Mechanical and Micrography Analysis of Armour Plate Weldment Using Tungsten Inert Gas and Oxy-Acetylene Welding Methods

Defence Industries Corporation of Nigeria (DICON) has compared the effect of Tungsten Inert Gas (TIG) and Oxy-Acetylene welding methods on microstructural and some mechanical properties of Armour plate for the modification of military troop carriers. The optical emission spectrometer (OES) at DICON was used to analyse the chemical composition of the armour plate strip. It was then machined and cut to various test piece dimensions for both welding processes, following which the weldment samples were subjected to post-weld mechanical tests (tensile, impact, and hardness) and metallographic examination. The samples were then welded according to the procedure outlined in this study. The fundamental composition of armour plates was preserved in the samples. When compared to Oxy-Acetylene (OA) welding, Tungsten Inert Gas (TIG) welding produced better results, with an average ultimate strength (UTS) of 603.52 MPa and an impact strength of 10.53 J. In addition, the TIG analysis hardness strength for the source material, heat affected zone (HAZ), and weldment sample is 510.3, 502, and 511-HV, respectively. At x200 magnification, the micrography of the TIG weldment revealed a small coarse grain size of ferrite and larger areas of pearlite.

Concentration of selected elements in the hair of Madagascar girls in relation to nutritional status and place of residence

Although the children malnutrition in Madagascar and the environmental pollution of this country has been widely discussed, there is no research on the differences in toxic elements accumulation in human body in dependence on nutritional status of Malagasy. Nine elements concentration (Al, As, Cd, Cr, Hg, Ni, Pb, Sn and Sb) was determined in scalp hair of 103 schoolgirls (8–15 years old), living in two areas: urban - close to Antananarivo (UR) and rural Berevo region (RU). Samples were analyzed by an inductively coupled plasma-optical emission spectrometer. The nutritional status was evaluated by Cole’s Index. Underweight was related to higher accumulation of Al, Cd, and Cr in the hair girls, and more common among girls living in RU than UR region (42% vs 28%). Two-factor analysis of variance showed differences in the Al and Cr content in the girls’ hair depending both on their place of residence and nutritional status. This indicates additional consequence of malnutrition to the girls development and health.

Evolution of the mineral concentration and bioaccumulation of the black soldier fly, Hermetia illucens, feeding on two different larval media

Intensive black soldier fly (BSF) Hermetia illucens (Diptera: Stratiomyidae) rearing has a great importance for the feed industry. The objective of the present work was to perform a systematic study about the effect of the feeding media on the concentration and bioaccumulation factor (BAF) of Ca, K, Mg, Na, Cr, Cu, Fe, Mn, Ni and Zn in BSF fractions. Therefore, the evolution of the concentration of these elements has been studied along the stages of the BSF life cycle (larva, pupa and adult) as well as during its growth (exuviae) and metamorphosis (empty puparia). Two diets consisting of beer bagasse and commercial hen feed moistened with water have been chosen. An inductively coupled plasma optical emission spectrometer has been used to perform the elemental analyses. The obtained results demonstrated that the behaviour was generally, similar for all the elements studied, i.e. an accumulation in exuviae and puparia followed by their further elimination. Moreover, no significant differences in the results as a function of the feeding media have been found. This may be attributed to the fact that the chosen diets were equally favourable for this insect’s growth. The obtained concentrations have been expressed on a dry as well as a wet sample basis. BAF results also suggested that exuviae and puparia could be used as supplements or as bioactive compounds.

INVESTIGATION OF METALS RELEASED FROM IMPORTED COOKWARE COLLECTED FROM A LOCAL MARKET IN RIYADH, SAUDI ARABIA

Monitoring the presence of heavy metals in cookware intended for use by both humans and animals is of interest, because of their toxic effects. In this report, a study has been conducted to determine the heavy metals released from 46 items of metallic cookware purchased from a local market in Riyadh. Mn, Fe, Cu, Cr, As, Zn, Ni, Al, Cd and Pb, were analyzed using an inductively coupled plasma-optical emission spectrometer. The order of concentration of essential and toxic elements in all samples showed the following trend: Mn > Al > Pb = As > Fe > Zn > Cu = Ni = Cd > Cr. This study highlighted the importance of the metal release monitoring from cooking utensils in order to protect people from the dangers posed by toxic metals.

Miniaturized UV-LED Array Chip Photochemical Vapor Generator Coupled with Point Discharge Optical Emission Spectrometer for Determination of Trace Selenium

An ultraviolet light emitting diode (UV-LED) array chip as irradiation source for nano-TiO2 catalyzed photochemical vapor generation (PCVG) was combined with a hollow electrode point discharge microplasma optical emission spectrometer...

Size distribution measurement of microplastics using a temporally and spatially resolved inductively coupled plasma optical emission spectrometer (ICP-OES)

We studied microplastics in water using a temporally and spatially resolved ICP-OES with an inverted-type torch.