Aims: This study aims to investigate the sensorial and physicochemical suitability of sweet potato to be processed into gari. Study Design: TiB1 potatoes variety were grated and the obtained paste was left to ferment for 0, 1, 2, 3 or 4 days. Different fermented pastes were roasted at 90ºC with palm oil to obtain the various garis (G0, G1, G2, G3 and G4). Place and Duration of Study: This study was carried out in the Life and Earth Science Laboratory, at the University of Maroua, Cameroon between the periods of January to April 2013. Methodology: The physicochemical characteristics, hydratation capacities and sensory properties of the different products were evaluated. The analysis were done by using a commercial cassava gari as reference. Results: Results showed that the fermentation time (p = 0.05) affects significantly the physicochemical properties and sensory attributes of the garis. Decrease of pH, ash content (19 to 11%), phenolic compounds content (8 to 5 mg / g), soluble sugars and starch content (17-13%) have been observed during fermentation. But in contract the titrable acidity (9 to 27 mg acetic acid / g), the bulk volume, the gel strength (12 to 24 g/100 mL) and protein content (10 to 14%) increased during fermentation process. Comparatively to potato gari, cassava gari exhibited a high titrable acidity (26 mg acetic acid / g), starch (23%) and protein content (15%) but low phenolic compounds (2.94 mg / g), free sugars content (1.01 mg / g) and the best hydration capacity. According to physicochemical analysis and organoleptic tests, the best potato gari is G2 followed by G1 and G3. Color, mouth feel and acidity as well as food habit were found to be the determining attributes for panellists’ preference. Conclusion: From the present results, processing sweet potatoes into gariis one of a good way to reduce post-harvest losses.
This research project presents the result on the study for the use of Cow Dung Ash (CDA) as partial replacement in production of concrete. The experiments were designed to study the effects of adding Cow Dung Ash (CDA) in various percentages by weight (10%, 20% and 30%) of cement and cure for the periods of 7, 14, 21 and 28, days respectively before testing for the Compressive strengths. It also involves determination of setting time, Bulk Density, and Workability of Cow Dung Ash in various percentages by mixing with Portland cement. The Compressive test results are 21.33 N/mm3, 21.11 N/mm3, 11.11 N/mm3 and 6.00 N/mm3 for 0%, 10%, 20% and 30% replacement of cement with CDA respectively at 28 days. The Workability results gives 40mm, 48mm, 80mm and 100mm respectively for 0%, 10%, 20% and 30% replacement of cement with CDA. Among the main conclusions, it should be highlighted that the initial and final setting time increases as the percentage of Cow Dung Ash is added, (CDA) has an advantage that offers lightness of weight and low thermal conductivity, Cow Dung Ash requires more quantity of water as the percentage increases in the concrete therefore it has a serious limitation that must be understood before it is put to use. Cow Dung Ash concrete is recommended for use only when a ten percentage (10%) of Cow Dung Ash is added. While the concrete is suitable for use on certain floor and wall that will not be subjected to heavy load or structures that are of temporary use (CDA) concrete is not to be use in a water accumulated area or for structures that are related to water.
Aims: To evaluate the growth performance, their rates of transpiration and water-use efficiencies under different moisture levels. Study Design: A randomised complete design of three tree species, four treatments and three replicates. Place and Duration of Study: Screen house of the University of Buea from January to June 2012. Methodology: 144 uniform seedlings of Markhmia tomentosa, Funtumia africana and Prunus africana were treated to four soil moisture capacities (12.5, 25, 50 and 100%) determined gravimetrically and water supplied to the seedlings three times per week after pre-transplanting. The collar diameter, height and number of leaves were measured non-destructively every fortnight. The seedling biomass, leaf area, mass fractions, number of first order lateral roots, root/shoot ratio, specific leaf area, shoot and root lengths were determined six months after pre-transplanting. The seedlings’ rates of transpiration, evapotranspiration and water-use efficiencies were determined gravimetrically. Results: The growth trends with respect to collar diameter, height and the number of leaves showed significant variations at P = 0.05. The effects of the soil moisture capacities on the growth performances were significantly different at P< 0.001. Markhmia tomentosa seedlings supplied with 25% soil moisture showed maximum leaf number (42) and leaf area (10712.8 cm2) while those with 50% treatment had collar diameter and root/shoot ratio of 17.8 cm and 2.8 respectively. Funtumia africana seedlings at 50% soil moisture capacity showed maximum height (88.6 cm) and total biomass (60.3g). Prunus africana seedlings had the least growth performance. Markhmia seedlings had the maximum rate of transpiration (12.69 gH2O/s/m2) and evapotranspiration (14.20 gH2O/s/m2). Funtumia seedlings gave the best water-use efficiency (176.5 ml/g). The poor performance observed in P. africana seedlings was as result of low elevation (≤ 450 above sea level). Conclusion: Funtumia africana had the best water use efficiency while Markhmia tomentosa had the best root development. These two species would be suitable for the afforestation/reforestation of water catchment in humid areas of Cameroon.
Electrical resistivity prospecting method was used in evaluating the groundwater potential of Ita-Eku, southeastern part of Ado-Ekiti, Ekiti state, Nigeria using the vertical electrical sounding technique. A total of seven electrical soundings were conducted using the Schlumberger electrode array. The data acquired were interpreted qualitatively and quantitatively and were presented as tables, charts and section. The interpreted models revealed three to four geo-electric layers namely; topsoil, clay/lateritic soil, weathered/fractured layer and fresh basement. The topsoil which is relatively thin has thickness ranging between 0.8 and 2.5m while the resistivity values range from 26 to 171 Ω-m. The second layer has thickness ranging from 2.5 – 5.9 m and resistivity values from 5 to 19 Ω-m. The third layer is the weathered/fractured layer with thickness ranging from 5.9–35.3 m and the resistivity values range from 171 to 404 Ω-m. The basement resistivity values range between 711 and 3466 Ω-m. First and second order (Dar Zarrouk parameters) data were used to generate the geo-electric section, overburden thickness chart and longitudinal conductance chart. These section and charts were considered in generating the groundwater potential table. The groundwater potential table shows that about 28% of the entire study area falls within zone rated as having high groundwater potential, while about 28% of the study area constitutes the low groundwater potential rating and the remaining 44% has moderate groundwater potential rating.
Aims: Two diagnosing faults of the vehicle’s parts, an old and modern method, mechanical or electronic methods, before or after faulty occurring, One of methods which can be used before faulty occurring is Acoustic Emission (AE) for parts producing sound, this give an indication of the status of the part, and an expectation if the part is in good condition, needs repairing or replacing. Study Design: Mention the design of the study here. Place and Duration of Study: Department of Mechanical Engineering / Faculty of Engineering Technology Al-Balqa Applied University, P.O.Box (15008), North Marka, 11134 Amman - Jordan, between June 2012 and July 2013. Methodology: The detection software of MATLAB V7 were used (i.e. For signal analyses and processing of the results), a Crystal Piezoelectric microphone (sensor has a sensitivity - 60 dc, 5 mv/pa/1KHz). Sound recorder program (from Jet Audio Program V7.6 for recording sound from microphone and save it on a computer with wav file). Band pass filter (for filtering sounds which we recorded at a certain range of frequency of about 100-20000 Hz). Results: In this work, it was observed and concluded that the sound of the faulty parted has frequency fluctuation higher than frequency fluctuation of good part. In a similar trend found in the energy of sound, where the sound level of the faulty part is found to be much higher than the sound level of the good part. Hence, a healthy monitoring of the huge mechanical system such as vehicles and industrial machines can be achieved as a non destructive testing (NDT). Conclusion: The experimental and theoretical study in this project has been proven to be successful for the failure prevention for vehicle components by the combination of acoustic emission properties and a written code using MatLab software besides using very simple inexpensive signal collector.
Estimation of evaporation from reservoirs in arid and semi-arid regions is a very crucial issue. This paper presents an application of Artificial Neural Networks (ANN) and climate based models (Penman, Priestley-Taylor and Stephens-Stewart), for the estimation of evaporation from the Algardabiya Reservoir, near Sirt, Libya. Daily meteorological data were collected for the years 2004 to 2006 and used to develop the evaporation estimation models. The measured meteorological variables included daily observations of air temperature, relative humidity, and wind speed. A statistical analysis was undertaken to verify the accuracy of the studied models. The results of the climate based and ANN models are compared with observed evaporation data from the reservoir. The comparison shows that there was better agreement between the ANN model estimations and the observed evaporation than the climate based models.
The main concern of this paper is to derive the fuzzy estimators for the two-parameter Log-logistic distribution. The TL-moments, L-moments and LQ-moments formulas are obtained for the Log-logistic distribution. Also, the estimation of these parameters is considered using the maximum likelihood method, the TL-moments, L-moments and LQ-moments. Furthermore, a numerical comparison is considered between all these estimators for the Log-logistic distribution.
Spike detection as the first basic step is very important in analysing and classification of data, since the quality of resulting data depends crucially on a particular detection technique used. This paper presents the optimal spike detection technique based on amplitude threshold on a band pass filtered signal. Comparisons were made on four different filtered signals: voltage of the entire signal, power of the entire signal, voltage moving average and power moving average of the signal. MATLAB was used to generate six different realistic simulations with varying signal to noise ratio which resembles that of a real dataset. The six different simulations contain ten samples each. For each simulated signal, only one type of spike shape was used with same firing frequency following a Poisson distribution. The duration of the simulation was equal in all cases with the signal to noise ratio defined as the amplitude of the spikes normalized by the noise level. Also, the threshold for spike detection was calculated based on the estimation of the standard deviation of noise; the area under the receiver operating characteristic curve and statistical analysis of data were used to quantify their performance. The major finding is that the voltage technique superseded all other techniques mentioned above both in high and low signal to noise ratio. When voltage was compared with power, voltage moving average (vma) and power moving average (pma), it was observed that p (0.0022) < 0.05 and h = 1. This means that the test rejects the null hypothesis of equal medians. When power was compared with vma using Mann-Whitney U-Test, it was observed that p (0.0043) < 0.05 with h = 1, implying that the test rejects the null hypothesis of equal medians but when power was compared with pma, it was observed that p (0.1320) > 0.05 with h = 0, also implying that the test accepts the null hypothesis of equal medians. For comparison of vma and pma, it was observed that p (0.6991) > 0.05 with h = 0 which presents that the test accepts the null hypothesis of equal medians. However, is clear that voltage technique is the optimal spike detection technique based on amplitude threshold.
In this paper a new design for brushless doubly fed induction machine for operation as generator in wind energy systems is proposed. This machine, named single machine- brushless doubly fed induction generator (SM-BDFIG) is composed of three main components; a regular three phase wound rotor induction machine, a power electronic converter, and a pack of rechargeable Lithium-ion batteries. The converter is mounted on the outer surface of a web reinforced hollow metallic (aluminum) or fiber glass cylinder. The battery packs are embedded in the inner part of the cylinder between the webs. The hollow cylinder is mechanically coupled with the induction machine on the same shaft. Therefore, all the three main components of the SM-BDFIG rotate with the same angular speed. A brief description and analysis of the proposed machine merits, parameters, and characteristics are given. The authors could provide the detailed designs of SM-BDFIG and the required testing facilities to the manufacturer who is ready to fabricate the first product of SM-BDFIG and facilitate their testing.
Technology is the main cause of emerging careers in life science. As technological change occurs at unprecedented speeds, it becomes increasingly important to develop mechanisms that can foster skills highly demanded in emerging careers. Technical and Vocational Education and Training (TVET) is an integral part of the education system with mechanisms that can prepare such skills. Some of emerging careers in life science includes Biotechnology and Bioinformatics. This paper examines some of compelling issues and challenges for consideration in TVET training when aligning skills for emerging careers in life science. The paper also identifies priorities of improvement in science education and strategies for interventions that will link life science to job creation and career skills. The compelling issues and strategies includes; making quality education in science a priority in secondary schools and to recognize its impact far into the future for emerging careers in life science, training with strong link with the industries and innovative delivery of instruction which can actively engage students in learning and developing skills. Other considerations include a carefully sequenced and flexible curriculum which must meet increasing and ever-changing knowledge and skills demands. Also hands-on activities in laboratories should remain an indispensable constituent of effective learning and acquiring skills. Awareness rising for aspirants in emerging careers is also very important which includes encouraging more women in those emerging careers in life science. Emerging careers in life science are expected to substantially create an impact on scientific, social welfare and economic development of the world. Understanding the compelling issues and strategies for successful TVET implementation is very important for preparation skilled workforce in emerging life science careers.