Prediction of austenite grain growth during austenitization of a 0.7%C pearlitic rail steel

The prior austenite grain size of steels greatly influences the phase transformation kinetics during austenitization and the microstructure which determines the mechanical properties. The effect of temperature and time on austenite grain growth of 0.7% carbon rail steel during reheating was studied. The grain growth behaviour of this steel was investigated under different heating temperatures and holding times at a constant heating rate of 4°C/min. Samples were heated in a tube furnace at temperatures of 1150, 1200 and 1250oC and held for 0, 1800, 3600, 5400, 7200 and 9000 seconds before quenching into water. The prior austenite grains were observed using an optical microscope and austenite grain sizes were measured by the linear intercept method. The measured austenite grain sizes were used in determining the grain growth constants Q, A and n which were used in developing the constitutive equation for grain growth prediction. A good agreement was found between the actual and the predicted austenite grain size within the typical industrial soaking temperature range of 1150 and 1200oC.MINTEKhttp://www.satnt.ac.za/index.php/satntam2022Materials Science and Metallurgical Engineerin

Linking Community Participatory Research to Global Policymaking: Lessons Learned

The past two decades saw a proliferation of opportunities for the perspectives of people experiencing poverty and marginalisation to input into global policymaking spaces. So far these efforts have been contested, with attempts to embed participatory methodologies facilitating only limited consultation and falling into many pitfalls. While Participate was built on learning from previous attempts to influence global policy, we aimed to further understand participatory processes, and advance practical mechanisms for participation at every level of decision-making, from local to national and global. Participate emphasises the interactions between these levels and the importance of impacting multiple levels in order to create lasting, transformative change. This chapter describes what has been learnt about bringing the voices on the ground into global policymaking. We examine how and by whom the knowledge and evidence created were used, and the barriers and challenges to embedding this knowledge into global policy processes, through the following questions: • What have been the challenges to embedding participatory processes into global policy spaces? • What have these pathways of influence looked like, and what are some of the key lessons learned from these

Major flaws in conflict prevention policies towards Africa : the conceptual deficits of international actors’ approaches and how to overcome them

Current thinking on African conflicts suffers from misinterpretations oversimplification, lack of focus, lack of conceptual clarity, state-centrism and lack of vision). The paper analyses a variety of the dominant explanations of major international actors and donors, showing how these frequently do not distinguish with sufficient clarity between the ‘root causes’ of a conflict, its aggravating factors and its triggers. Specifically, a correct assessment of conflict prolonging (or sustaining) factors is of vital importance in Africa’s lingering confrontations. Broader approaches (e.g. “structural stability”) offer a better analytical framework than familiar one-dimensional explanations. Moreover, for explaining and dealing with violent conflicts a shift of attention from the nation-state towards the local and sub-regional level is needed.Aktuelle Analysen afrikanischer Gewaltkonflikte sind häufig voller Fehlinterpretationen (Mangel an Differenzierung, Genauigkeit und konzeptioneller Klarheit, Staatszentriertheit, fehlende mittelfristige Zielvorstellungen). Breitere Ansätze (z. B. das Modell der Strukturellen Stabilität) könnten die Grundlage für bessere Analyseraster und Politiken sein als eindimensionale Erklärungen. häufig differenzieren Erklärungsansätze nicht mit ausreichender Klarheit zwischen Ursachen, verschärfenden und auslösenden Faktoren. Insbesondere die richtige Einordnung konfliktverlängernder Faktoren ist in den jahrzehntelangen gewaltsamen Auseinandersetzungen in Afrika von zentraler Bedeutung. Das Diskussionspapier stellt die große Variationsbreite dominanter Erklärungsmuster der wichtigsten internationalen Geber und Akteure gegenüber und fordert einen Perspektivenwechsel zum Einbezug der lokalen und der subregionalen Ebene für die Erklärung und Bearbeitung gewaltsamer Konflikte

In vitro anti-malarial interaction and gametocytocidal activity of cryptolepine

YesBackground: Discovery of novel gametocytocidal molecules is a major pharmacological strategy in the elimination and eradication of malaria. The high patronage of the aqueous root extract of the popular West African anti-malarial plant Cryptolepis sanguinolenta (Periplocaceae) in traditional and hospital settings in Ghana has directed this study investigating the gametocytocidal activity of the plant and its major alkaloid, cryptolepine. This study also investigates the anti-malarial interaction of cryptolepine with standard anti-malarials, as the search for new anti-malarial combinations continues. Methods: The resazurin-based assay was employed in evaluating the gametocytocidal properties of C. sanguinolenta and cryptolepine against the late stage (IV/V) gametocytes of Plasmodium falciparum (NF54). A fixed ratio method based on the SYBR Green I fluorescence-based assay was used to build isobolograms from a combination of cryptolepine with four standard anti-malarial drugs in vitro using the chloroquine sensitive strain 3D7. Results: Cryptolepis sanguinolenta ( IC50 = 49.65 nM) and its major alkaloid, cryptolepine ( IC50 = 1965 nM), showed high inhibitory activity against the late stage gametocytes of P. falciparum (NF54). In the interaction assays in asexual stage, cryptolepine showed an additive effect with both lumefantrine and chloroquine with mean ΣFIC50s of 1.017 ± 0.06 and 1.465 ± 0.17, respectively. Cryptolepine combination with amodiaquine at therapeutically relevant concentration ratios showed a synergistic effect (mean ΣFIC50 = 0.287 ± 0.10) whereas an antagonistic activity (mean ΣFIC50 = 4.182 ± 0.99) was seen with mefloquine. Conclusions: The findings of this study shed light on the high gametocytocidal properties of C. sanguinolenta and cryptolepine attributing their potent anti-malarial activity mainly to their effect on both the sexual and asexual stages of the parasite. Amodiaquine is a potential drug partner for cryptolepine in the development of novel fixed dose combinations

Benthaminin 3, a Novel Antibacterial Cassane-Type Furanoditerpenoid from Caesalpinia benthamiana

The roots of Caesalpinia benthamiana (synonym. Mezoneuron benthamianum)are considered to be an effective remedy in Ghana for the management of skin diseases and wounds. Bioactivity-guided fractionation of the chloroform extract of the root bark of the plant has resulted in the isolation of a novel cassane-type furanoditerpenoid, designated as benthaminin 3. The structure of the compound was elucidated by the use of spectroscopic techniques. The antibacterial activity of the compound has been assessed using the microdilution assay method. The lowest MIC (63μg/mL) was recorded against Staphylococcus aureus and Bacillus subtilis. The compound wasalso observed to have a mild inhibitory effect against resistant strains of bacteria including methicillin-resistant S. aureus, tetracyline-resistant S. aureus and erythromycin-resistant S. aureus with MIC values greater than 1000μg/mL

Benthaminin 3, a Novel Antibacterial Cassane-Type Furanoditerpenoid from Caesalpinia benthamiana

The roots of Caesalpinia benthamiana (synonym. Mezoneuron benthamianum)are considered to be an effective remedy in Ghana for the management of skin diseases and wounds. Bioactivity-guided fractionation of the chloroform extract of the root bark of the plant has resulted in the isolation of a novel cassane-type furanoditerpenoid, designated as benthaminin 3. The structure of the compound was elucidated by the use of spectroscopic techniques. The antibacterial activity of the compound has been assessed using the microdilution assay method. The lowest MIC (63μg/mL) was recorded against Staphylococcus aureus and Bacillus subtilis. The compound wasalso observed to have a mild inhibitory effect against resistant strains of bacteria including methicillin-resistant S. aureus, tetracyline-resistant S. aureus and erythromycin-resistant S. aureus with MIC values greater than 1000μg/mL

Libya and the state of intervention

The international response to the crisis in Libya has been remarkably quick and decisive. Where many other cases of mass atrocity crimes have failed to generate sufficient and timely political will to protect civilians at risk, the early response to Libya in 2011 has shown that the United Nations Security Council is able to give effect to the ‘responsibility to protect’ norm. While not an implementing party in a legal sense, the Australian government has taken a forward-leaning diplomatic stance in helping to mobilise broad support for addressing this crisis. In light of the ongoing political controversy over armed humanitarian intervention, the Libya case shows that state-based advocacy for R2P matters, given the on-going need to bolster the legitimacy of the principle. A discussion of Canberra's diplomatic activity is a prelude to an examination of the proceedings of the UN Security Council and the two key resolutions, the second of which gave effect to the forcible action. The article then considers three dimensions of the Security Council's implementation of the responsibility to protect: the language of the resolutions and the intriguing absence of a textual reference to the international community's responsibility to act; the expansive mandate for civilian protection in Security Council resolution 1973; and the first unanimous referral to the International Criminal Court, with novel support from the United States of America