Solar photocatalytic degradation of phenol using nanosized ZnO and α-Fe2O3
November 2013
This work focuses on the solar photocatalytic degradation of phenol using nanosized ZnO and α-Fe2O3 synthesized via precipitation route. The synthesized ZnO and α-Fe2O3 were characterized using XRD, UV/Vis and surface area analysis. α-Fe2O3 was found to exhibit better solar photocatalytic activity than ZnO under identical experimental conditions due to the larger surface area and low band gap of...
BOD5 removal from tannery wastewater over ZnO-ZnFe2O4 composite photocatalyst supported on activated carbon
September 2013
Tannery wastewater with high biological oxygen demand (BOD5) was treated with ZnO-ZnFe2O4composite photocatalyst supported on activated carbon under visible light irradiation. Only 9% of BOD5 in the raw effluent were removed via adsorption on the surface of the photocatalyst in the dark for two hours. Photocatalysis with ZnO-ZnFe2O4 composite photocatalyst on activated carbon support removed 90% of...
Production of biolubricant from Jatropha curcas seed oil
September 2013
Extracted Jatropha oil was analyzed for their chemical and physical properties such as density, acid value, % FFA, saponification value as well as viscosities at 40 and 100oC and viscosity index. The result of the analyses of the Jatropha oil reveals that it has a very high %FFA (14.6%). Reduction was achieved by esterification with methanol (to 0.44%). The method employed for the production of biolubricant...
Annealing and light effect on structural and electrical properties of thermally evaporated Cu2SnSe3 thin films
September 2013
Thin films of Copper Tin Selenide (Cu2SnSe3), were successfully deposited on well-cleaned glass substrates by thermal evaporation technique. The as-deposited films were annealed in flowing purified nitrogen, N2, for 2 h in the temperature range from 100 to 500°C. The annealing temperature effect on thin films crystallization and light effect on electrical conductivity had been investigated. X-ray...
Study on effect of semi-angle between non-parallel walls on magneto hydro dynamic Jeffery Hamel flow using semi-analytical approach
June 2013
In this paper, magneto hydro dynamic (MHD) Jeffery-Hamel flow with nanoparticle has been investigated and its nonlinear ordinary differential equation has been solved through homotopy perturbation method (HPM). The governing boundary layer equations are written into a dimensionless form by similarity transformations. The effect of semi-angle has also been investigated in both convergent and divergent channel....
Performance evaluation of local clays from northern Nigeria for the refining of palm oil
June 2013
The effectiveness of adsorbents (unactivated and acid activated) developed from local raw materials - clay and diatomaceous earth samples - sourced from various geographical locations in northern Nigeria for use in the adsorptive bleaching of palm oil was studied. Two acids namely hydrochloric and sulphuric acids of varying strengths 20, 30 and 45% were used for the activation. A batch adsorption process of...
Low temperature synthesis of nickel silica nanocomposites through Sol-gel route
May 2013
Preparation of nickel (Ni) nanoparticles in the silica gel matrix for various concentrations has been achieved at low temperature. The presence of metallic Ni has been confirmed by x-ray diffraction and further supported by the presence of bright filed transmission electron microscope image, which shows presence of 5 to 8 nm diameter nanoparticles. The dielectric property was studied using complex...
Optimum design parameter determination of biogas digester using human faeces feedstock
May 2013
Biogas digester operation depends majorly on C/N ratio, hydraulic retention time, pH, temperature, and mixing ratio of the domestic waste used. Temperature of 15 to 45°C, C/N ratio of 20 to 30, Hydraulic retention time of 1 to 30 days, mixing ratio of 10 to 20 %w/v and pH of 6.5 to 8 were considered for the analysis. Analysis of Variance (ANOVA) was used to test whether there are statistically significant...
Failure analysis of bridle chain used for hoisting in mines
April 2013
Failure of engineering components due to presence of defects in the material is common. These defects are either present in the material from the casting stage or get developed during subsequent hot working and thermal treatment operations. Identification of the origins of defects is an important task while analyzing failures where pre-existing defects in the material are the causative factors. A case study...
Kinetics of demineralization of shrimp exoskeleton in chitin and chitosan synthesis
April 2013
Kinetic data obtained from acid demineralization (using 1.25 N hydrochloric acid solution) of deproteinized exoskeleton of shrimp was fitted to the shrinking core models for heterogeneous reactions. The element of interest was calcium which was the most abundant element in the deproteinized shrimp (66.27%) and the mostly affected by the demineralization. Experimental kinetic data was fitted to the shrinking...
Synthesis of branched fatty esters from Sterculia oil
February 2013
Biodiesel produced from vegetable oils are triglyceride. Their composition is generally of a straight-chain fatty acid length. The existence of long straight-chain fatty acids in triglycerides affects the physical and chemical properties of biodiesel. Problems associated with the use of biodiesel up to now are the high pour point and NOx emissions which are higher than that of diesel fuel. There are two physical...
Health and environmental components of sachet water consumption and trade in Aba and Port Harcourt, Nigeria
February 2013
80 sachet water products from 10 different brands were sampled in four study locations in Aba and Port Harcourt (PH) cities respectively. Sampling was carried out by stratified simple random techniques. The products were bacteriologically assessed weekly for 12 months between January and December, 2008. Samples were exposed to sunlight (SL) and room temperature (RT) and analysis done using membrane filter...
New development of spinel bonded chrome-free basic brick
January 2013
Due to the water solubility of Magnesia-Chrome bricks, the hexavalent chromium ion (Cr6+) present in these bricks has been reported for use from rotary cement kilns. Magnesia-Chrome bricks are being replaced with chrome-free brick mainly of magnesia-spinel type. So, the aim of the present study is to develop new Cr-free brick with the addition of TiO2. All of properties such as bulk density, apparent...
Effect of Co doping on structural, morphological, electrical and optical properties of nanocrystalline zinc oxide films
January 2013
We report the effect of cobalt doping on the structural, morphological, electrical and optical properties of nanocrystalline ZnO films febricated by chemical spray pyrolysis technique (CSPT). The structural studies reveals that films have strongly c-axis oriented wurtzite structure. However with the increase (at 5%) in Co doping percentage, an inclination from (0 0 2) to (1 0 1) orientation has been observed....
Autocatalysed oxidation of etophylline by permanganate in aqueous sulphuric acid medium- kinetics and mechanistic study
December 2012
The reaction kinetics of oxidation of etophylline by permanganate ions has been investigated in sulphuric acid medium using spectrophotometric techniques at 25°C and at constant ionic strength, 1.60 mol dm-3, under pseudo-first order conditions. An autocatalysis reaction is observed due to the formation of one of the products, MnII. The order with respect to etophylline and MnVII concentrations are...
Corrosion inhibition of mild steel in sulphuric acid solutions by using tetra methyl ammonium bromide (TMAB)
December 2012
The corrosion inhibition of mild steel in one normal sulphuric acid solution by tetra methyl ammonium bromide (TMAB) has been studied in relation to the concentration of the inhibitor as well as the temperature using electrochemical polarization (galvanostatic and potentiostatic polarizations) techniques. The results were supplemented with scanning electron microcopy and infra-red spectroscopy. All the...
Removal of ammonium and phosphates from aqueous solutions by activated and modified Bulgarian clinoptilolite
December 2012
Results from a laboratory investigation on the capability of activated and modified Bulgarian clinoptilolite samples from Beli plast deposit in Eastern Rhodopes for removing ammonium and phosphates from aqueous solutions are presented in this report. A series of ion exchange batch experiments were carried out using model water composed of NH4Cl and Na2HPO4.12H2O. Total ion exchange capacity was determined by...
Characterization of stainless steel SS-1672
November 2012
This research concerns characterization of stainless steel SS-1672 with 0.46 wt.% carbon concentration, at room temperature with respect to mechanical properties and morphology. Specimens were divided into two groups according to heat treatment, and were hardened at three different temperatures (250, 450 and 650°C) to obtain different martensitic content. Hardness results are compared with those of the...
Comparison of unconstrained search methods for correlation of binary vapor liquid equilibrium (VLE) by five variants of Wilson model
November 2012
A comparative evaluation of five variants of Wilson model and eight unconstrained optimization methods for correlating the binary VLE data of 2-butanol-Tetrachloroethene system at 101.08 kPa pressure is presented. The data reduction and correlation for vapor/liquid equilibrium of the above system is presented. The objective of this paper was to find the parameters of the five variants of the Wilson models for the...
Synthesis and characterization of (Thallium-Tin) doped Bismuth based superconducting materials
October 2012
Doping with combinations of Tl0.3-xSnx in a certain concentration range enhances the zero resistivity temperature Tc(0) from 104 to 108K. Both high-Tc (2223) and Low-Tc (2212) phases were detected by the X-ray diffraction analysis. However the low-Tc phase is found to dominate over the high-Tc phase with the increase in Sn content. Critical temperatures were determined by the electrical resistivity...
Kinetic and thermodynamic studies on the adsorption behavior of Rhodamine B dye onto animal bone meal
October 2012
Removal of Rhodamine B from aquoeus media was achieved onto animal bone meal (ABM) as a new low cost adsorbent. The latter was characterized by Infra-Red and X-ray diffraction. The adsorption of Basic Red 46 occurred by studying the effect of adsorbent amount, dye concentration, contact time and temperature. The adsorption rate data were analyzed using the pseudo-first order and the pseudo...
Chlorine adsorption kinetics of activated carbon from selected local raw materials
March 2012
Chlorine adsorption kinetics of activated carbons from Cattle bone, coconut-shell and wood as influenced by mode of activation (heat and acid) were studied using a commercial activated carbon (CAC) as control. Batch chlorine adsorption by each activated carbon was investigated by contacting with fixed amount of chlorine solution at 10, 15, 20, 25, and 30°C respectively at 10 min intervals. The residual...
Enhanced photoluminescence from ZnO/ZnS core-shell structure
March 2012
The effect of ZnS coating over ZnO core is discussed in this present report. Very simple two step wet chemical method was used for the fabrication of this core-shell structure. XRD and HRTEM data reveal the formation of good shell coating over the ZnO core. Photoluminescence spectra shows that emission intensity is at least four times higher when coated with ZnS compare to bare ZnO. Band gap is also...
Biosorption of copper(II) and lead(II) ions from aqueous solutions by modified loquat (Eriobotrya japonica) leaves (MLL)
February 2012
A modified loquat leaves (MLL) for the removal of copper(II) and lead(II) ions from aqueous solutions has been investigated. The biosorption of copper(II) and lead(II) ions was found to be dependent on solution pH, initial metal ion concentrations, biosorbent dose, contact time, and temperature. The experimental equilibrium biosorption data were analyzed by three widely used two-parameters; Langmuir,...
A kinetic and mechanistic study on the oxidation of arginine and lysine by hexacyanoferrate (III) catalysed by iridium (III) in aqueous alkaline medium
February 2012
The kinetics of Ir (III) catalysed oxidation of some amino acids like arginine and lysine by hexacyanoferrate (abbreviated as HCF) (III) ions in aqueous alkaline medium at constant ionic strength 0.5 mol dm-3 and temperature 35ºC has been studied spectrophotometrically. The reactions exhibit 2:1 stoichiometry and follow first order kinetics in [HCF (III)] and [alkali]. The dependence of the rate on...
Emissions control catalysts: Links between Fecralloy preoxidation and coating adherence Stephen A. Adegbite
November 2011
Tightening emissions legislation for vehicles across the world has caused the use of monolith catalysts in automobile emission control to become ubiquitous. In this study, the physiochemical transformations caused by thermal pre-oxidation of the surface of Fecralloy® foil, an integral component of emissions control catalysts, have been studied to assess their role on coating film adherence. The...
A simplified cost-effective biosand filter (BSFZ) for removal of chemical contaminants from water
November 2011
A study aimed at designing, constructing and evaluating a cost-effective biosand filter was undertaken. The biosand filter was modified with the addition of zeolites (clinoptilolite). The zeolites formed the largest part of the filter media which comprised of four layers. The complete filter had six zones which played a role during the filtration process. Filtration was done for 3 h to mimic water filtration...
Performance analysis of constricted tube ultrafiltration unit for production of food-grade protein concentrates from food wastes
October 2011
Tween 60 – amido black 10B – ascorbic acid system: Studies of photogalvanic effect and solar energy conversion
October 2011
Solar energy conversion and storage by use of photogalvanic cell was studied in Tween 60 – amido black – ascorbic acid system. Photogalvanic effect was studied in photogalvanic cell consisting of ascorbic acid as a reductant, Amido black 10B as photosensitizer and Tween 60 as surfactant in aqueous solution. The photopotential and photocurrent generated were 996.0 mV and 420 µA respectively....
Factors controlling the structural properties of carbon nitride films deposited by electrochemical method
October 2011
Polycrystalline carbon nitride thin films were deposited on Si (100) substrates by electrolysis of methanol-urea solution at atmospheric pressure and low temperature. The effect of the process parameters, namely deposition time, concentration and applied voltage on growth and bonding state of carbon nitride (CNx) thin films was studied using Fourier transform infrared (FTIR) spectroscopy, grazing incidence...
Preparation and characterization of exfoliated nano-composite of polyvinyl acetate and montmorillonite
August 2011
To improve the chemical, physical, and mechanical properties of polyvinyl acetate (PVAc), montmorillonite (MMT) was added in the synthesis of PVAc in conventional lab conditions. The final product was studied mainly by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), static tensile, and the rheology was also investigated by the power-law function...
Fracture behavior of cryogenically solidified aluminum-alloy reinforced with Nano-ZrO2 metal matrix composites (CNMMCs)
August 2011
Fracture behavior of LM-13 aluminum alloy reinforced with different wt.% of Nano-ZrO2particles, solidified under various shallow cryogenically cooled chills (at -80°C), cast using DMD (disintegrated melt deposition) technique followed by hot extrusion were investigated. The size of the particles dispersed varies from 50 to 80 nm and amount of addition varies from 3 to 15 wt.% in steps of 3 wt.%....
Design and simulation reconfigurable liquid crystal patch antennas on foam substrate
July 2011
In this article, the use of liquid crystal-based patch antenna is proposed. A first test device was, therefore, conceived in planar technology with a low-cost foam substrate. In order to have a reduced antenna structure, we have studied an antenna miniaturized by inserting slots. Moreover, the use of liquid crystal in the design of patch antennas allows adjustment of the resonance frequency. To benefit from...
Newly developed friction factor correlation for pipe flow and flow assurance
June 2011
The purpose of this research is to present petroleum and chemical engineers with a new, practical, and fundamental equation that accurately determines the friction losses in traditional and modern piping systems. The results of this study begin with a necessary mathematical and historical review of determining pipe friction factors under smooth and rough conditions. These formulas provided a base for a...
Investigation of turbulence mixed convection in air filled enclosures
June 2011
Mixed convection heat transfer is a process where natural and forced convection happens simultaneously. The effect of temperature difference in natural convection and momentum difference results in mechanical ventilation or pressure difference that result in indoor and outdoor flow. When used in an optimum way, it is one of the newly subjects in HVAC industry which is a prominent example of mixed convection...
CuO-CeO2 catalytic systems destined for CO removal synthesized by means of the Pechini method: An evaluation of the structures obtained
May 2011
In this work, catalytic systems based on CuO-CeO2 were synthesized by the Pechini method. These catalytic systems were prepared without the need to perform a step of impregnation of active species as is often seen in works of catalyst preparation. In the synthesis procedure, the CuO-CeO2 catalytic systems were synthesized with 0.1 and 0.5 mol of CuO. The CuO-CeO2 catalytic systems were...
Algorithm and computational complexity of biochemistry
May 2011
The modern science mainly treats the biochemical basis of sequencing in bio-macromolecules and processes in biochemistry. One can ask weather the language of biochemistry is the adequate scientific language to explain the phenomenon in that science. Is there maybe some other language, out of biochemistry, that determines how the biochemical processes will function and what the structure and organization of...
Equilibrium modeling for a dοwndraft biomass gasifier for cotton stalks biomass in comparison with experimental data
April 2011
Equilibrium modeling has been used to predict the composition of the fuel gas produced in a downdraft gasifier for cotton stalks biomass at 800°C with the moisture content from 0 to 30%. The calorific value of the fuel gas has been determined. The predicted values are in good agreement with the experimental data. The moisture content in the cotton stalks biomass and the variability in calorific value,...
Optimization of Li-Zn ferrite synthesis parameters using the experimental design method
April 2011
The conventional synthesis of ferrites involves mixing and sintering powder oxides. However, high sintering temperature deteriorates electrical properties of ferrites due to the formation of Fe2+ ions. Using sintering aid and decreasing particle size are easy and economical methods to decrease the sintering temperature and at the same time improve electrical properties of ferrites. In this research, the...
Purification of an industrial aluminum alloy by melt stirring during ohno continuous casting process
March 2011
With the purpose of upgrading the purity of a dilute industrial aluminum alloy during ohno continuous casting (OCC) process through the use of forced melt stirring; the critical stirring intensity required under a casting speed of 2 mm/min was numerically determined. The determined critical stirring intensity induces convective velocity magnitudes into the melt which are effective in transporting solutes from...
Short review on the crystallization behavior of PET/clay nanocomposites
March 2011
In recent years, the area of polymer nanocomposites based on organically modified clay has attracted much interest in academia and industry because of their peculiar and fascinating properties. Nanomaterials are presently considered to be high potential filler material, with high aspect ratio and extremely large surface area. They improve mechanical and physical properties of polymers. Lighter, thinner,...
Corrosion inhibition and adsorption behavior of methionine on Mg- Al-Zn alloy
February 2011
Corrosion inhibition behavior of Mg-Al-Zn alloy was investigated by different electrochemical techniques in neutral solutions containing chloride ions at different concentrations. The corrosion rate was calculated in the absence and presence of methionine as an environmentally safe corrosion inhibitor using polarization and impedance techniques. The results reveal that methionine inhibits the corrosion...
The estimation of the cooling tower height by modeling the water and air contact situation in cooling tower falling film
February 2011
Deterioration of the filling material in traditional cooling towers is of serious concern. In this study, cooling towers of Arvand and Boualisia Petrochemical plants in the South of Iran are used as the filling material. The size of the cooling towers and outlet conditions are measured in a real situation and compared with heat and mass transfer correlations by modeling the towers and then calculating the...
Modified exponentially weighted moving average (EWMA) control chart for an analytical process data
January 2011
This article introduces modified exponentially weighted moving average (modified EWMA) control chart. The modified EWMA control chart is very effective in detecting small and abrupt shifts in monitoring process mean. This chart is based on modified EWMA control chart statistic, which is a correction of EWMA chart statistic and it is free from inertia problem. The advantage of using modified EWMA chart is its...
Polyaniline based anticorrosive and anti-molding coating
January 2011
Polyaniline (PAni) was synthesized by miniemulsion polymerization. One coating solution of poly (epichlorohydrine-co-ethylene oxide) (ECO) and another of ECO and PAni mixture were prepared in a mixture of solvents and then applied on cast iron and stainless steel coupons using spin coating technique. The efficiency of these coatings to retard the environmental rust formation was studied as...
Application of statistical technique to the analysis of passivation of Al - Zn alloy systems in brine
September 2010
The high demand for light metals as engineering materials lies in their high strength - to - weight ratio with good corrosion resistance in diverse environments. Passivation phenomena in these materials especially Al - based binary alloys have well been documented. However, the present study which aims at using model equations to investigate the passivation trend in various compositions of duplex Al - Zn...
Electrochemical behaviour of some copper alloys in sodium chloride solutions containing different inorganic additives
September 2010
The corrosion behavior of Cu-Fe and Cu-Fe-Al was studied in NaCl solutions without and with different concentrations of some inorganic additives, Na2MoO4, K2Cr2O7, and KIO3. The measuring techniques used were, open-circuit potential, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The potentiodynamic polarization measurements indicated that the corrosion current, Icorr, o;f...
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