Sérgio Mascarenhas de Oliveira (b. May 2, 1928, Rio de Janeiro

Rio de Janeiro

Rio de Janeiro , commonly referred to simply as Rio, is the capital city of the State of Rio de Janeiro, the second largest city of Brazil, and the third largest metropolitan area and agglomeration in South America, boasting approximately 6.3 million people within the city proper, making it the 6th...

) is a noted Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

ian experimental physicist

Physicist

A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...

, educator and scientific leader.
Dr. Mascarenhas has been awarded the Brazilian Order of Scientific Merit

Brazilian Order of Scientific Merit

The National Order of Scientific Merit is an honor bestowed upon Brazilian and foreign personalities recognized for their scientific and technical contributions to the cause and development of science in Brazil.-Biology:* Marcelo Hermes-Lima* Jorge Curi...

 in the categories of Commander (1995) and Great Cross (2002), and several national and international prizes including, more recently (April 2007) the Conrado Wessel Prize for General Science.

One of his main contributions to physics has been the discovery of bioelectrets, i.e., electret

Electret

Electret is a dielectric material that has a quasi-permanent electric charge or dipole polarisation. An electret generates internal and external electric fields, and is the electrostatic equivalent of a permanent magnet. Oliver Heaviside coined this term in 1885...

s as a property of biological materials such as bone

Bone

Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...

 and biopolymer

Biopolymer

Biopolymers are polymers produced by living organisms. Since they are polymers, Biopolymers contain monomeric units that are covalently bonded to form larger structures. There are three main classes of biopolymers based on the differing monomeric units used and the structure of the biopolymer formed...

s. He used this knowledge to develop a new detector used in radiological

Radiology

Radiology is a medical specialty that employs the use of imaging to both diagnose and treat disease visualized within the human body. Radiologists use an array of imaging technologies to diagnose or treat diseases...

 dosimetry

Dosimetry

Radiation dosimetry is the measurement and calculation of the absorbed dose in matter and tissue resulting from the exposure to indirect and direct ionizing radiation...

 and to date human bones in archeological sites, such as shell mounds (sambaquis).

External links

• Biography. Inductees of the Order of Scientific Merit, Ministry of Science and Technology (in Portuguese)