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Several studies have been carried out on leafy vegetables but many did not assess the heavy metals in soil and leafy vegetables along urban-peri-urban gradient of Lagos State. The study assessed the concentration of heavy metals in the soil and leaves of three commonly consumed vegetables (Amaranthus hybridus, Celosia argentea and Corchorus olitorius) in Lagos State. Sampling was conducted in 2019 and 2020. Fe, Pb, Cu and Cd residues in the soil and the leafy vegetables samples were digested and determined using Atomic Absorption Spectrophotometer. The collected data were analyzed using simple descriptive statistics and Analysis of Variance. The range of values of the mean concentrations of the heavy metals in soil showed that Fe =20.76±0.20mg/kg – 107.83±17.02mg/kg, Pb = 0.13±0.07mg/kg –2.47± 0.45mg /kg, Cd=0.08 ± 0.02mg/kg – 6.07 ± 2.90mg/kg and Cu = 0.24±0.11mg/kg–40.20±4.90mg/kg. The range of values of the mean concentrations of the heavy metals in the leafy vegetables showed that Fe = 113.10±14.05mg/kg – 1.51±0.02mg/kg, Pb=0.51±0.09mg/kg - 0.001±0.001 mg/kg, Cd=0.51±0.01mg/kg-0.001±0.01amg/ kg, Cu=7.54±0.97 mg/kg - 0.36±0.03mg/kg. The Level of heavy metals residues in soil and the three leafy vegetables were at safe levels set by WHO/FAO except for Pb and Cd found in vegetables in Ketu and Yaba study locations.

The study investigated the incidence of drug abuse among student-teachers in two Nigerian colleges of education. The study’s population comprised all NCE II and III Social Studies and Early Childhood Education student-teachers in two colleges located in Oyo State, Nigeria. Data was analysed using frequency counts, percentage, mean and standard deviation. Of the 400 student-teachers, 213(53.3%) were male while 187(46.8%) were female. Only 148(37%) were from Early Childhood Education while 252(63%) were from Social Studies. The student-teachers may exert negative influence on young children when they eventually take up appointment as teachers in pre-primary and primary schools. Departments of Social Studies and Early Childhood Education together with the colleges counseling centers should organize regular counseling activities and services to educate the pre-service teachers about the danger and implications that could result from their involvement in abuse of drugs.

Few decades ago, the Internet became a new home for academic research and a spot where teaching and learning materials could be found. A cursory look at previous studies on university instructors' use of online resources shows intermittent influence students' academic outcomes in Nigerian schools. Although, several efforts have been put in place to establish a cordial and steady relationship between university instructors' use of online resources and the students' academic attainment in Nigerian schools, it seems that there is paucity of studies on the linkage between university instructors' use of online resources and students' academic attainment in Social Studies. This research explored the relationship between Social Studies lecturers' use of online resources and students' performance in the course. This study adopted descriptive research using correlational design, and purposive sampling technique. 398 students at two Bachelor of Education degree-awarding institutions in Nigeria responded to the questionnaire. The data collected were analyzed using frequency counts, percentage, mean and standard deviation and Pearson Product Moment Correlation. The outcomes of this discourse indicated no significant relationship between Social Studies lecturers' use of online resources and students' performance in the course. Additionally, it was evident from the results that the extent to which Social Studies students’ use of online resources in the selected tertiary institutions in Nigeria was high. This paper, therefore, concludes that the use of online resources has no significant relationship with students' performance in Social Studies. It was recommended that university instructors should grasp a new means in the use of online resources in the classroom in order to foster a good lecturer-students interaction that would eventually results in great academic attainment of students in the course.

β-galactosidase is an enzyme that converts lactose into glucose and galactose. It alleviates the issue associated with intolerance to lactose and pollution caused as a result of milk by-products (whey). This study aimed to isolate and select yeast strains that can produce β-galactosidase from fresh milk, yoghurt and locally made cheese. A total of 115 yeasts were isolated from the samples, 9 yeast isolates had the ability to produce β-galactosidase and three (3) were selected for further analysis. β-galactosidase producers were screened using Ortho-nitrophenyl-β-D-galactopyranoside (ONPG) assay. Kluyveromyces marxianus strain SLDY – 005 produced the highest β-galactosidase. It showed maximum enzyme activity (277U/mL) at temperature 30oC, pH 5.5, after an incubation period of 36 h. Glucose had a decrease in β-galactosidase production while yeast extract and urea were considered appropriate nitrogen sources for the best enzyme synthesis. Crude β-galactosidase produced by Kluyveromyces marxianus SLDY – 005 was purified. The partially purified enzyme after dialysis showed a specific activity of 165.12 U/mL and had a purification fold of 6.02 and yield of 45.91 %. The purified enzyme had an optimum temperature of 40oC and a pH 6.0. Kluyveromyces marxianus strain isolated from local cheese is a potential candidate for the production of βgalactosidase and it could be used for combating the problem of lactose intolerance.

Previous studies have established that pre-service teachers’ performance in Social studies is dwindling. Prior researches have focused largely on strategies to improve students’ performance in Social studies, with less attention to examining the relationship that the use of online resources have with students’ performance in the subject. This study assessed the impact of online resources on pre-service teachers’ academic performance in Social studies concepts. The study adopted descriptive research using correlational design, and purposive sampling technique. A total of 398 Students responded to the questionnaire. The data collected were analyzed using frequency counts, percentage, mean and standard deviation while the hypothesis was subjected to Pearson Product Moment Correlation. Findings of this study reported no significant relationship in students’ use of online resources and their performance in Social Studies. This paper, therefore, concludes that, students’ use of online resources has no significant relationship with their academic performance in the concepts selected in social studies. It was recommended that, adequate use of online resources by the students should be encouraged at all levels of education, to improve students’ academic performance.

The consumer demand for starch continues to grow to meet food consumption needs. However, starch producers are increasingly looking towards non-food, industrial applications to access new markets for revenue generation, while aiming for whole crop utilization to meet sustainability metrics. Native starch properties limit its utilization in many industrial applications, therefore, it is modified through different chemical, enzymatic, and physical processes. This review examines innovation in starch transformation processes, and how modified starch and its functional properties can be used in industrial applications beyond the traditional sectors of textiles and papermaking. Currently, the market value of modified starch is 2.7× greater than native starch and is anticipated to increase through next-generation applications (e.g. packaging, energy and regenerative medicine) enabled by emerging technologies in 3D printing and nanotechnology. Opportunities for increasing the use of other botanical starch sources besides industry-leading corn are also presented through the lens of global market trends.

This study investigated the effects of pretreatments and optimized osmotic dehydration (OD) of lowbush blueberries using response surface methodology (RSM) to produce dehydrated blueberries with high antioxidants content and shelf life. Fresh wild blueberries (WB) were initially pretreated and then subjected to osmotic dehydration. Microwave pretreated WB had shown better water loss during osmotic dehydration as compared to other pretreatment methods investigated. The highest levels of phenolics, flavonoids, and anthocyanin content of the dehydrated WB were found to be 742.61 mg/100 g, 263.12 mg/100 g, and 428.11 mg/100 g d.m respectively, at optimized temperature of 40 °C, for 5 h OD, with 65% (w/w) Brix and 1:5 ratio of sample to Brix%. These results revealed that with rigorous optimization of the critical osmotic dehydration parameters high level of antioxidants could be obtained in the dehydrated product.

Addition of surfactants to enzymatic hydrolysis has been reported to enhance the hydrolytic potential of enzymes in the bioconversion of lignocellulosic biomass to fermentable sugars. The objective of this investigation was to evaluate the effects of four non-ionic surfactants (PEG4000, PEG8000, TitronX-100, and Tween80) on the efficiency of enzymatic hydrolysis of steam-pretreated poplar using a commercial cellulase preparation (Cellic® CTec2). Statistical discriminant analysis at four variable factors (surfactant type, surfactant concentration, hydrolysis time, and substrate consistency) revealed that enzymatic hydrolysis was significantly enhanced in the presence of PEG4000, with 19.2% increase in glucose yield over control without surfactant, whereas ANOVA test indicated substrate consistency and hydrolysis time as the most significant factors (P

Biodiesel production from crude tall oil (CTO) in presence of a commercial lipase catalyst (Eversa Transform) was optimized using Taguchi method. Process parameters including reaction temperature, molar ratio of CTO to methanol, reaction time, and enzyme dose were examined for their effect on the in-situ esterification of fatty acids (FA) in CTO to fatty acid methyl ester (FAME). Fractional distillation was employed to separate the FAME fraction (biodiesel) from the rest of the CTO components. Using Taguchi (L9) Orthogonal Design, the optimum biodiesel yield was statistically predicted and experimentally verified as 97.02% and 96.57%, respectively. The optimal conversion of CTO to crude biodiesel was obtained at 16 h reaction time, 40 °C reaction temperature, 1:1.5 CTO to methanol molar ratio, and 1.0 wt% enzyme dose. The reaction time and CTO to methanol molar ratio were the two most contributing factors for the optimal conversion of CTO to biodiesel.

The study investigated academic self-confidence effects on test anxiety indicators of performance impairment and intrusive worry. Respondents were 206 Nigerian undergraduate students (mean age = 20.29, SD = 2. 22; female = 43.2%). The students took the Westside Test Anxiety Scale (Driscoll, 2004) and the Academic Self-confidence Scale (Jones, 2001). Data were analysed to predict performance impairment and intrusive worry from academic self-confidence, taking into account students' year of study and gender. Results suggest that academic self-confidence influenced both performance impairment and intrusive worry dimensions of test anxiety. Students who were high in academic self-confidence reported lower performance impairment or intrusive worry. Also, first year students reported higher intrusive worry than those in second, third, or fourth year of study. High manifestation of academic self-confidence is an asset for coping with test anxiety.

Post frying conditions play a very important role in consumer acceptability of French fries. During post frying holding time, from when fried potatoes are removed from a fryer to when consumed, texture of the product dramatically changes. Therefore, it is important to understand how and why these changes happen. In this study, the effect of different batter formulations and post frying holding time (with and without using a heat lamp) on fat and moisture distribution, textural and thermal properties of fried potato strips was studied. Moisture content ranged from 3.90 to 5.32 (in core region), 0.54 to 1.19 (in crust region), and 1.96 to 2.89 g/g db (in whole potato strips). Fat content of the core, crust and whole potato strip regions ranged between 0.01–0.03, 0.14–0.25, and 0.07–0.15 g/g db, respectively. A slight migration of moisture from the core to crust regions was observed under heat lamp holding, but this did not affect the total moisture content. Potato samples that were not kept under heat lamp showed lower hardness than samples kept under heat lamp. Brittleness values of potato samples increased from 0 to 10 min heat lamp duration and after that it significantly decreased. It was found that glass transition temperature of the samples was also affected by batter formulation and heat lamp duration.

In this study, the effects of ultrasonic parameters (amplitude, cycle and pulse) and major reaction factors (molar ratio and enzyme concentration) on the reaction kinetics of biodiesel generation from waste lard bio-catalyzed by immobilized lipase [Candida antarctica Lipase B (CALB)] were investigated. A Ping Pong Bi Bi kinetic model approach was employed to study the effect of ultrasonic amplitude on the enzymatic transesterification. Kinetic constants of transesterification reaction were determined at different ultrasonic amplitudes (30%, 35%, 40%, 45%, and 50%) and enzyme concentrations (4, 6, and 8 wt.% of fat) at constant molar ratio (fat:methanol); 1:6, and ultrasonic cycle; 5 kHz. Parametric effects on the yield were studied using three sets of experiments namely A, B, and C. In experiment set A, two factors (ultrasonic amplitude and cycle) were investigated at three levels; in experiment set B, two factors (molar ratio and enzyme concentration) were examined at three levels; and in experiment set C, two factors (ultrasonic amplitude and reaction time) were investigated at five levels. A yield of 96.8% was attained in 20 min at an ultrasonic amplitude (40%) at 5 kHz, fat:methanol molar ratio (1:4) and catalyst level 6% (w/w of fat). The fitted curves of the kinetic mechanism showed a sigmoidal curve due to mass transfer limitations which controlled the process at the beginning of the reaction. The kinetic model results also revealed interesting features of ultrasound assisted enzyme-catalyzed transesterification: at ultrasonic amplitude 40%, the reaction activities within the system seemed to be steady after 20 min which means the reaction could proceed with or without ultrasonic mixing. The kinetic model approach employed describes the whole methanolysis process accurately.

In this study, the effects of ultrasonic parameters (amplitude, cycle, and pulse) and major reaction factors (molar ratio and enzyme concentration) on the reaction kinetics of fatty acid methyl ester (FAME) generation from waste choice white grease (CWG) biocatalyzed by immobilized lipase [Candida antarctica lipase B (CALB)] were investigated. A yield of 98.2% was attained in 20 min at an ultrasonic amplitude (40%) at 5 kHz, fat/methanol molar ratio (1:4), and catalyst level of 6% (wt/wt of fat). The effect of ultrasonic mixing on the reaction kinetic of enzymatic transesterification was investigated using a Ping Pong Bi Bi kinetic model approach. Kinetic constants of the transesterification reaction were determined at different ultrasonic amplitudes (30, 35, 40, 45, and 50%) and enzyme concentrations (4, 6, and 8 wt % of fat) at a constant molar ratio (fat/methanol) of 1:6 and ultrasonic cycle of 5 kHz. The fitted curves of the kinetic mechanism showed a sigmoidal curve as a result of mass-transfer limit...

Non-edible feedstocks such as animal fat wastes (AFWs) have recently increased in popularity as alternatives to vegetable oils in the production of biodiesel. They are low cost, mitigate environmental damage and increase the quality of the resultant biodiesel fuel (low NOx emissions, high Cetane number and oxidative stability). Therefore, AFWs are an excellent feedstock for biodiesel production. Here we provide a comprehensive review trends and techniques in biodiesel production from AFWs. A critical overview of homogeneous and heterogeneous (one- or two-step) catalytic transesterification of AFWs is presented. Similarly, enzyme-catalyzed transesterification and the application of supercritical fluids conversion techniques in the production of biodiesel from AFWs are thoroughly assessed. Finally, cutting edge advances in assisted transesterification processes for biodiesel production are critically reviewed.

Nigeria is a multilingual and multicultural nation which is characterized by ethno-religious crises and insurgencies. The introduction of an active approach to teaching would ensure effective education and socialization for transformation in Nigeria. Effective teaching of group dynamic concepts (GDC) is relevant because of the diversity of students in our schools today. GDC are selected themes which could be used to help students from diverse racial, cultural, ethnic and language groups to experience unity through academic success. While academic knowledge and skills are essential, students must also develop positive attitude and skills necessary to interact positively in our diverse nation. This study, therefore, examined group dynamism as correlate of moral values and national unity in Ogun state, Nigeria. Two null hypotheses were generated and tested at 0.05 level of significance. The study adopted a quasi experimental design. A 30 item achievement test was administered on 150 junior secondary school (JSS) students randomly selected from five secondary schools in the south-west region of Nigeria. Data were analyzed using descriptive and inferential statistics. The Pearson product moment correlation and Scheffe Post hoc tests were used to determine the source of significant main effect where observed. The findings of this study revealed that effective teaching of GDC could help to inculcate the desired moral values in students and this could translate into national unity in and beyond Nigeria.

Antibacterial activities can be improved using mixed ligands. Mixed ligands involved in this research are sodium sulfadiazine (Na-sfz) and dithiocarbamate (ai-dtc). One-pot synthesis was used to synthesize ligand of aniline dithiocarbamate (ai-dtc) and the corresponding coordination compounds of [VO(sfz)(ai-dtc)] and [Zn(sfz)(ai-dtc)]. Crystals of ai-dtc, which grew from the solution when refrigerated after five days, were diffracted with technique of single crystal x-ray crystallography to reveal the structure. Other characterization techniques involving physicochemical parameters, FT-IR, UV-Vis and NMR (1H NMR and 13C NMR) were carried out on ligands of ai-dtc, sfz and corresponding coordination compounds. Differences in results of FT-IR, UV-Vis and NMR between ligands and their respective metal ions confirmed the coordination. The in vitro antibacterial studies showed that the ligands (not the metal complexes) had modest activity against Gram negative bacteria: Staphylococcus aureus, whereas, the coordination compounds had modest activities against the Gram negative bacteria: Escherichia coli and Pseudomonas aeruginosa.

The primary objective of this work was to investigate the thermal and rheological properties of crude tall oil (CTO), a low-cost by-product from the Kraft pulping process, as a potential feedstock for biodiesel production. Adequate knowledge of CTO properties is a prerequisite for the optimal design of a cost-effective biodiesel process and related processing equipment. The study revealed the correlation between the physicochemical properties, thermal, and rheological behavior of CTO. It was established that the trans/esterification temperature for CTO was greater than the temperature at which viscosity of CTO entered a steady-state. This information is useful in the selection of appropriate agitation conditions for optimal biodiesel production from CTO. The point of interception of storage modulus (G′) and loss modulus (G′′) determined the glass transition temperature (40 °C) of CTO that strongly correlated with its melting point (35.3 °C). The flow pattern of CTO was modeled as a non-Newtonian fluid. Furthermore, due to the high content of fatty acids (FA) in CTO, it is recommended to first reduce the FA level by acid catalyzed methanolysis prior to alkali treatment, or alternatively apply a one-step heterogeneous or enzymatic trans/esterification of CTO for high-yield biodiesel production.

This work evaluated essential quality parameters of binary blends of vegetable oils using a rapid and non-destructive method namely Fourier transform near-infrared (FTNIR) spectroscopy. Crude palm oil and canola oil from different vendors were blended at different ratios to obtain 40 oil samples with wide ranges of iodine values (IV), free fatty acids (FFA) and peroxide values (PV). FTNIR spectra of these oil samples were acquired and used in the calibration and test validation steps. The IV, FFA and PV of the oil samples were analyzed by AOCS methods. The FTNIR spectra were correlated to the AOCS data using partial least squares (PLS) regression. Calibration models were developed after test validation. The chemometric models were further improved through spectral processing. The optimal models were first derivative and first derivative + straight line subtraction. For IV, coefficient of determination (R2) = 0.98; root mean square error of prediction (RMSEP) = 2.54 and residual predictive deviation (RPD) = 6.11. The values for FFA were R2 = 0.9927; RMSEP = 0.35 and RPD = 11.6. While the values for PV were R2 = 0.9722; RMSEP = 0.49 and RPD = 6.4. The simultaneous characterization of the essential chemical quality parameters of vegetable oil blends by FTNIR spectroscopy is reported.

The rheological, thermal and physicochemical properties of animal fat wastes (tallow, lard, choice white grease, and yellow grease) are important parameters for an efficient design of equipment and to optimize the processing procedures of biodiesel production. In this study, the physicochemical properties of animal fat waste samples and the correlation of these properties to their thermal and rheological behaviors were elucidated. Pure lard was equally investigated to monitor the effects of impurities on the rheological and thermal properties of the animal fat wastes. It was established that the presence of impurities had effects on the rheological and thermal properties of fats. Additionally, due to the high level of free fatty acid (FFA) present in the wastes, transesterification cannot be applied directly. It will be necessary to reduce the FFA level by using acid pretreatment or enzyme catalyzed transesterification.

This study determined iodine value (IV) and free fatty acids (FFA) content of four different animal fat wastes and their blends using Fourier transform near-infrared spectroscopy (FT-NIR). Chemometric analysis by partial least squares (PLS) regression was used to correlate spectral data with IV and FFA reference values of the samples. The effects of four spectra pre-processing (first derivative (FD), second derivative (SD), multiplicative scatter correction (MSC) and vector normalization (VN)) methods were investigated to predict the reproducibility and robustness of the PLS-NIR model developed. A set of 70% of animal fat wastes and their blends were used for developing PLS calibration models for measuring IV and FFA content using the remaining 30% samples as an independent test set validation. The coefficient of determination ( R 2 ), the root mean square error estimation (RMSEE), and the residual prediction deviation (RPD) were used as indicators for the predictability of the PLS models. PLS-NIR models developed using first derivative and second derivative spectral preprocessing methods were the best for both IV and FFA content analysis (For IV, FD; R 2 = 0.9870, RMSEE = 1.40 gI 2 /100 g, RPD = 8.76, SD; R 2 = 0.9892, RMSEE = 1.28 gI 2 /100 g, RPD = 9.64 while For FFA, FD; R 2 = 0.9991, RMSEE = 0.195%, RPD = 34.00, SD; R 2 = 0.9993, RMSEE = 0.182%, RPD = 36.8). Overall, the results of this study demonstrate the suitability of FT-NIR spectroscopy for the quality control analysis of feedstocks for biodiesel production.

The civic competence of school age children has become questionable as a result of inappropriate leadership value manifestations. Active learning strategies have been suggested to serve as a panacea to this problem. However, the use of these strategies in the social studies and civic education classrooms are very rare in Nigerian secondary schools. This study, therefore, determined the effects of two modes of active learning strategies (case study and puzzle-based games) on school age children civic competence in leadership value concepts in social studies and civic education in Delta State, Nigeria. The study adopted the pre-test-post-test, control group quasi-experimental design. Junior secondary students in Delta state made up the population of the study. Multi-stage and simple random sampling techniques were employed in arriving at the sample. A total of two hundred and sixty – five students made up the study sample. Civic Competence Scale (r=0.68), Conventional Lecture Method Guide (r=0.78), Case Study Strategy Guide (r=0.60) and Puzzle-Based Instructional Games Strategy Guide (r=0.67) were used as instruments for data collection. Data were analysed using Analysis of Covariance, Estimated Marginal Mean and Scheffe Pair-wise Comparism at 0.05 level of significance. The findings of the study showed that though there is a significant main effect of treatment on school age childrens’ civic competence, the puzzle-based games strategy enhanced their civic competence better than the case study strategy. Consistent exploration of these strategies in the social studies and civic education classrooms in Nigerian schools was recommended. DOI: 10.5901/jesr.2016.v6n2p213

Western education in Nigeria led to the involvement of schools in the maintenance of appropriate leadership values.However, appropriate leadership value manifestations among school age children in Nigeria who are the futureleaders are lacking. To maintain these values, studies have suggested that the family structure of a child plays animportant role. This study, therefore, using two modes of active learning strategies as treatment packages,determined the moderating effect of family structure on school age children’s’ achievement in and attitude toleadership value concepts in social studies and civic education in Delta State, Nigeria. The study adopted thepre-test-post-test, control group quasi-experimental design. Junior secondary students in Delta state made up thepopulation of the study. Multi-stage and simple random sampling techniques were employed in arriving at thesample. A total of two hundred and sixty – five students made up the study sample. Students’ Achievement inLeadership Values Test (r=0.90) and Students’ Attitude to Leadership Values Scale (r=0.78) were used asinstruments for data collection. Data were analysed using Analysis of Covariance, Estimated Marginal Mean andScheffe Pair-wise Comparism. The findings of the study showed that though family structure has a significant effecton students’ achievement in leadership value concepts in social studies and civic education, it is not so for students’attitude. Based on this finding, it was recommended that classroom teachers should take into consideration home –background factors in the teaching – learning process and consciously guide the learners into healthy communicationand relationships among themselves and the teacher.

Thermal and physical properties of Detarium microcarpum seed flour, were studied. Thermophysical properties such as apparent density, bulk density, porosity and water activity of dry ground powder of the sample were determined and found to be 1.79 g/cm 3 , 0.44 g/cm 3 , 75.51% and 0.549, respectively. The Brix of the aqueous solutions of the sample ranged from 1.45 to 4.00 °Bx. Thermal properties studied include glass transition ( T g ), which varied from −74.9 to −73.2 °C for the aqueous solutions of the sample and showed two midpoints at 11.2 and 59 °C for the dry powdered D. microcarpum . Heat capacity of the aqueous solutions of the sample ranged from 1.79 to 18.83 J/g °C, while dry sample heat capacity was from 0.81 to 1.79 J/g °C. There was significant effect ( P P

The use of ultrasonic processing was evaluated for its ability to achieve adequate mixing while providing sufficient activation energy for the enzymatic transesterification of waste tallow. The effects of ultrasonic parameters (amplitude, cycle and pulse) and major reaction factors (molar ratio and enzyme concentration) on the reaction kinetics of biodiesel generation from waste tallow bio-catalyzed by immobilized lipase [Candida antarctica lipase B (CALB)] were investigated. Three sets of experiments namely A, B, and C were conducted. In experiment set A, two factors (ultrasonic amplitude and cycle) were investigated at three levels; in experiment set B, two factors (molar ratio and enzyme concentration) were examined at three levels; and in experiment set C, two factors (ultrasonic amplitude and reaction time) were investigated at five levels. A Ping Pong Bi Bi kinetic model approach was employed to study the effect of ultrasonic amplitude on the enzymatic transesterification. Kinetic constants of transesterification reaction were determined at different ultrasonic amplitudes (30%, 35%, 40%, 45%, and 50%) and enzyme concentrations (4, 6, and 8 wt.% of fat) at constant molar ratio (fat:methanol); 1:6, and ultrasonic cycle; 5 Hz. Optimal conditions for ultrasound-assisted biodiesel production from waste tallow were fat:methanol molar ratio, 1:4; catalyst level 6% (w/w of fat); reaction time, 20 min (30 times less than conventional batch processes); ultrasonic amplitude 40% at 5 Hz. The kinetic model results revealed interesting features of ultrasound assisted enzyme-catalyzed transesterification (as compared to conventional system): at ultrasonic amplitude 40%, the reaction activities within the system seemed to be steady after 20 min which means the reaction could proceed with or without ultrasonic mixing. Reversed phase high performance liquid chromatography indicated the biodiesel yield to be 85.6±0.08%.

The effect of different concentrations of sugar solution (hypertonic) (30%, 45% and 60% w/v) and carboxyl methyl cellulose (CMC) (0%, 1% and 2% w/v) coating on freeze drying of apple slices was studied. In total, nine treatments with respect to concentrations of hypertonic solution and coating layer were prepared to analyze their influence on the physical and chemical properties of freeze dried apple slices. It was observed that increase in the sugar solution concentration, decreased the moisture content of the apple slices significantly impacting its water activity, texture and sugar gain. Application of different concentrations of CMC coating had no significant effect on the properties of dried apple slices. A significant change was observed for color of CMC coated freeze dried apple slices pretreated with 60% sugar solution. Drying kinetics of pretreated apple slices were fitted by using two drying models, Newton's and Page's. Page's model showed higher R-square and lower root mean square error (RSME) compared to Newton's model.

Geography studies and describes the earth. It concentrates on both physical and human or cultural features of the earth. The study of which should not be limited to the classrooms. Geographical fieldwork is essential for a better comprehension of phenomena that are being studied from time to time, and it is also required for the purpose of acquisition of right skills among others. However, in Nigerian schools especially at primary and secondary levels, geographical fieldwork appears to be at lower ebb or is no longer in existence. This paper makes a wakeup call for a revival of geographical fieldwork in Nigerian schools. It clarifies what fieldwork is all about, pointing out the differences between it and other similar words, and emphasizes its importance. It finally debunks all flimsy excuses which teachers always give for not organizing fieldwork and makes a call for fieldwork to come alive once again.

Hydrographs are vital tools in the design and construction of water-control structures in urban and rural systems. The purpose of this study was to explore the development of design storm hydrographs for the small tropical catchment with limited data. In this study, Clark’s Unit Hydrograph method was used to develop synthetic hydrographs for the University of Ilorin Agricultural and Biosystems Engineering field plot. This method was selected for evaluation because the field plot has very limited stream flow data. Kunrun stream, which is the discharge outlet for the watershed, has no gauge stations. Clark's method was evaluated in this study for peak discharge and storm hydrograph analysis of the field plot. The total area of the field plot measures 18.4 ha and is characterized according to its land use: pasture range land (34%), cultivated land (49%), wood or forest land (9%) and 'dirt' (8%). The three necessary inputs needed for the development of the synthetic hydrograph using Clark’s method are: time of concentration, a storage coefficient, and a time-area histogram. The time of concentration was estimated using the Natural Resources Conservation Service method (NRCS) with the lag time determined from Snyder’s equation. The storage coefficient was estimated at 0.75 hr while the time of concentration was 1.98 hr. Convolution procedures were used in determining the storm hydrograph from the unit hydrograph. Runoff volume and peak discharge from the unit hydrograph were estimated to be 2.4 x 104 m3 and 1.02 m3/s, respectively. According to the 24hour, 100year storm hydrograph, the runoff volume was 5.23 x 104 m3 while the peak discharge was 2.15 m3/s. It was found that Clark's Unit Hydrograph Method was very suitable in the development of design storm hydrograph for small tropical catchment with limited data.Keywords: Clark’s unit hydrograph, Storm hydrograph, Peak discharge, ungauged watershed.