Asian Journal of Chemical Sciences

The screening of the process parameters on the enzymatic hydrolysis of a blend of two lignocellulosic materials - corn cob (CC) and deseeded fluted pumpkin fruit (DFPF) using Trichoderma reesei was the focus of the present study. Four process parameters – time, temperature, substrate blend ratio and pH were screened for statistical significance using a 4 x 4 matrix of Graeco-Latin square design of experiment. The reducing sugar yield was determined using the dinitrosalisylic acid (DNS) method and maximum reducing sugar yield of 57.92mg/ml obtained in 2days at 40^oC, blend ratio of 0.2:0.8 (CC:DFPF) and pH 5.5. Result of the Analysis of Variance (ANOVA) obtained showed that with 3 degrees of freedom and 6 residual degree of freedom at 95% confidence level (i.e. 0.05 significance), time, temperature and substrate blend ratio significantly affected the enzymatic hydrolysis process whereas the effect of pH was not significant. However, only time was significant at 99% confidence level (0.01 significance) while temperature, substrate blend ratio and pH were not significant. This study has highlighted the significant factors among the process variables in emzymatic hydrolysis of a blend of CC and DFPF.

The present study aimed at exploring the potential of producing biofuels from unconventional vegetable oils extracted from Anacardium occidentale kernels. Accordingly, oils were extracted from Anacardium occidentale kernels and subjected to physical and chemical characterization namely: density; lower calorific value (PCI); quality indexes; fatty acid profile, viscosity using French and ISO standards.

Results revealed that Anacardium occidentale almonds have a lipidic potential of 52.54%, the transesterification reaction yield was 78.28%. As for the quality indices of the vegetable oil: acidity (˃1%); saponification index (205.29 mg KOH/g-oil); peroxide value (8.08 meq O2/kg-oil) and iodine value (108.84 mg iodine/g-oil) were considerably reduced for biodiesel. The vegetable oil was unsaturated type with the predominance of oleic acid (43.86%). The fuel characteristics of the oil obtained were: acidity (2.89%), density at 40°C (0.796 g/cm³) cetane number (41.47). The raw extracted oil is not usable as fuel for engine due to its very high viscosity ranging 30.69 mm²/s. As a consequence, a prior chemical treatment is necessary to reduce the viscosity. 

Our results provided an insight on the energetic potential of the investigated oil, with respect to its use as a source for biodiesel in replacement of the current conventional diesel fuel.

The physicochemical properties and the concentrations of heavy metals of water samples collected from four different rivers of Nkanu east and west Local Government Areas of Enugu of state Nigeria were investigated because of the prevalent water borne diseases in these localities attributable to the drinking of contaminated water. The water samples were collected from different sites of Esu, Umuekwe, Umuobeagu and Atafu rivers and their physicochemical properties and heavy metal contents were measured. Sampling Stations were selected; samples were collected avoiding contamination from the selected sites in same season, from same depth. On site measurement of parameters was done with the same instruments. Rests of the parameters were measured in Laboratory. Lead (Pb) was present in Esu, Umuekwe, Umuobeagu and Atafu rivers at a concentration of 0.14, 0.03, 0.00 and 0.16 mg/L respectively; Zn was only detected in Esu and Umuobeagu at 0.07 and 0.01 mg/L respectively and cadmium (Cd) concentrations of 0.14, 0.14. 0.08 and 0.08 mg/L respectively. Iron was detected in only Umuekwe river having 0.17 mg/L and Atafu river having 0.21 mg/L while Ni was detected at 3.01, 4.20, 1.20 and 3.83 mg/L respectively. Only Atafu river had Cr at 0.01 mg/L, only Esu river had Co content at 0.05 mg/L, Mn content in Esu, Umuekwe, and Umuobeagu was found to be 0.01, 0.02 and 0.02 mg/L respectively with Atafu river having none. Hg concentration was found to be 0.57, 0.06, 0.42 and 0.82 mg/L for Esu, Umuekwe, Umuobeagu and Atafu rivers respectively. The concentrations of Pb and Cd were higher in all the four samples especially in Esu river as a result of its closeness to construction sites and refuse dump and the concentrations were above the acceptable limits of WHO standard of 0.010 and 0.005 mg/L respectively for drinking water while Hg, Fe, and Ni were found within the W.H.O limits of 0.001, 3.000 and 0.100 mg/L respectively. The rest were below the standard, thus confirming conclusively that the rivers are polluted with the presence of heavy metals.

Catalases are key components of cellular detoxification pathways that prevent the formation of highly reactive hydroxyl radicals through catalyzing the decomposition of hydrogen peroxide into water and molecular oxygen. Their presence in brewery grains prevent the inactivation of important brewery enzymes and also stop lipid peroxidation. To determine their occurrence and establish some of its properties in sorghum, which has become as an important brewery grain similar to barley, crude catalase was obtained from a sorghum grain variety. Preliminary purification of catalase from the sorghum grain variety used, NRL-3, showed that the enzyme was purified 3.2-fold from the crude protein to give a 49% yield of the partially purified enzyme, with a final specific activity of 32 Umg-¹ proteins. There was also a positive indication of sorghum catalase presence on SDS PAGE with positive bands occurring between the range of 48-62 kDa. Therefore, the molecular weight of sorghum catalase most likely falls within the two bands. The enzyme showed a narrow pH range with optimum activity occurring at pH 7. Similarly, its optimum activity temperature occurred at 40°C.  This work is the first reported attempt at purifying catalase from sorghum.

A novel modified walnut shell (TWNS) was prepared through sequentially reacting the walnut shell (WNS) with thionyl chloride and triethylamine in N-methyl pyrrolidone to remove Reactive Brilliant Blue from dye wastewater. Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) were used to characterize the TWNS. The effects of different experimental conditions such as the reaction temperature, the reaction time, the dosage of thionyl chloride and triethylamine on the quaternary ammonium grafting percentage of TWNS have been studied. The results reveal the quaternary ammonium grafting percentage (Y) is up to 18.37% when the dosage of thionyl chloride (V₁) is 35 mL, the reaction time (t₁) is 3 h in the first step reaction; the dosage of triethylamine (V₂) is 40 mL, the reaction temperature (T) is 80°C and the reaction time (t₂) is 12 h in the second step reaction.

Developed a thin layer chromatography (TLC) method for the quantification of piperine in Trikatu Churna formulation it is a major and important ingredient in the formulation. TLC methods for the determination of piperine in the Trikatu churna along with its raw materials have been developed, as per the ICH guideline. The developed method has been validated, experimented with parameters like linearity, accuracy, the limit of detection, the limit of quantification, inter-day and intra-day assay precision, repeatability of measurement, and repeatability of a sample application. Performed a degradation study in different conditions. Prepared a calibration curve in the concentration range (100-800 ng/spot) with correlation coefficients r² (0.997) with Rf value 0.46 ± 0.03. The Limit of detection (LOD) and Limit of quantification (LOQ) value has 100 ng and 329 ng, respectively. The maximum degradation found in the bench top (98%) follow with an acidic condition (86%), almost similar in the range of condition basic, oxidation and wet (75-77%), and a minimum in dry heat condition (49%). The freeze-thaw stability study, the accelerated stability study, the real-time stability study result of these conditions almost is the same range (92-99%).

Fats and oils are essential in human nutrition, and an important component of many foods where they significantly contribute to product quality. The quality of different samples of fats from various companies in Saudi Arabia was determined based on its physicochemical properties such as melting point, moisture, acid value, free fatty acid, peroxide value and insoluble impurities. Four samples were selected randomly as goody, hanaa, fork & spoon and Mazola. The percentage of the moisture was found to be 0.167±0.0438, 0.1045±0.0021, 0.061±0.0141 and 0.101±0.0339%, respectively for goody, hanaa, fork & spoon and mazola. The acid values were found to be 0.1402, 0.148, 0.151 and 0.220 mg NaOH/g for goody, hanaa, fork & spoon, and mazola, respectively. The free fatty acid was found to be 0.0989, 0.105, 0.106 and 0.155% for goody, hanaa, fork & spoon and mazola, respectively. The peroxide values were found to be 4.25±0.0141, 3.245±0.0353, 1.145±0.1485 and 5.15±0.0707 m.eqO₂/Kg for goody, hanaa, fork &spoon, and mazola, respectively. The percent of insoluble impurities was found to be 1.61, 0.71, 1.32 and 1.33% for goody, hanaa, fork & spoon and Mazola, respectively. The melting points were found to be 40±0, 35±0, 33.5±0.707 and 39±0°C for goody, hanaa, fork & spoon, and Mazola, respectively.

Polycrystalline alloys based on cobalt and elaborated by classical foundry are known since the middle of the last century. They are currently still used, notably for geometrically complex components working at high temperature. Beyond the oldest ones reinforced by chromium carbides, new principles of carbides–strengthened cobalt–based alloys have recently appeared. MC–type refractory mono–carbides allow maintaining the melting start temperature at a high level when they are present as single carbide phase. Their high temperature stabilities and script–like morphologies also favor high mechanical properties at elevated temperatures. Optimized MC–carbides fractions can be obtained with carbon contents, close to 0.4 wt.%C, for achieving significant strengthening without threat for the low and high temperature toughness. Controlling the carbon content is thus of prior importance. Unfortunately the most common metallographic apparatus used for measuring the chemical composition of alloys – the Energy Dispersion Spectrometers (EDS) attached to Scanning Electrons Microscopes (SEM) – are not able to analyze, with sufficient accuracy, carbon with so low contents. A simple indirect method using both EDS and SEM is proposed here to get some information about the carbon content in several MC–reinforced Co–based superalloys.

This study aims at determining the concentration of heavy metal contaminants in the soil around Dangote cement factory Kogi State, Nigeria. It also seeks to understand the relationship between the heavy metals and the level of concentration with respect to distance and direction as well as the ecological risk it poses. The monitoring and assessment of soil pollution have over the years become a very important area of study due to the significant threat it poses to the food web. A total of 33 soil samples were collected in the Northern, Eastern and Western axis within a radius of 4km of Dangote cement factory at a depth of 0-15cm using a stainless steel auger. The contamination factor indices for Cr and Cu show moderate pollution across all the samples collected from different axis at a different distance from the factory. Zn also pose a moderate pollution across the samples except for WK4 and NK4 where it is in a low level of contamination. The geo-accumulation indices for Pb and Cr show unpolluted to moderately polluted across all samples at different locations expect for sample location EK4. The results of the ecological risk assessment revealed that Cd poses the highest ecological risk of all the five heavy metals investigated.

Aim and Objectives: Nowadays, nanomaterials technology is developing very quickly and bringing high economic efficiency for many industries including paint. The purpose of this study is to assess the effect of paint properties when replacing TiO₂ powder coating with nano TiO₂ at different ratios.

Materials and Methods: The research method is selecting the traditional alkyd paint formula, then replacing this coating powder TiO₂ with nano TiO₂ to monitor the properties of the paint film over time. Methods of analyzing the properties of the paint film are based on Vietnam standards.

Results: The study results showed that TiO₂ coating powder replaced by TiO₂ nanomaterials has increased the properties of the paint film, improving the thickness, gloss, and durability of the paint film. Nano TiO₂ increases from 0.5% to 24% by weight, the impact increased by about 11% (73 to 82 kg.cm), Glossy 60° increased by about 12%, Glossy 85° increased by about 12%, especially the durability of paint film over time increased nearly double. Nano TiO₂ is a more expensive material than TiO₂, so it should replace less than 4% by weight to increase the quality of the paint film, this ratio is changed according to the actual equipment requirements.

Conclusions: The higher the rate of replacing TiO₂ materials with TiO₂ nano, the better the properties of the paint film. Therefore, nano-material TiO₂ is a good coating in alkyd resin for metal paint, it improves the properties of paint film better than TiO₂ material.

In this work uncovered is the basic principle governing the chemical reaction dynamic/kinetic process of chemical reaction (kt=4.6 and Ea/RT=4.6), which is ignored before. Based on the “yin and yang” philosophy (see appendix A), the discovered principle has been elucidated clearly. In addition, we also demonstrate: 1. how to optimize the condition of chemical reaction, such as reaction time and temperature; 2. how to suppress the side chemical reaction. Furthermore the potential application of the discovered principle has been discussed.