Abstract Six amorphous alloys (Alloy 1: Fe56Co24Nb4B13Si2Cu1, Alloy 2:Fe68.5Co5Nb3Cu1Si15.5B7, Alloy 3: Fe75.3Ni0.8Cr0.9Si8.7B14.3, Alloy 4:Fe56Co24Cr10Nb4B3Si1Cu2, Alloy 5: Fe72.9Nb3Cu1Si16.2B6.9, Alloy 6:Fe83.3Si8.6Nb5.5B1.4Cu1.2) were selected in terms of their composition and mag netostriction constants and uniformly irradiated in a high radiation environ ment in Hall A of the Thomas Jefferson National Accelerator Facility. The 2 GeV electron beam irradiation-induced effects were characterized by Mӧssbauer spectroscopy. The microstructural changes were related to the evolution of the hyperfine magnetic field distributions and isomer shifts. In particular, the occurrence of stress centers in the amorphous materials was evidenced.

Abstract This work aims at the characterization of the clay of the locality of Dolisie for its valorization. The mineralogical analysis was determined by the following techniques (DRX, IR, ATG and ATD), chemical analysis was determined by ICP-AES, CEC was assessed by the Metson method. The geothermal proper ties were determined by the granulometric analysis of the clay soil and allowed us to position the Dolisie clay in the texture triangle, the landings limits ob tained allowed to place the Dolisie clay in the abacus of Casagrande and on the workability map of Bain and Highy. Chemical analysis showed that silica alumina as well as iron oxides are the major constituents in Dolisie clay The mineralogical balance showed that kaolinite and illite have similar percentag es which are (20.51%) kaolinite, (28.08) illites. This leads us to believe that kaolinite is not the dominant mineral and the IR spectrum shows that kaoli nite is poorly crystallized.

Abstract All plants, especially cocoa and oil palm, require magnesium (Mg) along with other macro- and micro-nutrients. Kieserite as the most common Mg-supplying fertilizer for crops is still imported for Indonesia due to lack of natural depo sits in the country. On the other hand, dolomites (CaMgCO3) are found ab undantly and mostly used as liming material due to low MgO content and solubility as well. Many efforts have been carried out since a century ago to convert dolomite into Mg fertilizer substituting kieserite. However, there are no efficient processes available yet and therefore it is the objective of this study to develop a potentially efficient process by employing bio-physico-che mical activation approach in converting dolomite into kieserite-like product. A series of experiments were conducted by using a calcinated dolomite from Sidayu, Gresik, East Java, reacting with H2SO4, and inoculating with Mg-so lubilizing microbes. An 80-mesh calcined dolomite powder was reacted with water at 1:3 ratio (% w/v) and after one hour stirring added with technical grade H2SO4 improving 27.7% MgO content from 18% to 23%. The formula was then tested its effectiveness for cocoa and oil palm seedlings in the greenhouse for three and six months, respectively. By combining NPK ferti lizer at standard dosage with the formula of Mg-fertilizer at 75% of kieserite rate yielded the highest performances by six-month-old oil palm seedlings in a greenhouse experiment. To obtain conclusive results under field conditions, the formula was tested at field experiments using immature and mature oil palm trees. At 0.9 kg/tree/year dosage, the Mg-fertilizer formula was superior to conventional kieserite at 1.6 kg/tree/year rate in supporting vegetative growth of immature oil palm. From the mature oil palm trial, it can be con cluded that the use of the new formulated Mg-fertilizer at 50% rate of con ventional kieserite (2 kg/tree/year) resulted in an insignificant different yield of fresh fruit bunches (FFB) compared to standard kieserite dosage.

Abstract Huge amounts of tailing dumps as a result of mines’ blasting operations were impacting economic and environmental problems. Evaluation of one of these tailing dumps of the Eastern Desert of Egypt showed the presence of reasona ble amount of cassiterite mineral reaching 0.199% SnO2. The mineral cassite rite was found as finely disseminated particulates, reached to 5 microns, with in varieties of quartz-feldspar-hornblende-biotite granitic formations. In the present study, the processing regime considered from the beginning the align ment between reaching cassiterite mineral liberation size, and its extreme brittleness character. Stirring ball milling technique was applied to produce −0.51 mm product with minimum fines as possible, which was left aside for a separate study. The ground product −0.51 + 0.074 mm was subjected to joint shaking table/dry high intensity magnetic separation techniques after splitting it into two fractions, −0.51 + 0.21 mm and −0.21 + 0.074 mm. Each fraction was separately subjected to “Wilfley” shaking table. At optimum conditions, a shaking table concentrate was obtained with 0.29% SnO2 and an operational recovery reached 96.94% from a feeding contained 0.19% SnO2. The heavies and the two middling products after shaking table were directed separately after dryness to dry high intensity magnetic separation using “Eriez” rare earth roll separator, meanwhile the light fractions were rejected. Mathemati cally designed experiments were applied to optimize the separation process. At optimum conditions, a final cassiterite concentrate was obtained with 11.25% SnO2, and an operational recovery 94.08%. In addition, a topaz mineral con centrate was separated at splitter angle 65˚.

Abstract This study assesses the reactivity of four (04) different types of clayey earthen materials (Kamboinsé, Pabré, Saaba, and Kossodo) with Ca(OH)2, analytical lime (AL) versus lime residu (LR), in ambient conditions. The effect of the stabilization of the earth with the LR was also studied on the performances of compressed earth blocks (CEB). The lime content varied from 0% to 20% with respect to the mass of dry earth material. The analysis of the reactivity and physico-mechanical properties were respectively carried out on the solu tions of the mixtures (earth + LR and earth + AL) and CEB (earth + LR). The mixtures were cured between 0 and 60 days at the ambient temperature of laboratory (30˚C ± 5˚C). The results showed that the reactivity of the clayey earth materials with AL is comparable to that with the LR. At the same time, this reactivity improved the physical and mechanical properties of stabilized CEB depending on the type of earth material, lime content and curing time. The maximum values of the dry compressive strength, observed for each ma terial stabilized with 20% LR, are 6 and 7 MPa (Kamboinsé), 8.8 and 9.3 MPa (Pabré), 6 and 6.5 MPa (Saaba), 8.8 and 9.7 MPa (Kossodo) respectively at curing time of 28 and 45 days. The structural efficiency of CEB was also im proved which implies that, in the current conditions, the stabilization of earth materials using LR allows to produce the CEB for potential applications in wall masonr.

Abstract The Metal Matrix Composites application has increased in many areas of science and technology, because of its additional physical, wear and mechan ical properties. In comparison with all MMC’s, aluminum-based MMC’s are finding wide applications due to their better strength to weight ratio, better stiffness, and high thermal conductivity as well as very good wear and corro sion properties. The properties of a composite mainly depend on better dis tribution of reinforcement in the matrix, which is very difficult to achieve.Basically Redmud is a byproduct of alumina, and it is waste product obtained during Bayer’s process. This waste product must be recycled else it may be dangerous to the environment. Redmud can be used as reinforcement for alu minium composites in order to achieve better properties. The proposed re search work includes preparation of Aluminum 6061-Red mud metal matrix composites using liquid metallurgy route following stir casting technique. An alloy Al6061 containing 0.60 percent silicon and Magnesium of 0.82 percent was used as the matrix material. Two different compositions of the Alumi num 6061-Red mud composites are prepared in addition to the base matrix and evaluated for mechanical properties also the force acting on the cutting tool at different spindle speeds during machining of the composite materials were analyzed.

Abstract Sodium acid phthalate C8H5NaO4 is one of the suitable semiorganic single crystals hired in second harmonic generation conversion applications. In the present work, optically transparent Benzophenone doped with sodium acid phthalate (SAPB) single crystals were grown successfully by slow evaporation solution technique. Single crystal XRD analyses exposed that the crystal lattice of SAPB crystal is a monoclinic crystal system with unit cell parameters a = 6.77 Å, b = 9.31 Å, c = 13.58 Å, and space group B2cb. The crystalline nature of SAPB material was confirmed by powder XRD pattern. The functional groups present in the grown crystals were identified by the FTIR analysis ranging between 4000 and 500 cm−1. The optical transparency and band gap of grown crystals were measured from UV-Visible spectroscopy. The fluorescence emis sion spectrum of the SAPB crystal having a strong Yellow emission peak at 574 nm and the red emission at 631 nm are identified. The Vickers micro hardness number (Hv) increases with increasing load. Meyer’s index num ber (n) calculated from Hv shows that the material belongs to the soft ma terial category. Preliminary measurement using Kurtz powder technique with Nd-YAG laser light of wavelength 1064 nm indicates that their second harmonic generation (SHG) efficiencies of the grown crystals were presented 2 times in comparison with Potassium Dihydrogen Phosphate (KDP) was confirmed.

Abstract Six amorphous alloys (Alloy 1: Fe56Co24Nb4B13Si2Cu1, Alloy 2:Fe68.5Co5Nb3Cu1Si15.5B7, Alloy 3: Fe75.3Ni0.8Cr0.9Si8.7B14.3, Alloy 4:Fe56Co24Cr10Nb4B3Si1Cu2, Alloy 5: Fe72.9Nb3Cu1Si16.2B6.9, Alloy 6: Fe83.3Si8.6Nb5.5B1.4Cu1.2) were selected in terms of their composition and magnetostriction constants and uniformly irradiated in a high radiation environment in Hall A of the Thomas Jefferson National Accelerator Facility. The 2 GeV electron beam irradiation-induced effects were characterized by Mӧssbauer spectroscopy. The microstructural changes were related to the evolution of the hyperfine magnetic field distributions and isomer shifts. In particular, the occurrence of stress centers in the amorphous materials was evidenced.

Abstract Cement, a major binding material in concrete making, influences the quality of concrete so produced with it; as such its chemistry dictates the chemistry of the concrete. Poor quality cement has recently been implicated as the main causes of incessant building collapses in Nigeria. The physicochemical analysis of limestone used in the production of various brands of Portland cement in four geopolitical zones of Nigeria (north east NE, north west NW, north central NC, and south west SW) was investigated using standard methods. Each of the limestone and cement samples was randomly collected from their respective sample points at the four different geopolitical zones of Nigeria. Each of the collected samples was ground and sieved to 2 mm mesh size. The limestone was rich in lime content that ranged from 45.91% ± 0.30% to 49.0% ± 0.19%. Among the cement samples, percent SiO2 ranged from 19.95 ± 0.25 (NW) to 20.18 ± 1.02 (NC), Al2O3 4.98 ± 0.18 (NW) to 5.82 ±0.38 (NE), Fe2O3 2.76 ± 1.00 (NE) to 3.82 ± 0.21 (SW), CaO 60.18 ± 0.27 (NE) to 65.10 ± 0.98 (NC), MgO 1.93 ± 0.04 (NC) to 2.50 ± 0.10 (NE), SO3 0.93 ±0.50 (NE) to 2.02 ± 0.13 (NW). The results showed that virtually all the cement samples analyzed conformed well to the BSEN 196-2 standard. However, the loss on ignition (LOI) deviated considerably (7.82% to 8.72%) from 4% maximum by the standard. Also, the lime saturation factor (99.70%) obtained for north central cement was slightly higher than the specified range of 92.0 to 98.0%. It could be deduced from this study that the various cements available in Nigerian market from the four geopolitical zones are of good quality. Nevertheless, other processes that lead to the production of a good concrete such as the mix ratio of cement, gravel, sand and water, use and quality of iron rods, and other building materials need to be professionally checked for quality assurance. The findings from this study can be a useful guide to the chemist, environmentalist, construction industry, and the general public on the quality of cements available in Nigerian market.

Abstract Cerium oxide has a great capacity to remove nonbridging oxygen atoms (NBO) from the glass network and serves as glass former units. The well formed CeO4 units played the role of decreasing NBO from the silicate network and cause a reduction in the concentration of tetrahedral boron groups (N4). The highest content of NBO in glass of lower CeO2 (1 mol%) has a dominant role in constructing crystalline clusters in the glass. Higher CeO2 concentration leads to formation of an amorphous glass network as documented by XRD and TEM-EDP spectra. Coordination of cerium with oxygen atoms gives uniform units of spherical morphology in the pure CeO2 as well as in cerium rich glass. Clustered species has a great benefit in the field of application, used as a shielding material for ionized radiations.

Abstract This study determined mineral value and antioxidant activity of Senegal fruits for contributing to improving healthy diet and preventing some chronic diseases. Mineral element contents of Dialium guineense, Landolphia heudelotti, Mangifera indica, Cyperus esculentus and Saba senegalensis, which are widely available and consumed, were studied. The results by ICP-OES spectrophotometry after acid mineralization showed highest levels of (per 100 g fruits), calcium (158 mg), potassium (1018 mg), magnesium (532 mg), zinc (26 mg) with juice of Landolphia heudelotti fruit pulp. Mangifera indica pulp is richer in sodium (89 mg), phosphorus (556 mg), sulphur (384 mg) and silicon (110 mg). Dialium senegalensis pulp is richer in iron (23 mg) and manganese (19 mg). Lyophilized Cyperus esculentus rhizomes analyzed by atomic absorption spectrophotometry gave highest concentrations of (per 100 g fruits), calcium (2550 mg), potassium (11,843 mg) and magnesium (7669 mg) but sodium content (22 mg) is lower. In vitro antioxidant activity evaluation with the DPPH radical showed for 10 mg/ml concentration, highest inhibition percentage for Saba senegalensis 4.03%, followed by Landolphia heudelotti and Dialium guineense, which were significantly similar 2.29% and 2.20% respectively, Mangifera indica 1.7% and finally Cyperus esculentus 0.5%, but much lower compared to the ascorbic acid equal to 96.32% used as a reference.

Abstract A sulphuric acid bake–leach method for the treatment of mixed copper-cobalt oxide minerals was investigated as an alternative to the reductive leaching method. Sulphuric acid bake-leach process of the mixed copper-cobalt oxide ore was carried out by mixing the sample with sulphuric acid followed by baking of the mixture in a muffle furnace. Baking tests were conducted at different conditions such as temperature, time, and varying amounts of acid. The reacted samples were then subjected to water leaching at room temperature to determine the leachability of copper and cobalt from the baked material. The dissolutions of copper and cobalt were dependent on acid concentration with cobalt showing more sensitivity to the amount of acid. Both copper and cobalt were extracted from the baked material within short leaching times and without the addition of reducing agents. The outcome of this work has shown that the sulphuric acid bake-leach process is a possible alternative to the reductive leaching method for copper-cobalt oxide ores.

Abstract This study was carried out with a view to appreciate the value of clay, raw materials in eco-construction. To achieve this, we sampled two clay raw materials denoted Aga and Bak and then characterized. The results obtained from geotechnical and mineralogical tests have shown that the clay samples Aga and Bak are fine soils moderately plastic class A soils consisting essentially of quartz with 73.13% and 74.56% respectively for Aga and Bak and clay minerals (kaolinite and illite) with 12.73% kaolinite and 8.55% illite for Aga against 8.31% kaolinite and 13.72% for Bak. Moreover, these samples do not contain swelling clays and contain a sufficient quantity of iron oxides which allows them to be valued in ceramics, in particular in compressed earth bricks (CEB).

Abstract Additive manufacturing (AM), while enabling the production of parts with complex geometries, presents new challenges. In particular, the achievement of the basic mechanical properties of the alloy must be ensured. In general, the strength-ductility properties of metals depend strongly on their microstructure, and controlling these properties requires paying attention to the alloy composition, processing technique and heat treatments. Austenite 316L stainless steel parts produced by AM demonstrate good ductility and high yield strength—higher than that obtained with annealed 316L. Some preferred orientation of the mechanical properties was found as a function of the laser path, namely, the Young’s modulus varied with respect to the angle between the build direction and the normal to the build direction. In the present study, samples of AM 316L in three orientations relative to the print direction (0˚, 45˚ and 90˚) are compared to a forged sample. Mechanical properties, scanning electron microscopy-SEM fractography, energy dispersive X-ray spectroscope-EDS analysis of the fracture and optical cross section images of the samples along the stress tension after the failure are presented.