Parametric investigation of water loading on heavily carbonaceous syngases

An outwardly propagating spherical flame was used to characterise the influence of water loading on the premixed combustion of an applied high CO/H2 ratio syngas fuel blend (converter gas). A nonlinear extrapolative technique was used to obtain values of laminar flame speed for combustion with air, for varying temperature, pressure and equivalence ratio. With increased attention given to the accurate measurement of laminar flame speed, a concerted effort was made to quantify experimental uncertainty, and a detailed methodology is presented. Change in relative humidity was shown to have a substantial impact on laminar flame speed for the syngas, increasing measured values by up to 70% from the driest cases. This observed increase results from the dissociative influence of H2O addition, and enhancement in the formation of chain carriers that catalyse CO oxidation, increasing net heat release rate. In addition to relative humidity, the decoupled influences of initial temperature and pressure were investigated parametrically; holding the mass ratios of fuel and H2O constant for a step change in condition. Temperature rise was shown to enhance H2O induced acceleration, with greater relative change in heat release rate for a corresponding drop in flame temperature, and the opposite effect observed for increased pressure. The effect of water addition was shown to be non-monotonic, with flame speed reduction achieved at the highest water loadings for the hottest tests, and discussed as a function of initial CO/H2 ratio. Attention was given to the dominant reaction kinetics, with the performance of several published reaction mechanisms evaluated against experimental data using CHEMKIN-PRO; with flame speed consistently overpredicted when H2O was added to the mixture. A modified reaction mechanism is presented for the humidified combustion of high CO/H2 mixtures, changing the rate parameters of two chain branching reactions to give higher relative indeterminate H2O formation, and a reduction in OH carriers. Results obtained using the modified mechanism demonstrate improved agreement with all experimental data presented here and from a previous study, including changes in H2O concentration at elevated temperatures and pressures. The results also highlight relative humidity as a potential source of error in the experimental measurement of uL, significant for fuels comprising large CO fractions, but also potentially for other gaseous fuels, emphasising that relative humidity should be carefully considered when comparing experimental data

Community pharmacy and the extended community pharmacist practice roles: The UAE

Background: The pharmaceutical care and ‘extended’ roles are still not practiced optimally by community pharmacists. Several studies have discussed the practice of community pharmacy in the UAE and have shown that most community pharmacists only counsel patients. However, UAE, has taken initiatives to allow and prepare community pharmacists to practice ‘extended’ roles. Aim of the review: The aim was to review the current roles of community pharmacists in Abu Dhabi Emirate, United Arab Emirates (UAE). Objective: The objective was to encourage community pharmacists toward extending their practice roles. Methods: In 2010, Health Authority Abu Dhabi (HAAD) surveyed community pharmacists, using an online questionnaire, on their preferences toward extending their counseling roles and their opinion of the greatest challenge facing the extension of their counseling roles. Results: Following this survey, several programs have been developed to prepare community pharmacists to undertake these extended counseling roles. In addition to that, HAAD redefined the scope of pharmacist roles to include some extended/enhanced roles. Abu Dhabi Health Services (SEHA) mission is to ensure reliable excellence in healthcare. It has put clear plans to achieve this; these include increasing focus on public health matters, developing and monitoring evidence-based clinical policies, training health professionals to comply with international standards to deliver world-class quality care, among others. Prior to making further plans to extend community pharmacists’ roles, and to ensure the success of these plans, it is imperative to establish the views of community pharmacists in Abu Dhabi on practicing extended roles and to gain understanding and information on what pharmacists see as preferred change strategies or facilitators to change. Conclusions: In an attempt to adapt to the changes occurring and to the growing needs of patients and to maximize the utilization of community pharmacists’ unique structured strategies are needed to be introduced to the community pharmacy profession