Dr. Shadi Mahjoob is an Assistant Professor at Mechanical Engineering Department, California State University, Northridge. Her field of expertise and interest is thermofluids sciences and has worked on a wide range of mechanical engineering projects, using Computational Fluid Dynamics (CFD), analytical and experimental techniques. She received her BSc and MSc degrees in Aerospace Engineering from Amirkabir University of Technology (Tehran Polytechnic) and her PhD degree from University of California, Riverside. She worked as a Postdoctorate Research Scientist, at Nano and Micro-Fluidics Institute (Center of Smart Interface) at TU Darmstadt, Germany. She then joined a company in North California as a Principal Scientist. She is currently an Assistance Prof. at CSUN. Her research expertise and interest include, but not limited to: thermal transport through biological media, cooling of biomedical devices, electronics cooling, heat transfer through porous media, multi phase flow, boiling and phase change, thermal transport in micro-channels and advanced heat exchangers, renewable energy, fan design and testing, rotor aerodynamics, wind and gas turbines, energy recovery systems, jet impingement mixing and film cooling.
- Numerical Investigation of Transport through Biological Media
- Cooling of Biomedical Devices Employing Conductive Porous Substrates
Research Lab – Thermofluid Research and Design Lab
Background and Purpose
Bioheat transfer is the study of heat transfer through biological tissue. It is one of the important research topics to understand how heat penetrates through tissues and organs during medical thermal therapeutic applications. Knowing accurate temperature distribution within tissues and organ provides a great opportunity to avoid any damages to healthy tissues and to develop new medical devices or treatments to reduce the pain and side effects. One of the principal issues in medical thermal therapeutic applications, such as hyperthermia cancer treatment, is to properly predict temperature variation within biological tissues and body organs subjected to thermal treatment. Hyperthermia treatment is one of the four main cancer therapy techniques following surgery, chemotherapy, and radiation techniques. In hyperthermia, the tumor cells will be overheated to a high value of around 40–45 °C to kill or damage the cancer cells. There are different techniques to provide heat in hyperthermia cancer treatment, including microwave ablation (MWA), radiofrequency ablation (RFA), ultrasound, hot water blankets, and thermal chambers. In this work, modeling of bioheat transport through the tissue/organ will be carried out during microwave and radiofrequency ablation process. The effects of several parameters such as applied hyperthermia heat flux intensity, volume fraction of the vascular space, blood and tissue matrix thermal conductivities, tissue matrix permeability and size, blood pressure and velocity and metabolic heat generation on blood and tissue phase temperatures and thermal transport during the treatment will be investigated. In addition, heat transfer in biomedical devices and in advanced heat management devices for cooling of biomedical devices will be investigated.
Research Questions or Hypothesis
A principal issue in medical thermal therapeutic applications, such as hyperthermia treatment, is modeling and understanding the heat transport and temperature variation within biological tissues and body organs. Biological media generally consist of cells, blood vessels, and interstitial space that categorize as vascular and extra- vascular regions. Biological structure can be modeled as a porous matrix, including cells and interstitial space, called tissue in which the blood flows through. Utilizing the porous media theory, non-thermal equilibrium between the blood and the tissue is addressed and the blood–tissue convective heat exchange is taken into account. In this work, numerical modeling will be performed utilizing CFD (computational fluid dynamic) commercial software. Both local thermal non-equilibrium and local thermal equilibrium models in porous media will be employed in the studies. Experimental and numerical studies are also performed to develop cooling techniques for biomedical devices.
Commercial CFD software such as ANYSY FLUENT will be employed for numerical modeling and advanced techniques in porous media will be utilized. In addition, experimental and numerical studies are performed for development of cooling techniques for biomedical devices.
The sophomore, junior, and senior undergraduate students may assist the graduate students and the PI for developing the experimental set-up, performing experimental measurements, data collection, and post-processing of data while doing literature review, getting involve in numerical simulations and preparing the reports and papers.
Enthusiastic students interested in thermofluids sciences, bioheat transfer and cooling of biomedical devices are encouraged to join the lab to perform hands on experimental or computational thermofluid projects. Undergraduate students can gain research experience and assist graduate students to perform research and have research publications or conference presentations. The students should follow all lab regulations and be responsible, on time, self motivated, honest, detail oriented, good listener and reader, and should collaborate properly with other students.
Conferences Typically Attended
Some of the related conferences the PI attends are CSUPerb conferences (CSU Annual Biotechnology Symposium), ASME conferences such as (Summer Heat Transfer conf.) and IEEE conferences (such as IEEE Itherm conf. and IEEE Sustch conf.).
Find all publications at her lab website.
Selected Peer Reviewed Journal Publications
- Zing, C., Mahjoob, S. and Vafai, K., “Analysis of porous filled heat exchangers for electronic cooling,” International Journal of Heat and Mass Transfer, vol. 133, pp. 268-276, April 2019.
- Hardt, S., Herbert, S., Kunkelmann, C., Mahjoob, S., and Stephan, P. “Unidirectional bubble growth in microchannels with asymmetric surface features,” International Journal of Heat and Mass Transfer, Vol.55, pp. 7056-7062, 2012.
- Mahjoob, S. and Vafai, K., "Analysis of Heat Transfer in Consecutive Variable Cross-Sectional Domains:Applications in Biological Media and Thermal Management," ASME Journal of Heat Transfer, Vol. 133, pp.011006-1 - 011006-9, 2011.
- Mahjoob, S. and Vafai, K., "Analysis of Bioheat Transport through a Dual Layer Biological Media," ASME Journal of Heat Transfer, Vol. 132, pp.031101 - 031101-14, 2010.
- Mahjoob, S. and Vafai, K., “Analytical Characterization of Heat Transport through Biological MediaIncorporating Hyperthermia Treatment,” International Journal of Heat and Mass Transfer, Vol.52, pp. 1608-1618, 2009.
- Mahjoob, S. andVafai, K., “Analytical Characterization and Production of an Isothermal Surface forBiological and Electronic Applications,”ASME Journal of Heat Transfer, Vol.131, pp. 052604-1 - 052604-12, 2009.
- Mahjoob, S. and Vafai, K., “A Synthesis of Fluid and Thermal Transport Models for Metal Foam HeatExchangers,” International Journal of Heat and Mass Transfer, Vol.51, pp. 3701-3711, 2008.
- Mahjoob, S. and Vafai, K., “Rapid Microfluidic Thermal Cycler for Polymerase Chain Reaction NucleicAcid Amplification,” International Journal of Heat and Mass Transfer, Vol.51, pp. 2109-2122, 2008.
- Mahjoob, S., Taeibi_Rahni, M. “Parameters Affecting Turbulent Film Cooling- RANS Computational Simulation,” AIAA Journal of Thermophysics and Heat Transfer, Vol.20, No.1, 2006.
- Mahjoob, S., Mani, M., Taeibi_Rahni, M., “Aerodynamic Analysis of Circular and Non-Circular Bodies UsingComputational and Semi-Empirical Methods,” AIAA Journal of Aircraft, Vol. 41, No. 2, March-April 2004.
Bioheat Transfer, CFD, Computational Fluid Dynamics, Hyperthermia, microwave ablation (MWA), radiofrequency ablation (RFA), Cooling of Biomedical Devices
Ph.D. 2005, Idaho State University M.A. 2001, Idaho State University B.A. 1998, Andhra University
Background and Purpose
Diabetic mellitus patients have problems with loss of sensation in their feet, insufficient blood flow to lower extremities and alterations in shape of their pressure patterns causing concentrated high pressure regions. These peaks due to dysfunctional feedback system from their mechanoreceptors may lead to complex problems such as amputation if they are not identified and treated in timely manner. Our main objective is to protect the foot by sensing these abnormal peaks and redistribute the pressure from excessive pressure regions.
Research Question(s) or Hypothesis
The foot anatomy and its mechanical loading effects the loading pattern which is very critical to determine the pressure distribution. The research is to create a study of anatomy, and connect the analysis to the foot pressure distribution. The main goal is: Measurement of the plantar pressure and shear forces actively using foot insert and examine the interrelationship of these forces.
In this research we are developing a design prototype for an adaptable shoe insert useful for diabetic foot care and comparing to the existent diabetic foot wears. The proposed design will consider human anatomy and anthropometry of the foot to properly sense the sensory regions during standing and walking. The developed design will be evaluated to the existent diabetic foot care available to validate and for market analysis.
This research will include the pros and cons of the existent technology. It is indeed an STEM multi-disciplinary research opportunity, which gives our undergraduate students a good knowledge and experience of how to integrate the science (biology, physics), technology, engineering and mathematics fundamentals into a biomechanical footwear design for diabetic foot care. The students who are in junior level with understanding of system design and modeling will get a hands-on experience developing and simulating a real world biomedical problem. This will not only help them understand how to relate the mechanical design concepts into biomedical modeling but also use modern computing tools such as Solid works and Matlab to simulate and show the pressure pattern.
The students will get an opportunity to present in such organizations giving them a great opportunity to connect with the scientific network. The results will also be published in poster to share the research with the CSUN community. The primary deliverable will be a comprehensive report that provides the detailed design, modeling, and simulation results.
Conferences Typically Attended
The research results will be disseminated to promote the findings to peer reviewed conference proceedings and journals in American Society of Mechanical Engineers (ASME) and Institute of Electrical and Electronics Engineers (IEEE) societies.
To view her publications, visit her mechanical engineering page.