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Corrosion, which has become a menace to humans and the society is a subject of concern especially in the food and pharmaceutical industries. Research in mitigating corrosion has generated lots of interests especially in the development of organic inhibitors such as potato peels, siam weeds, harmal leaves, with promising results. This work investigated the potentials of the leaves of Editan (Lasienthera Africanum) extract for use in formulating inhibitor in corrosion prevention of Aluminum alloys. The leave was subjected to phytochemical screening, Characterization was done using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) for the protective layer and the extracts respectively. Corrosion test using gravimetric measurement on Al-Si-Mg alloy coupon in 3.5% NaCl solution was investigated. The result obtained showed that Lasienthera Africanum contains phytochemical properties of terpenoids, saponin, alkaloids, glycosides, tannins. The inhibitor efficiency was found to improve with increase in inhibitor concentration. Inhibition efficiency for Editan was obtained to be 100% at high concentration of extract (5v/v%), obtained at a temperature of 303 K The results have confirmed that the leave extract of Editan is a good inhibitor against corrosion inaluminum alloys.

Cement plants use fuel in burning limestone to make clinker in kilns. Due to high cost of fuels, most Cement plants are changing from high-cost liquid fuel like heavy fuel to cheap solid fuel like coal. Ashaka adopt the later. The coal is first pulverised in a ball mill and leaves the mill through a riser duct by pneumatic transport before been used in the kiln as fuel. The riser duct undergoes excessive wear which result in frequent downtime and affect the intendent purpose of fuel substitution. Also, the pulverised coal escaping under pressure through eroded areas on the duct increase the risk of fire and reduce the overall safety of the workshop. Current method which involved patching the duct by welding fail to solve the problem. This work investigates the root cause of the frequent wear of the riser duct by checking the abrasiveness of the coal being transported, checking the effect of the duct profile on wear through simulation using computational fluid dynamics (CFD). Checking the duct material rate of wear and providing the best solution in terms of cost and feasibility. After simulation using CFD it was revealed that the duct profile contributed to the wear rate. Since changing the profile will be costly, a different solution approach was considered i.e., surface finishing. Different Material samples suggested to be used as surface finishing on the duct were tested for wear at different angles using an abrasive test equipment. The test equipment which conforms with ASTM was designed, simulated using CFD and constructed. The best material with good wear resistance was found to be galvanised steel coated with automobile anti gravel and grounded with P1000. Coating the internal of the riser duct with the above material is considered to be the optimum solution in terms of cost and feasibility.

The use of waste materials to produce engineering components is currently attracting so much interest due to their low cost, availability and environmental impact. In this study, coconut shell ash (CSA) and kyanite particles (KP) produced from coconut shells and kyanite mineral respectively were characterized. X-ray Florence (XRF), X-ray diffractometer (XRD) and scanning electron microscope (SEM) were used to analyze the oxide compositions, crystalline phases and microstructures of CSA and KP. The XRF analysis revealed major oxides in CSA and KP as SiO2 and Fe2O3; and Al2O3 and SiO2 respectively. The XRD analysis revealed the presence of Quartz, Hematite, Andradite and Gaultite phases at major peaks in diffractogram of CSA; and Quartz and Beryl phases at major peaks in the diffractogram of KP. The crystallite sizes of the quartz phases in CSA and KP at diffraction angle of 26.72°C and 20.91°C were determined as 638.28 A and 789.38 A respectively. From the SEM image of CSA, it was observed that particles of different sizes are present in the microstructure of CSA. The average size of the particles in the microstructure of CSA is 26.24 μm. A similar result was observed in the SEM image of KP and average size of the particles is 3.074 μm. Also, the energy dispersive X-ray (EDX) spectrums of CSA and KP revealed the presence of many elements with calcium as the major element in CSA and Aluminium as major element in KP. The presence of the crystalline phases in CSA (SiO2, Al2O3, andradite, gaultite and hematite) and KP (SiO2 and Al2O3) will make them good strengthening materials for the production of Aluminium based composites that can be used in applications where a good combination of strength and wear characteristics is a basic requirement like brake disc.

Francis Hydraulic Turbine Guide-vane shear pin is a mechanical sacrificial component designed to break when the mechanical overload arises to prevent severe damage of guide-vane, which is an expensive component in the turbine assembly of hydro-power station. The pin is expected to serve for a minimum period of 10 years under normal working condition before failure occurs as obtained in most hydro-electric power stations globally. The shear pins in Shiroro hydro-electric power generation station located in Niger state of Nigeria were found to be frequently failing within a year of operation before reaching its predetermined load. This research investigated the possible causes of the frequent failure of the shear pins with a view to proffer solution. Analyses of the existing shear pin with respect to material specifications, micro-structural analysis using spectrophotometer where both visual and scanning electrode microscopy (SEM) was done in addition to mechanical tests to ascertain conformity with standards. The results showed that the shear pin material conforms to the ASTM 420, which is the standard for production of the shear pin. The SEM results shows that the failure of the shear pins was due to low cyclic fatigue growth attributed to the effect of intermittent and unsteady operations of the turbine. The visual examination revealed no defect on the phases of the material indicating that the fractured failure was not due to any form of inconsistency resulting from segregation or related effects. The mechanical test revealed yield strength of 600 N/mm2, ultimate tensile strength of 750 N/mm2 and hardness of 29 HRC which agreed with standard specifications for the shear pin. The results indicated that the frequent failure of shear pins could be as a result of other sources other than material specifications.

Investigation into development of advanced lightweight composite materials with low densities and tailored properties that could comfortably replace conventional ones is currently the direction of many researches especially in the automobile and aerospace industries. Aluminum reinforced composites are mostly considered due to their inherent properties of low density, good thermal and electrical conductivity, as well as superior mechanical properties. This research focused on production of A356 (Al-7%Si-0.3%Mg)/Locust Bean Pod Ash (LBPA) composites for brake rotor applications using Design Expert software which determined the number of runs of experiments and percentage composition of the input elements. The LBPA which was found to contained crystals such as Al2O3, SiO2 and Fe2O3 which are the main elements responsible for improving hardness and wear to the composite was used as reinforcement in the production of the composite by sand casting. The produced composite was machined and subjected to heat treatment. Hardness and wear rate properties tests were conducted followed by metallographic examinations. Models for hardness and wear rate were developed and analyzed using Analysis of Variance (ANOVA), other interfaces of the Design Expert and simulation in Excel environment. The best combination for hardness and wear rate was reached when the volume fraction of the reinforcement was 25% the hardness value of 40.41 HBR and wear rate of 0.0489mm3/Nm which showed that the hardness and wear rate of the composite samples improved by 57.23% and 47.10% respectively as compared to the matrix alloy. ANOVA results showed that effect of LBPA was significant. The photo-micrograph of the composite shows clearly the homogeneity of dark dispersion of the LBPA and predominantly white metallic phases. From the results, it can be concluded that LBPA can be utilized as reinforcement in the production of brake rotors.

BACKGROUND: Endoscopic ultrasound (EUS) guided Fine Needle Aspiration (FNA) is an effective modality for tissue acquisition in the diagnosis of GI and non-GI pathology. The optimal method of FNA is not known. The main focus is on maximisation of each FNA pass. There is little emphasis on the number of times or actuations the needle is moved within the target lesion during each FNA pass. AIMS: The aim of this study was to determine the optimal number of actuations for obtaining high diagnostic yield in each FNA pass. METHODS: This is a retrospective study carried out at Vancouver General Hospital. EUS guided FNA of solid lesions in the GI tract were included. FNA was performed with a 22G FNA needle. Three different passes were performed on each mass lesion. A standardised technique was adopted for all passes which involved no stylet, fanning, and wet suction at 20cc. There were 10 actuations performed for the 1(st) pass, 20 actuations for the 2(nd) pass, and 30 actuations for the 3(rd) pass. The cellularity and diagnosis for each pass were determined by GI pathologists blinded to patient inclusion in the study. RESULTS: 32 patients were included in this study with 10 males and 22 females. The average age was 68 years with a median age of 67.5 years. Pancreatic masses were the most common tissue type with pancreatic ductal adenocarcinoma being the most common diagnosis. The number of actuations did not affect the ability to obtain a diagnosis. Tissue obtained from all three pass types were considered adequate for evaluation by pathologists. Passes with 10, 20 or 30 actuations provided equal yield in pathologic diagnosis. The 1(st) pass was diagnostic in all 32 cases. CONCLUSIONS: Our data suggest that lower number of actuations can reliably be used during tissue acquisition for EUS guided FNA without affecting the diagnostic yield. Fewer actuations may lower the risk of procedural complications including bleeding and seeding. FUNDING AGENCIES: None

The microstructural study via scanning electron microscope (SEM) and thermal study via differential scanning calorimetric (DSC) study of Al-7%Si-0.3Mg/melon shell ash particulate composite has been carried out. The melon shell ash was used in the production of MMC ranging from 5% to 20% at interval of 5% addition using stir casting method. The melon shell ash was characterized using X-ray fluorescent (XRF) that reveal the presence of CaO, SiO2, Al2O3, MgO, and TiO2 as major compounds. The composite was machined and subjected to heat treatment. Microstructural analyses of the composite produced were done using scanning electron microscope (SEM). The microstructure obtained reveals a dark ceramic (reinforcer) and white metallic phase. Equally, the 5 wt% DSC result gives better thermal conductivity than other proportions (10 wt%, 15 wt%, and 20 wt%). These results showed that an improved property of Al-Si-Mg alloy was achieved using melon shell ash particles as reinforcement up to a maximum of 20 wt% for microstructural and 5% wt DSC respectively. Keywords: Microstructural analysis, Melon shell ash, Stir casting, X-ray fluorescent, Reinforcement, Composite

This study was aimed at assessing envenomations caused by snakebite in Niamey National Hospital, between July 2005 and September 2006. We included 53 victims of snakebites. The wounded distribution indicated more wounded males than females (sex ratio = 1.78:1). The mean age was 29 ± 17 years. September to November seemed a period of higher risk. The snake was not identified in 60% of the cases. The bite occurred during March in 43% of the cases. Clinically, 6% of the patients showed no signs of envenomation and 7% presented bleeding disorders; 88% of the patients did not receive anti-venom. The lethality rate was 15%.

Department of Chemistry. Dr. Babasaheb Ambedkar Marathwada University, Aurangabad-431 004, Maharashtra, India E-mail : abr_chem@yahoo.co.in Manuscript received 27 July 2010, revised 31 March 2011, accepted 31 March 2011 Densities and ultrasonic velocity of the binary mixtures of 2-butanone with alkyl acetates such as methyl acetate, ethyl acetate, 1-propyl acetate and 1-butyl acetate were measured at 298.15, 303.15 and 308.15 K over the entire composition range. This experimental data were used to calculate excess molar volumes (VE), deviations in isentropic compressibility (ΔK,). These results were fitted to Redlich-Kister polynomial equation and results have been discussed in terms of molecular interaction and structural effects. The excess properties were found to be either positive or negative depending on the molecular interaction and the nature of liquid mixtures.

Department of Chemistry, Dr. Babasaheb Ambedkar Marathwada University. Aurangabad-431 004, Maharashtra, India E-mail : abr_chem@yahoo.co.in Manuscript received 26 March 2009, accepted 3 July 2009 Densities and viscosities of the binary mixtures of 1,2-ethanediol with primary alcohols such as methanol, ethanol, 1-propanol and 1-butanol were measured at 293.15, 303.15 and 313.15 K and refractive index for same systems were measured at 303.15 K over the entire composition range. This experimental data were used to calculate excess molar volumes (VE), viscosity deviations (∆η) and refractive index deviations (∆nD). These results were fitted to RedlichKister polynomial equation and results have been discussed in terms of molecular interaction and structural effects. The excess properties were found to be either positive or negative depending on the molecular interaction and the nature of liquid mixtures. &nbsp

This study was aimed at assessing envenomations caused by snakebite in Niamey National Hospital, between July 2005 and September 2006. We included 53 victims of snakebites. The wounded distribution indicated more wounded males than females (sex ratio = 1.78:1). The mean age was 29 ± 17 years. September to November seemed a period of higher risk. The snake was not identified in 60% of the cases. The bite occurred during March in 43% of the cases. Clinically, 6% of the patients showed no signs of envenomation and 7% presented bleeding disorders; 88% of the patients did not receive anti-venom. The lethality rate was 15%.

To report the formulation and implementation of an organ system based integrated curriculum for MBBS students at Ziauddin Medical University (ZMU) Karachi.The Basic Medical Science Faculty (Anatomy, Physiology and Biochemistry) along with representatives from Medicine, Surgery and Community Health Sciences held joint meetings spread over weeks to design a system based integrated curriculum for the first two years of the MBBS class. Objectives of an integrated course were devised and the duties of term coordinator determined.Horizontal integration of Basic Science subjects can be achieved, with the subject specialists coordinating the teaching of a system based as opposed to subject based curriculum. The basic sciences can also be integrated with Community Health Sciences to achieve partial vertical integration.

Etude des composants du stockage de l'hydrogene et du systeme de gestion de la charge thermique dans un procede au circuit ferme de conversion de l'energie solaire et energie electrique compose de panneaux de cellules au silicium immerge dans l'acide bromhydrique pour la production de brome et d'hydrogene par electrolyse, d'un stockage de brome et d'hydrogene, d'une pile a combustible brome-hydrogene et d'une pompe a chaleur pour la recuperation de l'energie thermique de basse temperature