Evaluation of acid corrosion resistance of Portland cement composites impregnated with polymer sulfur composite

Purpose Specific chemical environments step out in the industry objects. Portland cement composites (concrete and mortar) were impregnated by using the special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot were applied as the industrial waste. Portland cement composites were made of the same aggregate, cement and water. The durability of prepared cement composite samples was tested in 5 per cent solution of HCl and 5 per cent solution of H2SO4 as a function of immersion time. The changes in mechanical strength and mass of the samples were periodically measured. Cement composites impregnated with sulfur composite exhibited limited mechanical strength and mass loss, whereas physico-mechanical properties of Portland cement concrete regressed rapidly. The loss in weight of ordinary concrete impregnated with sulfur composite, kept in aqueous solutions of acids, hydroxides, salts and in water for a year was determined using 100 × 100 × 100 mm samples. The same samples were then used in compressive strength tests. Design/methodology/approach Specific chemical environments affect industrial objects. Portland cement composites (concrete and mortar) were impregnated with a special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot were applied as industrial waste. Portland cement composites were made of the same aggregate, cement and water. The durability of the prepared cement composite samples was tested in 5 per cent solution of HCl and 5 per cent solution of H2SO4 as a function of immersion time. The changes in mechanical strength and mass of the samples were periodically measured. Cement composites impregnated with sulfur composite exhibited limited mechanical strength and mass loss, whereas the physico-mechanical properties of the Portland cement concrete regressed rapidly. The loss in weight of ordinary concrete impregnated with sulfur composite, kept in aqueous solutions of acids, hydroxides, salts and in water for a year was determined using 100 × 100 × 100 mm samples. The same samples were then used in compressive strength tests. The image analysis used for surface destruction monitoring, performed by scanning microscopy for the determination of damaged surface area and the original surface area before acid resistance testing, showed similar results. Based on the image analysis results, a model for predicting the degradation of mechanical strength during durability testing was established. The fact that the calculated and experimental strength values were not vastly different proved the validity of the proposed model. A brief summary of new products related to the special sulfur composite is given as follows: impregnation, repair, overlays and precast polymer concrete will be presented. Sulfur composite as a polymer coating impregnation, which has received little attention in recent years, currently has some very interesting applications. Findings Author comments: The article is original. The article has been written by the stated authors who are all aware of its content and approve its submission. 3. The article has not been published previously. 4. The article is not under consideration for publication elsewhere. 5. No conflict of interest exists, or if such conflict exists, the exact nature must be declared. 6. If accepted, the article will not be published elsewhere in the same form, in any language, without the written consent of the publisher. Originality/value Author comments: 1. The article is original. 2. The article has been written by the stated authors who are all aware of its content and approve its submission. 3. The article has not been published previously. 4. The article is not under consideration for publication elsewhere. 5. No conflict of interest exists, or if such conflict exists, the exact nature must be declared. 6. If accepted, the article will not be published elsewhere in the same form, in any language, without the written consent of the publisher.

More Sondheim

Sondheim provided original music for five movies: one or more songs forThe Seven-Per-Cent Solution(1976),Dick Tracy(1990), andThe Birdcage(1996), and scores forStavisky(1974) andReds(1981). The two scores reflect divergent trends in this era. Warren Beatty’sRedsuses music sparingly, and Alain Resnais’sStaviskycontains a complicated score that reflects compositional trends of the 1930s. Sondheim’s songs for the other films are crafted to entertain and to further their respective stories. ForDick Tracy, Sondheim composed five songs; several accompany montages, others crosscut with live action, and two, both performed by Madonna, have multiple reprises. Among the latter is the Oscar-winning “Sooner or Later.”

Cocaine versus tetracaine in septoplasty: a prospective, randomized, controlled trial

Background: Successful local anaesthesia is of critical importance for the success of septoplasty, and many surgeons prefer to use cocaine for this purpose. The aim of this study was to evaluate the efficacy of cocaine 4 per cent solution, compared with tetracaine 2 per cent plus adrenaline, as a local anaesthetic for patients undergoing septoplasty.Methods: From December 2002 to February 2005, a prospective, randomized, controlled trial was conducted. One hundred and eight patients underwent septoplasty under local anaesthesia. Patients were randomly classified into group A and group B, in which was used respectively cocaine 4 per cent solution and tetracaine 2 per cent solution plus adrenaline. A visual analogue scale was used to evaluate the severity of patients' pain during their procedure.Results: Group B (tetracaine; mean rank=43.77) reported significantly less pain (p<0.001) compared with group A (cocaine; mean rank=65.23).Conclusions: On the basis of these findings, we recommend tetracaine as the first choice anaesthetic for nasal septoplasty; the use of cocaine should be limited.