John "Jack" D. Marrelli

John D. “Jack” Marrelli of Houston, TX passed away at the age of 79 on May 9th, 2024. Jack was born on December 21, 1944, in West Hartford, CT and raised by doting parents, John and Mary Marrelli. He was a loving and generous husband, idolized father, and beloved grandfather. He was also a respected scientist and inventor and a devoted friend or mentor to many. He is survived by his wife Julie Kris Colantonio, his son Sean Marrelli (wife Danica), and his three grand-daughters Caroline, Abby, and Olivia Marrelli. He is also survived by Natalie DeLong and her mother Mitzi Reynolds.

Jack was the first in his family to attend college. He attended the University of Connecticut as a member of the Army ROTC, ultimately reaching rank of Lieutenant in the US Army Reserves. From the University of Connecticut, he earned a BS in Electrical Engineering as well as an MS and PhD in Bio-Engineering. He then embarked on his first career in academic research, focusing on the neurophysiology of motor control. He was a National Institutes of Health (NIH) postdoctoral fellow and conducted research at the University of North Carolina, University of Miami, and University of Texas. He was subsequently awarded an NSF-funded foreign exchange scholarship to conduct research at the National Center for Scientific Research (CNRS) in Marseille, France. Upon moving back to the US in 1976, he began an Assistant Professorship position at the University of Texas in Austin. He began the second phase of his career in 1982, when he moved to Houston to join Getty Oil as a research scientist. He continued in the role of scientist/engineer for over 30 years, working at both Texaco and Chevron. He retired from Chevron in 2015, at which time he founded MultiPhase Systems LLC and served as the CEO & Chief Scientist. In this third phase of his career, he developed microwave-based technologies for multiphase metering in the upstream oil industry. Through his career, Jack obtained over 25 US patents, authored more than 30 publications, and received numerous awards.

Jack was known for his fun and unique approach to life and disdain of the conventional. His Jeep was immediately recognizable by the metal loop he installed on the roof of the removable top, which was used in combination with the matching electric winch system he built in his garage. The rest of his garage and multiple other locations around the house were converted to the design, testing, and prototype fabrication of microwave metering devices. This is also a testament to the tolerance and understanding of his wife, Julie. As a former gymnast, Jack was known for performing handstands or hand-balancing at various landmarks across the world (e.g. The Parthenon in Greece). While Jack will be sorely missed, he will live on through the many people that he touched, influenced, or inspired during the course of his life.

A graveside service will be held on May 24th, 2024 at 11 AM at the Glenwood Cemetery at 2525 Washington Avenue in Houston. Direction to the gravesite will be provided upon entry to the cemetery. A reception immediately after the service will take place at the Center for Glenwood (building at the main entrance of the cemetery).

PLEASE NOTE: If using Google Maps - Directions to “Glenwood Cemetery” will lead to a Closed Entrance. Instead, input “2525 Washington Ave” for directions to the main entrance of the Cemetery and Reception building.