, "Flexure FET biosensors to break the fundamental sensitivity limits of nanobiosensors using nonlinear electromechanical coupling", Proceedings of the National Academy of Sciences (PNAS), USA, 2012.
  8. C. Jeong, P. R. Nair, M. Khan, M. Lundstrom, and M. A. Alam, "Prospects of Nanowire-Doped Polycrystalline Graphene Films for an Ultratransparent, High Conductive Electrode", Nanoletters, 2011.
  9. B. Reddy, O. Elibol, P. R. Nair, B. Dorvel, F, Butler, Z. Ahsan, D. Bergstrom, M. A. Alam, and R. Bashir, "Silicon Field Effect Transistors as Dual-Use Sensor-Heater Hybrids", Analytical Chemistry, 2011.
  10. B. Reddy, B. Dorvel, J. Go, P. R. Nair, O. Elibol, C. Credo, J. Daniels, E. Chow, X. Su, M. Varma, M. A. Alam, and R. Bashir, "High-k dielectric Al2O3 nanowire and nanoplate field effect sensors for improved pH sensing", Biomedical Microdevices, 2011.
  11. B. Ray, P. R. Nair, and M. Alam, "Annealing Dependent Performance of Organic Bulk-Heterojunction Solar Cells: A Theoretical Perspective", Solar Energy Materials and Solar Cells, 2011.
  12. A. Jain, P. R. Nair, and M. A. Alam, "Strategies for Dynamic Soft-Landing in Capactive Microelectromechanical Switches", Applied Physics Letters, vol. 98, 2011.
  13. P. R. Nair and M. A. Alam, "Theoretical Detection Limits of Magnetic Biobarcode Sensors and the Phase Space of Nanobiosensing", Analyst, vol. 135, pp. 2798 , 2010.
  14. P. R. Nair and M. A. Alam, "Kinetics of Surfaces Defined by Finite Fractals", Fractals, vol. 4, pp. 461 , 2010.
  15. O. H. Elibol, B. Reddy Jr., P. R. Nair, B. Dorvel, F. Butler, Z. S. Ahsan, D. E. Bergstorm, M. A. Alam and R. Bashir, "Localized heating on silicon field effect transistors: Device fabrication and temperature measurements in fluid", Lab On a Chip, vol. 9, pp. 2789-2795, 2009.
  16. K. Lee, A. Scott, D. B. Janes, P. R. Nair, and M. A. Alam, "Device Considerations for Development of Conductance-Based Sensors", Journal of Applied Physics, vol. 105, pp. 102046 , 2009.
  17. P. R. Nair and M. A. Alam, "Screening Limited Response of NanoBiosensors", NanoLetters, vol. 8, 2008.
  18. K. Lee, P. R. Nair, M. A. Alam,, D. B. Janes, H. H. Park, D. Y. Zemlyanov,, and A. Ivanisevic, "Electrical Detection of the Biological Interaction of a Charged Peptide via Gallium Arsenide Junction Field Effect Transistors", Journal of Applied Physics, vol. 103, 2008.
  19. P. R. Nair and M. A. Alam,, "Dimensionally Frustrated Diffusion towards Fractal Adsorbers", Physical Review Letters, vol. 99, 2007.
  20. P. B. Kumar, R. Sharma, P. R. Nair, and S. Mahapatra,, "Investigation of Drain Disturb in SONOS Flash EEPROMs", IEEE Transactions on Electron Devices, vol. 54, 2007.
  21. P. B. Kumar, P. R. Nair, R. Sharma, S. Kamohara and S. Mahapatra, "Lateral Profiling of Trapped Charge in SONOS Flash EEPROMs Programmed Using Channel Hot Electron Injection", IEEE Transactions on Electron Devices, vol. 53, 2006.
  22. A. K. Gupta, P. R. Nair, D. Akin, M. Ladisch, S. Broyles, M. A. Alam and R. Bashir, "Anomalous resonance of nanocantilever biosensors", Proceedings of the National Academy of Sciences, vol. 103, no. 36, 2006.
Conferences
<hr style="height:2px;border-width:0;color:gray;background-color:gray"
  1. M. A. Alam, S. Kumar, N. Pimparkar, P. Nair, J. Go. And A. Jain, "The Physics of Nanonet Fabrics and Its Application in Electronic, Optoelectronics, Biosensing, Energy Storage, and MEMS Applications" in 219the ECS Meeting, vol. 35(3), pp.55-65, Dec. 2011.
  2. Biswajit Ray, Pradeep R. Nair, And M. A. Alam, "Morphology Dependent Short Circuit Current In Bulk Heterojunction Solar Cell" in IEEE Photovoltaic Specialists Conference, pp.85-89, Dec. 2010.
  3. J.-H. Go, P. Nair, B. Reddy, R. Bashir, M. Alam, "Beating the Nernst Limit of 59 mV/dec by Double Gated Nano-Scale Field-Effect Transistors and Its Applications to Ultra-Sensitive DNA Biosensors" in International Electron Device Meeting, Dec. 2010.
  4. B. Dorvel, O. Elibol, J. Reddy, P. Nair, A. Alam, R. Bashir, "Silicon nanoplate arrays: Implications for biosensing and electronic label-free detection" in 237th National Meeting of the American Chemical Society (ACS), Salt Lake City, Oral Presentation, Monday, March 23, Dec. 2009.
  5. Bobby Reddy, Jr., Oguz H. Elibol, Brian R. Dorvel, Pradeep R. Nair, Muhammad A. Alam, and Rashid Bashir, "SOI Nanofet Devices for Ultra-Sensitive Detection of Biomolecules" in Biophysical Society Annual Meeting, March 1, Dec. 2009.
  6. P. R. Nair, and M. A. Alam, "Nanobiosensors: Modeling Challenges" in SISPAD, Dec. 2009.
  7. B. Ray, P. R. Nair, and M. A. Alam, "Modeling and Optmization of Bulk Heterojunction Solar Cells" in IEDM, Dec. 2009.
  8. B. Dorvel, O. Elibol, J. Reddy, P. R. Nair, A. Alam, R. Bashir, "Fabrication and characterization of silicon nanoplates for biosensing applications" in 237th National Meeting of the American Chemical Society (ACS), Salt Lake City, Poster Presentation, Monday, March 23, Dec. 2009.
  9. P. R. Nair and M. A. Alam, "Cantor Transforms for Random Systems" in NCN Student Seminar, Dec. 2009.
  10. M. A. Alam and P. R. Nair, "Theory and Practice of Modern Nanobiosensors" in ULIS 2008, Udine, Italy , Plenary Talk, Dec. 2008.
  11. P. R. Nair and M. A. Alam, "Predictive Model for Label-Free detection of Biomolecules" in APS March meeting, Dec. 2008.
  12. M. A. Alam, and P. R. Nair, "Simulation of Nanobiosensors" in IEEE-Nano, Hong-Kong, Aug. 2-5, Invited Talk, Dec. 2007.
  13. O.H. Elibol, B. Reddy, Jr., P. R. Nair, M.A. Alam ,D.E. Bergstrom and R. Bashir, "Selective Heating Characterization of Nanoplate Devices for Sensing Applications" in NSTI Nanotech Conference, Santa Clara, CA, May 20-24, Dec. 2007.
  14. M. A. Alam, P. R. Nair, and R. Bashir, "Scaling Limits of Nanoelectromechanical Sensors" in International Workshop on Nanomechanical Sensors, Montreal, May 27-30, Invited Talk, Dec. 2007.
  15. P. R. Nair and M. A. Alam, "Scaling Challenges of Nanoscale biosensors" in Nano DDS, Washington DC, June 18-20, Invited Talk, Dec. 2007.
  16. P. R. Nair, J. Go, and M. A. Alam, "Physics of Nanoscale biosensors" in Molecular Conduction Workshop, Purdue University, Dec. 2007.
  17. M. A. Alam, N. Pimparkar, S. Kumar, P. R. Nair, J. Murthy, "Performance Limits of Nano-composite Transistors and Nanobio-Sensors: A Bottom-up Perspective" in 65th International Device Research Conference, Notre Dame, June 18-20, Invited Talk, Dec. 2007.
  18. P. R. Nair and M. A. Alam, , "Simulation of Silicion Nanowire Bio-sensors" in Device Research Conference, Dec. 2006.
  19. M. A. Alam, and P. R. Nair, "Performance Limits and Design Considerations of Nanobio Sensors" in 208 ECS Meeting: Symposium on Bioelectronics, Biointerfaces, and Biomedical Interfaces, Cancun, Mexico, Oct. 29-Nov. 3, Invited Talk, Dec. 2006.
  20. M. A. Alam and P. R. Nair, "Geometry of Diffusion defines Performance of Nanobio Sensor" in 4th Annual Molecular Conduction and Sensors Workshop, Charlottesville, VA, July 26-28,, Invited Talk, Dec. 2006.
  21. P. R. Nair and M. A. Alam, "Simulation of Electronic Detection of DNA" in Workshop on Electronic Detection of Bio-molecules, Dec. 2005.
  22. P. B. Kumar, R. Sharma, P. R. Nair, D. R. Nair, S. Kamohara, S. Mahapatra and J. M. Vazi, "Drain Disturb Mechanism in SONOS Flash EEPROMS" in IEEE Reliability Physics Symposium (IRPS), Dec. 2005.
  23. P. R. Nair, P. B. Kumar, R. Sharma, S. Kamohara and S. Mahapatra, I, "A Comprehensive Trapped Charge Profiling Technique for SONOS Flash EEPROMS" in EEE Electron Devices Meeting (IEDM), Dec. 2004.
Other professional Acivities
<hr style="height:2px;border-width:0;color:gray;background-color:gray"
  1. Reviewer for the following journals: Applied Physics Letters, Journal of Applied Physics, IEEE Electron Devices Letters, IEEE Transactions on Electron Devices, IEEE Transactions on Nanotechnology, IEEE Transactions on Biomedical Engineering, IEEE Transactions on Industrial Electronics. Contact Information
  2. Member of IEEE

Address
Pradeep R. Nair
Qualifications

• Ph. D. School of ECE, Purdue University, West Lafayette, IN, USA 2009.
• M. Tech. EE, Indian Institute of Technology (IIT), Bombay, India 2004.
• B. Tech. ECE, National Institute of Technology (NIT), Calicut, India 2002.

Research Interests

• Nanoscale devices for energy and healthcare applications.
• Semiconductor device physics and reliability.
• Microelectromechanical systems (MEMS)

Work Experience

• Post-doctoral research (School of ECE, Purdue University, 2009-2011).

Journal Papers
<hr style="height:2px;border-width:0;color:gray;background-color:gray"

  1. Sumanshu Agarwal and Pradeep R. Nair, "Device Engineering of Perovskite solar cells to achieve near ideal efficiency", Applied Physics Letters, vol. 107, pp. 123901, 2015.
  2. Raghu Chavali, Sanchit Khatavkar, C. V. Kannan, V. Kumar, Pradeep R. Nair, Jeff Gray, and Muhammad A. Alam, "Multi-Probe Characterization of Inversion Charge for Self-Consistent Parameterization of HIT Cells", IEEE Journal of Photovoltaics, vol. 5, pp. 725-735, 2015.
  3. Sumanshu Agarwal, M. Seetharaman, M. Kumawat, A. Subbiah, S. Sarkar, D. Kabra, M. A. G. Namboothiry , and Pradeep R. Nair, "On the Uniqueness of Ideality Factor and Voltage Exponent of Perovskite-Based Solar Cells", Journal of Physical Chemistry Letters, vol. 5, pp. 4115-4121, 2014.
  4. P. R. Nair and M. A. Alam, "Unified analytic model for current transients at nanostructured electrodes", --, 2012.
  5. J. Go, P. R. Nair, and M. A. Alam, "Theory of signal and noise in double-gated nanoscale electronic pH sensors", Journal of Applied Physics, 2012.
  6. J. Go, P. R. Nair, B. Reddy, B. Dorvel, R. Bashir, and M. A. Alam, "Coupled Heterogeneous Nanowire–Nanoplate Planar Transistor Sensors for Giant (>10 V/pH) Nernst Response", ACS Nano, 2012.
  7. A. Jain, P. R. Nair, and M. A. Alam, "Flexure FET biosensors to break the fundamental sensitivity limits of nanobiosensors using nonlinear electromechanical coupling", Proceedings of the National Academy of Sciences (PNAS), USA, 2012.
  8. C. Jeong, P. R. Nair, M. Khan, M. Lundstrom, and M. A. Alam, "Prospects of Nanowire-Doped Polycrystalline Graphene Films for an Ultratransparent, High Conductive Electrode", Nanoletters, 2011.
  9. B. Reddy, O. Elibol, P. R. Nair, B. Dorvel, F, Butler, Z. Ahsan, D. Bergstrom, M. A. Alam, and R. Bashir, "Silicon Field Effect Transistors as Dual-Use Sensor-Heater Hybrids", Analytical Chemistry, 2011.
  10. B. Reddy, B. Dorvel, J. Go, P. R. Nair, O. Elibol, C. Credo, J. Daniels, E. Chow, X. Su, M. Varma, M. A. Alam, and R. Bashir, "High-k dielectric Al2O3 nanowire and nanoplate field effect sensors for improved pH sensing", Biomedical Microdevices, 2011.
  11. B. Ray, P. R. Nair, and M. Alam, "Annealing Dependent Performance of Organic Bulk-Heterojunction Solar Cells: A Theoretical Perspective", Solar Energy Materials and Solar Cells, 2011.
  12. A. Jain, P. R. Nair, and M. A. Alam, "Strategies for Dynamic Soft-Landing in Capactive Microelectromechanical Switches", Applied Physics Letters, vol. 98, 2011.
  13. P. R. Nair and M. A. Alam, "Theoretical Detection Limits of Magnetic Biobarcode Sensors and the Phase Space of Nanobiosensing", Analyst, vol. 135, pp. 2798 , 2010.
  14. P. R. Nair and M. A. Alam, "Kinetics of Surfaces Defined by Finite Fractals", Fractals, vol. 4, pp. 461 , 2010.
  15. O. H. Elibol, B. Reddy Jr., P. R. Nair, B. Dorvel, F. Butler, Z. S. Ahsan, D. E. Bergstorm, M. A. Alam and R. Bashir, "Localized heating on silicon field effect transistors: Device fabrication and temperature measurements in fluid", Lab On a Chip, vol. 9, pp. 2789-2795, 2009.
  16. K. Lee, A. Scott, D. B. Janes, P. R. Nair, and M. A. Alam, "Device Considerations for Development of Conductance-Based Sensors", Journal of Applied Physics, vol. 105, pp. 102046 , 2009.
  17. P. R. Nair and M. A. Alam, "Screening Limited Response of NanoBiosensors", NanoLetters, vol. 8, 2008.
  18. K. Lee, P. R. Nair, M. A. Alam,, D. B. Janes, H. H. Park, D. Y. Zemlyanov,, and A. Ivanisevic, "Electrical Detection of the Biological Interaction of a Charged Peptide via Gallium Arsenide Junction Field Effect Transistors", Journal of Applied Physics, vol. 103, 2008.
  19. P. R. Nair and M. A. Alam,, "Dimensionally Frustrated Diffusion towards Fractal Adsorbers", Physical Review Letters, vol. 99, 2007.
  20. P. B. Kumar, R. Sharma, P. R. Nair, and S. Mahapatra,, "Investigation of Drain Disturb in SONOS Flash EEPROMs", IEEE Transactions on Electron Devices, vol. 54, 2007.
  21. P. B. Kumar, P. R. Nair, R. Sharma, S. Kamohara and S. Mahapatra, "Lateral Profiling of Trapped Charge in SONOS Flash EEPROMs Programmed Using Channel Hot Electron Injection", IEEE Transactions on Electron Devices, vol. 53, 2006.
  22. A. K. Gupta, P. R. Nair, D. Akin, M. Ladisch, S. Broyles, M. A. Alam and R. Bashir, "Anomalous resonance of nanocantilever biosensors", Proceedings of the National Academy of Sciences, vol. 103, no. 36, 2006.
Conferences
<hr style="height:2px;border-width:0;color:gray;background-color:gray"
  1. M. A. Alam, S. Kumar, N. Pimparkar, P. Nair, J. Go. And A. Jain, "The Physics of Nanonet Fabrics and Its Application in Electronic, Optoelectronics, Biosensing, Energy Storage, and MEMS Applications" in 219the ECS Meeting, vol. 35(3), pp.55-65, Dec. 2011.
  2. Biswajit Ray, Pradeep R. Nair, And M. A. Alam, "Morphology Dependent Short Circuit Current In Bulk Heterojunction Solar Cell" in IEEE Photovoltaic Specialists Conference, pp.85-89, Dec. 2010.
  3. J.-H. Go, P. Nair, B. Reddy, R. Bashir, M. Alam, "Beating the Nernst Limit of 59 mV/dec by Double Gated Nano-Scale Field-Effect Transistors and Its Applications to Ultra-Sensitive DNA Biosensors" in International Electron Device Meeting, Dec. 2010.
  4. B. Dorvel, O. Elibol, J. Reddy, P. Nair, A. Alam, R. Bashir, "Silicon nanoplate arrays: Implications for biosensing and electronic label-free detection" in 237th National Meeting of the American Chemical Society (ACS), Salt Lake City, Oral Presentation, Monday, March 23, Dec. 2009.
  5. Bobby Reddy, Jr., Oguz H. Elibol, Brian R. Dorvel, Pradeep R. Nair, Muhammad A. Alam, and Rashid Bashir, "SOI Nanofet Devices for Ultra-Sensitive Detection of Biomolecules" in Biophysical Society Annual Meeting, March 1, Dec. 2009.
  6. P. R. Nair, and M. A. Alam, "Nanobiosensors: Modeling Challenges" in SISPAD, Dec. 2009.
  7. B. Ray, P. R. Nair, and M. A. Alam, "Modeling and Optmization of Bulk Heterojunction Solar Cells" in IEDM, Dec. 2009.
  8. B. Dorvel, O. Elibol, J. Reddy, P. R. Nair, A. Alam, R. Bashir, "Fabrication and characterization of silicon nanoplates for biosensing applications" in 237th National Meeting of the American Chemical Society (ACS), Salt Lake City, Poster Presentation, Monday, March 23, Dec. 2009.
  9. P. R. Nair and M. A. Alam, "Cantor Transforms for Random Systems" in NCN Student Seminar, Dec. 2009.
  10. M. A. Alam and P. R. Nair, "Theory and Practice of Modern Nanobiosensors" in ULIS 2008, Udine, Italy , Plenary Talk, Dec. 2008.
  11. P. R. Nair and M. A. Alam, "Predictive Model for Label-Free detection of Biomolecules" in APS March meeting, Dec. 2008.
  12. M. A. Alam, and P. R. Nair, "Simulation of Nanobiosensors" in IEEE-Nano, Hong-Kong, Aug. 2-5, Invited Talk, Dec. 2007.
  13. O.H. Elibol, B. Reddy, Jr., P. R. Nair, M.A. Alam ,D.E. Bergstrom and R. Bashir, "Selective Heating Characterization of Nanoplate Devices for Sensing Applications" in NSTI Nanotech Conference, Santa Clara, CA, May 20-24, Dec. 2007.
  14. M. A. Alam, P. R. Nair, and R. Bashir, "Scaling Limits of Nanoelectromechanical Sensors" in International Workshop on Nanomechanical Sensors, Montreal, May 27-30, Invited Talk, Dec. 2007.
  15. P. R. Nair and M. A. Alam, "Scaling Challenges of Nanoscale biosensors" in Nano DDS, Washington DC, June 18-20, Invited Talk, Dec. 2007.
  16. P. R. Nair, J. Go, and M. A. Alam, "Physics of Nanoscale biosensors" in Molecular Conduction Workshop, Purdue University, Dec. 2007.
  17. M. A. Alam, N. Pimparkar, S. Kumar, P. R. Nair, J. Murthy, "Performance Limits of Nano-composite Transistors and Nanobio-Sensors: A Bottom-up Perspective" in 65th International Device Research Conference, Notre Dame, June 18-20, Invited Talk, Dec. 2007.
  18. P. R. Nair and M. A. Alam, , "Simulation of Silicion Nanowire Bio-sensors" in Device Research Conference, Dec. 2006.
  19. M. A. Alam, and P. R. Nair, "Performance Limits and Design Considerations of Nanobio Sensors" in 208 ECS Meeting: Symposium on Bioelectronics, Biointerfaces, and Biomedical Interfaces, Cancun, Mexico, Oct. 29-Nov. 3, Invited Talk, Dec. 2006.
  20. M. A. Alam and P. R. Nair, "Geometry of Diffusion defines Performance of Nanobio Sensor" in 4th Annual Molecular Conduction and Sensors Workshop, Charlottesville, VA, July 26-28,, Invited Talk, Dec. 2006.
  21. P. R. Nair and M. A. Alam, "Simulation of Electronic Detection of DNA" in Workshop on Electronic Detection of Bio-molecules, Dec. 2005.
  22. P. B. Kumar, R. Sharma, P. R. Nair, D. R. Nair, S. Kamohara, S. Mahapatra and J. M. Vazi, "Drain Disturb Mechanism in SONOS Flash EEPROMS" in IEEE Reliability Physics Symposium (IRPS), Dec. 2005.
  23. P. R. Nair, P. B. Kumar, R. Sharma, S. Kamohara and S. Mahapatra, I, "A Comprehensive Trapped Charge Profiling Technique for SONOS Flash EEPROMS" in EEE Electron Devices Meeting (IEDM), Dec. 2004.
Other professional Acivities
<hr style="height:2px;border-width:0;color:gray;background-color:gray"
  1. Reviewer for the following journals: Applied Physics Letters, Journal of Applied Physics, IEEE Electron Devices Letters, IEEE Transactions on Electron Devices, IEEE Transactions on Nanotechnology, IEEE Transactions on Biomedical Engineering, IEEE Transactions on Industrial Electronics. Contact Information
  2. Member of IEEE

Address

IIT Bombay was established in the year 1957 and the department of Electrical Engineering (EE) has been one of its major departments since its inception.

Contact Us

IIT Bombay was established in the year 1957 and the department of Electrical Engineering (EE) has been one of its major departments since its inception.

Contact Us

IIT Bombay was established in the year 1957 and the department of Electrical Engineering (EE) has been one of its major departments since its inception.

Contact Us

About | IITBEducation | Research | Site Map | Feedback | RTI | Contact Us

© 2023, IITB. All rights reserved.

About | IITBEducation | Research | Site Map | Feedback | RTI | Contact Us

© , IITB. All rights reserved.

About | IITBEducation | Research | Site Map | Feedback | RTI | Contact Us

© 2023, IITB. All rights reserved.