EXPERIMENTAL EVALUATION OF A CONICAL-SCREW BRIQUETTING MACHINE FOR THE BRIQUETTING OF CARBONIZED COTTON STALKS IN SUDAN

Briquetting of the carbonized agricultural residues represents one of the possible solutions to the local energy shortages in many developing countries. It constitutes a positive solution to the problem of increasing rates of desertification in many areas worldwide. Agricultural residues are not attractive as a household fuel source for urban areas because they are very bulky and have low energy intensity. Also, to eliminate the smoke generation when burning agricultural residues requires processing it by carbonization before being used as a house-hold indoor fuel. Previously investigated, briquetting machines lacked high productivity and were of complicated designs. The present study puts forward a machine of simple design which could be manufactured locally in Sudan and of much higher productivity. The local Sudanese briquetting experience was overviewed, studying all the alternative available options and the market potential. The study presents a detailed design study of the new briquetting machine. The prototype was made and tested in the field at Al-Gazeera area in Sudan. The investigation results show that the new machine has a production rate better than all the previous alternatives. This low pressure screw briquetting machine was found to have a production rate equivalent to about eight times better than the production rate of the best local competitor. The production cost was found to be lower due to the lower binder requirement for the new machine, which is lower by about 65%. The initial moisture content of the feed stock required for this machine is lower by about 30 % compared to the best alternative, which results in shorter drying time for the fuel briquettes produced. The quality of the produced briquettes was found to be better and of lower smoke generation when burned due to the lower binder content

Irrational prescribing of over-the-counter (OTC) medicines in general practice: testing the feasibility of an educational intervention among physicians in five European countries

Background: Irrational prescribing of over-the-counter (OTC) medicines in general practice is common in Southern Europe. Recent findings from a research project funded by the European Commission (FP7), the “OTC SOCIOMED”, conducted in seven European countries, indicate that physicians in countries in the Mediterranean Europe region prescribe medicines to a higher degree in comparison to physicians in other participating European countries. In light of these findings, a feasibility study has been designed to explore the acceptance of a pilot educational intervention targeting physicians in general practice in various settings in the Mediterranean Europe region. Methods: This feasibility study utilized an educational intervention was designed using the Theory of Planned Behaviour (TPB). It took place in geographically-defined primary care areas in Cyprus, France, Greece, Malta, and Turkey. General Practitioners (GPs) were recruited in each country and randomly assigned into two study groups in each of the participating countries. The intervention included a one-day intensive training programme, a poster presentation, and regular visits of trained professionals to the workplaces of participants. Reminder messages and email messages were, also, sent to participants over a 4-week period. A pre- and post-test evaluation study design with quantitative and qualitative data was employed. The primary outcome of this feasibility pilot intervention was to reduce GPs’ intention to provide medicines following the educational intervention, and its secondary outcomes included a reduction of prescribed medicines following the intervention, as well as an assessment of its practicality and acceptance by the participating GPs. Results: Median intention scores in the intervention groups were reduced, following the educational intervention, in comparison to the control group. Descriptive analysis of related questions indicated a high overall acceptance and perceived practicality of the intervention programme by GPs, with median scores above 5 on a 7-point Likert scale. Conclusions: Evidence from this intervention will estimate the parameters required to design a larger study aimed at assessing the effectiveness of such educational interventions. In addition, it could also help inform health policy makers and decision makers regarding the management of behavioural changes in the prescribing patterns of physicians in Mediterranean Europe, particularly in Southern European countries

Performance Study of Methane Dry Reforming on Ni/ZrO₂ Catalyst

Dry reforming of methane (DRM) has important and positive environmental and industrial impacts, as it consumes two of the top greenhouse gases in order to produce syngas (H2 and CO) and thus hydrogen (H2). The performance of DRM of conversions of CH4 and CO2 was investigated over Ni/ZrO2 catalysts. The catalytic performance of all prepared catalysts for DRM was assessed in a micro-tubular fixed bed reactor under similar reaction conditions (i.e., activation and reaction temperatures at 700 °C, a feed flow rate of 70 mL/min, reaction temperature, and a 440 min reaction time). Various characterization techniques, such as BET, CO2-TPD, TGA, XRD, EDX, and TEM, were employed. The zirconia support was modified with MgO or Y2O3. The yttria-stabilized zirconia catalyst (5Ni15YZr) provided the optimum activity performance of CH4 and CO2 conversions of 56.1 and 64.3%, respectively, at 700 °C and a 70 mL/min flow rate; this catalyst also had the highest basicity. The Ni-based catalyst was promoted with Cs, Ga, and Sr. The Sr-promoted catalyst produced the highest enhancement of activity. The influence of the reaction temperature and the feed flow rate on 5Ni15YZr and 5NiSr15YZr indicated that the activity increased with the increase in the reaction temperature and lower feed flow rate. For 5Ni3Sr15YZr, at a reaction temperature of 800 °C, the CH4 and CO2 conversions were 76.3 and 79.9%, respectively, whereas at 700 °C, the conversions of CH4 and CO2 were 66.6 and 79.6% respectively

Modification of CeNi0.9Zr0.1O3 Perovskite Catalyst by Partially Substituting Yttrium with Zirconia in Dry Reforming of Methane

Methane Dry Reforming is one of the means of producing syngas. CeNi0.9Zr0.1O3 catalyst and its modification with yttrium were investigated for CO2 reforming of methane. The experiment was performed at 800 °C to examine the effect of yttrium loading on catalyst activity, stability, and H2/CO ratio. The catalyst activity increased with an increase in yttrium loading with CeNi0.9Zr0.01Y0.09O3 catalyst demonstrating the best activity with CH4 conversion >85% and CO2 conversion >90% while the stability increased with increases in zirconium loading. The specific surface area of samples ranged from 1–9 m2/g with a pore size of 12–29 nm. The samples all showed type IV isotherms. The XRD peaks confirmed the formation of a monoclinic phase of zirconium and the well-crystallized structure of the perovskite catalyst. The Temperature Program Reduction analysis (TPR) showed a peak at low-temperature region for the yttrium doped catalyst while the un-modified perovskite catalyst (CeNi0.9Zr0.1O3) showed a slight shift to a moderate temperature region in the TPR profile. The Thermogravimetric analysis (TGA) curve showed a weight loss step in the range of 500–700 °C, with CeNi0.9Zr0.1O3 having the least carbon with a weight loss of 20%