Acid resistance of palm oil fuel ash and metakaolin ternary blend cement mortar

This paper examines the effects of blend of Palm Oil fuel ash (POFA) and Metakaolin (MK) on the resistance of cement mortar to sulphuric acid (H2SO4) attack. Tests were conducted on POFA and MK ternary blended cement mortar immersed in a 3% H2SO4 solution for up 180 d. Binaries of POFA/cement and MK/cement as well as plain ordinary Portland cement (OPC) mortar was also tested for comparison. The parameters measured include residual compressive strength and residual mass. Additionally, the microstructures of the specimens were analysed using the X-ray diffraction and Fourier transformed infrared techniques. The residual compressive strengths of the mortar specimens for plain OPC, binary blend of POFA and cement, binary blend of MK and cement, and ternary blend of POFA, MK and cement after 180 d of immersion in the acid solution were 25, 30, 33, and 32%, respectively. Moreover, the corresponding residual masses of the specimens were 39, 52, 58, and 54%. Accordingly, the ternary blended mortar performed better in resisting H2SO4 attack than the plain OPC and binary blend of POFA/cement mortars

Cytotoxic activities of fractionated ethanol extract of the root bark of terminalia catappa and isolation of eriodictyol-7-O-β-D-glucopyranoside from the ethyl acetate soluble fraction

The crushed root bark of terminalia catappa Linn was extracted using aqueous ethanol. The crude extract was suspended in water and successively partition into n-hexane, dichloromethane, ethyl acetate and n-butanol soluble fractions. The fractions i.e.; n-hexane, dichloromethane, ethyl acetate, n-butanol and water were subjected to cytotoxic activity using brine shrimp lethality bioassay and proton nuclear magnetic resonance (1H NMR) analyses. The cytotoxicity of the isolates were evaluated in terms of lethality concentration (LC50). Comparing the result obtained to vincristine sulphate with LC50 of 0.61 μg/ml, ethyl acetate and n-hexane fractions demonstrated a significant cytotoxic activity having LC50 value of 0.82 μg/ml and 1.21 μg/ml. The LC50 values of the water, dichloromethane and n-butanol fractions were 11.90 μg/ml, 13.25 μg/ml and 17.10 μg/ml respectively. The ethyl acetate fraction with significant activity in in-vitro cytotoxic activity and a good proton NMR profiles, was further fractionated and purified using column chromatography, preparative thin layer chromatography (PTLC) and the isolate obtained were characterized using spectroscopic techniques (MS, IR, 1H and 13C NMR, 1H-1H COSY and 1H-13C HSQC). We concluded that the compound isolated was eriodictyol-7- O-β-D-glucopyranoside

Management of squamous cell carcinoma on the thigh of a Nigerian Albino horse

The albino horse is the choice horse traditionally for ceremonial parade amongst the military and the police force in Nigeria because of their bright and attractive appearance on parade ground. Incidentally, squamous cell carcinoma (SCC) is the most common neoplasia of the skin in horses especially the albinos. An 8-year old albino parade stallion of Nigerian breed was presented with the chief complaint of growths on skin of right thigh and a tentative diagnosis of SCC was made. This case reports a successful management of SCC in albino horses with a view to improving management of the condition especially in veterinary settings with limited facility. The horse was restrained in standing position using hobbles and xylazine sedation. Local anaesthesia was achieved using Lidocaine hydrochloride. Growths were debulked in two surgeries, conducted 60 days apart. Vincristine 2 mg was administered intravenously twice at 3 weeks apart after each surgery but additionally, 1g was infiltrated at site after the second surgery, necessitated by re-growth of lesion. Wound was regularly cleaned and dressed. Blood and tissue samples were collected and analyzed for haematological and histopathological alterations respectively. Pre-treatment, haemogram showed neutropenia, lymphocytosis and hyperproteinemia. Histopathological examination revealed focal areas of keratin pearls, massive undifferentiated tumour cells at different stages of mitosis. It was concluded that surgical excision of lesions and vincristine therapy should be used in squamous cell carcinoma management in horses. Therefore, it was recommended that surgeons should be patient as multiple surgeries may be indicated depending on severity of squamous cell carcinoma.Keywords: Albino, Carcinoma, Horse, Management, Nigerian, Squamous Cell, Thig

Polarization Response in InAs Quantum Dots: Theoretical Correlation between Composition and Electronic Properties

III-V growth and surface conditions strongly influence the physical structure and resulting optical properties of self-assembled quantum dots (QDs). Beyond the design of a desired active optical wavelength, the polarization response of QDs is of particular interest for optical communications and quantum information science. Previous theoretical studies based on a pure InAs QD model failed to reproduce experimentally observed polarization properties. In this work, multi-million atom simulations are performed to understand the correlation between chemical composition and polarization properties of QDs. A systematic analysis of QD structural parameters leads us to propose a two layer composition model, mimicking In segregation and In-Ga intermixing effects. This model, consistent with mostly accepted compositional findings, allows to accurately fit the experimental PL spectra. The detailed study of QD morphology parameters presented here serves as a tool for using growth dynamics to engineer the strain field inside and around the QD structures, allowing tuning of the polarization response.Comment: 8 pages, 6 figures; accepted for publication in IOP Nanotechnology journa