This study summarizes an investigation into the performance of different ground granulated blastfurnace slag (GGBS)-based binders in toxic waste solidification/stabilization (S/S). The properties of two real industrial heavy metal wastes solidified/stabilized (S/S) with GGBS-based binders, including conventional ordinary Portland cement (OPC) + GGBS mixes and alkali-activated slag (AAS), were compared with those of wastes treated with conventional S/S systems involving OPC and 50% OPC + 50% pulverized fuel ash (PFA). The S/S wastes properties investigated were unconfined compressive strength (UCS), pore solution chemical composition, and leachability (using a modified version of the ANSI/ANS 16.1). This study showed that despite the higher strength of wastes treated with pure OPC, S/S wastes have variable leachability behavior primarily related to pore solution composition. In fact, leachates generated by ANSI/ANS 16.1 resembled diluted pore solution chemical compositions. The variation in concentrations of different elements in pore solution is attributed to the difference in pore solution characteristics of different binders. This leads to precipitation or dissolution of phases of different solubility and is reflected in lower Cr concentration and higher concentrations of Fe, Ni, and P in pore solutions of AAS compared with OPC-based binders.

Pharmaceutical care (PC) involves the active participation of the pharmacist in the improvement of the quality of life of the patient through the dispensation, counselling, and monitoring of drug therapy. Community pharmacists often encounter patients first, and, for some patients, the pharmacist is their only contact with a healthcare professional. It is easier and quicker for patients to contact a community pharmacist. However, there is a very limited or a total absence of PC services in community pharmacies of the KSA. To describe the inter-professional collaboration between primary care physicians and community pharmacists concerning PC services, a qualitative study was designed using a thorough, in-depth interview carried out in the cities of Dhahran and Dammam of the Eastern province of the Kingdom.

Self-compacting concrete (SCC) is a special type of concrete able to flow and compact under its self-weight. The SCC requires high powder content (mainly of cement) up to 600kg/m3 to achieve its properties. This will be problematic if all cement content in the powder exceeded 400 kg/m3used in hot weather of Sudan. This paper investigates addition of Sudanese limestone powder (LSP) to reduce cement content. The LSP dosages between 20% and 28 % (by cement weight) are used in six mixes having maximum cement content 380kg/m3. Results show that five trial mixes achieved the self-compactibility tested by slump flow, sieve segregation, V-funnel and U-box tests. Compressive strength of these mixes show that the LSP increases strength with dosage. Therefore, further investigations of hardened concrete properties are recommended for the successful mixes to be applied in real projects in the Sudan. Also, it has been found that dry batching and forced-action pan mixers are the most suitable for producing SCC with high homogeneity compared to commercial tilted-drum mixers.

No abstract

This paper aims to assess the pozzolanic characteristics of the volcanic ash obtained from Jebal Tagabo (Tagabo Mountains) in western Sudan (North Darfur State) as potential Supplementary Cementitious Materials for use in blended cement and concrete. Four natural Pozzolanic materials samples have been obtained; the first is volcanic ash from the Garma region (TG1VA), the second from the Mabo region (TG2VA), the third from the Mawo region (TG3VA) and the last from the Daim Sanosi region (TG4VA). This study has investigated the chemical and physical characteristics of the samples and their pozzolanic activities with Ordinary Portland cement (OPC) at different substitution levels of cement by weights, which are 10, 20, 30, 40, and 50%. And the results of chemical analysis show that all samples can be classified as Class N according to the American standard ASTM C618. The strength activity indices of the four samples at 20% level were found to be 75, 84, 89, and 83% respectively. These results indicate that the Jebal Tagabo Pozzolans are potential supplementary cementitious materials for use in blended cement.