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15This study aims to investigate the ability of using biopolymer (environmental friendly material) to enhance 16 the mechanical characterizations of collapsible soil. Two types of biopolymers were used in this study 17 (xanthan gum and guar gum) because of their stable behaviour under sever conditions and their availability 18 with reasonable prices. The experimental program focused on three major soil properties, which are; 19 compaction characterizations, collapsible potential and shear parameters, these three properties are 20 essential in any soil improvement process. Different biopolymer concentrations were used in this study and 21 the experimental program was performed at two curing periods (soon after mixing the soil with the 22 biopolymer and after one week curing time). shear parameters were measured for the treated specimens in 23 both soaked and unsoaked conditions, while a collapsible potential test was performed under different 24 mixing conditions (wet mix and dry mix). A numerical model was built to predict the behaviour of the 25 treated collapsible soil after and before inundation. The analysis of results indicated the ability of both 26 xanthan gum and guar gum to be used as soil improvement materials for collapsible soil treatment. The 27collapsible potential has been reduced significantly from 9% to 1% after mixing the soil with 2% 28 biopolymer concentration in the wet case. After one week curing period, the cohesion stress has been 29 increased from 8.5 to 105 kPa by increasing the xanthan gum concentration from zero to 2%, leading to 30 overall improvement in the soil shear strength. Also, it proved that the superiority of guar gum over 31 xanthan gum in improving the shear strength is about 30% more than xanthan gum at the same conditions 32 and reduces the collapsible potential by about 20% more than xanthan gum at the same conditions. 33 34 35

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Africa is the second populous continent, and its population has the fastest growing rate. Some African countries are still plagued by poverty, poor sanitary conditions and limited resources, such as clean drinking water, food supply, electricity, and effective waste management systems. Underfunded healthcare systems, poor training and lack of awareness of policies and legislations on handling medical waste have led to increased improper handling of waste within hospitals, healthcare facilities and transportation and storage of medical waste. Some countries, including Ethiopia, Botswana, Nigeria and Algeria, do not have national guidelines in place to adhere to the correct disposal of such wastage. Incineration is often the favoured disposal method due to the rapid diminishment of up to 90% of waste, as well as production of heat for boilers or for energy production. This type of method – if not applying the right technologies – potentially creates hazardous risks of its own, such as harmful emissions and residuals. In this study, the sustainability aspects of medical waste management in Africa were reviewed to present resilient solutions for health and environment protection for the next generation in Africa. The findings of this research introduce policies, possible advices and solutions associated with sustainability and medical waste management that can support decision-makers in developing strategies for the sustainability by using the eco-friendly technologies for efficient medical waste treatment and disposal methods and also can serve as a link between the healthcare system, decision-makers, and stakeholders in developing health policies and programmes.

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Rosetta Promontory, Egypt has been suffering from a continuous erosion problem. The dramatic retreatment was observed during the last century. It is basically due to the construction of Aswan High Dam in 1964, which reduced the flow and sediment discharges. In this paper, four Landsat images (two Thematic Mapper and two Enhanced Thematic Mapper) covering the period from 1984 to 2014 were used. These Landsat images were radio-metrically and geometrically corrected, and then, multi-temporal post-classification analysis was performed to detect land cover changes, extracting shoreline positions to estimate shoreline change rates of the Nile delta coast around Rosetta Promontory. This method provides a viable means for examining long-term shoreline changes. Four categories, including seawater, developed (agriculture and urban), sabkhas (salt-flat), and undeveloped areas, were selected to evaluate their temporal changes by comparing the four selected images. Supervised classification technique was used with support vector machine algorithm to detect temporal changes. The overall accuracy assessment of this method ranged from 97% to 100%. In addition, the shoreline was extracted by applying two different techniques. The first method is based on a histogram threshold of Band 5, and the other uses the combination of histogram threshold of Band 5 and two band ratios (Band 2/Band 4 and Band 2/Band 5). For land cover change detection from 1984 to 2014, it was found that the OPEN ACCESSLand 2015, 4 217 developed area that increased by 9% although the land in the study area has been contracted by 1.6% due to coastal erosion. The shoreline retreat rate has decreased more than 70% from 1984 to 2014. Nevertheless, it still suffers from significant erosion with a maximum rate of 37 m/year. In comparison to ground survey and different remote sensing techniques, the established trend of shoreline change extracted using histogram threshold was found to be closely consistent with these studies rather than combining band ratio with histogram threshold.