Quantitative estimation of vitamin C in some local fruits

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Seasonal influence on microbial quality of water sources in some rural communities of Zaria, Nigeria.

This work examined fifteen (15) different water sources in some rural communities of Zaria, Nigeria for microbial index of water quality in relation to seasonal influence from June, 2005 to May, 2006. The microbiological quality indices indicated widespread fecal contamination with the on-set of rainy season Escherichia coli MPN-index indicated highly significant difference between seasons, stations, season by stations and year by stations (

Crystallization and dielectric behavior of PLA and PHBV in PLA/PHBV blends and PLA/PHBV/TIO 2 nanocomposites

The morphology, crystallization behavior and mechanical properties of PLA, PHBV and their blends and nanocomposites with TiO 2 as filler were investigated. An uncommon morphological change was observed with increasing PLA content in the blends, and this complicated the isothermal crystallization kinetics analyses of the different samples. It was, for example, observed that PLA, which do not normally crystallize during the cooling of the sample, showed isothermal crystallization for certain blend compositions. TiO 2 was found to be mainly present in the PLA phase, which was also confirmed through broadband dielectric analysis. The blend composition, as well as the presence of TiO 2 nanoparticles, had an influence on the cold crystallization of the PLA. The tensile properties changed with blend and nanocomposite composition, and these changes could to a certain extent be related to the respective morphologies. Very little could be said about differences between the melting behavior of the different samples, because the PLA and PHBV melted at almost exactly the same temperature.Scopu

Optimization of Levulinic acid production from groundnut shell using Taguchi orthogonal array design

The exploitation of lignocellulosic biomass is receiving an increasing attention due to its renewability, abundance and low price value, and can be converted into various valuable platform compounds such as furfural, lactic acid, formic acid and levulinic acid. Among these products, levulinic acid (LA) is the main compound of biomass hydrolysis, which has been classified by the United States Department of Energy as one of the top-12 promising building blocks. This work reported the transformation of groundnut shell into LA. The production of LA was carried out in a 50 cm3 Teflon lined stainless steel reactor. The LA produced was extracted from the aqueous mixture using ethyl acetate, about 1g of sodium sulphate anhydrous were added to remove the water in the organic layer after the aqueous layer was drained and then heated at a temperature of about 78 oC for the solvent to evaporate and LA was the residue. The production process was optimized using a Taguchi orthogonal array design, with optimum yield of 74.54 % at reaction conditions of temperature (180 °C), time (3.5 h), and acid concentration (0.3 M). The FT-IR spectrum of the produced LA showed absorption at about 1705.13 cm-1 and 3039.91 cm-1 indicating the conjugated carbonyl and the hydroxyl of carboxylic acid functional group. It was recommended that high yields of LA can be achieved across a range of optimization variables as long as two out of the three conditions are met: high acid catalyst concentration, long reaction time or high temperature within the range tested, as LA is relatively stable once formed. Moreover, the results obtained revealed that groundnut shell could be a potential substrate for levulinic acid production. Keywords: Groundnut shell, Levulinic acid, Optimization, Hydrolysis, Taguchi design

The use of Biological Index of Pollution (BIP) in assessing quality of rural water sources in Zaria, Nigeria

The biological index of pollution (BIP) which hinges on the responses of aquatic biota to pollution of water sources was used to assess the quality of some water sources in Zaria area, Nigeria. Water samples were collected from 15 stations comprising three open water sources (lakes) and twelve hand-dug wells on a monthly basis for a period of 24 months. Ten liters of the samples from wells were concentrated to 50 ml by filtering through 70 meshes per cm2 plankton net. Collections from the lakes was by means of dragging net over a 3 meter distance in the water. The water was also concentrated to 50 ml. Using the BIP of Horasawa as modified by Palmer, the water quality situation of the sources were classified into betasaprobic and alphasaprobic. Some of the water sources, especially in the rainy season, gradually shifted in quality from betasaprobism to alphasaprobism. The BIP method gave a satisfactory indication of the quality status of each water source especially when the results obtained were compared with the result of physico-chemical analysis of the water sources. However, unless the water sources contain both phytoplankton and zooplankton, which are key variables in the BIP computation, the index proved difficult to apply. Key Words: Rural Water Sources, Water Quality, Biological Index

Information and communication technology, cyber crime and the administration of criminal justice system in Nigeria.

Information and Communication Technology (ICT) refers to technologies that provide access to information through telecommunications. ICT covers any product that will store, retrieve, manipulate, transmit or receive information electronically in a digital form such as personal computers, digital television and robots. Other products include the internet, emails, wireless networks, cell phones and other means of communication. Cybercrimes, on the other hand, include offences that are committed against individuals or groups of individuals with a criminal motive to intentionally harm the reputation of the victim directly or indirectly, using modern telecommunication networks. Nigeria is confronted with the challenges of cybercrimes and the problems of weak administration of the criminal justice system. However, the coming into force of two important laws in 2015 is a pointer to the fact that the menace of cybercrime in Nigeria are about to be contained. This paper while giving an overview of the nexus between these two new laws examines how their application will bring about the speedy dispensation of justice as well as a cybercrime free society

Cogeneration Power-Desalting Plants Using Gas Turbine Combined Cycle

The gas-steam turbine combined cycle (GTCC) is the preferred power plant type because of its high efficiency and its use of cheap and clean natural gas as fuel. It is also the preferred type in the Arab Gulf countries where it is used as cogeneration power-desalting plant (CPDP). In this chapter, descriptions and analysis of the GTCC components are presented, namely, the gas turbine cycle (compressor, combustor, gas turbine), heat recovery steam generator, and steam turbine. Combinations of the GTCC with thermally driven desalination units to present CPDP are presented. A parametric study to show the effect of using GTCC on several operating parameters on the CPDP is also presented, as well as cost allocation methods of fuel between the two product utilities (electric power and desalted seawater are also presented)

A NEW METHOD IN THE IDENTIFICATION OF NOISE AND VIBRATION CHARACTERISTICS OF AUTOMOTIVE DISK BRAKES IN THE LOW FREQUENCY DOMAIN

Noise and vibration characterization is an important benchmark to reduce brake noise.Brake noise and vibration measurement is commonly done on an actual vehicle or on a brake dynamometer. A full scale brake dynamometer takes into account the attached mass which resembles the mass of a quarter scale vehicle. This paper proposes a testing method which eliminates the need for attached masses. This is achieved through the scaling of the brake system parameters to accommodate the loss of mass and produce similar conditions to those in actual braking. The measurement of noise and vibration is measured simultaneously and an FFT is performed to identify the frequencies of noise and vibration. An experimental modal analysis (EMA)is done to obtain the frequencies which the brake system tends to produce as a validation to the proposed method. It is shown that through this method the noise and vibration characteristics of the brake system and the unstable frequencies can be identified

Effect of fertilizer levels and plant spacing on the performance of Mucuna prureins (velvet bean) in the Northern Guinea Savanna of Nigeria

Fertilizer recommendation for crop and plant spacing is dynamic process in view of the generation of new knowledge with management practices. Information such as (phosphorus levels and plant spacing) on maintaining adequate soil fertility is very much important for producing better forages for livestock. Leguminous crop such as Velvet bean (Mucuna pruriens) can alleviate some of these problems. Field experiment was conducted to access the effect of phosphorus fertilizer application level at 0, 80 and 120kg/ha and plant spacing interval of 30, 60 and 90cm of Velvet bean. Application of 80kg/ha of phosphorus fertilizer significantly influenced the performance of Mucuna plant such as plant height, number of branches and forage yield. Plant spacing interval of 30cm resulted in better stand count, taller plant, higher number of branches and forage yield per plant. Famers in Northern Guinea Savanna of Nigeria can adopt the application of phosphorus fertilizer at 80kg/ha and using narrower spacing (25cm by 30cm) for better yield of Mucana, thereby increasing farm output and animal performance.Keywords: phosphorus level, plant spacing, Mucuna pruriens, Velvet bea

An Analytical Model to Identify Brake System Vibration within the Low Frequency Domain

This paper presents the analytical model of a brake system to investigate the low frequency vibration. The purpose of this study is to model and validate brake system vibration. The brake model was developed by applying the theory of sinusoidal traveling waves and wave super positioning. An experimental modal analysis (EMA) of the brake disc has been carried out to obtain the natural frequencies. Wave equations were then formulated based on the experimental data. These waves are super positioned to be shown as a single spatial and temporal function that will provide periodic excitation to the brake pad. The brake pad was modeled as a beam element with distributed friction force. The differential equations were solved using Green's dynamic formulation. The model is capable of predicting vibration behavior of the brake pad for whole range below 1 kHz which has shown strong agreement with the experimental results validated through in-house brake dynamometer. This brake model can serve as a tool to investigate the relationship between braking parameters and other variables within the brake system