Showing papers in "chemistry and materials research in 2015"

Corrosion Inhibition of Mild Steel by Extract of Bryophyllum Pinnatum Leaves in Acidic Solution

Abstract: Bryophyllum pinnatum leaves extract has been evaluated as mild steel corrosion inhibitor in 0.5 M HCl solution by gravimetric analysis and Scanning electron microscope techniques. Effect of temperature and inhibitor concentrations on the corrosion behaviour of mild steel were studied and found that inhibition efficiency increases as inhibitor concentration increases but decreases as the temperature increases. The activation energy and thermodynamic parameters were studied, results direct that corrosion process involve the exothermic process and adsorption of inhibitor molecules follows the physical adsorption on metal surface. Linearity of Langmuir adsorption isotherm shows the formation of monolayer over the metal surface by deposition of inhibitor molecules. SEM analysis reveal the smooth surface which indicate the protective adsorption of inhibitors molecules on metal surface. The results reveal that the extract of bryophyllum pinnatum act as an effective corrosion inhibitor for the mild steel corrosion in 0.5 M HCl medium. Keywords: Adsorption, Corrosion, SEM, Weight loss

Instrumental Characterization of Montmorillonite Clay by FT-IR and XRD from J.K.U.A.T Farm, in the Republic of Kenya

Abstract: Montmorillonite clay is a phyllosilicate mineral belonging to smectite clay group with a wide range of applications. This study demonstrates the Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray Diffractometer (XRD) characterization of raw montmorillonite clay from J.K.U.A.T farm located in Juja, Kiambu county in the Republic of Kenya. The raw montmorillonite clays from different locations contained impurities and were subjected to mineral acids of different concentrations in order to enhance the analysis. The structural composition was carried out using FT-IR which revealed presence of various functional groups of Si-O, AL-OH and Si-O-AL as the major constituents. Mineralogical composition analysis was carried out using XRD and the patterns confirmed presence of aluminium oxide and silicon dioxide. Peaks of the resultant montmorillonite clay samples were compared with the published literature. This further confirmed the usefulness of spectroscopic technique in determination of crystalline nature of montmorillonite clay from J.K.U.A.T farm, Juja in the Republic of Kenya. Keywords: Instrumental characterization; FT-IR, XRD.

Changes in Oil Palm Frond Fiber Morphology, Cellulose Crystallinity and Chemical Functional Groups during Cellulose Extraction Phases

Abstract: Oil palm fronds (OPF) are agricultural by product and economical natural fibers resources. Cellulose is the main constituent in plant cell wall and because of its mechanical properties, cellulose fibers are potential to be utilized as reinforcement in composite product. The strength of cellulose is affected by its crystalline structure. To extract cellulose from natural fibers, lignin and hemicellulose have to be separated for instance by pulping and bleaching process. The main goal of this study was to observe changes in the OPF fibers morphology, cellulose crystallinity and chemical functional groups during cellulose extraction phases. Soda pulp of OPF was bleached using hydrogen peroxide. Subsequently, the bleached pulp was reacted with potassium hydroxide to eliminate hemicellulose. Afterward, further hydrogen peroxide bleaching was conducted to extract the cellulose. Surface morphological study using SEM revealed that there was a reduction in fiber diameter during cellulose extraction. Cellulose crystallinity and chemical functional groups at each phase of cellulose extraction were slightly different as demonstrated by XRD and FTIR analysis. Keywords: oil palm frond soda pulp, cellulose extraction, fiber morphology, cellulose crystallinity

Antibacterial Activity of the Crude Phenolic, Alkaloid and Terpenoid Compounds Extracts of Lactuca serriola L. on Human Pathogenic Bacteria

Abstract: Objective : To reveal the effect of the crude phenolic, alkaloid and terpenoid compounds extracts of Lactuca serriola L. on some Human Pathogenic Bacteria. Methods: Antibacterial activities of the crude Phenolic, Alkaloid and Terpenoid of medicinal plant were determined by in vitro by agar diffusion-method against some human pathogenic bacteria. Results: obtained results showed that among nine pathogenic bacteria, only Staphylococcus aureus and Staphylococcus saprophyticus Gram-positive were susceptible for Terpenoid, Alkaloid and Phenolic compounds while Staphylococcus epidermidis was resistant to active compounds. Conclusion: This study demonstrates that we can conclude that the effect of active compounds in same plant has different effect on different pathogenic organisms in different concentration. Keywords: Antibacterial Activity; Lactuca serriola L; Pathogenic Bacteria

Influence of Hydrated Calcium Sulphate (CaSO4.2H2O) and Nitrogen Levels on Water Infiltration Rate and Maize Varieties Productivity in Rainfed Area of Swat, Pakistan

Abstract: An experiment was conducted at Departmental Maize SMP and Demonstration Plots in all Circles Of district Swat during summer 2014. To study the response of maize to hydrated calcium sulphate (CaSO4.2H 2 O) and nitrogen levels and to enhance the water infiltration rate in rainfed areas of swat. Experiment was laid out in randomized complete block design (RCBD) with split plot arrangement. Data were recorded on days to tasseling, days to silking, ear length, grain ear -1 , thousand grains weight (g) and grain yield (kg ha -1 ). Statistical analysis of the data showed that the effect of nitrogen and hydrated calcium sulphate (CaSO4.2H 2 O) on grains ear -1 was not significant. The effect of nitrogen and hydrated calcium sulphate (CaSO4.2H 2 O) on days to tasseling, days to silking, ear length (cm), thousand grains weight (g) and grains yield (kg ha -1 ) were significant. The effect of varieties was significant on all parameters. Higher grain yield (1819 kg ha -1 ) and thousand grains weight (279 g) were recorded with the application of 120-40 kg NS ha -1 . Delayed days to tasseling (58.8) and silking (63.5) were observed at 200-0 kg NS ha -1 . Higher days to tasseling (57.6 days), silking (63.5 days), thousand grains weight (278 g) and grain yield (1730 kg ha -1 ) were recorded in Pahari variety while Baber variety produced higher grains (422) ear -1 and ear length(15.9 cm). 40-120 kg NS ha -1 produced high yield.

Physico-Chemical and GC/MS Analysis of Castor Bean (Ricinus communis L.) Seed Oil

Abstract: The hexane extract of the castor bean seed oil yielded 42.23 ± 0.208%. The physico-chemical characteristics of the hexane extract I reported here were: saponification, iodine and acid values of 123.3 ± 3.428 mgKOH/g , 76.93 ± 0.397g I 2 /100g and 2.39 ±0.065 mgKOH/g respectively. The Major fatty acids derived from the castor bean oil as indicated by the GC-MS results were Oleic acid (C 18 H 34 O 2 ), Palmitic acid (C 16 H 32 O 2 ), Stearic acid (C 18 H 32 O 2 ) , Undecylenic acid (C 11 H 20 O 2 ), Methyl ricinoleate (C 19 H 36 O 3 ), Behenic acid (C 23 H 46 O 2 ), Tridecylic acid (CH 3 (CH 2 ) 11 COOH), Nonadecanoic acid(CH 3 (CH 2 ) 17 COOH ). The results showed the potential of the hexane extract of the seed oil in cosmetics, perfumery and pharmaceuticals. Keywords: Castor bean oil, Physico-chemical, GC-MS, cosmetics, pharmaceuticals.

Adsorption of Metal Ions from Carwash Wastewater by Phosphoric Acid Modified Clay: Kinetics and Thermodynamic Studies

Abstract: The adsorption kinetics and the thermodynamic parameters for the removal of metal ions from carwash effluent using phosphoric acid modified clay were investigated in this study. Kinetic parameters were determined by analysing the modified second-order and intra-particle models. In the second order kinetics, Cd 2+ had adsorption capacity q e of 7.5mg/g with the regression coefficients of linearization (R 2 ) of 1.0 followed by Ni 2+ with q e of 1.36mg/g with R 2 of 0.949. For the intra-particle kinetics, Cd 2+ had Kid of 1.0 with R 2 of 0.959, while Pb 2+ had Kid of 0.144 with R 2 of 0.997. Adsorption generally increases with temperature and time. At 240minutes, all Cd 2+ had been removed from solution, same at 50 o C with trend of removal following the order Cd 2+ ? Pb 2+ ? Cr 3+ ?Ni 2+. ?H o ranged from -1.4KJ/mol for Cr 3+ to -6.0KJ/mol for Cd 2+ indicating physical adsorption. ?S o ranged from 12..7J/mol for Cd 2+ to 100J/mol for Cr 3+ while ?G were negative for all metal ions indicating that the adsorption was spontaneous and feasible. Keywords: Carwash wastewater, adsorption, phosphoric acid modified clay, kinetics and thermodynamics

Effect of Al2O3 and SiO2 Nanopartical on Wear, Hardness and Impact behavior of Epoxy composites

Abstract: A growing need for materials with good tribological and mechanical properties led to prepare , characterize and measure wear, hardness and impact properties of epoxy (EP) with different weight percentage of SiO 2 and Al 2 O 3 nano particles (0.5%, 1%,1.5%,2%,2.5%,3%) . Silica and alumina nanoparticles have average diameter size 16.69 and 46.73 nm respectively measured by scanning probe microscope.A combination of two different techniques (high shear mixing followed by ultrasonication) was used to prepared the nanocomposites. Fourier transition infrared (FTIR) was used to characterize the nanoparticles (Al 2 O 3 an SiO 2 ) .Wear rate, hardness and impact energy properties were measured for EP/ Al 2 O 3, EP/ SiO 2 nanocomposites . Decreasing in wear values with addition of nanoparticles ( especially nano Al 2 O 3 ) were observed. Approximately 30% and 80% increasing in hardness values and impact energy were observed. An enhancement in whole measurement for all composites was observed, yet (EP/ Al 2 O 3, EP/ SiO 2 ) composites with 2.5%nano Al 2 O 3 show in general better hardness and impact results. Keywords: Nanoparticles, Nanocomposites, wear, Impact, hardness.

Synthesis Of Fe3O4 Nanoparticles Of Iron Sand Coprecipitation Method With Polyethylene Glycol 6000

Abstract: This study aimed to obtain a particle size-based nano Fe 3 O 4 iron sand, determine the effect of Polyethylene Glycol (PEG) -6000 to be produced from iron sand in synthetic by using coprecipitation method and the nature of magnetization. Synthetic done by mixing natural sand with HCl as solvent and NH 4 OH as a precipitant, as templates are added PEG-6000 .. Then, characterized by using X-Ray Diffractometer (XRD). Vibrating Sample Magnetometer (VSM) and Fourier Transform Infra Red (FTIR). From the test results (XRD) shows the crystal size Preparation Fe3O4 nanoparticles with PEG 6000 (1: 3), (1: 4), (1: 5) in a sequence that is 14.90 nm, 22:16 nm, 33.11 nm while without PEG 6000 29.08 nm , Vibrating Sample Magnetometer measurement results (VSM) shows that the value of Ms saturation field for without PEG-6000 Fe3O4, Fe 3 O 4 with PEG-6000 (1: 3), (1: 4), (1: 5) respectively 27.9 emu / g, 47.4 emu / g, 35.3 emu / g, 51.7 emu / g and field coercivity (Hc), each for 0,013 Tesla, 0.022 Tesla, Tesla 0.14, 0.009 Tesla. FTIR results showed that there was a shift peaks indicating increased number of PEG. From each sample came the peak of Fe-O owned by Fe 3 O 4 where the wavelength of Fe-O at sample PEG has a lower value than the wavelength Fe 3 O 4 caused the PEG Key words : Nanoparticles Fe 3 O 4 , PEG 600, particle size, magnetic properties

Heavy Metal Contamination of Soil by Quarry Dust at Asonomaso in the Ashanti Region of Ghana

Abstract: Environmental pollution caused by quarry dust and heavy metals is a problem for many years in Asonomaso. The main aim of this paper was to determine the amount and types of heavy metal pollutants associated with the quarrying and also identify the probable adverse effects they have on human health and the environment. About 30 quarry dust samples were collected from two sampling sites between August and November, 2011 for analysis using AAS. Evaluation using SPSS 17.0 statistical programme revealed appreciable amounts of As, Hg, Mn, Cu Zn and Pb and Fe which differ from one site to another. AAS analysis revealed relatively higher concentrations of As, Ag, Cu and Zn in both primary and secondary quarry dust than dust away from the site. However, concentrations of Mn, Fe and Pb were higher in secondary quarry dust and dust away from the primary site. Heavy metal pollution of the Asonomaso environ attributable to the quarry is thus significant and its repercussions on the health of the residents must be seriously looked at. Keywords : Quarry Dust, Heavy-metal, Impact, Asonomaso.

Palm Kernel Shells as a partial replacement for Sand in Sandcrate block production

Abstract: The study explores and compares the properties of masonry blocks produced with palm kernel shell (PKS) as partial replacement to the traditional sandcrete blocks in an attempt to establish the percentage replacement of PKS that yields properties and characteristics that meets acceptable standards. After a review of relevant literatures, samples of materials required were collected and batched by weight to a mix proportion of (1:6). The PKS replacement varies from 0%, 10%, 20%, 30%, 40% and 50% with water cement ratio of 0.5. Total of 24 blocks were moulded, cured for 28days, subjected to various tests including water absorption, weight, density, and compressive strength. The water absorption test result indicates that up to 40% PKS replacement, the water absorption capacity of the block produced exceeds the minimum standard recommended by ASTM. The weight and density of the PKS block increases up to 10% PKS replacement, and furthermore reduces when the PKS exceeds 10%. With regard to strength test, it was revealed that, the compressive strength of the PKS blocks exceeds the minimum requirement of 2.8N/mm2 when the PKS replacement do not exceeds 40%. For blocks with PKS as partial replacement to meet standard specification, the PKS content should not exceed 40%. Further studies must focus on the factors that can effective the durability of blocks with KPS, and the socio-economic dimensions that impart on its acceptability as an alternative material to the conventional blocks.

Mechanical Properties of Carbon/Polypropylene Fiber Reinforced Rubber-Modified Epoxy System

Abstract: Epoxies as a thermoset polymer have gained a considerable attention in structural, electrical, and marine applications. To widen their usage and overcome their brittleness, many polymers were blended with it. The addition of Polysulfide rubber helps in increasing the impact resistance of Epoxy, while in the other hand ; it reduces strength , modulus, hardness and creep resistance. That leads to the need for another material to compensate the reduction in these properties. Carbon, polypropylene as an inorganic and polymeric short fibers with their exceptional and different mechanical properties will compensate many drawbacks of polysulfide addition in enhancing mechanical properties. The composite material with Epoxy-Polysulfide matrix properties were evaluated by conducting the mechanical tests which include compression test, hardness test, impact resistance test. The fracture surface of composite impact specimens was observed by Scanning Electron Microscopy SEM on all designed experimental samples. Elongation and impact strength of epoxy- polysulfide blend were found to increase with increasing rubber content while compressive strength and modulus decrease. The influence of fiber adding on the mechanical properties of the composite was studied , the mechanical properties of the blend matrix were found to be better than those of the pure epoxy. The morphology of the fractured surfaces showed significant signs of plastic deformation such as shear bands, high deformation, and cavitations due to rubber addition, and this correlates well with mechanical properties which resulted in an increase in toughness of the composites when rubber content was increased. The results of this investigation clearly show the possibility of balancing strength and toughness of the material when adding rubber, fiber to epoxy. Results of compression test showed that the compressive strength decreases as Polysulfide percentage (PS) increase. While the carbon fiber addition helped in balance or overcomes the original compressive strength reduction up to 30 vol.%. of fiber. The results confirmed that the best modification is the addition of 6% polysulfide considering compressive strength, Impact and hardness. While 20% carbon fiber and 30% Polypropylene fiber gives the optimum mechanical properties in compression and Impact, respectively, for the composite samples. Keywords: Epoxy resin, Liquid rubber, Mechanical properties.

Biogradable Starch Film from Cassava, Corn, Potato and Yam

Abstract: Starch is the major carbohydrate reserve in plant tubers and seed endosperm where it is found as granules each typically containing several million amylopectin molecules accompanied by a much larger number of smaller amylose molecules. Starch films were prepared from starch extracted from cassava, corn, potato and yam with and without plasticizers to evaluate the effects of the type and quantity of plasticizer on the mechanical properties of the starch films obtained. Ubbelohde viscometer was used to determine the intrinsic viscosity and molecular weight of the prepared films in dimethylsulfoxide (DMSO)/water solution (90%/10% v/v). The molecular weights of the films were found to range from 2.70 × 10 13 – 2.14 × 10 17 for films prepared from corn starch, 2.86 × 10 10 – 1.01× 10 17 for films prepared from yam starch, 2.69 × 10 13 - 3.97 × 10 17 for films prepared from potato starch and 4.15 x 10 6 - 4.05 × 10 8 for films prepared from cassava starch. The molecular weights of the films were found to decrease with increase in the plasticizer content because the bonds between starch-starch molecules were replaced with the bond between starch-water molecules. This led to the reduction in the chain length of both the amylopectin and amylose, and hence reduction in the molecular weight average. Amylose and amylopectin molecules contribute to mechanical properties and hygroscopic properties of starch. The effects of plasticizer on mechanical properties of film prepared from corn starch and yam starch were investigated at six levels of plasticizer content. The tensile strength of the films prepared from corn starch ranged from 0.10MPa - 5.20MPa, 0.05MPa - 5.10MPa for films prepared from yam starch, 0.09MPa - 5.74MPa for films prepared from potato starch and 0.51MPa – 5.33MPa for films prepared from cassava starch. The value of Young’s modulus was found to range from 0.39MPa -104.06MPa for films prepared from corn starch, 0.33MPa - 49.32MPa for films prepared from yam starch, 0.36MPa – 191.33MPa and 3.14MPa – 97.5MPa for films prepared from cassava starch. The tensile strength of films was influenced by the type and the content of plasticizer used.Generally, the Young’s modulus and the tensile strength of the films decreased with increase in plasticizers content, with concurrent increase in elongation at break and tensile strain of the films due to increase in ductility of the films. Glycerol exhibited more plasticizing effect on both starches than sucrose due to the hygroscopic or hydrophilic nature of glycerol. Keywords: biodegradable, starch films.

Characterisation of Agbabu Natural Bitumen and Its Fractions Using Fourier Transform Infrared Spectrometry

Abstract: Physico-chemical characterization of bitumen is very germane to its applications. There have been many physico-chemical investigations on Agbabu natural bitumen (ANB), but there appears to be some discrepancies in the results of some of the findings. Thus, the need to re-examine some of the physico-chemical parameters of the ANB. Raw sample of ANB was obtained from one of the observatory wells in Agbabu, Ondo State, Nigeria. The sample was dehydrated, purified and asphaltene component precipitated through addition of n-pentane to the sample. The maltene component was fractionated into saturate, aromatics and resin using column chromatographic method. The purified ANB sample and its fractions were each subjected to infrared analysis. In addition, the elemental composition and trace metals in the whole purified ANB were quantified using CHNS-O Analyzer (FlashEA® 1112) and Atomic Absorption Spectrometer (AAS) respectively. Infrared spectral features obtained for the whole bitumen and its fractions bear a good degree of resemblance to the results of earlier workers on the subject with some minor differences. The values obtained for structural indexes from Infrared (IR) spectra showed that all the fractions contained branch and straight chain hydrocarbons. The structural indexes also showed that asphaltenes and resin fractions are strongly polar, both of which contain hetero–atomic compounds. Results of compositional analysis are: C (86.62%), H(10.98%), S (0.92%) N (0.48%), O (0.83%), Maltene (78.34%) aand Asphaltene (21.67%). The concentrations of the trace metals are: Mg (792.00 ppm), Mn (28.40 ppm), Fe (3633.10 ppm), Ca (1082.10 ppm), Zn (17.50 ppm), Cu (17.90 ppm), Cr (153.90 ppm), Pb (93.78 ppm), Ni (103.65 ppm), V (156.53 ppm) and Na (3740.00 ppm). Results of compositional and trace metals analyses of this study are at variance with the earlier results on characterization of ANB in the literatures. The differences in the results might be attributed to variation in the method of sample preparation especially the inclusion of dehydration of the raw ANB in the purification step prior to characterization as introduced in this study. Keywords: Aromatics, Asphaltenes, Agbabu Natural Bitumen, IR, Resins, Saturates

Removal of Phenol from Paint Wastewater by Adsorption onto Phosphoric Acid Activated Carbon Produced from Coconut Shell: Isothermal and Kinetic Modelling Studies

Abstract: The feasibility of using phosphoric acid activated carbon produced from coconut shell to remove phenol from paint wastewater under batch mode was investigated. The results showed that adsorption of phenol was contact time, adsorbent particle size and adsorbent dosage dependent. The batch equilibrium adsorption data were analyzed by two-parameter adsorption isotherm models of Langmuir and Freundlich using the linear regression method. Both isotherm models fitted very well to the equilibrium adsorption data, however, the Freundlich isotherm equation provided the best model to describe the adsorption of phenol onto coconut shell activated carbon. Adsorption capacity of 2.01 mg/g and adsorption intensity of 1.07 was obtained for granular coconut shell activated carbon and corresponding 3.63 mg/g and 1.55 for powdered coconut shell activated carbon at 30 o C. The adsorption kinetic data were fitted to three adsorption kinetic models (pseudo first-order, pseudo second-order and intra-particle diffusion) using the linear regression method. The three kinetic models fitted well to the adsorption kinetic data; however, the pseudo second-order kinetic model gave the best fit and the adsorption mechanism was controlled by film diffusion. Thus, phosphoric acid activated carbon produced from coconut shell has the potential for application as an effective adsorbent for phenol removal from wastewater. Keywords: Activated carbon; Adsorption isotherms; Adsorption kinetics; coconut shell; paint wastewaters.

Bioadsorption of 2,6-Dichlorophenol from Aqueous Solution onto Plantain and Pineapple Peels Mixture Used as Adsorbent: Optimization Studies Based on Taguchi Method, Batch Equilibrium, and Kinetic Modelling

Abstract: The feasibility of using pineapple/plantain peels mixture to remove 2, 6-dichlorophenol (2,6-DCP) from its aqueous solutions was investigated under batch mode. The effects of factors such as pH, initial 2, 6-DCP concentration, temperature and pineapple/plantain peels adsorbent ratio on the removal process were evaluated. Four factors and three levels according to Taguchi’s (L9) orthogonal array were used to assess and optimize the bioadsorption behaviour of pineapple/plantain peels mixture. Analysis of variance was applied to determine the significant factors that affect bioadsorption. The levels of significant factors were optimized using Signal to Noise ratio. The results showed that bioadsorption of 2, 6-DCP was dependent on these factors. However, pH was the major factor that affects the percentage (%) removal of 2,6-DCP with its % contribution of 52.23. An optimum parameter combination for the maximum percentage removal of 2,6-DCP was obtained using the analysis of Signal to Noise (S/N) ratio. The best conditions for bioadsorption of 2,6-DCP were determined by the Taguchi method and desirability approach as pH = 7, initial 2,6-DCP concentration of 300 mg/l, temperature 50 °C, and pineapple/plantain adsorbent ratio of 2:1. The equilibrium bioadsorption data were analyzed by Langmuir and Freundlich isotherm models. The Freundlich isotherm model provided the best fit ( R 2 = 0.9980) to the experimental data. The maximum monolayer bioadsorption capacity ( ) was found to be 76.92 mg/g. The bioadsorption kinetics data of 2, 6-DCP were analyzed by pseudo-first-order, pseudo-second-order and intraparticle diffusion models. The pseudo-second order kinetic model gave the best fit. Therefore, pineapple/plantain peel adsorbent mixture has potential for application as an effective bioadsorbent for 2, 6-DCP removal from aqueous solution. Keywords: Bioadsorption; Bioadsorption isotherms; Kinetics; Pineapple-Plantain peel mixture; 2, 6-Dichlorophenol; Taguchi method.

Cactus Potential in Heavy Metal (Pb and Cd) Removal in Water Sample Collected from Rural Area around Adigrat Town

Abstract: The main objective of this study is to investigate the heavy metals (Pb and Cd) removal capability of cactus powder from water sample using FAAS adsorption techniques by considering the influence of contact time, adsorbent dose and temperature on adsorption of Pb and Cd ions by cactus powder. The results revealed that adsorption of Pb and Cd ions increased as the dose of adsorbent increased at a certain limits. The heavy metal removal capability of cactus powder is affected by the present of NaCl salt. The heavy metal removal capability of cactus powder decreased from 65% up to 7% for Pb, and from 70% up to 14% for Cd as the dose of NaCl increased from 1g to 5g. The decrement in the removal of both Pb and Cd ions from water sample with increasing of NaCl is due to the formation of outer sphere complex with the NaCl salt which screening the functional group of cactus powder from heavy metals. The heavy metal removal capability of cactus powder also increased with contact time. The adsorption rate initially increased from 20% to 58 % for Pb ion, and 17% to 43% for Cd ion when the contact time increased from 30-120 min. After 120 min there was no significant change in heavy metal removal of both Pb and Cd ions. This might be due to end point at which adsorption phase reached to equilibrium. The percentage removal of Pb by cactus powder decreased from 65.05% to 29% as the temperature increased from 25 o C to150 o C. In similar condition, the percentage removal of Cd by cactus powder also decreased from 43% to 31% as the temperature increased from 25 o C to150 o C. This decrement in percentage removal of both Pb and Cd ions with increase temperature is due to the weak binding interaction between the active site of cactus powder and (Pb, Cd) ions which support physicosorption process. Keywords: Cactus Powder, Heavy Metal, Adsorbent, Adsorbate, Dose, Heavy Metal Removal and Active Site.

Evaluation of Near Infrared Spectroscopy for Sugarcane Quality Determination in Western Kenya

Abstract: In Kenya, sugar is produced exclusively from sugarcane cultivated in Nyanza, parts of Rift Valley counties, Western Kenya and coastal region. Since the industry inception in early 1900s, farmer payments for delivered milling sugarcane has been based on tonnage delivered, with no consideration for quality of cane. However, in early 2000s, Kenya, attempted to put in place structures for paying farmers based on quality as measured by sucrose content amongst other factors. An effective, fast and accurate method of determining such quality has been missing, thus delaying implementation. Near Infrared (NIR) spectroscopy has been suggested as an accurate, non destructive and high-speed method for estimating the quality of milling cane. This research evaluated performance of a Matrix-F FT NIR spectrophotometer for estimation of cane quality in Nzoia Sugar Company, western Kenya. A total of 688 milling cane samples were obtained from randomly selected trucks delivering cane to the factory using a core sampler. The samples were finely shredded and analyzed by a method combining wet disintegration and core press as the primary measurements and NIR. The NIR spectrometer was calibrated using OPUS Lab Chemometrics software for pol, brix, fibre, moisture in cane . Results from wet chemistry were linearly regressed against the NIR results. The R 2 values were 0.9787, 0.9503, 0.8432 and 0.8725 for brix, pol, moisture and fibre, respectively. The results demonstrate that NIR spectroscopic analysis is an acceptable method for use in Kenya for quality based cane payment system. Keywords: NIR spectroscopy, sugarcane quality, Kenya.

Microwave Assisted Synthesis, Characterizations and Antibacterial Activity of Some of Thiazole Schiff Base and Azetidinone Derivatives

Abstract: A series of substitution thiazole Schiff base (SB1-SB12) were synthesis by reaction substitution phenyl 2-amino thiazole with 4-N,N-dimethyl benzaldehyde Azetidinone (AZ1-AZ12) were also synthesised by reaction substitution thiazole Schiff base with acetyl chloride. The synthesis compounds have been characterized by M.P., TLC, CHN, UV, FT-IR, 1 HNMR, 13 CNMR and MS. The biological screening data of the synthesized compounds were also studied. Keyword s : Microwave, Thiazole, Schiff base, Azetidinone, Anti-bacterial

X-Ray determination of crystallite size and effect of lattice strain on the Debye-Waller factors of Ni nano powders usig high energy ball mill

Abstract: The synthesis of Ni nanocrystalline powder by high-energy ball milling has been investigated Ni powders were ball milled in an argon inert atmosphere The milled powders were characterized by X-ray diffraction and scanning electron microscopy measurements The high-energy ball milling of Ni after 12hours resulted in crystalline size of about 48 nm The lattice strains in nickel (Ni) powders produced by milling have been analyzed by X-ray powder diffraction The lattice strain (e) and Debye-Waller factor (B) are determined from the half-widths and integrated intensities of the Bragg reflections In Ni the Debye-Waller factor is found to increase with the lattice strain From the correlation between the strain and effective Debye-Waller factor, the Debye-Waller factors for zero strain have been estimated for Ni The variation of energy of vacancy formation as a function of lattice strain has been studied Keywords: X-ray diffraction, lattice strain, crystallite size, Debye-Waller factor, vacancy formation energy

Experimental (FT-IR and FT-Raman spectra) and Theoretical (Ab initio/HF, DFT/B3LYP) Study of 2-Amino-5-Chloropyridine and 2-Amino-6-Chloropyridine

Abstract: The Fourier transform infrared (FT-IR) and FT-Raman spectra of 2-amino-5-chloropyridine (2A5CP) and 2-amino-6-chloropyridine (2A6CP) have been recorded in the regions 4000–400 cm -1 and 4000–100 cm -1 , respectively. The observed FT-IR and FT-Raman data, a complete vibrational assignment and analysis of the fundamental modes of the compounds were carried out. All the geometrical parameters have been calculated by HF and DFT (B3LYP) methods with 6-311++G (d, p) basis set. The vibrational wavenumbers, IR intensities and Raman activities are calculated at the same theory levels used in geometry optimization. The calculated frequencies are scaled and compared with experimental values. The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values. The calculated HOMO–LUMO energies show that charge transfer occurs in the molecules. Keywords: FT-IR, FT-Raman, ab initio, DFT, 2-amino-5-chloropyridine, 2-amino-6-chloropyridine.

Fabrication, characterization and deformation behavior of a new Acrylate Copolymer - based Nonwoven Structure

Abstract: A method of fabricating nonwoven structure from dry-laid cotton fibers and atomized acrylate copolymer is presented. The method based on a consolidation pressure of about 2kPa and room temperature curing, is used to produce structures with fiber mass to binder volume ratio (FBR) of 0.7, 0.5, 1, 1.5, 2 and 3. Structurally stable structures are produced and characterized in terms of their bursting strength, areal density, water absorption, and monotonic deformation behavior. At constant FBR, the bursting strength and areal density of the structures increases with the fiber mass. The structures’ water absorption capacity reduces with the increase in the volume of binder applied. At FBR of 1 and area density of 295 grams per square meter, the structure’s load-strain curve is characterized by a linear and non-linear behavior corresponding to elastic and inelastic strain, respectively. At peak loads, the structure’s deformation is relatively uniform but becomes localized as the failure point is approached. A good correspondence is established between the strain assessment based on uniaxial tensile test and on image correlation using Particle Image Velocimetry (PIV) method. The average vector magnitude derived from PIV measurement, correlate well with the engineering strain and can thus be used for strain estimation. Keywords: Nonwoven, Dry-laid, Deformation, Particle Image Velocimetry, acrylate copolymer

Formulation of Emulsion Paint from a Copolymer Composite of Dimethylol Urea/Polystyrene

Abstract: Dimethylol urea (DMU) with reduced formaldehyde emission was synthesized in this work and copolymerized by blending with polystyrene (PS) obtained by constituting waste expanded polystyrene into liquid form. The determined physical properties of the copolymer composite (i.e. DMU/PS) compared to the pure DMU revealed improvements in its disadvantageous properties such as hardness and moisture uptake. Paint samples were formulated using the pure DMU, DMU/PS and commercially obtained acrylic PVA binder resin, and analyzed. While the DMU/PS and APVA paints passed, the pure DMU failed such critical coating tests as flexibility, adhesion and blistering. Again, the DMU/PS and PVA paints show good chemical resistance while the DMU paint blisters in the alkaline medium. However, all paint samples passed tackiness, opacity and stability, and exhibit acceptable pH, viscosity, and drying time. Keywords: Dimethylol urea, Polystyrenes, Copolymer composite, Emulsion paint

Utilization of Laboratory Facilities and Students’ Academic Performance of Chemistry Students in Calabar, Nigeria

Abstract: The study investigate the utilization of laboratory facilities and their relationship with students’ academic performance in Calabar. A total of three hundred and fifty students drawn from fourteen public secondary schools were used for this study. The data were analyzed using two instruments which include; questionnaire on utilization (QULF) Chemistry and Achievement Test (CAT). The data collected were analyzed using population t-test and Pearson Product Moment Correlation. However, it was observed from the data analyzed that laboratory facilities are not adequately utilized in secondary schools for teaching Chemistry. It was also noticed that laboratory facilities do not significantly contribute to the variance in students’ academic performance in Chemistry. Keywords: Academic, Facilities, Chemistry laboratory, utilization.

Electrochemical Linear Polarization Studies of Amodiaquine Drug as a Corrosion Inhibitor for Mild Steel in 0.1M HCL Solution

Abstract: The effect of amodiaquine on corrosion of mild steel in hydrochloric acid was investigated by linear polarization resistance (LPR) electrochemical method. The results indicated that corrosion inhibition efficiency and degree of surface coverage were increased with rise in the concentration of amodiaquine. The inhibitor followed monolayer chemisorption since it obeyed the Langmuir adsorption isotherm. Keywords : linear polarization resistance (LPR), amodiaquine drug, corrosion inhibitor, mild steel, HCl

Biosorption of Selected Heavy Metals by Green Algae, Spirogyra Species and Its Potential as a Pollution Biomonitor

Abstract: In this paper, adsorption features of freshwater green algae as a function of contact time, initial pH and initial metal ion concentrations were studied using model solutions of metal ions with subsequent determination by flame atomic absorption spectrometry (FAAS). Green algae samples were employed as bioindicators of selected heavy metals in environmental water samples with determination using FAAS and ICP-OES (inductively-coupled plasma-optical emission spectrometry). The optimum pH for cadmium (Cd), chromium (Cr), copper (Cu) and lead (Pb) biosorption were found to be 5.5, 5.8, 5.9 and 5.0, respectively. The biosorption process follows second order kinetics and is well described by the Langmuir isotherm model. Adsorption capacities were found to be 22.52, 38.19, 35.59 and 94.34 mg/g for Cd, Cr, Cu and Pb, respectively, at contact times of 15-50 minutes and initial metal ion concentrations of 500-700 mg/L. Biomonitoring studies revealed great potential for freshwater green algae as a bioindicator with mean concentration factors in the range of 367-7154 for the selected elements, the uptake being mainly via a metabolically mediated pathway. This work has demonstrated the potential of freshwater green algae as both a biosorbent and a bioindicator for heavy metal pollution in water systems. Keywords: Green algae, Biosorption, Biomonitoring, Toxic metals, FTIR, ICP-OES.

Adoption of Information Communication Technology on Teaching and Learning in Public Pre-Schools in North Rift Region, Kenya

Abstract: To achieve vision 2030, the Kenyan Government had an ambitious plan to give laptops to school children which was however opposed by parents and various stake holders who said that the money for the computers should instead go toward raising teachers' salaries and feeding children. Given that the implementation of ICT in teaching pre-school learners has worked in various parts of the world, it is prudent to investigate; adoption of ICT in the Kenyan context.The purpose of this study was to evaluate the effect of adoption information communication technology on teaching in pre-schools in North Rift Kenya. The study is informed by diffusion of innovation theory. The study used combination of cross-sectional and descriptive survey and explanatory research design. The study employed stratified sampling. To collect primary data, questionnaires and interview schedules was used. Quantitative data collected was analyzed using descriptive statistical techniques which were frequencies, mean, standard deviation. The researcher used inferential statistics Pearson correlation to show the relationships that existed between the variables. Pearson correlation was used to assess the linear relationship between variables. The findings of the study showed that skilled teachers in ICT have a higher likelihood of using it in the classroom. Moreover, teachers’ knowledge together with a positive attitude towards ICT plays a key role in the adoption and use of ICT in schools. The teachers trained to teach ICT are not sufficient to facilitate its adoption. Not to mention the fact that schools in the rural areas lack basic necessities such as electricity and ICT facilities which inhibit the adoption of ICT. Schools need to avail opportunities for teachers to expand their knowledge and skills on ICT Keywords : Information Communication Technology, pre-school curriculum, Teacher’s preparedness teachers, Skills and competences

Preparation and Characterization from Natural Zeolite Sarulla of North Sumatera Polyurethane Nanocomposite Foams

Abstract: Has made the manufacture of natural zeolite from the Sarulla, District Pahae, North Tapanuli North Sumatra Province in the form of chunks with the process of grinding to a size 200mesh (74μm). The natural zeolite refining and calcination process is carried out at a temperature of 600°C for 1 hour and without the process of purification and calcination and then processed into nano particles of natural zeolite with the ball mill for 21 hours. The method used in research on nanocomposite processing of polyurethane foam are: 1) Preparation of natural zeolite nanoparticles; 2) Preparation of nanocomposite made by mixing nano particles of zeolite in the mixture of PPG and TDI in the mold to room temperature at a rate of 100rpm for 30 seconds, with a composition of nanoparticles of natural zeolite (0%, 5%, 10%, 15%, 20% and 25%) wt; 3) Preparation of specimens for each sample testing in accordance with ASTM D 638 standard sizes for the dumbbell Type V tensile strength; and 4) The characters include: mechanical properties (tensile strength, elongation and modulus of elasticity) and morphological analysis by SEM. From the analysis of natural zeolite preparation obtained particle size 129,7nm for natural zeolite calcination, for natural zeolite without calcination obtained 95,8nm particle size. Results of the analysis of chemical constituents of natural zeolite nanoparticles obtained by calcining SiO 2 content of the element (70.98%) and Al 2 O 3 (17:22%) while natural zeolite nanoparticles without calcination obtained element SiO 2 content (80.28%) and Al 2 O 3 (14.21%). The influence of the quantity of filler PU / zeolite in tensile strength, elongation, and modulus of elasticity was found that the optimum concentration of filler is at 20%. Results of analysis of the morphology of nanocomposite polyurethane foam is homogenous and spread evenly. Results of XRD analysis of the natural zeolite is mordenite types. Keywords : PPG, TDI, natural zeolite nanoparticles, mechanical analysis, FTIR analysis, and morphology analysis.

Spectrometric Detection of Organic Compounds and Toxicity of Ethanolic Leaves Extracts of Prosopis Juliflora

Abstract: Spectrometric detection of saponins, tannins and alkaloids in Prosopis juliflora using Fourier Transform Infrared (FTIR) spectroscopy is reported in this paper. Crude dry plant powders and corresponding ethanolic extracts were mixed with potassium bromide (KBr) powder and compressed to a thin pellet for infrared examination. The plant powders, ethanolic extracts and leaves ethanolic extract (LEE) fractions exhibited characteristic infrared spectra due to various functional groups –OH, -C=O, C-H, and C=C absorptions. Phytochemical analysis confirmed the presence of saponins, tannins and alkaloids in the tested specimens. Prosopis juliflora whole plant parts were used as a reference sample. Toxicity and safety levels of P. juliflora were also investigated. Acute and sub-acute toxicity of P. juliflora ethanolic leaves extract was evaluated using Swiss albino rats. All clinical signs and symptoms were recorded within 24 hours. These results indicated that direct detection of bioactive compounds was possible by infrared analysis. Toxicity symptoms were moderately observed and post mortem did not show any major gross effects on the internal organs. Keywords: Prosopis juliflora , infrared examination, potassium bromide, acute and sub-acute toxicity, clinical signs, doses, symptoms.

In-Situ Deposition, Optical Characterization and Bandgap Shift of AgO Thin Films

Abstract: Porous and specularly reflective films of inorganic silver oxide (AgO) with thickness ranging from 275-435nm have been deposited by chemical bath (CBD) in a mixed solution of silver nitrate AgNO 3 and precursor of triethanolamine (TEA) maintained at a temperature of 318K Surface morphology of the films was characterized by scanning electron microscopy (SEM) Optical and structural studies were performed to find the optical attenuation, some solid state properties and crystallographic structure for the individual films High quality films with low transmittance < 1150% in the visible and near infrared (NIR) region are obtained Direct optical bandgap for the films lies in the range 15-17eV, whereas the refractive index developed peak in the dispersion region near 450nm X-ray diffraction study indicates that the films composed of polycrystalline AgO with cubic structure belonging to the space group, fm3m Keywords: Inorganic silver oxide, Triethanolamine (TEA), X-ray diffraction, Transmittance