Rauvolfia vormitoria Effect on the Degradation of Aluminium Alloy in 2.5 M Hydrochloric Acid Solution

The deterioration of aluminium alloy in 2.5 M hydrochloric acid in the presence Rauvolfia vormitoria extract was examined using both gasometric and gravimetric techniques. Aluminium coupons measuring 4 cm by 1 cm were introduced into test solutions of uninhibited acid and also those containing extract quantities of 10, 20, 30 and 40 cm3 at ambient temperature of 250C for a total cumulative period of 117 minutes. The volumes of hydrogen gas evolved and weight loss readings were recorded and analyzed to obtain weight loss and corrosion rate for each coupon at specific time intervals. The results however, showed that while extract quantity was increasing; weight loss measurements increased but inhibitor efficiency decreased. Also, the metal surface-phytoconstituent interaction mechanism was consistent with the Temkin adsorption isotherm and the 3 minutes curve showed the best exposure time for phytochemicals to adsorb to alloy surface. Furthermore, microstructural studies showed an indirect relationship between metallic degradation and extract quantity, while uniformity of the irregular intermetallic phases increased with increasing extract quantity

Investigations on the Material Efficacy of Failed Helical Gears in a Gear Train

An investigation on the material efficacy of failed helical gears in the gearbox of an automobile has been carried out. Two helical gear samples taken as representatives of the whole of six in the gearbox were denoted as samples A and B. Methods employed in the failure investigation include visual examination with the unaided eye and fractography; compositional analysis; hardness measurements and microstructural analysis. The results obtained showed that Gear sample A failed by oxidative wear essentially caused by insufficient lubrication. On the other hand, Sample B exhibited no outward sign of failure. Processes culminating in the formation of a wear particle were however noticed few micrometers below the surface of Gear Sample B. Furthermore, in the absence of sufficient lubrication, numerous carbide precipitates formed in both samples contributed to wear of the gear material. It was concluded that the premature service failures of the gears was caused by inadequate lubrication and not inadequate material selection

THE RADIO GIVE AWAY PROGRAM

Radio give away programs are those productions which offer some type of reward to a participant for his efforts on the program. This person mayor may not be present at the actual broadcast. This type of program is of recent origin, but it is rapidly becoming one of the more outstanding forms of radio entertainment

Mass Influx and the Dublin System: A Critical Assessment of the EU Response to the Syrian Refugee Crisis

The mass influx of asylum seekers in 2015 exposed the Common European Asylum System (CEAS), especially the application of Dublin III Regulation. CEAS was rendered ineffective in the face of large-scale movements of asylum seekers. The bulk of academic explanation available falls short in pointing out tangible mechanisms within the European Union (EU) asylum system on how mass influx of asylum seekers can be effectively managed. This scholarly vacuum runs the danger of leaving serious questions unanswered, especially on how future influxes can be adequately managed. The study therefore examines the Syrian refugees’ experiences with the application of CEAS at the peak of the refugee crisis of 2015. It points out the non-activation of Temporary Protection Directive (TPD) in the face of 2015 refugee crisis and how prima facie approach was not adopted in tackling the refugee crisis. It also acknowledges the growing influence of the far-right movement within the Union, with their antimigrant rhetoric, that can possibly influence the asylum policy formulation at Union and MS levels. It assesses the impact of a mass influx of asylum seekers on the EU frontline states and examines the ineffectiveness of the EU asylum system in the face of a mass influx of asylum seekers. It further assesses the unilateral and collective responses of the EU to the Syrian refugee crisis. The study adopts a qualitative method, and a phenomenological approach, with interview and document analysis as the data collection tools. The data analysis focuses on the interviews conducted with the Syrian refugees in the UK, France, Germany, and Austria as well as European Asylum Support Office (EASO) and Frontex officials. It also reviews relevant jurisprudence; examines the evaluation report on the Dublin III Regulation, reviews the proposed Dublin IV Regulation, and proffers solutions concerning how similar influxes can be effectively managed in future

Effect of Heat Treatment on Microstructure and Mechanical Properties of SAE 1025 Steel: Analysis by one-way ANOVA

The effect of heat treatment at 850oCon the microstructure and mechanical properties of SAE 1025 carbon steel has been studied. Annealing, normalizing and age-hardening heat-treatments at 850oC were used for the experimental work. Hardness tests, tensile tests and metallography were carried out on the heat-treated and control samples. The results were further analyzed using the one-way ANOVA test. Results obtained showed significant differences in the microstructure and mechanical properties of the different heat-treated samples. The hardness profile determined using a Brinell ball indenter showed decrease in hardness of the heat-treated samples when compared with the control. A microstructure of enhanced quality was obtained with normalizing heat-treatment. A higher tensile strength of 313.55MPa was obtained with annealing heat treatment in comparison to age-hardening (212.94MPa), normalizing (167.79MPa) and the control test (269.12MPa). ANOVA test confirmed the results at 90% confidence and further showed that there was significant difference amid the four test conditions

Engines with ideal efficiency and nonzero power for sublinear transport laws

It is known that an engine with ideal efficiency ($\eta =1$ for a chemical engine and $e = e_{\rm Carnot}$ for a thermal one) has zero power because a reversible cycle takes an infinite time. However, at least from a theoretical point of view, it is possible to conceive (irreversible) engines with nonzero power that can reach ideal efficiency. Here this is achieved by replacing the usual linear transport law by a sublinear one and taking the step-function limit for the particle current (chemical engine) or heat current (thermal engine) versus the applied force. It is shown that in taking this limit exact thermodynamic inequalities relating the currents to the entropy production are not violated

MATERIAL PERFORMANCE INVESTIGATION ON THE FAILURE OF AN AIRCRAFT (ABT-18) NOSE WHEEL STRUT

The study investigated the cause and mechanism of failure of the nose wheel strut of a trainer aircraft with respect to material selection.Various methods and tests ranging from visual examination via unaided eye and fractography, hardness tests, chemical analysis and microstructural examination were employed for the study. The results show chevrons on the fracture surface which indicates fatigue failure characteristic of brittle fracture. Also, thefractographshowsincidence of a ductile pull and high energy fracture.This is evident by the cone shape of the fractograph and the observed tear.Hardness tests results showed high discrepancy between the values of the failed and undamaged samples indicating loss of strength and ductility in the failed sample as a result of fatigue. The outcomeof chemical analysis revealed that the component is made from medium carbon steel of the tough grade instead of the required spring steel.Therefore, a major cause of the failurecan be linked to improper material specification for the nose wheel strut.The failure mechanism was further confirmed by microstructural examination which revealed fatigue cracks propagated from inclusions in the microstructure of the failed sampl