Emad Y. Tanbour

A photo of Emad Tanbour

Associate Professor

Engineering

111C Sill Hall

734.487.1865

[email protected]

Office Hours

Mondays - 11:30-12:30
Tuesdays - 11:30-12:00
Wednesdays - 11:30-12:30
Thursdays - 11:30-12:00

Education

  • Ph.D., Mechanical Engineering, University of Iowa, Iowa City, IA
  • MS, Mechanical Engineering, Jordan University of Science and Technology
  • BS, Mechanical Engineering, Jordan University of Science and Technology

Professional Summary

  • Assistant Professor, September 2016 - 2019
  • Associate Professor - ME Prgram Coordinator - 2018-Present

Dr. Emad Tanbour has more than 24 years of combined experience in mechanical engineering in both academia and industry. His industry experience spans over 18 years in the areas of product development, energy efficient appliances and sustainability, thermal systems design and engineering management. He is an expert researcher in industry and had been leading industry-academia funded research since 1997. Dr. Tanbour is an innovator with over 13 US pending and issued patents all of which resulted in products sold in North America. Most of his innovations are in the field of sustainable design of domestic and commercial appliances. Dr. Tanbour has advanced knowledge of computer aided engineering, CFD and computational mechanics. He is an expert user and trainer of computer aided design using solid modeling. He has conducted research in the areas of heat transfer, thermal-fluids, and energy systems and led many years of research and development projects in the interdisciplinary areas of mechanical engineering. He received his bachelor's degree in mechanical engineering and ranked third over his cohort and received full scholarship to pursue graduate studies towards his Ph.D. in mechanical engineering from the University of Iowa. During his studies at Iowa, Dr. Tanbour led the thermal design of all control circuits for NASA Cassini spacecraft that was launched to Saturn. Dr. Tanbour is the recipient of Arch T. Colwell Award from Society of Automotive Engineers and had served for five years as an ABET industry consultant. He also received EMBA training courses at the University of Iowa.

Interests and Expertise

  • CAE
  • Virtual reality
  • Product development
  • Thermofluids
  • Energy and sustainability
  • Engineering education and assessment

Courses Taught

  • ME 316: Thermodynamics
  • ME 317: Fluid Mechanics
  • ME 312: Dynamics
  • ME 330: Machine Design
  • ME 313: Mechanics of Materials
  • ME 492: Mechanical Engineering-Capstone Design I
  • ME 493: Mechanical Engineering-Capstone Design II
  • EM 509: Engineering Project Management (Graduate course)
  • EM520: Engineering Value and Economic Analysis (Graduate course)
  • EM 549: Planning Manufacturing Processes (Graduate course)
  • EM 570: Design for Manufactring and Assembly (Graduate course)
  • IET 680: Sustainability and Green Technology (CMU-Graduae course)

Selected Publications

  • M.Dado, M. Airbai, E. Tanbour and J. Al Asfar, Performance Assessment of a Novel Mechanism Design of Spark ignition Internal Combustion Engine, accepted for publication to Applied Energy, Feb, 2021.
  • M. Aldadou and E. Tanbour, Slider-Crank Mechanism for Eliminating Side Forces, US Patent.  Published by US Patent Office May 16, 2019.  Patent Number US 2019/0145507 Al.
  • Kasim A. Korkmaz and Emad Y.H. Tanbour, Augmented Reality Technology for Highway, Presented by co-auther Kasim Korkmaz at ICVARS 2018 held duringFebuary 24-26, 2018, in Brisbane, Austrailia, Paper ID: RS0018
  • Barry, Oumar Rafiou, Tanbour, Emadeddin Y., Vaja, Nitish Kumar, and Tanbour; Hesham, Asymmetric Aeolian vibration damper, USA Patent Office, Patent No.: US 9,948,081 Bl, Date of Patent: Apr. 17, 2018.  http://www.freepatentsonline.com/9948081.html
  • Emadeddin Y. Tanbour, Moh'd-Eslam Dahdolan, Mahmoud R. AlOmari, Oumar R. Barry, Characterization of Aerogel Based Thermal Insulation Blankets, Economics, and Applicatons for Domestic Water Heaters, Journal of Thermal Engineering, 4-5 July, 2018. http://eds.yildiz.edu.tr/journal-of-thermal-engineering/Submission/MyManuscripts
  • M. Bukhari, Oumar Barry and Emadeddin Tanbour, On the vibration analysis of power lines with moving dampers, Journal of Vibration and Control, Published July 4, 2017. http://journals.sagepub.com/doi/abs/10.1177/1077546317719194
  • M. C. Greenfield, Emad Y. Tanbour, 2017, Gap Analysis of a Newly Developed Electrical Engineering Program using NCEES FE Exam, International Journal Of Engineering Research & Technology (IJERT) Volume 06, Issue 01 (January 2017).
  • Oumar Barry and Emadeddin Tanbour, Resonant Frequencies of Perforated Plates with Rectangular Slots, Journal of Mechanical Engineering Science, UK Institute of Mechanical Engineers, December 13, 2016, manuscript ID is JMES-16-0518.R1. http://journals.sagepub.com/doi/10.1177/0954406216683974
  • Nitish Kumar Vaja, Oumar Barry, Emadeddin Y. Tanbour, On the Dynamic Modeling and Analysis of an Asymmetric Stockbridge Damper, Proceedings of the Sixth International Conference on Structural Engineering, Mechanics and Computation, Cape Town, South Africa, 5-7 September 2016. https://www.crcpress.com/Insights-and-Innovations-in-Structural-Engineering-Mechanics-and-Computation/Zingoni/p/book/9781138029279
  • M. Freund, E. Joubaneh, O. Barry and E. Tanbour, Study Of Vibration Of Electric Power Steering Systems Using A Continuous System Model. International Mechanical Engineering Congress and Exhibition, ASME IMECE 2017, November 3-9, 2017, Tampa, Florida, USA. https://mail.google.com/mail/u/0/#search/barry1o%40cmich.edu/WhctKHTKgrdpWgzdWsfKGjgqNldcqHgBhkZbdgLsQFwSPGnLRBfRDlJVbQxMKDSMFMpZpKQ?projector=1&messagePartId=0.2
  • N.K. Vaja, O.R. Barry, E.Y. Tanbour, On the Dynamic Modeling and Analysis of an Asymmetric Stockbridge Damper, Presented at SEMC 2016: The 6th International Conference on Structural Engineering, Mechanics and Computation, September 5-7, 2016, Cape Town, South Africa.
  • Emadeddin Y. Tanbour and Oumar R. Barry, Free Vibration of flame Arrestors: Theoretical and Numerical Analysis, AMSE Journal of Vibrations and Acoustics, September 2015
  • Emad Tanbour and Suleiman Ashur, Gap Analysis of Engineering Course Learning Outcomes using NCEES FE Exam, ASME 2015 International Mechanical Engineering Congress and Exposition, Huston, Texas Nov.13-19, 2015
  • Emadeddin Y. Tanbour, Molu Olumolade and Oumar R. Barry, Newly Introduced Capstone Design Course for Mechanical Engineering Technology – Lessons Learned From Two Cohorts and Two Types of Projects, presented at the 123rd ASEE Annual Conference & Exposition. June 26 - 29, 2016 New Orleans, LA
  • E. Y. Tanbour, Design Optimization and Frequency Analysis of Blast Resistant Doors for 30 G-Force Rating, Canadian Journal on Mechanical Sciences & Engineering, vol. 2, No. 7, November 2011, pp. 157 - 162
  • M. F. Alzoubi, E. Y. Tanbour and R. Al-Waked, Compression and Hysteresis Curves of Nonlinear Polyurethane Foams under Different Densities, Strain Rates and Different Environmental Conditions. Proceedings of IMECE11 2011 ASME International Mechanical Engineering Congress & Exposition November 11-17, 2011, Denver, Colorado, USA
  • E. Y. Tanbour, “Institutional Effectiveness, The Point Of View of Southern Association of Colleges and Schools (SACS),” Presented in the conference of the Vice Rectors for Quality in Saudi Universities, King Saud University, February 27-28, 2011
  • Emad Y. Tanbour, Rafat Al-Waked and Mohamed F. Alzoubi, Experimental Study of a Waste Heat Recovery System for Supplemental Heater, proceedings of 3rd International Conference on Energy and Sustainability, 11 - 13 April 2011, Alicante, Spain
  • Ramin K. Rahmani, Anahita Ayasoufi, Emad Y. Tanbour and Hosein Molavi, “Enhancement of Temperature Blending in Convective Heat Transfer by Motionless Inserts With Variable Segment Length” Journal of Thermal Science and Engineering Applications, September 2010, Vol. 2
  • Ramin K. Rahmani, Emad Y. Tanbour, Anahita Ayasoufi and Hosein Molavi, “Enhancement of Convective Heat Transfer in Internal Compressible Flows by Stationary Inserts” Journal of Thermal Science and Engineering Applications MARCH 2010, Vol. 2
  • Emad Y. Tanbour, Ramin K. Rahmani and Anahita Ayasoufi (2009), “Large-Eddy Simulation of Turbulent Flow Through Small Gage Gas Appliance Orifice,” Proceedings of IMECE 2009, 2009 ASME International Mechanical Engineering and Exposition, November 13-19, 2009, Lake Buena Vista, Florida, USA
  • Emad Y. Tanbour and Ramin K. Rahmani, (2009), “Enhancement of Temperature Blending in Convective Heat Transfer by Motionless Inserts with Variable Segment Length ,” Proceedings of IMECE 2009, 2009 ASME International Mechanical Engineering and Exposition, November 13-19, 2009, Lake Buena Vista, Florida, USA
  • Emad Y. Tanbour and Ramin K. Rahmani, (2009), “A Numerical Study of The Thermal Performance of Two Stationary Insert Design in Internal Compressible Flow,” Proceedings of 2009 ASME Summer Heat Transfer Conference, HT2009, July 19-23, 2009, San Francisco, Ca, USA
  • Emad Y. Tanbour and Ramin K. Rahmani, (2008), “Enhancement Of Natural Convection Heat Transfer Rate In Internal Compressible Flows By Inserting Stationary Inserts,”
  • Proceedings of 2008 ASME Summer Heat Transfer Conference, HT2008, August 10-14, 2008, Jacksonville, Florida USA
  • Emad Y. Tanbour and Ramin K. Rahmani, (2008), “Experimental Study Of Convective Heat Transfer In A Vertical Pipe With Stationary Inserts,” Proceedings of 2008 ASME Summer Heat Transfer Conference, HT2008, August 10-14, 2008, Jacksonville, Florida USA
  • K. Abdel-Malek, J. Yang, R. Brand, M. Vannier, and E. Tanbour. Towards understanding the workspace of human limbs. International Journal of Ergonomics, Oct 22, 2004; 47(13): pp. 1386-1405
  • Butler, P. B., Tanbour, E., Rahman, S., and Smith, T. F., “Virtual International Design Teams,” Proceedings of 2002 ASEE Midwest Section Meeting, Madison, WI, September 2002
  • Abdel-Malek, K., Yang, J., Brand, R., and Tanbour, E., (2002), “Towards Understanding the Workspace of The Upper Extremities,” 2001 SAE Transactions, Journal of Passenger Cars: Mechanical Systems, Vol. 110, Section 6, pages 2198-2206.
  • Mi, Z., Kim, J., and Abdel-Malek, K., Nebel, K., Tanbour, E., “Optimization Based Posture Prediction,” Seventh International Symposium on the 3-D Analysis of Human Movement, Newcastle, United Kingdom, July 10 - 12 2002
  • Abdel-Malek, K., Yang, J., Brand, R., and Tanbour, E., “Towards Understanding the Workspace of the Upper Extremities,” Proceedings of SAE Digital Human Modeling for Design and Engineering, 2001-01-2095, June 26-28, Arlington, VA, USA. [2001 Arch T. Colwell Merit Best Paper Award]
  • Abdel-Malek, K., Yu, W., Tanbour, E., Jaber, M., (2001), “Posture Prediction versus Inverse Kinematics,” Proceedings of the ASME 27th Design Automation Conference, 2001 ASME Design Engineering Technical Conferences, Pittsburgh, Pennsylvania, U.S.A. September 9-12, 2001
  • K. Abdel-Malek, Y. Wei and E. Tanbour, “Inverse Kinematics using Cost Functions,” IASTED International Conference, Robotics and Manufacturing (RM 2001), Cancun, Mexico, May 2001
  • Tanbour, E. Y., and Ahmarow, M. E., “Design and Optimization of Fire-tube Boilers for Large Diary Processing Plants,” Caroline Diary Company, Amman, Jordan, Final Report, ME Department, Yarmouk University, Irbid Jordan, 1987.
  • Tanbour, E. Y. and Ahmarow, M. E., “Design Calculations for Cooling Systems of Industrial Gas Turbines,” ME final Report, Yarmouk University, Irbid, Jordan, 1987.
  • Tanbour, E. Y., “Pressure Distribution on Rotating Cylinders in Cross Flows,” ME final Report, Graduation Project, ME department, Jordan University of Science and Technology, Irbid, Jordan, 1987.
  • Tanbour, E. Y., “Design and manufacturing of new pressure measurement mechanism on rotating bodies in cross flows,” Final Report, ME Department, Jordan University of Science and Technologies, Irbid, Jordan, 1988.
  • Tanbour, E. Y., “Wind Energy in Jordan,” Department of Energy, Jordan, and Jordan University of Science and Technology, Irbid, Jordan, 1989. Project was funded by United Nations
  • Tanbour, E. Y., “Heat Transfer to Gas-Solid Suspension Flows in Vertical Pipes,” M.S. Thesis, Jordan University of Science and Technologies, Irbid, Jordan, 1990.
  • Tanbour, E. Y., “Modeling non-isothermal multiphase-multicomponent flow and transport in porous media using the two phase mixture approach,” Ph.D. Thesis, The University of Iowa, Iowa City, Iowa, USA, 1997.
  • Tanbour, E. Y., “Modeling spillage from an open door gas fired fire place using ANSYS Flotran module,” Final Report - HNI Corporation, Muscatine, Iowa, USA, 2001
  • Tanbour, E. Y., “CFD and Heat Transfer Simulation of flow in co-axial elbows with internal baffles. Application to venting of zero-clearance fireplace chimney pipes.” Hearth and Home Inc., Lakeville, MN, USA, 2000
  • Tanbour, E. Y., Ryan B. and Smith, T., “Development of a Waste Heat Recovery Heat Exchanger for Supplemental Heaters,” Technical Report ME-01-002, Department of Mechanical Engineering, The University of Iowa, Iowa City, Iowa, 52242, USA, Feb. 2001
  • Tanbour, E. Y., Hu, J. and Smith T., “Waste Heat Recovery Heat Exchanger for Supplemental Heaters,” Technical Report ME-01-006, Department of Mechanical Engineering, The University of Iowa, Iowa City, Iowa, 52242, USA, July 2001
  • Tanbour, E. Y., Yu, X. and Smith, T., “Literature Review of Flexible and Adaptive HVAC Distribution Systems for Office Buildings,” Technical Report ME-01-005, Department of Mechanical Engineering, The University of Iowa, Iowa City, Iowa, 52242, USA, July 2001
  • Tanbour, E. Y., “Prince M. Bin Fahd University, Strategic Plan for National Commission for Academic Accreditation and Assessment”. August 2009
  • Tanbour, E. Y., “Prince M. Bin Fahd University, College of Engineering Strategic Plan for ABET Accreditation”. August, 2009 to February 2011
  • Tanbour, E. Y., “Prince M. Bin Fahd University, College of Engineering Academic Catalog, Revision”. August, 2009 continuing
  • Tanbour, E. Y., “Prince M. Bin Fahd University, Strategic Plan for (Sothern Association of Colleges and Schools) SACS Accreditation”. August, 2009.
  • Tanbour, E. Y. (Joint author with Professor Jamal Nayfeh, Dean of College of Engineering),” Master of Science in Mechanical Engineering, Program Specifications, Courses Specification and Syllabi in compliance with National Commission for Academic Accreditation and Assessment (NCAAA). Prince M. Bin Fahd University, December 2011.
  • Tanbour, E. Y. (Joint author with Professor Jamal Nayfeh, Dean of College of Engineering),” Master of Science in Energy Systems Engineering, Program Specifications, Courses Specification and Syllabi in compliance with NCAAA. Prince M. Bin Fahd University, December 2011.
  • Tanbour, E. Y. (contributing author with Professor Jamal Nayfeh, Dean of College of Engineering),” Master of Science in Electrical Engineering, Program Specifications, Courses Specification and Syllabi in compliance with NCAAA. Prince M. Bin Fahd University, December 2011.

Selected Presentations

  • Oumar Barry and Emadeddin Tanbour, Resonant Frequencies of Perforated Plates with Rectangular Slots, accepted for publication in the Journal of Mechanical Engineering Science, UK Institute of Mechanical Engineers, August, 2016, manuscript ID is JMES-16-0518.R1
  • N.K. Vaja, O.R. Barry, E.Y. Tanbour, On the dynamic modeling and analysis of an asymmetric Stockbridge damper, Accepted for publication and presentation in SEMC 2016: The 6th International Conference On Structural Engineering, Mechanics And Computation, September 5–7, 2016, Cape Town, South Africa.
  • Emadeddin Y. Tanbour and Oumar R. Barry, Free Vibration of flame Arrestors: Theoretical and Numerical Analysis, submitted to AMSE Journal of Vibrations and Acoustics, September, 2015
  • Emad Tanbour and Suleiman Ashur, Gap Analysis of Engineering Course Learning Outcomes using NCEES FE Exam, accepted for publication and presentations ASME 2015 International Mechanical Engineering Congress and Exposition, Huston, Texas Nov. 1319, 2015
  • Emadeddin Y. Tanbour, Molu Olumolade and Oumar R. Barry, Newly Introduced Capstone Design Course for Mechanical Engineering Technology – Lessons Learned From Two Cohorts and Two Types of Projects, presented at the 123rd ASEE Annual Conference and Exposition. June 2629, 2016 New Orleans, LA
  • E. Y. Tanbour, Design Optimization and Frequency Analysis of Blast Resistant Doors for 30 G-Force Rating, Canadian Journal on Mechanical Sciences and Engineering, vol. 2, No. 7, November, 2011, pp. 157162
  • M. F. Alzoubi, E. Y. Tanbour and R. Al-Waked, Compression and Hysteresis Curves of Nonlinear Polyurethane Foams under Different Densities, Strain Rates and Different Environmental Conditions. Accepted for publication and will appear in: Proceedings of IMECE11 2011 ASME International Mechanical Engineering Congress & Exposition November 1117, 2011, Denver, Colorado, USA
  • E. Y. Tanbour, "Institutional Effectiveness, The Point Of View Of Southern Association Of Colleges And Schools (SACS)," Presented in the conference of the Vice Rectors for Quality in Saudi Universities, King Saud University, February 2728, 2011
  • Emad Y. Tanbour, Rafat Al-Waked and Mohamed F. Alzoubi, Experimental Study of a Waste Heat Recovery System for Supplemental Heater, proceedings of 3rd International Conference on Energy and Sustainability, April 1113, 2011, Alicante, Spain
  • Ramin K. Rahmani, Anahita Ayasoufi, Emad Y. Tanbour and Hosein Molavi, "Enhancement of Temperature Blending in Convective Heat Transfer by Motionless Inserts With Variable Segment Length" Journal of Thermal Science and Engineering Applications, September, 2010, Vol. 2
  • Ramin K. Rahmani, Emad Y. Tanbour, Anahita Ayasoufi and Hosein Molavi, "Enhancement of Convective Heat Transfer in Internal Compressible Flows by Stationary Inserts" Journal of Thermal Science and Engineering Applications March, 2010, Vol. 2

Patents / Awards / Grants

  • US 2019/0145507 Al Slider-Crank Mechanism For Eliminating Side Forces
  • US Patent Number D607094, Air intake for water heater
  • US Patent Number 20090308332 Water Heater With Forced Draft Air Inlet
  • US Patent Number 20100065203 Sealable Water Hater Manifold Doors
  • US Patent Number D614680, Sight glass and frame
  • US Patent Number 20100101510 Water Haters With Sealed Door Assembly
  • US Patent Number 20100154724 Water Heater Burner Tube and Door Assembly
  • US Patent Number 8490580, Water Heaters with Sealed Door Assembly
  • US Patent Number 20100101508 Water Heaters with Sealed Door Assembly
  • US Patent Number 20130284118 Water Heaters with Sealed Door Assembly
  • US Patent Number 20100101509 Water Heaters with Sealed Door Assemblies
  • US Patent Number 20100101507 Water Heaters with Fuel Line and Door Assembly
  • US Patent Number 8596226 Water Heater Burner Tube and Door Assembly
  • US Patent Number 20090084328 Water Heaters with Combustion Air Inlet
  • US Patent Number 20040011348 Apparatus and Method for Cooling a Surface of a Fireplace
  • US Patent Number 56848441, Apparatus and method for cooling a surface of a fireplace (also issued by WIPO)
  • US Patent Number 6848441 Apparatus and Method for Cooling a Surface of a Fireplace
  • US Patent Number 9,948,081 Asymmetric Aeolian Vibration Damper

Professional Memberships and Affiliations

  • Member of the founding body at Aramco Combustion Institute - Chapter, 2010present
  • Professional Member of the American Society of Metals (ASM), 2004present.
  • Member of Combustion Institute, 1998present.
  • Member of the American Society of Mechanical Engineers (ASME), 1992present.
  • Member of Jordan Society of Engineers, Mechanical Engineering, 1987present.
  • Member of the Pioneers' Committee, American Institute of Sustainable Science and Technology, Iowa, 1999present
  • Member of the Advisory Board of the Digital Human Lab-Center for Computer Aided Design (CCAD), The University of Iowa, Iowa City, Iowa, 2000present

Additional Information

In January 2014, Dr. Tanbour joined Central Michigan University (CMU) as a visiting scholar and he served as tenure track assistant professor of mechanical engineering technology for 2.5 years. During his first year at Central Michigan University, Dr. Tanbour taught engineering mechanics courses for both engineering and engineering technology majors, thermodynamic for ME major, applied fluid mechanics, machine design and capstone projects for senior engineering technology cohort. He served on the SET Graduate Committee where he led the process to develop the assessment plan for the new Master of Science in Engineering. Dr. Tanbour built a state of the art virtual reality laboratory at CMU.  He served in MET Assessment Committee and as MET Program Coordinator. During the spring of 2015 and of 2016, Dr. Tanbour taught the Senior Capstone Industrial Design course for all BSET graduating seniors where he managed to attract three externally sponsored design projects (2015) and five externally sponsored projects (2016). Dr. Tanbour is active in research and has published in engineering education conferences (ASEE and ASME), and mechanical engineering periodicals and conferences.

In 2009, Dr. Emad Tanbour joined Prince M. B. Fahd University (PMU) faculty of mechanical engineering. He has led the university strategic plans to achieve total quality assurance. He served as senior advisor to the rector on accreditation and was promoted to dean of quality and accreditation reporting directly to the rector.

During 2005 to 2009, Dr. Tanbour managed product development engineering for Whirlpool and AO Smith water heaters. He led the development of several energy efficient residential water heaters. He was successful in developing the world first ultra-low NOX water heater and the production of many DOE-rated Energy Star power-vented water heaters. His experience included utilization of CFD and state of the art CAD deployment through the industry. He also established industry-largest development and reliability labs for residential water heaters at Whirlpool.

During 1997 to 2005, Dr. Tanbour worked as research and development senior manager at HNI Corporate Technical Center, the second largest manufacturer of office furniture and hearth systems in North America. He led research and development projects utilizing computational mechanics and founded the Hearth Lab at the corporate center. His eight years at HNI included numerous industry-academia funded research projects and strong collaboration relationship with the University Of Iowa College Of Engineering and the Center for Computer Aided Design. During the same period, Dr. Tanbour was active in service in the State of Iowa where he served as co-chair to advanced technical training at the Iowa Department of Economic Development and several industry-academia service capacities.

During 1993 to 1997, Dr. Tanbour was leading Gail Industry high pressure pumps manufacturing where he successfully developed hydrostatic testing piston pumps and mud pumps for oil and gas operations in California and Texas.

Dr. Tanbour has a proven teaching and research record. He served as adjunct assistant professor at the University of Iowa (2000 to 2005) teaching undergraduate and graduate mechanical engineering curriculum and as full time faculty (2009–2013) at Prince M. B. Fahd University. He was principal investigator in several HNI - U of Iowa funded research projects. He managed to secure $300,000 seed funding of the virtual reality lab jointly at HNI/Allsteel and U of Iowa. This seed funding attracted over $18 million in research grants over the past 10 years to the Center for Computer Aided Design at Iowa where he is still an affiliate research scholar. His record of service and research is evident in the list of publications in thermo- fluids and interdisciplinary mechanical engineering. Dr. Tanbour is still active in consulting projects for manufacturers in KSA and USA in the area of mechanical engineering design.