Strength and Ductility of Forged 1200 Aluminum Alloy Reinforced with Steel Particles

Strength and ductility responses of forged AA1200 aluminum alloy reinforced with steel particles have been studied. Steel particles of sizes 106, 181, 256, 362 and 512μm were separately added to the aluminum alloy to produced cylindrical shape samples, which were homogenized at 4200C for 10 hours, further processed through upset forging at 320C and finally annealed at 4700C for 8 hours. Results show that forged composites with 106μm had a tensile strength of 280MPa and ductility of 1.75 after 10 percent reduction and subsequent annealing. With 50% reduction and fine-sized steel particles (512μm) in aluminum alloy, tensile strength dropped to 160MPa without significant decrease in ductility (1.7). Microstructure of cast samples show the presence of fine Fe particles at grain boundaries after annealing with most of the particles in solid solution. Al3Fe and AlFeSi intermetallics were also present in the matrix with significant influence on the mechanical properties.http://dx.doi.org/10.4314/njt.v34i4.

EFFECT OF ALUMINUM DROSS AND RICE HUSK ASH ON THERMAL AND MOULDING PROPERTIES OF SILICA SAND

Moulding properties of foundry sand should be controlled so as to minimize casting defects. Its thermal characteristics are vital in defining the solidification kinetics of a cast part,  evolving microstructure and mechanical properties. Modification of the thermal properties of the moulding sand mix is important in achieving desired structure and mechanical properties in the cast component. This study investigates the incorporation of 2-12 wt. % aluminium dross (AlDr) and 1-6 wt. % rice husk ash (RHA) in silica sand on moulding and thermal properties of the resulting sand mix. Results show that RHA significantly reduced thermal conductivity of the moulding sand from 1.631-1.141 W/m. K (a 30% reduction).However, AlDr increased its thermal conductivity from 1.631-1.787 W/m.K for 1-6 wt. % AlDr, which later dropped progressively from 1.753-1.540 W/m.K for 8-12 wt. %. The moisture content increased abruptly from 4.0-4.2 % for 6-8 wt. % AlDr addition but decreased from 4.0-2.8% for0-6 wt. % RHA addition in the moulding sand mix. http://dx.doi.org/10.4314/njt.v36i3.1

Congenital bilateral fusion of the maxillomandibular alveolar processes with craniosynostosis: report ofa rare case

A rare congenital anomaly of maxillomandibular fusion with pectus excavatum and craniosynostosis in a neonate is presented. The child was kept alive by nasogastric tube feeding.Amodification of classification of syngnathia is proposed. The aetiopathogenesis and difficulty in management in our environment are discussed. Keywords: Bilateral; alveolar fusion; craniosynostosis; pectus excavatum Nigerian Journal of Clinical Practice Vol. 11 (1) 2008: pp.78-8

Morphological, Mechanical and Thermal Characteristics of PLA /Cocos nucifera L Husk and PLA/Zea mays Chaff Lignin Fibre Mats Composites

Polylactide (PLA) is a biodegradable polymer with low elongation which limits its use in some applications. The incorporation of biowaste particles has been employed to improve its properties. This work thus examines the impact of lignin particles reinforced on electrospun PLA fibre mats. Acid hydrolysis (1M of HCl at 60 and 100 0C for  2 and 4 h was used to extract lignin from Cocos nucifera L (CNHL) and Zea Mays Chaff (CCL). Lignin particles were added to molten PLA, stirred, and electrospun at 26 kV, using a static aluminum collector plate placed at 121mm from the spinneret tip. Morphological examination reveals that fibre diameter of neat PLA (9.7 µm) increased from 107 – 285 % with the additions of reinforcements. Maximum tensile strength of 1.03 MPa is recorded for PLA/CNHL 60 0C /2 h. This composite maintains the highest elongation of 0.069 % compared to neat PLA (0.046 %). X-Ray diffractometer (XRD) result informs that the crystallinity of neat PLA (67.6 %) improves by 3%, with the use of CNHL 60 0C/ 2 h. Thermo gravimetric analysis (TGA) result shows that both fibre composites possess better thermal stability (380 0C) compared to reinforcing PLA fibre (3190 C)

Bright ligand-activatable fluorescent protein for high-quality multicolor live-cell super-resolution microscopy

We introduce UnaG as a green-to-dark photoswitching fluorescent protein capable of high-quality super-resolution imaging with photon numbers equivalent to the brightest photoswitchable red protein. UnaG only fluoresces upon binding of a fluorogenic metabolite, bilirubin, enabling UV-free reversible photoswitching with easily controllable kinetics and low background under Epi illumination. The on- and off-switching rates are controlled by the concentration of the ligand and the excitation light intensity, respectively, where the dissolved oxygen also promotes the off-switching. The photo-oxidation reaction mechanism of bilirubin in UnaG suggests that the lack of ligand-protein covalent bond allows the oxidized ligand to detach from the protein, emptying the binding cavity for rebinding to a fresh ligand molecule. We demonstrate super-resolution single-molecule localization imaging of various subcellular structures genetically encoded with UnaG, which enables facile labeling and simultaneous multicolor imaging of live cells. UnaG has the promise of becoming a default protein for high-performance super-resolution imaging. Photoconvertible proteins occupy two color channels thereby limiting multicolour localisation microscopy applications. Here the authors present UnaG, a new green-to-dark photoswitching fluorescent protein for super-resolution imaging, whose activation is based on a noncovalent binding with bilirubin

Plasma Levels of Total Proteins, Albumin, Globulin and Plasma Albumin/Globulin Ratio in Human Immunodeficiency Virus Infection in Ile-Ife, Nigeria

Plasma levels of total protein, albumin and globulin were estimated in 25 HIV positive subjects and 25 age and sex-matched controls. Test subjects were recruited from the Haematology day Clinic and Medical wards of theOAUTHC, lle-Ife. The controls were equally obtained from staff and students within the OAUTHC, lle-lfe who tested negative for H1V in the last six months. The albumin/globulin ratios were also computed for each group. This study was undertaken to determine the plasma levels of these biochemical analytes as well as their profiles in complications of Human Immunodeficiency virus /Acquired immune deficiency syndrome (HIV/AIDs) subjects. The mean plasma levels of total protein and globulin in HIV positive subjects were significantly higher than those of their respective controls (

Estrogen receptor beta agonist alters RNA splicing factor expression and has a longer window of antidepressant effectiveness than estradiol after long-term ovariectomy

Title on article: ERβ receptor beta agonist alters RNA splicing factor expression and has a longer window of antidepressant effectiveness than estradiol after long-term ovariectom