Research Area:

• Mathematical Modelling in Fluid Mechanics and Heat Transfer

  • Newtonian and non-Newtonian fluids

  • Laminar boundary layer flow (steady and unsteady flows)

  • Stagnation-point flow (orthogonal and oblique flows)

  • Convection flow

Research Grant: 

1. 2019-2022, Mathematical Modelling of Steady Bödewadt Flow and Heat Transfer in Nanofluids with Suction, Fundamental Research Grant Scheme (FRGS), RM55,200.

2. 2013-2016, Theoretical Investigation on Unsteady Separated Stagnation-Point Flow Towards a Stretching or Shrinking Sheet, Fundamental Research Grant Scheme (FRGS), RM65,000.

3. 2011-2012, Stagnation Flow Towards a Shrinking Sheet in an Upper Convected Maxwell Fluids, Short Term Research Grant USM, RM26,600.

4. 2011-2012, Magnetohydrodynamic Stagnation Point Flow with Mass Transfer Towards a Shrinking Sheet, Incentive Grant USM, RM5,000.

5. 2008-2010, Mathematical Modelling of Stagnation Flow Towards a Shrinking Sheet, Fundamental Research Grant Scheme (FRGS), RM54,000.

6. 2005-2006, Mathematical Modelling of Stagnation Point Flow Induced by Accelerating Motion in Micropolar Fluid, Short Term Research Grant KUTKM, RM7,500.

Research Publication:

A. Research Book

1. Merkin, J.H., Pop, I., Lok. Y.Y. and Grosan, T. (2021). Similarity Solutions for the Boundary Layer Flow and Heat Transfer of Viscous Fluids, Nanofluids, Porous Media and Micropolar Fluids. New York: Academic Press, Imprint of Elsevier.

B. Research Article

1. Merkin, J.H., Lok, Y.Y. and Pop, I. (2023). Numerical and Asymptotic Solutions of the Unsteady Mixed Convection Boundary-Layer Flow over an Expanding/Contracting Vertical Cylinder. International Journal of Numerical Methods for Heat and Fluid Flow, Vol 33 (2), pp 801-824. (ISI, Emerald)

2. Lok, Y.Y., Pop, I. and Merkin, J.H. (2022). A Note on the Asymptotic Behaviour of Axisymmetric Stagnation-Point Flow and Heat Transfer of a Viscous Fluid past a Permeable Stretching/Shrinking Cylinder. International Communications in Heat and Mass Transfer, Vol. 138, 106362. (ISI, Elsevier)

3. Waini, I., Ishak, A., Lok, Y.Y. and Pop, I. (2022). Micropolar Nanofluid Flow in a Stagnation Region of a Shrinking Sheet with Fe3O4 Nanoparticles. Mathematics, Vol. 10 (17), 3184. (ISI, MDPI)

4. Mahyuddin, A.A., Lok, Y.Y. and Ahmad, S. (2022). Bodewadt Flow and Heat Transfer in Nanofluid over a Permeable and Radially Stretching Disk. Sains Malaysiana, Vol. 51 (2), pp 619-632 (ISI, Penerbit UKM)

5. Tan, J.G., Lok, Y.Y. and Pop, I. (2022). Mathematical Modelling of Boundary Layer Flow over a Permeable and Time-Dependent Shrinking Sheet – A Stability Analysis. Journal of Mechanical Engineering and Sciences, Vol. 16 (2), pp 8837-8847 (MyJurnal, Penerbit UMP)

6. Merkin, J.H., Lok. Y.Y. and Pop, I. (2021). A Note on Non-Symmetric Flow: Surface Shrinking in Mutually Orthogonal Directions. Meccanica, Vol. 56, pp 1727-1737 (ISI, Springer)

7. Lok, Y.Y., Merkin, J.H. and Pop, I. (2019). Non-Symmetric Flow over a Stretching/Shrinking Surface with Mass Transfer. Mathematical Modelling and Analysis, Vol. 24, pp 617-634 (ISI, VGTU Press)

8. Merkin, J.H., Lok. Y.Y. and Pop, I. (2019). On an Equation Arising in Natural Convection Boundary Layer Flow in a Porous Medium. Zeitschrift für angewandte Mathematik und Physik (ZAMP), Vol. 70, 143 (ISI, Birkhäuser)

9. Lok, Y.Y., Merkin, J.H. and Pop, I. (2018). Axisymmetric Rotational Stagnation-Point Flow Impinging on a Permeable Stretching/Shrinking Rotating Disk. European Journal of Mechanics/B Fluids, Vol. 72, pp 275-292 (ISI, Elsevier)

10. Lok, Y.Y., Ishak, A. and Pop, I. (2018). Oblique Stagnation Slip Flow of a Micropolar Fluid Towards a Stretching/Shrinking Surface: A Stability Analysis. Chinese Journal of Physics, Vol. 56, pp 3062-3072 (ISI, Elsevier)

11. Lok, Y.Y., Merkin, J.H. and Pop, I. (2017). Mixed Convection Non-Axisymmetric Homann Stagnation-Point Flow. Journal of Fluid Mechanics, Vol. 812, pp 418-434 (ISI, Cambridge University Press)

12. Merkin, J.H., Lok, Y.Y. and Pop, I. (2016). A Note on the Stagnation-Point Flow over a Permeable Shrinking Sheet with Slip Effects. International Communications in Heat and Mass Transfer, Vol. 71, pp 101-107 (ISI, Elsevier)

13. Lok, Y.Y., Merkin, J.H. and Pop, I. (2015). MHD Oblique Stagnation-Point Flow towards a Stretching/Shrinking Surface. Meccanica, Vol. 50, pp 2949-2961 (ISI, Springer)

14. Lok. Y.Y. and Pop, I. (2014). Stretching or Shrinking Sheet Problem for Unsteady Separated Stagnation-Point Flow. Meccanica, Vol. 49, pp 1479-1492 (ISI, Springer)

15. Lok. Y.Y., Merkin, J.H. and Pop, I. (2013). Mixed Convection Boundary-Layer Flow Over Vertical Surface Embedded in a Porous material Subject to a Convective Boundary Condition. Transport in Porous Media, Vol. 98, pp 451-463 (ISI, Springer)

16. Merkin, J.H., Lok, Y.Y. and Pop, I. (2013). Mixed Convection Boundary-Layer Flow On a Vertical Surface in a Porous Medium with a Constant Convective Boundary Condition. Transport in Porous Media, Vol. 99, pp 413-425 (ISI, Springer)

17. Lok Y.Y., Ishak, A. and Pop, I. (2013). Stagnation-Point Flow and Heat Transfer Towards a Shrinking Sheet with Suction in an Upper Convected Maxwell Fluid. Zeitschrift für Naturforschung A – Physical Sciences, Vol. 68a, pp 693-700 (ISI, Walter De Gruyter GMBH)

18. Ishak, A., Lok, Y.Y. and Pop, I. (2012). Non-Newtonian Power-Law Fluid Flow Past a Shrinking Sheet with Suction. Chemical Engineering Communications, Vol. 199, pp 142-150 (ISI, Taylor & Francis)

19. Lok, Y.Y., Merkin, J.H. and Pop, I. (2012). Mixed Convection Flow near the Axisymmetric Stagnation Point on a Stretching or Shrinking Cylinder. International Journal of Thermal Sciences, Vol. 59, pp 186-194 (ISI, Elsevier)

20. Lok, Y.Y. and Pop, I. (2011). Wang’s Shrinking Cylinder Problem with Suction near a Stagnation Point. Physics of Fluids, Vol. 23 (8), 083105, 2011. (ISI, American Institute of Physics)

21. Lok, Y.Y., Ishak, A. and Pop, I. (2011). MHD Stagnation-Point Flow Towards a Shrinking Sheet. International Journal of Numerical Methods for Heat and Fluid Flow, Vol. 21, pp 61-72 (ISI, Emerald)

22. Lok, Y.Y., Ishak, A. and Pop, I. (2011). MHD Stagnation Point Flow with Suction Towards a Shrinking Sheet. Sains Malaysiana, Vol. 40, pp 1179-1186 (ISI, UKM)

23. Lok, Y.Y., Pop, I. and Ingham, D.B. (2010). Oblique Stagnation Slip Flow of a Micropolar Fluid. Meccanica, Vol. 45, pp 187-198 (ISI, Springer)

24. Ishak, A., Lok, Y.Y. and Pop, I. (2010). Stagnation-Point Flow over a Shrinking Sheet in a Micropolar Fluid. Chemical Engineering Communications, Vol. 197, pp 1417-1427 (ISI, Taylor & Francis)

25. Lok, Y.Y., Pop, I. and Ingham, D.B. (2009). Steady Two-dimensional Periodic Motion of a Micropolar Fluid near an Infinite Array of Moving Walls. Zeitschrift für Angewandte Mathematik und Mechanik (ZAMM), Vol. 89, pp 570-586 (ISI, Wiley-VCH Verlag GmbH)

26. Lok, Y.Y., Pop, I. Ingham, D.B. and Amin, N. (2009). Mixed Convection Flow of a Micropolar Fluid Near a Non-Orthogonal Stagnation-Point on a Stretching Vertical Sheet. International Journal of Numerical Methods for Heat and Fluid Flow, Vol. 39, pp 459-483 (ISI, Emerald)

27. Lok, Y.Y., Amin, N. and Pop, I. (2009). Unsteady Boundary Layer Flow Induced by Accelerating Motion near the Rear Stagnation Point in a Micropolar Fluid. International Journal of Fluid Mechanics Research, Vol. 36, pp.30-42 (Scopus, Begell House)

28. Lok, Y.Y., Amin, N. and Pop, I. (2007). Mixed Convection Flow Near a Non-Orthogonal Stagnation-point Towards a Stretching Vertical Plate. International Journal of Heat and Mass Transfer, Vol. 50, pp 4855-4863 (ISI, Elsevier)

29. Lok, Y.Y., Pop, I. and Chamkha, Ali, J. (2007). Non-orthogonal Stagnation Point Flow of a Micropolar Fluid. International Journal of Engineering Science, Vol. 45, pp 173-184 (ISI, Elsevier)

30. Lok, Y.Y., Amin, N. and Pop, I. (2007). Comments on the paper “Steady Two-dimensional Oblique Stagnation-Point Flow Towards a Stretching Surface” by M. Reza and A.S. Gupta, published in Fluid Dynamic Research 37 (2005) 334-340. Fluid Dynamic Research, Vol. 39, pp 505-510 (ISI, Elsevier)

31. Lok, Y.Y., Amin, N. and Pop, I. (2007). Unsteady Boundary Layer Flow of a Micropolar Fluid near a Stagnation Point with Uniform Suction or Injection. Jurnal Teknologi, Vol. 46 (C), pp 15-32 (Scopus, Penerbit UTM)

32. Lok, Y.Y., Amin, N. and Pop, I. (2006). Unsteady Mixed Convection Flow of a Micropolar Fluid Near the Stagnation Point on a Vertical Surface, International Journal of Thermal Sciences, Vol. 45 (12), pp 1149-1157 (ISI, Elsevier)

33. Lok, Y.Y., Amin, N. and Pop, I. (2006). Mixed Convection Near a Non-orthogonal Stagnation Point Flow on a Vertical Plate with Uniform Surface Heat Flux. Acta Mechanica, Vol.186, pp 99-112 (ISI, Springer)

34. Lok, Y.Y., Amin, N. and Pop, I. (2006). Non-orthogonal Stagnation Point towards a Stretching Sheet. International Journal of Non-linear Mechanics, Vol.41, pp 622-627 (ISI, Elsevier)

35. Lok, Y.Y., Amin, N., Campean, D. and Pop, I. (2005). Steady Mixed Convection Flow of a Micropolar Fluid near the Stagnation Point on a Vertical Surface. International Journal of Numerical Methods for Heat and Fluid Flow, Vol. 15, No. 7, pp 654-670 (ISI, Emerald)

36. Lok, Y.Y., Phang, P., Amin, N. and Pop, I. (2003). Unsteady Boundary Layer Flow of a Micropolar Fluid Near the Forward Stagnation Point of A Plane Surface. International Journal of Engineering Science, Vol. 41, pp 173-186 (ISI, Pergamon)

37. Lok Y.Y., Amin, N. and Pop, I. (2003). Steady Two-Dimensional Asymmetric Stagnation Point Flow of a Micropolar Fluid. Journal of Applied Mathematics and Mechanics (ZAMM), Vol. 83, No.9, pp 594-602 (ISI, Wiley-VCH Verlag GmbH)

38. Lok Y.Y., Amin, N. and Pop, I. (2003). Unsteady Boundary Layer Flow of a Micropolar Fluid Near the Rear Stagnation Point of A Plane Surface. International Journal of Thermal Sciences, Vol. 42, pp 995-1001 (ISI, Elsevier)

39. Lok, Y.Y. and Amin, N. (2002). Local Nonsimilarity Solution for Vertical Free Convection Boundary Layers, Jurnal Matematika (Malaysian Journal of Industrial and Applied Mathematics), Vol. 18(1), pp 21-31 (Penerbit UTM)

C. Scopus Conference Proceedings

1. Mahyuddin, A.A., Lok, Y.Y. and Ahmad S. (2021). Bödewadt Flow and Heat Transfer in Nanofluid Over a Stagnant Disk with Suction. Proceedings of the International Conference on Mathematical Sciences and Technology 2020 (MathTech 2020), AIP Conference Proceedings 2423, pp 020012-1020012-7 (Scopus, AIP Publishing)

2. Lok, Y.Y., Ahmad, S. and Pop, I. (2014). Unsteady Separated Stagnation-Point Flow with Suction Towards a Stretching Sheet. Proceedings of the 3rd International Conference on Mathematical Science, AIP Conference Proceedings 1602, pp 317-322 (Scopus, AIP Publishing)

3. Lok, Y.Y. and Ahmad, S. (2014). Unsteady Boundary Layer Separated Stagnation-Point Flow Towards a Permeable Shrinking Sheet. Proceedings of the 21st National Symposium on Mathematical Sciences (SKSM21), AIP Conference Proceedings 1605, pp 298-301 (Scopus, AIP Publishing)

4. Lok, Y.Y., Abdul Karim, M.F. and Pop, I. (2013). Stagnation Point Flow towards a Melting Shrinking Sheet in an Upper Convected Maxwell Fluid. Proceedings of the 20th National Symposium on Mathematical Sciences (SKSM20), AIP Conference Proceedings 1522, pp 614-619 (Scopus, AIP Publishing)

Other Publication:

1. Academic Textbook, Title: Numerical Methods (Third Edition), Prentice Hall, Pearson Malaysia, 2009. ISBN: 978-967-349-007-3

   Authors: Khoo Chin Foon, Sharifah Sakinah Syed Ahmad, Zuraini Othman and Lok Yian Yian

2. Teaching and Learning Module, Title: Analisis Item, Peperiksaan dan Pencapaian Learning Outcome (LO), UTeM Press, 2011.

   Authors: Lok Yian Yian dan Norasiken Bakar

Master (Completed):

1. Anis Anisah binti Mahyuddin, 2022, Mathematical Modelling of Steady Bödewadt Flow and Heat Transfer in Nanofluid and Hybrid Nanofluid

Awards:

1. Anugerah Perkhidmatan Cemerlang (Excellent Service Award), PPPJJ, USM, 2019.

2. Hadiah Sanjungan (Category of Journal Publication), USM, 2019, 2018, 2017, 2011.

3. Anugerah Sanggar Sanjung (Category of Journal Publication), USM, 2016, 2012.

4. Dean’s Award (Excellent Services), PPPJJ, USM, 2011.

5. Anugerah PERSAMA (Main Prize of Category of Ph.D. Thesis), PERSAMA, 2009.

6. European Union Marie Curie Short Term Fellowship, Host: Centre for Computational Fluid Dynamics, School of Process, Environmental and material Engineering, University of Leeds, U.K. (The Sixth Framework Marie Curie Actions Programme), 2007.

7. Highly Commended Award (Category of Journal Article), Emerald Literati Network, 2006.

Recognitions:

1. Internal Examiner for Thesis:

Doctor of Philosophy (Mathematics) – Research, USM, 2021.

Asma Izzati binti Asnor, High Order Variable Step Variable Order Block Backward Differentiation Formulae for Solving Higher Order Stiff Ordinary Differential Equations

2. External Examiner for Thesis:

(i). Master of Science (Mathematics) – Research, UTM, 2018.

Koo Meng Lian, Mathematical Modelling of Blood Flow in a Catheterized Artery with Time Variant Multiple Stenoses.

(ii). Master of Science (Engineering Mathematics) – Mixed Mode, UniMAP, 2017.

Nur Athirah binti Azami, Boundary Layer Flow and Heat Transfer Over Stretching/Shrinking sheet in a Nanofluid with Slip Effect.

(iii). Master of Science (Engineering Mathematics) – Mixed Mode, UniMAP, 2013.

Nurul Najwa binti Mansor, Stagnation Point Flow and Heat Transfer towards a Stretching Sheet with Suction in a Nanofluid.

(iv). Master of Science (Mathematics) – Research, UTM, 2011.

Abdul Rahman Mohd. Kasim, Free and Mixed Convection Boundary Layer Flow of Viscoelastics Fluids Past a Horizontal Circular Cylinder.

3. Accessor, Research Grant:

(i). Research University Grant Individual (RUI), Final Report, 2023

        University Level (Appointed by RCMO)

(ii). Fundamental Research Grant Scheme, 2023

        PTJ Level (Appointed by PPPJJ)

(iii). USM Short Term Grant, 2022

      Cluster: Pure Sciences & Applied Sciences; University Level (Appointed by RCMO)

(iv). Fundamental Research Grant Scheme, 2022

          PTJ Level (Appointed by PPPJJ)

(v). USM Short Term Grant, 2022

       PTJ Level (Appointed by PPPJJ)

(vi). Research University Grant Individual (RUI), Progress Report, 2020

       University Level (Appointed by RCMO)

(vii). Fundamental Research Grant Scheme, 2018

       University Level (Appointed by RCMO)

4. Reviewer, Book Chapters, Penerbit UTM Press, 2023.

Title of Book: Discovering Mathematics in Music, Agriculture and Applied Sciences

Title of Accessed Chapter: Heat Transfer in a Rectangular Thin Surface

5. Reviewer, Articles in Academic Journal:

• • Ain Shams Engineering Journal (Elsevier)

  • Alexandria Engineering Journal (Elsevier

  • Applied Thermal Engineering (Elsevier)

  • Boundary Layer Problems (Springer)

  • Chemical Engineering Communication (Taylor & Francis)

  • International Journal for Numerical Methods in Fluids (John Wiley & Sons)

  • International Journal of Ambient Energy (Taylor & Francis)

  • International Journal of Applied and Computational Mathematics (Springer)

  • International Journal of Heat and Mass Transfer (Elsevier)

  • International Journal of Non-Linear Mechanics (Elsevier)

  • International Journal of Numerical Methods for Heat and Fluid Flow (Emerald)

  • Journal of Mechanics (Cambridge University Press)

  • Journal of Science and Technology (UTHM Press)

  • Journal of the Franklin Institute (Elsevier)

  • Malaysian Journal of Mathematical Sciences (MJMS) (UPM Press)

  • Mathematical Problems in Engineering (Hindawi Publishing)

  • Meccanica (Springer)

  • Microfluidics and Nanofluidics (Springer)

  • Nanoscale Research Letters (Springer

  • Physica A (Elsevier)

  • Propulsion and Power Research (Elsevier)

  • Sains Malaysiana (UKM Press)

  • The European Physical Journal Plus (Springer)

  • Thermal Science (Vinča Institute of Nuclear Sciences, Belgrade)

  • ZAMM - Journal of Applied Mathematics and Mechanics (Wiley-VCH Verlag GmbH)

  • Zeitschrift für Naturforschung A – Physical Sciences (Walter De Gruyter GmbH)

6. AJK Tetap Penilaian Awal Kenaikan Pangkat Staf Akademik, USM, 2019.

Jawatan Pensyarah Kanan & Profesor Madya

Category: Pure Sciences

7. Judge, 3-Minute Thesis Competition, Computer Science Postgraduate Colloquium CSPC, 2018.

8. Visiting Researcher, School of Mathematical Sciences, UKM, 15 Jan – 29 Jan 2015.

Research title: Convective Boundary Layer Flows and Heat Transfer

Project Leader: Prof. Dr. Roslinda Mohd Nazar

9. Panelist, Sambutan Hari Wanita Antarabangsa (International Women Day) Peringkat USM, 2016

Organizer: Women’s Development Research Centre (KANITA), USM

Training Course:

1. Bridging Program, USM, 2014 and 2011

Module 1: Basic Mathematics 1

Module 2: Basic Mathematics 2

Module 3: Introduction to Statistics

2. Mathematics in Control Systems Workshop, UTeM, 2008

Module 1: Differential Equation & Laplace Transform

Module 2: Inverse Laplace & Partial Fraction

Module 3: Solving Problems & Tutorial

3. Basic Courses for Teaching and Learning, UTeM, 2009 and 2010

Module 4A: Concepts of Tests, Measurements and Assessments

Module: 4C Analysis Question Items and Examination

Community Engagement:

1. Upacara Konvokesyen ke-50 & ke-54, USM, Pembawa Cokmar, 2014 & 2016.

2. Persatuan Kakitangan Akademik dan Pentadbiran (PKAP) USM, Juru Audit (2020-2021), Naib Presiden (2016-2017), Ahli Exco (2012-2015, 2018-2019).

3. Majlis Bersama Jabatan, USM, 2012-2013, 2016-2017.

4. Badan Kebajikan Kakitangan PPPJJ, Bendahari, 2013-2015.

5. Project, Committee Member, Reviewing Mathematics Proficiency of Graduated Polytechnics Students, 2009.

6. Program Ceramah Kerjaya, Sekolah Menengah Kebangsaan Ghafar Baba, Maskid Tanah, Melaka, 2008.

7. Nationalism Module for National Service Training Programme, Coach, 2004.

8. Persatuan Sains Matematik Malaysia (PERSAMA), Life Member.

9. Malaysian Nature Society, Member, 2010, 2011.