An Alternative Radiation Shielding Material Based on Barium-Sulphate (BaSO)-Modified Fly Ash Geopolymers.

Unlabelled: Geopolymers are a new environmentally friendly cementitious material, and the application of geopolymers can reduce the carbon dioxide emissions caused by the development of the cement industry.

Purpose: This study investigates the radiation shielding capacity of fly ash geopolymers (FAGP) as a viable alternative to conventionally used ordinary Portland cement (OPC) due to the high demand for an environmentally friendly, cost-effective and non-toxic shield material.

Methods: The FAGP material was fabricated and combined with Barium sulphate (BaSO) at different ratios (0, 5, 10 and 15%).

A Brief Review for Common Doppler Ultrasound Flow Phantoms.

In this review, the flow phantoms and the wall-less flow phantoms with recognized acoustic features (attenuation and speed of sound), interior properties, and dimensions of tissue were prepared, calibrated, and characterized by Doppler ultrasound (US) scanning which demands tissue-mimicking materials (TMMs). TMM phantoms are commercially available and readymade for medical US applications. Furthermore, the commercial TMM phantoms are proper for US purpose or estimation of diagnostic imaging techniques according to the chemical materials used for its preparation.