Osman Ahmed

The global energy demand is projected to rise by almost 28% by 2040 compared to current levels. Biomass is a promising energy source for producing either solid or liquid fuels. Biofuels are alternatives to fossil fuels to reduce anthropogenic greenhouse gas emissions. Nonetheless, policy decisions for biofuels should be based on evidence that biofuels are produced in a sustainable manner. To this end, life cycle assessment (LCA) provides information on environmental impacts associated with biofuel production chains. Here, we review advances in biomass conversion to biofuels and their environmental impact by life cycle assessment. Processes are gasification, combustion, pyrolysis, enzymatic hydrolysis routes and fermentation. Thermochemical processes are classified into low temperature, below 300 °C, and high temperature, higher than 300 °C, i.e. gasification, combustion and pyrolysis. Pyrolysis is promising because it operates at a relatively lower temperature of up to 500 °C, compa...

Food waste is a major constituent in municipal solid wastes and its accumulation or disposal of in landfills is problematic, causing environmental issues. Herein, a techno-economic study is carried out on the potential of biogas production from different types of food waste generated locally. The biogas production tests were at two-time sets; 24-h and 21-day intervals and results showed a good correlation between those two-time sets. Thus, we propose to use the 24-h time set to evaluate feedstock fermentation capacity that is intended for longer periods. Our approach could potentially be applied within industry as the 24-h test can give a good indication of the potential substrate gas production as a quick test that saves time, with minimal effort required. Furthermore, polynomial models were used to predict the production of total gas and methane during the fermentation periods, which showed good matching between the theoretical and practical values with a coefficient of determinat...

Background: Recycling the ever-increasing plastic waste has become an urgent global concern. One of the most convenient methods for plastic recycling is pyrolysis, owing to its environmentally friendly nature and its intrinsic properties. Understanding the pyrolysis process and the degradation mechanism is crucial for scale-up and reactor design. Therefore, we studied kinetic modelling of the pyrolysis process for one of the most common plastics, polyethylene terephthalate (PET). The focus was to better understand and predict PET pyrolysis when transitioning to a low carbon economy and adhering to environmental and governmental legislation. This work aims at presenting for the first time, the kinetic triplet (activation energy, pre-exponential constant and reaction rate) for the PET pyrolysis using the differential iso-conversional method. This is coupled with the in-situ online tracking of the gaseous emissions using mass spectrometry. Results: The differential iso-conversional met...

Concussion is widely discussed in online sports news articles, but the terms used to report this injury vary. This study aimed to use a systematic search strategy and explore the description of sports concussion in online sports news articles. A systematic approach was employed to obtain online articles related to sports concussion from four sports associated with concussion (hockey, football, soccer, and rugby). Included articles were evaluated for the descriptors used in relation to concussion and possible consequences associated with concussion. Data was analysed to determine trends between each sport as well between the countries of origin of the articles. From 200 articles retrieved, 153 were included for analysis. The terms "Head injury" (30.1%) and "Brain injury" (20.9%) were most used to describe a concussive injury, and the most frequently mentioned consequence of concussion was "Chronic Traumatic Encephalopathy" (15%). Modifiers which potentia...

To compare measures of clinical success, such as the need for subsequent intervention and mortality, in patients with left ventricular assist devices (LVADs) undergoing mesenteric angiography for gastrointestinal (GI) bleeding with respect to a control group. A retrospective study was conducted on 48 consecutive patients undergoing anticoagulation whose GI bleeding was assessed with angiography between August 2007 and June 2014: 24 patients with LVADs and 24 control patients without LVADs. The χ2 and t tests were used for statistical analysis. Mean ages were 62.1 years ± 9.6 and 74.5 years ± 11.3 in the LVAD and control groups, respectively. No significant difference was observed in hemodynamic instability, presenting hemoglobin level and International Normalized Ratio, or hemoglobin nadir. Two patients with LVADs (8.3%) and 8 control patients (33.3%) had bleeding detected on angiograms (P = .032). Six embolizations were performed in patients with LVADs and 8 were performed in contr...