The search for higher energy efficiency of industrial-scale burners to attain low emission especially Nitrogen Oxide (NOx) has demanded experimental studies that are complemented with Computational Fluid Dynamics (CFD) simulations. While there exist numerous emission control techniques, the passive control technique was the main focus of the present review study. Biodiesel fuel crude palm oil (CPO) was found to reduce emission components, particularly carbon components and particulate matter (PM). Biodiesel CPO has the capability to mitigate cavitation inside the injector’s orifice which contributes to damage reduction on the orifice. Moreover, although cavitation can improve spray atomization and produce finer spray droplets, it also causes damage to the orifice of injectors. Orifice characteristics such as orifice’s diameter and pattern can also reduce cavitation inside the orifice. Orifice’s pattern is divided into cylindrical shape orifice and conical shape orifice. The conical orifice is found to reduce the cavitation inside the orifice while cylindrical orifice was indicated as a highly cavitating orifice. Alternatively, as rapid swirling motion is capable to enhance the fuel and air mixing, a new concept of swirling fuel-air premix inside the injector is invented and it is proven to reduce emissions. It was, however, learned that spray characteristics are still playing an important role in the prediction of combustion performance, particularly droplets Sauter Mean Diameter (SMD) which is a worldwide parameter that needs further investigations in order to predict the fineness of spray production and combustion.

Food fortification with micronutrients was initially justified in developed countries by lack of availability of micronutrients in staple crops, mainly due to soil exhaustion. However, in Sub-Saharan arable lands soil fatigue is not predominant and communities consume mostly home-grown organic non-processed crops. African food systems are nevertheless deeply entwined with food insecurity, driver of illnesses. Family production can promote subsistence, food stability and self-sufficiency, the main African setback being the vicious cycle of poverty and the lack of dietary variety, contributing to malnutrition. Poverty reduction, and women's education, are significant strategies for reducing child and adolescent undernourishment. Fortification of foods consumed daily by individuals makes sense and can minimize if not entirely eliminate deficiencies. Mass fortification in Sub-Saharan Africa with single micronutrients is however controversial working in synergy among each other and the food matrix, for optimal absorption and metabolism. Since the causes of malnutrition are many, caused by diverse, unequal and unjust food distribution, interrelated with political, social, cultural or economic factors, education status of the population, season and climatic changes, and effectiveness of nutrition programmes, just food fortification cannot solve the composite of these elements. Further, compulsory fortification is excessive, unproductive and likely harmful to human health, while many challenges remain in accessing quality of premixes. However, aiming at dietary diversification is the best approach of increasing trace elements intake from commonly accessible and easily available food sources.