Yeshayahu, son of Rachel and Pinchas Mordechai, was born on December 3, 1938 in Tel Aviv, attended the religious elementary school “Tachkemoni”, the “Yavneh” elementary school and the ” In his youth he was a member of the Scouts movement and he was very artistic in literature, music, music, Painting and sculpture, which was a wondrous combination of scientific talents, discovered at an early age, along with artistic talents, and all these were adhering to tradition. Set 1966 and assigned to the Artillery Corps. During his service, he underwent a basic officer’s course, an artillery officers course, a field battery commanders course, and an air support officers course. In the opinion of his commanders, it was said: “Isaiah is a quiet officer, very poetic and loyal.” At the beginning of September 1958, Yeshayahu finished his compulsory service and began studying at the Faculty of Mechanical Engineering at the Technion. After receiving his bachelor’s degree, he went on to continue his studies at Brown University in the United States, where he studied in the field of gas and plasma dynamics and was awarded the degrees of Master and Doctor. Due to his academic excellence, he received a special scholarship at the university and was elected to two associations of outstanding scholars: Tao-Beta-Pi and Sigma-Kasi. Immediately after receiving his doctorate in 1966, he was accepted as a research fellow at the Faculty of Mechanical Engineering at MIT in Boston with a group of Professors Shapiro, Prostejn and Pai, where he continued his work in the field of plasma dynamics. In 1967 he joined the Technion as a senior lecturer in the Faculty of Mechanical Engineering, and shortly thereafter was appointed head of the Energy Laboratory. After returning to Israel, he debated how to exploit the knowledge he had acquired in the United States for a purpose of national importance, and then discovered that his experience in the field of gas and plasma dynamics could be applied to desalination problems, especially electrolysis. Together with other faculty members, began his research in electrolysis of water in the Faculty of Mechanical Engineering. In the course of these studies, a number of graduate and doctoral students have completed their studies and have been published in international journals and conferences. In addition to his research in desalination, he also engaged in research in the production of a new drilling method, which enables the drilling of very fine holes in particularly hard materials with sparks. He also investigated the spread of blood pressure from the Lev to the arteries in order to understand the relationship between blood pressure measured and the action of the blood system. In 1971 he was promoted to Associate Professor. During his service in the reserves he attained the rank of major. During these years of academic activity and military service, he married Ruth, and eventually they had three children: Sigal, Alon and Michael. Isaiah, or Shai – as his acquaintances called him, was a remarkable and extraordinary person; A man who found the path to a perfect family life, an active science life, religion, art, and, if necessary, military life. He was a very dynamic person, and in addition to his research at the Technion, he was active in the research of the Negev Research Institute and lectured at the universities of Be’er Sheva and Tel Aviv. Despite the intensity of his professional work, he did not refrain from other pursuits – he was involved in social life and was an art lover. His work in painting and sculpture filled his house, and even his office and laboratory showed his interest in the art and beauty of life. Above all, there is the mitzvah of honoring parents. In any case, he made sure to call his parents and make sure everything was okay with them. As a father and an educator, made sure to educate his children on the knees of Judaism, but more than anything else he made sure to instill in them a sense of respectFather and mother, as he himself did. As evidenced by his friends, was loved by all his acquaintances and was always willing to help anyone in need. For his family – his parents, his wife and his children – Shai was a supreme authority, who always turned to her, asked her, and heard her words, there was no limit to their love for him. Even in a computer-based referendum, it turned out that Yeshayahu, who was the youngest of the professors, was considered the most beloved professor. In the Yom Kippur War he served as a battery commander on the northern front. This was not his first war. When he enlisted in the IDF, he was able to participate in Operation Kadesh on the southern front, but during the War of Attrition he served as a reservist in the Sinai, and also contributed to the IDF’s technical inventions. On the tenth of Tishrei 5734 (October 11, 1973), in the battle that took place in the Golan Heights, Isaiah was in the tank of the commander of the invading force. The tank was hit directly by the turret and he was killed. He was brought to eternal rest in the Haifa cemetery. He left behind a wife and three children, a father, a mother and two brothers. In a letter of condolence to the family, his commander wrote: “Shai was loved by all the soldiers in the unit, and his good spirit and courage helped his soldiers stand firm during the most difficult times. The Municipal-Religious School in Tel Aviv published a pamphlet in memory of its victims, with a list of Yeshayahu as well; In addition, a memorial list is included in the journal of the Technion in Haifa.
