Mechanical Engineering MS Thesis Defense by Mr. Ayomikun Adebanjo on August 29

By Press release submission

Aug 22, 2022

Mechanical Engineering MS Thesis Defense by Mr. Ayomikun Adebanjo

WHEN: Monday, August 29, 2022

11:00 AM - 1:00 PM

WHERE: > See description for location

DESCRIPTION: Mechanical Engineering MS Thesis Defense by

Mr. Ayomikun Adebanjo

DATE:

August 29, 2022

TIME:

11:00 a.m.- 1:00 p.m.

LOCATION:

ZOOM: https://umassd.zoom.us/j/98983538979

Meeting ID: 989 8353 8979

Passcode: 228816

TOPIC:

Numerical Modeling of the Thermal History of Livers During Cryopreservation

ABSTRACT:

The current standard method for organ preservation is Static Cold Storage (SCS) which allows for preservation times of up to 12-16 hours for livers. This time constraint limits the availability of donor organs for transplantation which is the only cure for end-stage organ failure. Different techniques are being studied for their potential to improve preservation times, and the most promising is cryopreservation. This method involves freezing a biological material to subzero temperatures where metabolic functions are completely halted without significantly affecting its viability when thawed. Mathematical modeling of the thermal history during this procedure can provide better insight into the injury mechanisms that occur during this process and help to improve cryopreservation techniques. The goal of this work was to create a numerical model to predict the freezing profile of a liver perfused with a cryoprotective agent (CPA). A one-dimensional (1-D) finite difference scheme was developed, and the enthalpy method was used to account for the phase change process. The model was used to predict the thermal profiles for freezing experiments of rat livers loaded with different solutions. The results showed that the rat livers perfused with the University of Wisconsin (UW) solution behaved differently compared to the ones loaded with the UW + 12% Propylene Glycol (PG) solution, as the UW + 12% PG solution has a lower freezing point and undergoes binary freezing. The temperature profiles for rat liver

thawing experiments were also modeled. The results showed that the numerical model was not able to successfully capture the temperature gradient within the liver shown by the experimental data, and further investigation needs to be carried out to incorporate the missing thermal resistance effect into the model. This work gives new insight into the freezing behavior of livers loaded with a binary solution, and there is potential to improve the modeling capabilities of this numerical scheme, including scaling up to multiple dimensions and incorporating mass transfer (water transport) effects into the model.

ADVISORS:

-Dr. Sankha Bhowmick, Professor of Mechanical Engineering, UMassD

-Dr. Mehdi Raessi, Associate Professor of Mechanical Engineering, UMassD

COMMITTEE MEMBERS:

Dr. Hangjian Ling, Assistant Professor of Mechanical Engineering, UMassD

Open to the public. All MNE students are encouraged to attend.

For more information, please contact Dr. Sankha Bhowmick (sbhowmick@umassd.edu).

Thank you,

â€‹

Sue Cunha, Administrative Assistant

UMass Dartmouth Mechanical Engineering Department

scunha@umassd.edu