MSN  *  15th Annual International Conference, Nigerian Materials Congress (NIMACON - 2016)

The increasing human population and demand for food is imposing pressure on water, land and energy resources. This affects the various economic sectors, especially agriculture. Recently, Food Agricultural Organization (FAO) has recognized the potential of algae and has designated algal culture as agriculture based on the ability of algae cultivation to provide biomass that has potential for Chemical production, environmental bioremediation, biofuels, and animal feed production. The need to carry out studies into the production of furfural from algae is very paramount in that it enhances biotechnology through the use of algae materials and can serves as a means of converting waste to wealth. Furfural is a promising platform chemical for the production of fuels and high value-added chemicals in industries. It can be produce from acid hydrolysis of hemicelluloses present in algae biomass to obtain xylose, which then passes through a dehydration reaction to produce furfural. Furthermore, furfural can be used as feedstock for the production of a wide range of value added products due the presence of an aldehyde group and a conjugated system of double bounds. This article review furfural production from algal biomass and highlighting its chemical properties which enable its uses in different industrial applications of economic interest.

Keywords: algae, feedstock, furfural, hydrolysis, properties, uses.
Correspondence: mailoguchejohn@yahoo.com

Rubberized Asphalt is a mixture of crumb rubber (which is used tyres), aggregate and bitumen. In pavement construction, just the bitumen and aggregates may not meet the optimum performance requirement due to whether variations, loading and climatic conditions in Nigeria. It is thought that the application of this used automobile tyres as rubber additives which is in abundance as waste material, will not only reduce the environmental problems associated with its disposal, it will enhance the elastic responses of bitumen at higher ambient temperatures, and result in a material that has a marked increase in resistance to deformation simultaneously with reduced brittleness at low temperatures. This is an ongoing research work investigating the suitability of crumb rubber as a partial/total replacement for bitumen and aggregate for low traffic road maintenance works. With the help of grinders and debeaders, the sourced used tyres were processed by separating the fibre and steel after which the remaining tyres were reduced into small particles of desired mesh sizes for blending into the bitumen and aggregate. Laboratory investigations were conducted on the samples to determine and analyse the optimum mix ratio for bitumen, crumb rubber and aggregate. 5%, 15%, 20% and 25% respectively, of bitumen was replaced by crumb rubber (fine size). 10% aggregate was also replaced by crumb rubber of 4 mm size for the different mix ratios. Penetration test, water absorption test, flash point test and Marshall Stability and flow test were conducted. Based on the laboratory results, for the 5%, 15%, 20% and 25%, the stability values were 10220, 5054, 7180 and 5617N respectively, which meets the minimum requirement of 3336N for a low traffic road. The mixture shows better performance in the laboratory test, production for field deployment is ongoing.

Keywords: Rubberized asphalt, crumb rubber, bitumen, aggregate, marshall test.

Novel perovskite-type nanomaterials with the composition La1-x(Bix)FeO3-δ (where x = 0.5 and 0.2) were synthesized by using a modified citric acid sol-gel route and annealed at 900°C in (1) in air (LB0.5FO-air and LB0.2FO-air), and (2) in Argon atmosphere (LB0.5FO-Ar and LB0.2FO-Ar). Scanning electron microscopy and powder X-ray diffraction analysis of the powders showed that they contain crystalline perovskite-type nanoparticles with crystallite sizes 37-41 nm. The lattice parameters, after refinement, showed that the particles crystallized in an orthorhombic structure. The BET specific surface areas (SSA) ranged between 1.76-4.37 m2 g-1 with powders synthesized under argon having the higher SSAs. Vibrating sample magnetometer analysis of the hysteresis loop showed a slightly higher magnetization value for the samples synthesized in air. Photoluminescence spectroscopy showed that the powders were all active in the visible region and could be useful for visible light photodegradation of organic dyes. The powders were all screened for photocatalytic activity against an organic dye (Rhodamine B) in the visible region of the solar spectrum and the photocatalytic activities were good for powders synthesized in argon, In addition, a mineralization of up to 80% was achieved after 3 hrs of photodegradation for these powders as well. The materials therefore, show good potential for the photocatalytic degradation of organic pollutants and photocatalyst recovery after photodegradation.

An analysis is presented for vibration and rotation of thermoelastic annular thin disk with uniform thickness subjected to a linear steady temperature in the radial direction. The problem is described by elasticity equation of motion, heat conduction equation, and Duhamel-Neumann constitutive relation. Invoking the hypothesis of plan stress, the governing differential equation of the system is obtained by the method of separable variables. A closed form solution of the displacement, strain and stress fields were obtained which have wide applications in physics and engineering, also the results obtained generalized some known results in literatures.

In this study, Daucus Carota (Carrot) leaves were sorted out, pounded and extracted dyes using soxhlet apparatus with methanol and ethanol, each for 45 and 90minutes respectively. The extracted dyes were concentrated and dried. Methanol gives higher percentage yield compared to ethanol. The dyes were characterised by colour, pH, melting point, solubility, FTIR and UV-visible spectroscopy. The extracted dyes appear green in colour with pH of 4.2 – 5.6, melt at 120°C and insoluble in water. Dye extracted using methanol presents higher maximum absorbance at wavelength near to 400nm. The spectra of the dyes shows peaks above 3300 cm-1 for O–H stretch (H-bonded), 2974–2896cm-1 for C–H stretch (alkanes) and 2031–1651 cm-1 for C=O stretch (conjugated) or C–N bend (amines). Peaks at 1450 cm-1 for C–H stretch (alkanes) and above 1088cm-1 for C–O stretch (carboxylic acid/alcohol) or C–N stretch (amines) were also observed. The dyes were applied on cotton, wool, polyester and nylon 6.6 fabrics. Nylon 6.6 shows good to very good wet fastness. Wool and polyester has fair to good, and cotton presents poor to fair wet fastness.

Keywords: Daucus Carota, Dye, Wavelength, Yield

A self-compensation (SC) doping mechanism was used to study the dielectric properties (permittivity and dielectric loss) of Barium Titanate perovskite ceramics (BTPC) with the view of improving these important properties for application in Multi-layer ceramic capacitors (MLCCs). Conventional solid state sintering (SSS) also known as “shake-and-bake” (SnB) method was used to process the ceramic powder. Compositions were made according to the formula Ba1-xYxTi1-xYxO3 (0 ≤ x ≥10). The processed powders were characterised using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Impedance Spectroscopy (IS) and Inductance-Capacitance-Resistance (LCR) studies, respectively. The XRD suggests a solid solubility limit of not greater than 1mol% and was supported with the SEM micrographs which revealed a cubic phase believed to be a pyrochlore, Y2Ti2O7. Electrical measurements from these compositions evolved from an initial random ferroelectric behaviour in shifting of the Curie temperature TC to an ideal relaxor type behaviour. The activation energy (Ea) for all compositions suggest that the highest Ea, ~1.38 eV was found in the 3mol%. In all compositions, there was a gradual reduction in the temperature dependence of capacitance TCC as the sharp peak at TC was broadened significantly. The dielectric loss (Tan-delta) otherwise known as dissipation loss factor was significantly low for all compositions at ~ 3 – 5%.

Keywords: Self- Compensation, doping, permittivity, tan-delta, dielectric, Curie-temperature.

This study was carried out to determine the optimum fusion temperature in the extraction of Tantalum from Tantalite-columbite ore using Potassium Hydroxide (KOH) and subsequent water leaching. The Tantalite-columbite ore samples procured from Okene, Kogi state and Oke-Onigbin, Kwara state were ball milled for six hours and sieved through a 125µm laboratory test sieve. The elemental/oxide composition of tantalum and niobium in the ball milled ores were determined using X-Ray Fluorescence (XRF). From the XRF result, the Tantalum and Niobium content, about 19.46% and 28.50% respectively for the sample from Kogi state was higher than 14.72% & 27.50% respectively for the sample from Kwara state; hence all fusion experiments with KOH (ore to KOH ratio 1:5) were conducted using the sample from Kogi state. For each run 10g of the ground Tantalite-columbite ore was mixed with 50g of the KOH in a ceramic crucible. The mixed samples were fused at varying temperatures of 350°C, 400°C, 450°C, 500°C & 550°C in an electric furnace for a duration of one hour. The fused mass was cooled and leached with 400ml of distilled water. From the resulting XRF analysis of the dried residues after filtration process, the composition of Tantalum and Niobium obtained respectively for the various fusion temperatures are; 12.35% & 11.75% at 350°C, 4.12% & 3.40% at 400°C, 4.84% & 4.14% at 450°C, 1.12% & 1.69% at 500°C, and 2.23% & 2.36% at 550°C respectively. The concentration of Tantalum and Niobium extracted were computed to be; 36.54% & 58.77% at 350°C, 78.83% & 88.07% at 400°C, 75.13% & 85.47% at 450°C, 94.24% & 94.07% at 500°C and 88.08% & 91.72% at 550°C respectively. Thus a temperature of 500°C was obtained to be the optimum fusion temperature in the extraction of tantalum using KOH as 94.27% Tantalum and 94.07% Niobium concentration was extracted from the ore.

ZnO-Cellulose acetate nanocomposite was synthesized using the in-situ co-precipitation technique and characterized using Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analyses. The nanocomposite was applied as an adsorbent for the adsorption of Orange II dye from aqueous solution. The effect of concentration, pH, time contact, adsorbent dosage and temperature were investigated, and maximum percentage removal of the dye was calculated to be 83%. The Langmuir and Freundlich isotherm model gave a positive result with the adsorption experimental data with value of b and n equal to 0.075 and 1.197 respectively while regression coefficient R2 equal to 0.839 and 0.859 in each case. The thermodynamics studies of the adsorption show that the adsorption reaction is exothermic and the process follows a pseudo second order kinetic model.

This research project was aimed at extracting manganese from locally sourced tantalite-columbite ore using aqueous biphasic system (ABS). Two samples of the tantalite-columbite ore were procured from two notable sources in Nigeria, Kwara and Kogi states. The tantalite-columbite ore samples were crushed, ground and ball-milled for six hours in a laboratory ball mill and sieved through a 200 sieve mesh (74 µm). The composition of oxides in the ore were determined using X-ray florescence (XRF) analysis. From the XRF analysis, the manganese content was higher, about 5.3%, for the ore procured from Kwara state; as such the experiment was carried out using this ore. 10g of the ball milled tantalite-columbite ore was mixed with 50g of potassium hydroxide (KOH) which was earlier crushed in a ceramic. The fusion experiment was carried out in an electric furnace using ceramic crucibles at 4000C for one hour. After the reaction, the fused mass was cooled and subsequently leached with distilled water at room temperature. The resulting filtrate known as the leached liquor and the residue were analyzed for manganese by atomic absorption spectrometer (AAS) and XRF. The percentage of manganese leached was calculated to be 58.49%. Three samples, sample A (100% dilution), sample B (50% dilution) and sample C (undiluted) of the leached liquor were prepared for the aqueous biphase extraction experiment. Polyethylene glycol (PEG) of molecular weight 8000 and sodium sulphate salt Na2SO4 were used to form the aqueous biphase systems (ABS) at PEG to salt ratio of 2:1. The ABS formed was subsequently mixed with 1ml each of these samples (A, B and C) and shaken to enhance partitioning between the two phases formed. Results showed that manganese was extracted using ABS. The percentage recovery for the samples A, B and C were 65.59%, 58.34% and 64.61% for the upper phases and 28.45%, 23.61% and 16.93% for the lower phases respectively. The calculated distribution ratios for Sample A, B and C were 2.89, 2.47 and 3.82 respectively. The total percentage of manganese removed in sample A was 94.04% which was higher than the total percentage removed for sample B and sample C.

Over the years, the comparative advantage laterite has over conventional construction materials is its availability, affordability and reusability. However, it often requires stabilization with a binder to guarantee rigidity and improved water resistance. This research work experimented on polymer-stabilization of lateritic soil using Poly Ethylene Terephthalate (PET) sourced from waste plastic water bottles. The experimental procedure included melting 65, 70, 75 and 80% shredded PET bottles by weight of soil at a temperature of 240o C in a crucible. To each of the varied percentages of molten PET, 2, 3, 5, 7 and 10% of grade 60/70 bitumen by weight of soil was added. 900g of sieved laterite was then added to the molten plastic/ bitumen mix and stirred to homogeneous workability from which cubes of 50mm3 were moulded. Control cube samples of the same size were produced at 0% plastic and bitumen contents and 0% plastic and 10% bitumen contents by weight of laterite and Compressive Strength and Water absorption Tests were conducted after 24 hours of casting and demolding of cubes to obtain optimum strengths and water absorption levels. The experimental results indicated that at an optimum of 75% plastic and 5% bitumen content by weight of laterite, the sample block had a compressive strength of 18 N/mm2 while the control samples had compressive strengths of 3.6 N/mm2 and 3.9 N/mm2 respectively. It can be deduced that a 70% increase in product strength was achieved at optimum as compared to the control samples which indicated an increase in strength of 17% and 13% respectively. It can thus be inferred that the polymer additive to laterite aside creating a sustainable use for non-biodegradable plastic bottles, enhances the strength and water resistance qualities of laterite as a construction material, with possible applications as alternative material for walling of buildings and/or non-traffic pavement elements.

Keywords: Polymer-stabilization, lateritic soil, bitumen, Compressive Strength, Water absorption.

It has been said that no meaningful industrialisation can take place in a nation without Iron and Steel. In fact, the Iron and Steel is the bedrock of Nigeria’s industrialisation and ultimate factor in the realisation of our industrialisation efforts. Most of the Steel industries have been constructed and erected and they have to go into full operation in view of the huge money already sunk into these projects and the relative irreversibility of investment. Harnessing the local raw materials for engineering and technological development in Nigeria. The development of the economy could therefore be vibrate if the available local raw materials are harnessed. Metallurgical Research and Development are have been carried out which have assisted the industry to discover the use of locally sourced raw materials for the operation of these industries. Apparently, most of the imported raw materials are expensive and some time difficult to import them due to bureaucratic process and challenges faced at this present stage of steel development in Nigeria. The need for sustained availability of the raw materials for these steel industries calls for drastic reduction in the imported raw materials and this paper will therefore focus on availability of local raw materials which could be harnessed and translate to engineering and technological development in Nigeria . The paper further highlights the local raw materials needed for steel industry; processes for metallurgical coke and of refractory clay were reviewed. Local deposits of theses materials were mentioned. The future of metallurgical research and development were brought to the fore and finally some suggestions and recommendations were given which will assist Government, stakeholders and those that are involved in the practice of steel operations and other engineering processes but with emphasis to the steel industries.

Key Words: Harnessing, Local, Raw, Materials, Engineering and Technology

The Steel Industry will continue to serve as stimulus to national development and economy boaster to industrial development of a country. The industry will serve as the backbone of industrialization of our great country, Nigeria if all the necessary parameters are put in place. The benefits of having a functional steel industry will translate to a functional country. It should also be noted that steel industry will contribute to all the facets of the economy, including the important role steel plays in economic development and growth. In this presentation, the paper will highlight on the multiplier effects in the development and sustenance of agriculture, health care and virtually every other sector of the economy. The role of steel in defence was also identified. Discussion and emphases were place on the efforts made in the development of Steel Industry in Nigeria with a view to discussing the potentials that could be accrued for operating the industry. The paper also seek the concept of Government through this process of advocacies by requesting the Nigerian Government to complete the steel industry like Ajaokuta Steel Company Limited located at Ajaokuta in Kogi State. It should be noted that the steel industry was conceptualized as far back as 1958, because of the vital and strategic role of the steel industry in the transformation and reformation of the economy. If Nigeria ever desires to drop the toga of “underdeveloped economy” for that of “industrialized economy” catalyst and economy boaster the industry must be completed and make operational. If the steel industry had been completed, commissioned and effectively operated thirty-four years ago as conceptualized in the vision of the initiators, Nigeria would have been a different country in terms of industrial and economic development today.

Key words: Steel, Industry, Stimulus, National and Development

In historical perspective, the need for the establishment of an iron and steel industry in Nigeria was first expressed in 1958. Further action was taken by the immediate post independence government as is evidenced in the 1st National Development Plan (1962 - 1969), which states inter alia that “Substantial progress had been made in plans for a steel complex which will utilize Nigerian raw materials.” From the onset therefore policy formulation as regards the establishment of an iron and steel industry envisaged the availability, locally of at least the major raw materials inputs. In 1967, the Military Government (headed by General Yakubu Gowon) invited the Government of USSR to assists in setting up the steel project based on the availability of iron ores from Agbaja-Koton Karfi deposits. These deposits did not meet the specifications for use in the Ajaokuta blast furnace. As a follow up, the government with the support of USSR sponsored an extensive aeromagnetic survey of over 22% of the whole country. Ground magnetometric surveys and drilling for more suitable ones were subsequently undertaken. Exploration for iron ore was then concentrated at Birnin Gwari and Ayagba (Kaduna State), Ejigbo (Oyo State), Itakpe, Chokochoko, Ajabanoko and Agbado-Okudu (Kogi State). Investigations for coking coal centred on and around Afuze (Edo State), Lafia/Obi (Nasarawa State) and Gombe/Danduya (Gombe State). Initial results of this joint effort prepared the ground for the signing of contract 1717 (4th November 1970) between Nigeria and V/O Techno-export (USSR) and the subsequent establishment of NSDA in 1971. In collaboration with the technical partners, the Exploration Division of NSDA (now National Steel Raw Materials Exploration Agency) commenced actual detailed and systematic exploration for the ores and other minerals in 1971. It was based on the strength of the recommendations of NSDA following the establishment of proven iron ore reserve at Itakpe and other deposits that Government sited the iron and steel plant at Ajaokuta in 1975. The paper therefore discusses the usage of raw materials for the development of iron and steel in Nigeria. Summary and Recommendations were made with a view to harnessing all the potentials available for iron and steel development in Nigeria.

Key Words: Development, Iron, Steel, Industry and Nigerian Raw Materials

Advanced and underdeveloped countries of the global world,natural fibre reinforced polymer composite (NFRPC) have earlier been developed and are being further developed to greatly substitute artficial or synthetic fibres to successfully replace metals for wide engineering applications. Natural fibres can be greatly applied in building construction companies and in automobile industries in production of brake pads and car bumbers.This high technological area can play significant role in the industrial development and sustainability of nigeria when fully put to use.Natural fibres are biodegradable materials which does not affect the humans and its environ and replace the fast disappearing timbers by reducing carbondioxide (CO2) emissions which is the major cause of the global problem of climate change.Secondly, this sector of the economy when fully developed and harnessed it posses great economic potentials and can generate millions of employment for the industrial and agricultural sector and ensures safety in the environment by converting most of the waste into usesful products like car bumbers,brakepads and as well in structural areas.Annually natural fibres are wasted in nigeria in our farms without any value addition and yet most of them are imported into Nigeria for various industrial and domestic applications such as POP in orthopaedic hospitals and plumbing yarns.This work will highlight challenges and way forward which require great attention as to fully advance into the potentials of these new materials of today’s technological transformation and competitiveness for sustainable development of our country, Nigeria.

Coal is a fossil fuel created from the remains of plants that lived and died about 100 to 400 million years ago when parts of the Earth were covered with huge swampy forests. Coke is produced from high grade coking coal which must have ash and sulphur content below 12% and 0.8% respectively. Nigerian Chikila coal was collected at a depth of about 4.5m, air dried, crushed and pulverised. Fractions of -425+300µm and -75µm were preliminary leached with KOH, NaOH, Na2CO3 andNH4OH. Based on result, NH4OH was selected for comprehensive leaching of the coal using 24 factorial variables combination. Multistage leaching was carried out. Analyses using UV spectrophotometer and particle induced X-ray emission (PIXE) were done for the filtrates and coal concentrate obtained respectively. The as-received sample gave proximate analysis of 4.70% moisture, 42.12% volatile matter, 12.60% ash, 1.68% sulphur and 40.58% fixed carbon. The multistage leaching of -425+300µm fraction using H2O-NH4OH-H2O sequence produced a coal concentrate with 3.96% moisture, 36.63% volatile matter, 8.79% ash, 1.11% sulphur and 49.51% fixed carbon. The alkaline leaching resulted in a decrease of 30.23% in ash, 33.93% in sulphur and 13.03% volatile matter. Also an increase in carbon content of 22.01%. A successful upgrade of the leaching to pilot scale will make the coal available as a blend component for economical industrial cokemaking.

Keywords: Alkaline, Coking, coal, leaching, multistage, concentrate

In situ generation of hydrogen from alcohols and hydrocarbon is attracting attention of researchers as result of zero greenhouse gas emission, unstable fossil fuel market and the advent fuel cell technology. Challenges associated with hydrogen production such as transportation, handling and low volume energy of hydrogen can be addressed by in situ generation. Methanol steam reforming offers the benefit of relatively low temperature between 200-350°C, a high hydrogen to carbon ratio (4:1) and the absence of the C-C bonds which results in lowered soot formation. In this study, hydrothermally grown CuZnO micro-sized rods were characterized and tested to evaluate the performance for methanol reforming catalysts in hydrogen generation. ZnO rods were grown on the surface of a ceramic; cordierite. A 20mM precursor solution of CuNO3 was used for impregnation of Cu on the ZnO rods. SEM, XRD, XRF, FTIR, Raman Spectroscopy and BET surface area analysis were carried out on the CuZnO rods. The rods have an average diameter of 287nm with 0.146 wt% of copper impregnated on the ZnO surface. Catalyst testing was carried out in a stainless steel fixed bed reactor, 305mm in length and 9mm in diameter. The methanol reforming experiments were conducted at atmospheric pressure and temperatures between 200°C and 350°C. At lower temperatures, high methane selectivity was recorded with low CO formation. Methane formation was thermodynamically favoured at 200oC but dropped drastically as temperature increased while a rise in CO and CO2 was observed. The hydrogen yield also increased as temperature of the process increased. The permissible CO limit is less than 1% if intended use is for fuel cells. So despite having higher H2 produced at 350oC, reforming at that temperature is not recommended as CO poisons anode fuel cells. Methanol conversion of 96% was recorded for the reforming process at 250°C.

Underwater robots and mechanism require sealing of components in such a manner that it must not fail (by leakage). Simple O'ring (or other shapes) made from various grades of rubber or silicone does a decent job at creating very good seal even where high water pressure exist. In a dynamic situation, that is when the joint or seal itself is involved in cyclic motion, a different scenario is encountered by the seal. Mechanical factors such as damage mechanics must then be put into serious consideration in any design that uses such setup. This work is an experimental investigation into the mechanical damage that a latex rubber (obtained from condom) and exposed to elements (water, ethanol, sodium hydroxide (0.07mol/dm3 concentration)) for 45 days will experience. The samples were subjected to free vibration while simultaneously being put under tensile loading. The result obtained shows that the stiffness of the sample immersed in water increases as the stretch increases (1142.75 →1678.48 N/m), the sample soaked in ethanol decreases (1559.33 → 1173.38 N/m). Similarly, the one soaked in Sodium Hydroxide solution had a decrease in stiffness (1474 → 793N/m). The maximum stretch was 3cm.

Rapid prototyping using wood is not so novel, but creating prototypes for underwater devices (in this case, underwater robot) is an interesting experiment using wood. The reason is that wood is a naturally occurring bio-degradable plastic. In the presence of humidity or absorbed liquids, it is dimensionally unstable. These characteristics makes them unsuitable for the highly humid environment and for building dimensionally precise equipment . This work present a workaround these limitations by taking an advantage of the porosity nature of wood. Selected wood samples (5cm by 1cm) were treated with cyanoacrylate materials, rapid curing and slow curing epoxy materials and carpenter white glue. Furthermore, bending stress tests shows carpenter white glue is more suitable for flexible assembly than all treatment. Also, permeability test with saline water confirms that cyanoacrylate treated wood followed by slow curing epoxy does not absorbed any measurable water. The cyanoacrylate impregnation method was found to be the best for very salty water environment when the water temperature was raised to 50°C.

Rice husk (RH) /sawdust (SD) – polyester (PE) resin was characterized to get the best percentage ratio for ceiling board production. Different percentage ratios of RH/SD – PE resin were mixed at various ratios. The study was limited to two mechanical properties which are flexural strength and hardness. They were experimentally determined using flexural testing machine and rockwell hardness testing machine at engineering laboratory of standard organization of Nigeria (SON) emene Enugu. MATLAB (2014 version) was used to validate the experimental data obtained from SON laboratory. The results of the MATLAB analysis and that of SON laboratory are in close agreement with each other with optimum values for both flexural strength and hardness to be 6.24MPa and 190 respectively which are values for the percentage ratio of 50% RH/SD- 50%PE. This result will be useful in engineering applications in areas where light weight and resistance to bending of materials under load are required.

Keywords: Sawdust, Rice Husk, Polyester Resin, Ceiling Board

Semi-flexible pavement is generally a composite pavement which comprises a surface course with a semi-flexible material that provides significant advantages in comparison to both rigid and flexible pavements. The semi-flexible material generally known as grouted asphalt comprises a porous asphalt skeleton with 25-30% voids into which cementitious slurry is grouted. This hybrid mixture provides good rut and fatigue resistance and a surface highly resistant to fuel and oil spillage, which allow it to be used in industrial areas, airports and harbours and also where pavement are frequently associated with heavy and slow traffic. The objective of this study is to investigate grouted asphalt as an alternative to conventional asphalt concrete for pavement construction, hence some of its mechanical properties were evaluated. In the study three different grout mixtures named grout A, B and C were considered and the properties of the grouted asphalt like compressive strength, the indirect tensile strength, and the flexural were evaluated. The compressive strengths of the grouts A, B and C were 22.5, 21.2 and 22.4 MPa, respectively. The results showed that the 28-day compressive strengths of the grouted asphalts with grout A, B and C respectively were 2.6, 2.5 and 2.8 MPa, the flexural strength 1.1, 1.0 and 1.3 MPa, respectively while the indirect tensile strength were 2.0, 1.85 and 2.2 MPa, respectively. The results indicate the grouted asphalt has improved compressive, flexural and indirect tensile strengths. This implies it has a better resistance to rutting and fatigue. However, more tests like the repeated permanent deformation test, indirect tensile fatigue test and field trials are required to ascertain this. Also it was observed that the grouted asphalt produced using grout C gave the best results. This was because of the composition of the grout which allows it to fill all the voids in the porous asphalt.

This work deals with the treatment of tannery effluent using advanced oxidation method through the process of irradiating the effluent using ultraviolet light in the presence of hydrogen peroxide, while varying the concentration of hydrogen peroxide, the time and pH. The results obtained show that as the pH increases, the absorbance reduces, as time increases the degradation increases and after degradation, the BOD and COD values reduced. This process can be used in tanneries to make their effluents safer for discharge.

15g each of three ammonium phosphates [(NH4)3PO4, NH4H2PO4 and (NH4)2HPO4] were added, separately, to 100 g of PMMA and compression molded to prepare a sheet measuring 45.2 × 11.6 x 2.3 mm3 to serve as control. Nine sheets of the same dimension were also prepared by the same method after addition of 1.5, 3.0, 4.5, 6.0, 7.5, 9.0, 10.5, 12.0 and 13.5 g of pentaerythritol. Cone calorimeter was used to assess the mass loss rate, heat of combustion, total heat release and peak heat release rate of the 10 (control and nine pentaerythritol-containing) samples. Limiting oxygen index and vertical burn rating tests were used to determine, qualitatively, the flammability of the 10 samples. The quantitative flammability parameters (Burn time, ignition time, after-flame time, char length and flame spread) of the samples were also evaluated. The experimental results showed that the three ammonium phosphates had good flame retardancy in the PMMA sheet that improves with increase in concentration of pentaerythritol. The efficiency of the ammonium phosphates in flame retardation of PMMA was found to follow the order (NH4)3PO4 > NH4H2PO4 > (NH4)2HPO4 with the trend attributedto the quantity and the ease with which ammonia (NH3) gas is released on heating the ammonium phosphate–containing PMMA sheets. The cone calorimeter results showed decrease in values of all the four parameters investigated with increase in concentration of pentaerythritol with the difference between the control and the least pentaerythritol-containing sample being the highest (0.07 gs-1 in mass loss rate, 14.36 MJkg-1 in heat of combustion, 22.06 MJm-2 in total heat release rate and 222.12 kWm-2 in peak heat release rate). The ammonia gas released renders any combustible gas nonflammable by acting as a strong base in the condensed phase and as a diluent in the gas phase of the combustion process and, in combination with pentaerythritol, a polyhydric alcohol that burns to produce CO2 and water vapour, have greatly enhanced the flame resistance of PMMA. Since combination of pentaerythritol and the three ammonium phosphates used in this study is highly efficient in flame retardation and biodegradable, it was recommended for use as substitute to the non-biodegradable, environment hostile and toxic flame retardants and synergists in commercial production of PMMA and its products.

Keywords: Ammonia, cone calorimeter, flame, limiting oxygen index, methyl methacrylate

Sheet of pure poly(vinyl chloride) (PVC) measuring 45 x 11 x 3 mm3 was prepared to serve as control by compression moulding method. Sheets of the same dimension were also prepared by the same method after addition of 2.5, 5.0, 7.5, 10.0, 12.5, 15.0, 17.5 and 20.0 parts per hundred resin (phr) of three polyols (erythritol, xylitol and sorbitol). Glass-transition temperature (Tg), elongation-at-break, tensile strength, leaching and migration of the control and the eight polyol-containing PVC sheets were determined to evaluate effects of molecular weight and concentration of the three polyols on their plasticizing efficiencies in the prepared PVC sheets. The results showed that although both molecular weight and concentration affect their plasticizing efficiencies, plasticizer concentration was found to be the most important parameter that influences plasticizer efficiency in the PVC sheets. While Tg and tensile strength were drastically reduced by addition of the polyol plasticizers, weight loss (through leaching and migration) and, especially elongation-at-break of the plasticized sheets, were increased in direct proportion to the amount of polyols added. The plasticizing efficiencies of the three polyols were found to follow the order sorbitol >> xylitol > erythritol. The trends of results were attributed to the size of the polyol molecules represented by their molecular weights. Being larger in size, sorbitol is retained in the PVC sheets better than the relatively lower molecular weight xylitol and erythritol as obtained from their weight loss values (through leaching and migration). The plasticizers work by embedding themselves between the PVC chains and spacing them apart (increasing the "free volume"). This pushing further apart of the PVC molecules by the plasticizers helps in weakening the forces between the PVC molecules, thus making the PVC sheets softer and more flexible. Since an ideal plasticizer is that which significantly lowers the glass transition temperature (Tg) of a substrate without compromising its desired mechanical properties, is biodegradable, nonvolatile, nontoxic, and exhibits minimal leaching or migration during use or ageing, the three polyols were recommended for use in PVC sheets in place of the toxic and environment non-friendly phthalates conventionally used.

Keywords: Environment, phthalate, plasticizer, polyol, poly(vinyl chloride)

Natural sun drying is one of the most common ways to preserve agricultural products. Many agricultural products are spread on the ground to be dried by sun and wind. This results in poor quality products due to contamination and high loss caused by uneven or incomplete dehydration. Parametric design of a drying system for cassava starch was carried out using Simprosys 2.0 Process simulation package specifically designed for drying systems, the units considered in this design includes the air filter, blower, heater unit, solid dryer, input feeder, cyclone and product collector, a process flow diagram consisting of all the units was assembled. The drying system was designed on the basis of 20 kg/hr of wet cassava starch with moisture content of 40%. From the results generated, the air particle loading for the air filter and filter area were found to be 0.038 kg/hr and 0.267 m2 respectively, the blower suitable for the drying operation has a total discharge pressure of 3.296 kPa and power output of 0.505 kW. The heating unit have a total heating duty of 11.447 kW. Also from the process simulation results, for all range of temperature between 90oC to 120oC, an air flow rate of 450 kg/hr has the highest values of drying efficiency averaging 83.2%. Considering a circular transverse section, the suggested dryer diameter and length are 0.296 m and 2.366 m respectively. Therefore a total of 11 minute with an optimum temperature of 120oC can reduce the moisture content of cassava starch from 40 % wet basis to equilibrium moisture content of 10% wet basis suitable for storage.

Keywords: Solid Dryer, Drying, Simprosys, Design, Process Simulation, Moisture Content,

Researchers, industrialists, students and agencies often find it difficult to get appropriate voltage for experimentation, to measure or test their equipment due to unavailability of equipment offering such voltages.Thus the need for this work , a singular equipment that supplies both AC and DC voltages. It is a 2KVA AC/DC variable voltage supply with digital readout of 0.5-300 volts AC and 0.5-425 volts DC. With this equipment, electrical personnel in industries, schools, etc, now have access to any desired voltage (AC or DC), within the above range, for their daily operations. This equipment has a single-coil wound toroidal transformer, a shaft with attached knob for varying the voltages. A selector switch (toggle switch) is used to selector either AC or DC, depending on the required voltage type. There are digital meters(AC and DC) to display the selected voltage. In addition, there are output terminals to connect devices or equipment to be powered or tested. There is no doubt that every research work is designed to achieve a particular purpose or a number of purposes that will solve immediate or future problems of the society. The significance of any designed product is measured by how far it achieved the set goal. This work is considered significant for its ability to; Provide the 2 KVA 0.5-300V AC and 0-425V DC, broaden student research on the utilization of transformer in power distribution of electricity, step up a very low voltage that may be supplied as a result of distribution system fault. Provide students, electrical researchers or industrialists the opportunity to test their works with any conceivable voltage, AC OR DC.

Heavy metals are naturally found in the environment being present in human and animal body, rock, soil, plant, and water . The use of these metals and its exposure has increased over the years due to globalization and rapid development. Levels of heavy metals (Pb, Cd, Cu, Zn, and Ni) in road-side snacks commonly sold in Ilorin metropolis were studied. Samples were collected from four (4) locations characterized by heavy traffic and various human activities which were then compared with low traffic and less of human Activities (which serve as the control).Three replicates samples of each snacks (biscuits, puff-puff, bean cake, and roasted plantain) were ashed, digested and analyzed using a calibrated Atomic Absorption Spectrophotometer. Zinc and lead were found to be high in all the snack samples while copper were found to be very high in Bean Cake. Accumulation of these metals can be as a result of various human activities, vehicular emission, method of preparation, containers and ingredient used in the preparation. Therefore, this paper suggested a regular monitoring and management in order to reduce the risk of accumulation of heavy metal in the body of consumers.

To date, Hydroxyapatite (HAp) powder is an important inorganic biomaterial widely used in orthopedic and dental applications. Consequently, HAp powders were prepared from Calcite ore of Nigeria origin using diammonium hydrogen phosphate as the Phosphorus source through hydrothermal method. The chemical structure and nature of HAp crystals formed at different reaction temperature and time of operation were accordingly characterized by X-ray Fluorescence (XRF), Fourier Transform Infra-red (FT-IR), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM) coupled with Energy Dispersive X-ray (EDS) techniques. At a set of experimental conditions, different morphology, crystallinity and stoichiometric ratios were obtained and characterized. With 1 mol/L (NH4)2HPO4 solution, 850C reaction temperature, a rectangular, rod-like and layered HAp crystal was formed yielding the Ca/P ratio of 1.66 during 6 hours reaction duration. Hence, the value of Ca/P ratio obtained in this study is apparently very close to the stoichiometric HAp ratio of 1.67 that is required for use in industrial biomedical applications.

Keywords: Hydroxyapatite powder; Calcite ore; Nigeria; Hydrothermal method; Ca/P stoichiometric ratio, Biomedical applications.

LiSn2(PO4)3 of composition LiSn1.85Ti0.15(PO4)3 with NASICON structure was prepared by solid-state synthesis. XRD results show the formation of stable phase material of rhombohedral structure with the R3 ̅c space group.Traces of SnO2 unreacted phase and minor impurities of SnP2O7 were detected. SEM results show the doped sample with grain size of 1.073μm. Impedance and dielectric study in the microwave range show conductivity enhancement in bulk and grain boundary. The room temperature ionic conductivity is 4.74x10-5 S/cm and the conductivity is 2.37x10-3 S/cm at 740 K. The highest value of dielectric constant ε' is 2000 while the lowest value is 500. Imaginary modulus plot vs temperature indicates the presence of temperature relaxation in the material. The plot of relaxation frequency at different temperatures was used to calculate the activation energy which was found to be 0.23 eV.

Structural transformations of Li-doped Zn1-xLixO(0.10≤x≤0.70) which was synthesized by solid state reaction was investigated. XRD carried out on powder specimens of the samples show that they are polycrystalline in nature with a hexagonal wurzite structure having minor impurities. The result indicates the maximum limit of substitution of Zn atoms by Li is at x= 0.4. The lattice parameter a reduced from 3.01 to 2.99 Å while c reduced from 5.21 to 5.19 Å. Whereas the Zn-O bond length reduced from 1.88 to 1.87Å for the undoped, to x=0.60 for the doped, respectively. The c/a ratio is 1.73 and is almost constant for all samples. The grain size of the (100) peak of the undoped ZnO is 41.73 nm and that of x= 0.10 is 41.76nm. For x= 0.2 to 0.70, the grain size is 41.72 nm indicating that the grain size is almost independent of doping. The SEM results indicate a variation of grain size from 2.18 to 5.15 µm for the undoped ZnO to x= 0.50 ,which shows increase in grain size and reduction in grain boundaries as doping increases. The results show that x = 0.50 has the highest grain size, highest transition temperature and the marks the solubility limit. DTA results indicate the structural phase transition temperature of the doped ZnO ranged from ~371 to ~409 K and increased as the amount of Li increases. A single arc is observed in all the impedance plots of the ZnO together with the presence of a relaxation process which is non Debye. The impedance data show reduced resistance with increase in lithium content. A general increase in dielectric constant with increase in lithium content is observed.

High pressure die casting is a very important manufacturing process for machine parts, household utensil, construction equipment, etc and has been in use for ages now. However, the quality of its products still has need for improvement to further enhance their usage and life span in service. In this paper, we investigated the effect of the process parameters; shoot speed and pressure at fixed casting and mould temperatures on the microstructure of die cast parts using a 500 ton cold chamber high pressure die casting machine. The investigation concluded that:
1. Increase in pressure tends to reduce the grain size of die cast parts but at some point has possibility of developing a hot tear in the matrix which is a defect in casting which implies that the microstructure gets better with increased pressure, and considerable increase in shot speed.
2. The best microstructure was attained 120mpa and 8m/s

Geological environment is an intrinsic component of the universe that provides most of the world’s natural mineral supplements most especially for the sustenance of life. The importance of calcium in the proper growth of animals in nature cannot be overemphasized and as such must be studied. Thus, this study involved a detailed mapping of the lithologic units of Ikpeshi area of Edo State with the aim of understanding the geological occurrence of calcium-rich rocks and their possible use in livestock feed production. Geological field mapping as well as petrographic studies of various rock types obtained in the area was carried out and five (5) dominant lithologic units were revealed as marble, schist, calc-silicate gneiss, quartzites and diorite. Careful Petrographical studies showed that the marble and calc-slicate gneiss contains majorly calcite (CaCO3) and dolomite (CaMg (C03)2); and other minor minerals like quartz, feldspar, micas, opaque mineral (garnet, actinolite, lead and chlorite) etc. The rocks are found to be aligned along NW and NE-SW directions as a result of structurally deformation of their parent rocks. The manifestation of the great quantity of calcium-rich rocks present the area’s great potential for calcium harvest as supplements in the production of livestock feed for proper strengthening of bones.
Keywords: Geological, Petrographic, Marble, Calc-silicate gneiss, Calcite, Dolomite, Calcium-rich

This work has investigated gold cyanidation and characterization of Itagunmodi gold deposit using cyanide solution from cassava. The gold ore was subjected to selective removal of associated minerals and treated to varied concentrations of cassava based cyanide solution in order to precipitate gold. The precipitated gold was characterized using optical microscope, SEM - EDX, EDXRF and XRFS. The result showed that after 24 hours of cyanidation using analar grade sodium cyanide of 60mg/l, 10 g Itagunmodi gold ore concentrate yielded 0.096g (96mg) gold. Also, under the same condition, using cassava based cyanide concentration of 60mg/l, 10 g Itagunmodi gold ore concentrate yielded 0.08 g (80mg) gold. This work has shown that sourcing cyanide from cassava waste for gold leaching is a suitable alternative to the conventional cyanidation.

A Study on the quantitative leaching of gypsum ore in hydrochloric acid solution has been undertaken for possible development of hydrometallurgical route for the production of highly pure gypsum. The chemical composition, phase and morphology of ore with particle size-90+63μm were examined by X-ray Fluorescence (XRF), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM). The effects of contact time, acid concentration, temperature, particle size and solid-liquid ratio on the dissolution of the gypsum ore was investigated. The rate depends on the hydrogen ion concentration with temperature having little effect on the reaction system. The activation energy for the dissolution reaction was estimated to be 9.6 kJmol-1. About 99.7% dissolution was achieved within 120 min. by 6M HCl solution, temperature of 800C, stirring speed of 400 rpm and using – 90 + 63μm particle size.

Cadmium Sulphide (CdS) thin films were prepared by chemical spray pyrolysis technique on micro-slide glasses using cadmium acetate and thiourea as precursors. The substrate temperature was varied in the range of 250°C- 350°C. The prepared films were annealed at 5000C for 1-hour. The effect of the substrate temperature and annealing on the optical properties of the films were investigated. The films were characterized using UV-Visible Spectrophotometer. The absorption and transmission spectra revealed that the transmission increases with wavelength while the absorbance reduces as the wavelength increases in the visible region. The optical band gaps of the films were found to be 2.26eV, 2.07eV and 1.88eV with deposition temperature 250°C, 300°C and 3500C respectively. It was observed that the refractive index of the thin film obtained reduces as the substrate temperature increases and also annealing reduces the refractive index of the cadmium sulphide thin film. These show that Cadmium sulphide is one of the most promising materials to be used as a window layer in hetero-junction thin film solar cells and of good interest for its applications in some optoelectronic devices, like photoresistor and photodiode.

In this paper, the effect of metakaolin (MK) as cement replacement material on the compressive strength and hydration products of cement paste was investigated. Cement paste specimens with 20% MK replacing ordinary Portland cement (OPC) and a water binder ratio of 0.55 were produced and tested for compressive strength and hydration products compositions at 28 days. Specimens without MK (control) were also produced for comparison. For the hydration products analysis, the X-Ray Diffraction (XRD), Thermogravimetry Analysis (TGA) and Fourier Transform Infrared spectrometry (FTIR) techniques were utilized. The results showed that the compressive strength of metakaolin modified cement paste was higher than that of the control paste by 12%. The improvement in the compressive strength of MK paste as exhibited by the FTIR, XRD and TGA results can be related to the reduction of calcium hydroxide and the increase in calcium silicate hydrate. Therefore, MK can be used as cement replacement material to improve the strength of cement paste.

Synthetic fibres such as glass, carbon, aramid are presently the most used reinforcement in polymer matrix composites because of their favourable mechanical properties despite their high cost and non-biodegradability. However, natural fibres such as sisal, flax, hemp, jute, coir, bamboo, banana, are now being explored because of environmental concern of using synthetic fibres. Over the years, several natural fibres of plant and animal origin have been studied as reinforcement and suggestion on the improvement of their mechanical and water absorption properties have been suggested in order to make them competitive with the synthetic fibres. There still exist lots of natural fibres to be investigated and one of such is from the baobab pod which is abundant in the northern part of Nigeria. In this work, baobab pod fibre was used to reinforce polyethylene matrix. This was to establish the suitability of the fibre as reinforcement in composites material. The compounding was done in two roll-mills at temperature of 120oC and formed by compression in hydraulic press at pressure of 10kN at same temperature of compounding. Effect of fibre loading was studied at 5wt% to 30wt% at 5wt% interval. The fabricated composites were characterized for tensile strength, modulus of elasticity (MOE), impact, flexural strength, hardness and water absorption properties. The results showed that there was no significant difference between the tensile, flexural strength and hardness properties of the composite and the unreinforced LDPE. However, the MOE of the composite was higher than the unreinforced while the impact was lower. The values of most of the properties were highest at 10 wt% loading. As expected, the water absorption of the composite was higher than the unreinforced LDPE. The results showed that baobab pod fibre has potentials as reinforcement in composite fabrication due to improved MOE. The properties of the composite can be probably be improved by fibre treatment to remove wax and other impurities.

Keywords: Baobab fibres, Aramid, Bio-composites Mechanical properties.

Several treatment methods have been reported for the improvement of mechanical properties of natural fibre reinforced polymer composites. While alkaline treatment has been reported for the improvement of these properties onluffa fibre reinforced low density polyethylene copmosite, effect of double treatment has not been seen reported. This work aimed at the investigation of the influence of single alkali (sodium hydroxide) and double (alkali/stearic acid) chemical treatment on luffa fibre reinforced waste low density polyethylene composite. The fibre was treated with 8wt% NaOH and further treated with stearic acid at concentartion of 0.5-2.5 wt% at interval of 0.5wt%. Two roll-mill was used to compound the fibre and the wLDPE at temperature of 150oC and the composite fabricated by compression using hydraulic press at pressure of 13.8Mpa at the same temperature used for the compounding. The fabricated composite was characterized of tensile, impact and flexural strengths and morphological properties. The double treatment (8wt% NaOH/0.5wt% stearic acid) was found to be the best treatment combination which caused increase in tensile, impact and flexural strengths of 65.1%, 76.6% and 13.3% respectively over the single treatment fibre reinforced composite. The morphological properties of the reinforced composite using Scanning Electron Microscope (SEM) showed that more cracks and voids were present as the concentration of the chemical used in the treatment of the fibre was increased. The results indicated that the double treatment was more effective as shown by the improved properties, this could be as a result of the stearic acid treatment which aided the dispersion of fibre in the matrix after the removal of waxes in impurities present in fibre by the NaOH.

Keywords: Mechanical properties, Mophology, Luffa, Polyethylene, NaOH, Stearic Acid.

Drying time of car paint is one of an important physico-chemical property that determines its quality. This property is influenced by certain factors such as film thickness, temperature, humidity, air circulation and nature of the substrate. Published works on car paint formulation are scanty, thereby making it difficult to come across an established standard formulation based on the right proportions of each component to be used per batch. However, experimental design can be employ to model and optimize the formulation. This work employed response surface (RSM) methodology incorporated in design of experimental to optimize the drying time as response from binder, solvent and pigment interactions. The experiment was design based on lower and higher code specifications for the binder, solvent and pigment on RSM interface, after which the design simulation resulted to twenty (20) numbers of runs. From the first run specifications, 30g of pigment was dissolved in 70g of solvent and mixed together with 160g of binder in a mixer. As the mixing process continues, 1% of additives (anti-settling agent, preservative, anti-skinning agent and dryer) were added and mixed properly until homogenous mixture was achieved. This procedure was repeated for the nineteen (19) other runs, after which the formulated paint was sprayed on car substrates for drying time investigation using ASTM D1640 standard procedure. The drying times were inputted as response for the analysis. The regression model developed was suitable for drying time optimization as evidence from its predicted and experimental values, which were sufficiently correlated. The subsequent ANOVA results showed that, the model was significant as prob > F value obtained as 0.0011 is less than 0.0500 with R2 value of 0.97. The optimized solution done reduced the number of runs from 20 to 7. Among the 20 runs, the highest drying time recorded was 96 minutes while among 7 runs the highest drying time was 44 minutes. This showed that the drying time was reduced after the optimization, hence successful optimization.

Keywords: Auto paint, Drying time, RSM, film, additives

Co-doped barium calcium stannate titanate (Ba0.88 Ca0.12 Ti0.975 Sn0.025 O3 ) ceramics was synthesized via solid state reaction and sintered at 1100 °C/3 h. The ceramics were irradiated with thermal neutrons of up to 1.4 × 1010 n/cm2 using a 5 Ci Am-Be source having an average flux of 2.7 × 104 n/cm2.s. Structural analysis of the ceramics indicate a majorly polycrystalline material with a minor secondary phase. The 2θ positions were observed to shift slightly to higher values but the microstrain remained constant with increase in fluence. The average crystallite size is ∼ 38 nm with anisotropy observed in lattice expansion. Rod-like grains, porous regions and agglomerations were observed in all the specimens together with a general increase in grain size with increase in fluence. The average grain size is 1 μm. Chemical analysis using EDS indicates slight deviation from nominal ones for some irradiated samples. It is concluded that the structural and microstructural changes observed would not affect the performance of the devices based on this material when used in radiation environments of neutrons since the maximum fluence has not exceeded the order of magnitude of threshold for radiation damage.

Aluminium-doped ZnO (AZO) thin films were deposited by metal oxide chemical vapor deposition technique to study its properties toward application in photovoltaics and transparent conducting oxides (TCO). A starting solution was prepared from zinc acetate dehydrate (Zn (CH3COO)2.2H2O) dissolved in methanol and acetic acid. Aluminium acetylacetonate (C15H21AlO6) was also dissolved in deionized water and acetic acid. The aluminium solution was then added to the zinc solution in order to dope the later solution with a concentration of 3%wt, and aluminium zinc-acetylacetonate solution was formed. The dried precursor of aluminium zinc-acetylacetonate obtained from the synthesis was used to deposit aluminium doped zinc oxide onto sodalime glass substrate at different substrate temperatures ranging from 390°C to 450°C with a flow rate of 2.5 dm3/min for 2 hours deposition period. We report the optical transmittance of AZO films deposited at different temperatures varying from 75 to 95% in the visible range of wavelength 400–700 nm and an optical band gap energy value between 3.27 eV and 3.30 eV. Scanning Electron Microscopy (SEM) analysis showed that films are polycrystalline with grain size ranging from 19.2 to 23.7 nm for different substrate temperatures using origin software. The electrical analysis of AZO films deposited at different substrate temperatures revealed resistivity value between 0.074 and 0.011 Ω cm, an average mobility of 2.55 cm2/Vs, and an average carrier concentration of 1.39 ×〖10〗^20 〖cm〗^(-3). Film deposited at 420°C with thickness 133nm revealed to be the best as it possessed very good optical and electrical properties. The deposited thin film is found to be a promising candidate as a window layer for cost effective photovoltaics.

There are different types of footwear for different purposes. Therapeutic footwear are used by diabetic patients with high risks foot ulceration to reduce the danger of foot problems by relieving mechanical pressure on the foot. Therefore, this work investigated the type of footwear use often by people suffering with diabetics in Kaduna State with the aim to understand the perceived role of footwear in the prevention of foot complications among diabetic patients. The study was carried out among diabetic patients in Kaduna State, between December 2012 and March 2013 through questionnaire survey. The results obtained indicate that the patients have very poor knowledge about diabetes and its complications, foot care, and the use of appropriate footwear. It was discovered that up to 53% female and 37% male of the patients were wearing slippers most often. None of the patients used custom-moulded footwear. Only 17% male and 13% female respondents wear shoes. The data from the questionnaire survey indicate that up to 75% of the diabetic subjects have not received information about the type of footwear they should wear most often. Our data give a very poor choice of footwear by people suffering with diabetes in this part of the World. The paper further revealed that financial constraint was a key factor to use of appropriate footwear by the patients. Many use cheap footwear regardless whether they provide the required protection and comfort to their feet or not. The work also provides critical areas that would require further investigations.

Key Words: Diabetes, Foot Health, Footwear, Kaduna State

The leather industry in Nigeria is under pressure to look for effective alternative locally sourced tanning agents because of the high cost of imported tanning materials. Thus, natural products like vegetable tannins, which are widely distributed in the plant kingdom, are regaining importance. Therefore, this work investigated the possible use of ficus polita bark as tanning material. Chemical analysis of the plant infusion indicates that the tannin is catechol with pH 5.75. The tanning trials of the sample were carried out using different pH and different percentages of the extract such as pH 4, pH 4.5, pH 5 and pH 6 and 20%, 30%, 40% respectively. In addition, the resultant leathers were subjected to physical testing and chemical analysis. Up to 80% percentage elongation with leather thickness of 1.5mm was recorded. Other tests performed include water soluble, Nitrogen content and degree of tannage with recorded values up to 6.0, 13%, and 35% respectively. The obtained results provided scientific basis for the use of this plant for the conversion of hides/ skins into leather. The paper also highlights areas for further research.

Keywords: Tanning,Vegetable Tannins, Leather Industry, Nigeria.

In this study, Jute fibre/ Unsaturated Polyester Resin and Maize Cob / Unsaturated Polyester Resin Composites were fabricated. Similarly, hybrid composites of Jute fibre (JF)/Maize Cob (MC) with Unsaturated Polyester Resin (UPR) were prepared using an open molding techniques at several percentage filler loadings, 10% Maize Cob and 10% Jute fibres were employed as the percentage for composites hybridization. The Mechanical properties of the composites were studied. The study reveals that, the hybrid composites shows moderates improvement in properties such as tensile strength of (32.86Mpa) for 5%JF/5%MC which has the highest strength compared to its control samples which has tensile strength of (12.84Mpa) for 10%JF/UPR and (21.55Mpa) for 10% MC/UPR respectively. The hybrid composite also shows moderate value of impact strength, hardness and flexural strength with (0.48J/m, 37.65 shore and 44.79Mpa) respectively for filler loading of 5%JF/5%MC and 0.35 J/m, 21.17 shore and 41.47Mpa for varying fillers of 9%JF/1%MC hybrid composite sample. The improvements are likely attributed to the extent of good intermingling between the fillers and the matrix. The mechanical properties of the composites indicate that it can be useful in application which required moderate strength.

The raw material under analysis is barium sulfate (baryte) BaSo4 sourced from Azara Awe local government Area of Nasarawa state Nigeria. It was analyzed using chemical analysis X-ray fluorescence (XRF) technique to view the oxide content which shows 1.00wt% of Al2o3, 0.912wt% of Sio2, 1.341wt% of Tio2, 20.529wt% of So3, 0.201wt% of Feo3, 0.079wt% of Nio, 0.0257wt% of Sro, and 75.678wt% of Bao. Also scanning electron microscope (SEM) was carried out which view the porosity 0.92µm2 and 02754.89µm2 been the smallest and largest respectively, texture of irregular and uneven fracture and other minerals present in the material. A batch base on barium oxide glass was made containing 33.034 baryte, 59.539g of quartz rock, 12g of potassium oxide, and 2g of soda, it was test melted in a gas heated furnace for some hours, which produced a glassy material confirming the material suitability in glass making.

Sugarcane bagasse like other natural fibres is abundantly available in Nigeria. Sugarcane bagasse is a by-product obtained from the processing of sugarcane. It is an agro-waste that is produced on a large scale as such its management and disposal is an environmental challenge. Also recycled low density polyethylene (RLDP) popularly known as pure water sachets are carelessly disposed in Nigerian cities and towns which makes its management and disposal a great challenge too. Therefore utilization of these materials in producing particleboard may reduce these effects. Also it could reduce deforestation by substituting wood-based particleboard with composite materials (sugarcane bagasse and RLDP). The chemical constituent of sugarcane bagasse and the binding power of RLDP at high temperature make them as gland materials to work with in this research. This study is directed toward identifying the optimum ratio of sugarcane bagasse and recycled low density polyethylene binder (pure water sachet) in the production of particleboard. The materials for this work were sourced locally; sugarcane bagasse obtained from Samaru market and recycled low density polyethylene from shop outlets in A.B.U. Samara Campus Zaria. Sugarcane bagasse was cut with knife into small pieces and sun dried to reduce moisture content. This was later crushed and sieved with standard sieve size range from 1.18mm to 150µm. The low density polyethylene from pure water sachets was washed with clean water, shredded to an average size of 3cm in length with a scissors and sun dried in preparation for mat formation. Four different compositions of sugarcane bagasse and RLDP were considered in ratios of 7:3, 6:4, 5:5 and 4:6. The thickness swelling and water absorption of the board were found to be adequate due to high interfacial bonding exhibited in the use of pure water sachet as binder which met the respective 13.3% and 9% specified by EN BS 317(1993), ANSI A208.1 (1999), ASTM D4442, BS 2604. The tensile, bending, hardiness, impact strength and density all surpass the minimum requirement specified by the various standards. Also sample with 60% bagasse filler and 40% RLDP proves to be the optimum mix.

As of the strategies for the development of sustainable civil engineering construction material, the use of Bamboo strips as alternative to steel reinforced concrete was investigated in this study. The study involved experimental investigation of the strength of the bamboo strips. Structural reliability analysis of the bamboo reinforced concrete slabs were also investigated using First Order Reliability Method through a developed program in MATLAB. The results were compared with the results obtained for controls steel reinforced concrete slab.

Laboratory investigation was conducted to evaluate the strength properties of compacted lateritic soil admixed with cement and hair fibres (HF) as road construction material. Soil specimens were prepared by mixing lateritic soil with up to 4% cement and up to 12% HF by dry weight of the soil in step concentration of 2% and subjected to geotechnical tests. The natural soil was classified as A-5 (4) soil group of the American Association of State Highway and Transportation Officials (AASHTO) soil classification system and ML- CL in the Unified Soil Classification System (USCS). Soil specimens were compacted with British Standard Light (BSL) or Standard Proctor and subjected to compaction, unconfined compressive strength (UCS) test and California bearing ratio (CBR) test. Results indicated a decrease in optimum moisture content (OMC) and no general trend were established for maximum dry density (MDD). In case of UCS and CBR values, an increased was observed with increase in both cement and HF content. Based on the laboratory results, an optimal blend of 3% cement 9% HF significantly improved the soil properties and is recommended for improving the geotechnical properties of cement/Hair fibre treated lateritic soil as road construction material.