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Low-cost lightweight geopolymer mortars based on ground granulated blast furnace slag, calcium carbonate, and silica sand flour were investigated as lightweight building materials. The effect of two chemical foaming agents such as hydrogen peroxide (H 2 O 2 ) and sodium perborate tetrahydrate (NaBO 3 .4H 2 O) on bulk density, porosity, and compressive strength was studied. FTIR, XRD, XRF, and SEM were used to investigate the raw materials and selected samples of prepared lightweight geopolymers. The use of grinding calcium carbonate and silica sand flour enhanced the compressive strength, workability, and homogeneity of the geopolymer.The lightweight geopolymer has given about 3.30 -17.60 and 1.70 -6 MPa of compressive strengths at 28 days of curing with bulk densities from 584 to 1340 kg/m 3 and 745 to 1770 kg/m 3 in the case of H 2 O 2 and NaBO 3 .4H 2 O, respectively. The images of morphology and microstructure results indicate that the porosity and pore size increase with the increase of the foaming agent due to the release of oxygen gas upon its decomposition. According to the results of bulk density MC-H1, MC-H1.25, and MC-B2.5 mixes can be considered ultra-lightweight geopolymers with proper compressive strength. The results show that hydrogen peroxide mixes have better performance in the physico-chemical and mechanical properties than sodium perborate mixes.

Background: Surgical evacuation is one of the most popular methods of termination of pregnancy in cases of missed miscarriage. The current study aims to compare the improvement of surgical evacuation of first trimester miscarriage when done with and without transabdominal ultrasonographic guide. The women were randomly assigned to either undergone surgical evacuation blindly (group I) or under ultrasound guidance (group II). The main outcome measures were achievement of complete miscarriage, operative time and blood loss during the procedure. Results: Two-hundred participants were recruited in the study. The mean amount of blood loss during the procedure was significantly higher in group I when compared with group II (P = 0.002). Also there was a statistical significant difference in the operative time between both groups, group I showed longer time than in group II (P = 0.0001). After surgical evacuation, 14 cases (14%) in group I and 3 cases (3%) in group II were reported to have remnants of conception. No cases of uterine perforation occurred in both groups. Conclusion: The use of intraoperative ultrasound during surgical evacuation is associated with a significant reduction in its complications, however; the cost of using ultrasound needs further investigations.

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