252 research outputs found
Growth performance, carcass and organ characteristics of growing rabbits fed graded levels of Moringa oleifera leaf meal in diets
An experiment was conducted at the Department of Animal Science teaching and research farm, Bayero University Kano, to evaluate the effect of feeding graded levels of Moringa oleifera leaf meal (MOLM) in diets on growth performance, carcass and organ characteristics of weaned rabbits. Twenty eight grower rabbits of averagely 975g in weight were allotted into four treatments of seven rabbits each in a completely randomize design. Four isonitrogenous diets (16% CP) were formulated in which MOLM was included at 0, 15, 30 and 45% for treatments 1, 2, 3 and 4 respectively. The diets were fed to the animals for eight weeks. The result showed that daily weight gain (5.95-13.39g/day) and carcass weight (497.70-727.65g) increased (P<0.05) with increasing levels of MOLM in diets, but dressing percentage (42.49-45.96%) was not affected by dietary treatments. Similarly, the weight of liver (40.35-57.05g), lungs (10.22-11.24g), heart (2.95-4.10g), kidney (8.30-10.70g), kidney fat (11.10-12.65g), small intestine (81.25-99.80g), large intestine (102.45-117.95g), caecum (20.50- 30.50g), stomach (90.75-114.65g), spleen (1.00-1.80g) and abdominal fat (7.89-11.25g) characteristics were not different across the treatments. The results indicate that weaned rabbits can utilize Moringa oleifera leaf meal at up to 45% level of inclusion in diets without any deleterious effects on growth performance, carcass yield and organ characteristics.Key words: Carcass yield, growth, Moringa oleifera, organ characteristics, rabbit
Effect of Water-Cement Ratio on the Mechanical Properties of Blended Cement Containing Bottom Ash and Limestone
This paper presents investigation on the effect of water requirement on compressive/ flexural strength of hardened cement mortar of ordinary portland cement (OPC) blended with 10% Limestone (L) and 10% coal bottom ash (BA) by weight ( 80C- 10L-10 BA). The water-cement ratio is one of the most important parameters that affect the performance (mechanical properties) of mortar, thus obtaining the best water requirement translates to the best mechanical properties. Class C bottom ash and Limestone (L) were used to partially replace Portland cement at 10% each by weight. The blended cement containing limestone and coal bottom ash and OPC were prepared at different water-cement ratios ranging from 0.35 to 0.55. Mortar mixtures were prepared for the blended cement and OPC control. 2, 7, 28, 60 days-compressive and flexural strengths of the mortar mixtures were determined. The strength results were compared to those of OPC and relative strengths are reported. It was observed that the compressive/flexural strength in comparison with the OPC control at water-cement ratio w/c = 0.4 was equivalent while at 0.45 and 0.50, the compressive strength experienced a reduction followed by compressive strength increment at 0.55. This can be attributed to the slow nature of the pozzolanic reaction which did not show effect until the water-cement ratio reached 0.55. But after 7 days, the pozzolanic reaction showed its effect with increment in flexural and compressive strength all through. At 28 days the compressive and flexural strengths were 40.85MPa and 9.34MPa respectively which were higher than OPC control for compressive and flexural strength of 33.85MPa and 8.92MPa respectively. It was observed that as the water-cement ratio was increased from 0.40 to 0.55 both blended cement and the control experienced increment in the compressive and flexural strength. Keywords: Compressive / Flexural strength, Water-cement ratio, Bottom ash, Limestone, Ternary cemen
Effect of Period and Storage Conditions on Essential Oil Yield And Composition of Eucalyptus Citriodora Leaves
Fresh eucalyptus citriodora leaves were harvested and kept under shade and sun for a period of four weeks. The effect of storage conditions and period of storage on the oil yield, oil composition and extraction pattern of the oil were investigated. It was observed that for the leave kept under sun there was significant decrease in the oil yield from 0.38% in the 1st week to 0.11% in the 4th week. However, for leaves kept under shade the oil yield slightly decreased from about 0.40% in the 1st week to 0.36% in the 4th week. The results further revealed that the storage condition and period of storage had no effect on the extraction pattern of the oil with about 72% of the oil extracted within 40 minutes of extraction time after induction period of 24 minutes. Two mathematical model equations were developed for the prediction of oil yield as a function of storage time for both conditions. The models predicted that for leaves stored in the shade and sun the expected oil yield would be 34.5% and 1% respectively. Physiochemical analysis of the oils revealed that the properties of the oil were not affected by both the period and condition of storage except the colour which changed from pale yellow to light brown. These results imply that the leaves should best be kept under shade before production in order to preserve its oil content and physiochemical properties
Hypolipidemic Activity of Solvents Extracts of Khaya senegalensis Stem Bark in Diet Induced Hyperlipidemic Rats
Introduction: Hyperlipidemia is a modifiable risk factor of an important killer disease “cardiovascular diseases”, which account for as much mortality as infectious disease, nutritional deficiency and maternal and prenatal disease combined together. Aim: To investigate the effect of oral administration of Aqueous-methanol stem bark extract of Khaya senegalensis and its solvents (hexane, chloroform and ethyl acetate) extracts on lipid profile of hyperlipidemic rats. Methodology: Hyperlipidemia was induced in rats via feeding on high lipid diet (HLD) for 6 weeks. A total of fifty five (55) rats were divided into two phases: For phase one, twenty five (25) rats were placed into five groups (GI - GV) of five rats each. GI served as normal control, GII serves as hyperlipidemic control group, while GIII, GIV and GV were hyperlipidemic and administered with crude extract (E1) at a dose of 250mg/kg, 350mg/kg and 450mg/kg body weight respectively for two weeks. For the second phase, thirty (30) rats were placed into six (6) groups of five (5) rats. GI served as normal control, GII served as hyperlipidemic control group, while GIII, GIV GV and GVI were hyperlipidemic and administered with hexane extract (E2), chloroform extract (E3), ethyl acetate extract (E4) and the residue (E5) at a dose of 250mg/kg body weight respectively for two weeks. The animals from each group were euthanized and serum was collected for analysis lipid profile (Total Cholesterol, LDL-Cholesterol, HDL-Cholesterol and Triglyceride). Results: The research found that aqueous methanol extract of Khaya senegalensis possess hypolipidemic ability with the ethyl acetate extract showing the highest potency with a significant (p<0.01) decrease in serum total cholesterol, triglyceride and LDL-cholesterol level when compared to hyperlipidemic control. Conclusion: The present study demonstrated that the ethyl acetate extract from the crude extract possesses the highest hypolipidemic activity. Keywords: High lipid diets; hyperlipidemia; lipid profile; Khaya senegalensis; sequential extraction
Engineering Properties of Industrial Wood Waste Ash-Concrete
This study investigated the use of industrial wood waste ash (IWWA) as partial replacement of Portland cement in the production of concrete. The IWW was incinerated in controlled environment in a kiln at a temperature of 550oc-600oc.The resulting ash was cooled and further ground using a Disk mill (FFC 15) with a sieve size of 0.66mm in it. X-ray fluorescence method was used to characterize the oxide composition of the resulting ash. By using absolute volume method of 1:2:4 concrete mix with a water/cement ratio of 0.55, concrete cubes measuring 150mm x 150mm x 150mm were made from five different concrete mixes prepared by using IWWA to replace 0%, 5%, 10%, 15% and 20% of Portland cement by mass. The workability of the fresh concrete mixes was evaluated using the slump test and the compressive strength of the concrete cubes was evaluated at 1, 7, 28, 56 and 90 days. Test results indicate that IWWA is pozzolanic, workability of the concrete mix decreases with an increase in replacement percentage of cement with IWWA. Compressive strength of IWWA-OPC concrete increases with age of curing and it decreases with increasing IWWA replacement. The compressive strength of IWWA concrete was lower at early stage compared to the control sample but improved significantly up to 90 days. The optimum compressive strength is 21.19N/mm2obtained at 20% replacement of cement with IWWA at 28 days. The maximum compressive strength at all ages of testing was obtained at 90 days for 5% (31.40N/mm2) replacement of cement with IWWA. A regression analysis using Minitab statistical software indicates that the variation of concrete compressive strength is significantly dependent on the variations of IWWA content and age of curing. The model R2 coefficients, residual and normality plots averaged about 90% showing adequate prediction of the model
Identification of Radar Signals Based on Time-Frequency Agility using Short-Time Fourier Transform
With modern advances in radar technologies and increased complexity in aerial battle, there is need for knowledge acquisition on the abilities and operating characteristics of intercepted hostile systems. The required knowledge obtained through advanced signal processing is necessary for either real time-warning or in order to determine Electronic Order of Battle (EOB) of these systems. An algorithm was therefore developed in this paper based on a joint Time-Frequency Distribution (TFD) in order to identify the time-frequency agility of radar signals based on its changing pulse characteristics. The joint TFD used in this paper was the square magnitude of the Short-Time Fourier Transform (STFT), where power and frequency obtained at instants of time from its Time-Frequency Representation (TFR) was used to estimate the time and frequency parameters of the radar signals respectively. Identification was thereafter done through classification of the signals using a rule-based classifier formed from the estimated time and frequency parameters. The signals considered in this paper were the simple pulsed, pulse repetition interval modulated, frequency hopping and the agile pulsed radar signals, which represent cases of various forms of agility associated with modern radar technologies. Classification accuracy was verified using the Monte Carlo simulation performed at various ranges of Signal-to-Noise Ratios (SNRs) in the presence of noise modelled by the Additive White Gaussian Noise (AWGN). Results obtained showed identification accuracy of 99% irrespective of the signal at a minimum SNR of 0dB where signal and noise power were the same. The obtained minimum SNR at this classification accuracy showed that the developed algorithm can be deployed practically in the electronic warfare field for accurate agility classification of airborne radar signals
PM3 and DFT Computational Studies of the Reaction Mechanism of Formaldehyde and Isoleucine
The reaction of formaldehyde and Isoleucine was studied using semi-empirical and density functional theory methods. Possible reactive sites are proposed and reaction mechanism postulated. It was found that the Isoleucine nitrogen attacks the carbonyl carbon of formaldehyde and forms a methylol intermediate that undergoes a condensation with another Isoleucine to produce a Methylenediisoleucine through a methylene bridge (cross-linking). The enthalpies of the reaction are -78.79 kJ/mol and -39.14kJ/mol for PM3 and DFT respectively also ΔSo and ΔGo, for the PM3 and DFT studies predicted. The reaction was found to be exothermic and second order
Knowledge, sources of information, and risk factors for sexually transmitted infections among secondary school youth in Zaria, Northern Nigeria
Background: Sexually transmitted infections (STIs) are responsible for a variety of health problems especially among the youth who engage in risky sexual behavior. There are few studies that describe STIs among the youths in Northern Nigeria. The objective of the study was to assess knowledge of STIs and risk factors among secondary school youth.
Materials and Methods: This was a cross‑sectional study in which structured, self‑administered questionnaire was used to collect data on socio‑demographics, knowledge on STIs, and risk factors. Three senior secondary schools were purposively selected for the study.
Results: A total of 1765 youths aged 10‑30 years with mean age of 16.9 ± 2.0 years participated in the study. 1371 (77.7%) and 394 (22.3%) were respectively Muslim and Christian. Mean age at first sexual intercourse was 16.7 ± 2.0 years.A majority (67.6%) of them heard about STIs; sources of information of STIs were school lessons 23.6%, mass media 23.3%, and health magazines 19.2%, respectively. Generally, knowledge on STIs was good as 75.4% of respondents knew how the disease is transmitted. This knowledge was significantly associated with class of student, place of treatment, and religious teaching (χ2 = 9.6, P = 0.047, χ2 = 22.1, P = 0.035 and 42.6, P = 0.001, respectively). Mean knowledge score was 0.698 ± 0.01. A majority of respondents were engaged in risky sexual behavior as only 16.2% use condom as a preventive measure. Eleven percent reported ever having an STI in the past and majority (52.8%) go to government hospital for treatment of acquired STI. 56% of the youth had two or more boy/girl friends and 30% had sexual relationships.
Conclusion: It was concluded that secondary school youth had good knowledge about STIs; however, the opposite is true when it comes to preventive practice (use of condom). Interventions such as periodic publicity awareness and school seminars focusing on STI preventions are needed to control the disease among the youth
Remediation of Heavy Metals Contaminated Soil Using Biochar-Modified Kaolin by Stabilization Technique
Soil contamination with heavy metals threatens ecosystems and human health. The objective of this paper is to evaluate the remediation of heavy metals (Pb, Cr, Cd, and Zn) contaminated soil using biochar-modified kaolin for the stabilization of Pb, Cr, Cd, and Zn in soils. Scanning electron microscope (SEM) X-ray diffraction (XRD) were used to analyze surface morphologies and phase compositions of remediation materials. Stock solutions of different metals were spiked onto the pre-weighed soil with 1mg/kg Pb, 2mg/kg Cr, 1.5mg/kg Zn, and 1mg/kg Cd concentrations above standards, respectively. This was then allowed for 1month aging period for acclimatization. After the aging period, the spiked soil was then treated with kaolin, biochar and biochar-modified kaolin in a 45 mL polypropvlene centrifuge tube and left for a week period for the remediation process. The toxicity characteristics leachability procedure (TCLP) test was used to assess the leachability tendency of residual metals in the treated soil. Amongst the biochar-modified kaolin, the 7:3 (kaolin:biochar ratio in grams) was the most effective compared to raw kaolin and biochar alone in stabilizing the target metals in the treated soil. To optimize the whole process, pretesting of the composites was conducted under constant temperature, dosage, contact time and pH. The residual concentrations of the target metals after TCLP were 2.321%, 10.846%, 0.091%, 0.295% and 3.796%, 22.133%, 0.136%, 0.561% after 30 minutes and 1-hour extraction for Pb, Cr, Cd, and Zn, respectively. The research findings demonstrate that biochar modification enhances kaolin's ability to firmly adsorb the target metals. Thus, the research presents a promising approach for the cost-effective and sustainable remediation of heavy metals in contaminated soils
Determination of morphological features and molecular interactions of Nigerian bentonitic clays using Scanning Electron Microscope (SEM)
This research focused on identifying the morphological features and molecular interactions of the Nigerian Bentonitic clays using Scanning Electron Microscope (SEM) characterisation technique. The SEM microstructure images indicated that the bentonite samples are generally moderately dispersive to dispersive with some large flocs which were apparently separate and dispersed from one another rather than located on the totality of the image. This property is more pronounced on the sodium (Na) activated and the treated samples than in the raw samples, which could be due to quartz removal and Na activation on the raw Bentonitic samples. Dispersive sample surfaces consist of loose flakes with no definitive mass structures observed on the treated samples due to added poly anionic cellulose (PAC) to the samplesKey words: SEM, microstructure, images, bentonite, flocs and PA
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