Technical Note: Application of Decision Theory Based Criteria for Structural Appraisal of a Building during Construction

In the earlier paper, a simple probabilistic model was formulated to predict the reliability of concrete in a structure during construction, a case study of laboratory block for College of Continuing Education, University of Port Harcourt, Rivers State. In this paper, the reliability of the structure is predicted using decision theory based criteria as a tool. The net probability of failure of the structure after assessment was 1.4898E-3 which exceeded the target value of probability of failure of 3.931E-6 for slabs, 4.78E-7 for beams in  exure, 1.591E-4 for beams in shear and 4.8E-5 for columns subjected to both dead and live-load combination.[1] Showing that the structure is not safe and can result in uncommon accidents to persons and damage to properties on collapse.Keywords: probabilistic model, decision theory based criteria, target value, uncommon accidents, collaps

Characteristics of Separated Flow Regions Within Altitude Compensating Nozzles Final Report

Characteristics of separated flow regions within altitude compensating nozzle

Assessment of some selected heavy metals in soot from the exhaust of heavy duty trucks and power generating plants in Nigeria by flame atomic absorption spectrophotometer

Some selected heavy metals were determined in soot samples collected from heavy duty automobiles and diesel power generating plants in Idah Local Government Area of Kogi State, Nigeria. The results ind 0icated a high concentration of Pb, Cr, Cu and Mn in all the samples. Cadmium was observed in six of the samples and was not detected in samples MB3 and G1. Of all the parameters analysed, Pb had the highest concentrations of 12.1352±5.007 ppm in sample T 2, followed by MB 3 at 5.1573±0.604 ppm. However the average discharge of Pb to the environment was 4.4511 ppm. Average discharge of Cd in the soot samples was 0.3964 ppm, while that of Cr, Cu and Mn were 0.4898 ppm, 0.8612 ppm and 1.8851 ppm respectively. These values are far above the World Health Organization maximum acceptable limits for air and water emissions and are therefore high source of pollution with its attendant health risks as previously reported in literature.© 2009 International Formulae Group. All rights reserved.Keywords: Soot, FAAS, Pollution, Heavy metals

Functions preserving nonnegativity of matrices

The main goal of this work is to determine which entire functions preserve nonnegativity of matrices of a fixed order $n$ -- i.e., to characterize entire functions $f$ with the property that $f(A)$ is entrywise nonnegative for every entrywise nonnegative matrix $A$ of size $n\times n$. Towards this goal, we present a complete characterization of functions preserving nonnegativity of (block) upper-triangular matrices and those preserving nonnegativity of circulant matrices. We also derive necessary conditions and sufficient conditions for entire functions that preserve nonnegativity of symmetric matrices. We also show that some of these latter conditions characterize the even or odd functions that preserve nonnegativity of symmetric matrices.Comment: 20 pages; expanded and corrected to reflect referees' remarks; to appear in SIAM J. Matrix Anal. App

On demand multicast routing in wireless sensor networks

The wireless networking environment presents imposing challenges to the study of broadcasting and multicasting problems. Developing an algorithm to optimize communication amongst a group of spatially distributed sensor nodes in a WSN (Wireless Sensor Network) has been met with a number challenges due to the characterization of the sensor node device. These challenges include, but are not limited to: energy, memory, and throughput constraints. The traditional approach to overcome these challenges have emphasised the development of low power electronics, efficient modulation, coding, antenna design etc., it has been recognised that networking techniques can also have a strong impact on the energy efficiency of such systems. A variety of networking based approaches to energy efficiency are possible. One of the well-known approaches is to apply clustering techniques to effectively establish an ordered connection of sensor nodes whilst improving the overall network lifetime. This paper proposes an improved clustering based multicast approach that allows any cluster head to be a multicast source with an unlimited number of subscribers, to optimize group communication in WSNs whilst ensuring sensor nodes do not deprecate rapidly in energy levels. We review several clustering approaches and examine multicast versus broadcast communication in WSNs

Phenolic Profiles of Four Processed Tropical Green Leafy Vegetables Commonly Used as Food

The phenolic profiles are presented of four tropical green leafy vegetables ( Ocimum gratissimum, Vernonia amygdalina, Corchorus olitorius and Manihot utilissima) commonly used as food, after application of traditional treatments, such as boiling and abrasion. The HPLC/DAD/MS technique was mainly used to carry out this study. Preliminary evaluation of the antioxidant properties of the vegetables was also performed using the DPPH in vitro test. For the first time, seasonal variations in the phenolic content of the four investigated vegetables were highlighted. Of the four plants, all showed only quantitative differences, except for Ocimum graticimum, in which cichoric acid, previously detected as one of the main constituents of this vegetable collected in November (dry season), was absent in the sample harvested in March. The phenolic constituents are chemically unmodified after a strong heating process, such as the traditional blanching (about 15 minutes) applied by Nigerian people prior to consuming these vegetables. Nevertheless, these typical preparations showed a consistent decrease in the total phenolic compounds with respect to the raw material, particularly for Corchorus olitorius (from 42.3 to 5.56 mg/g dried leaves) and Vernonia amygdalina (from 40.2 to 4.4 mg/g dried leaves). As expected, when the blanching treatment is reduced to a few minutes, as for Manihot utilissima leaves, the cooked vegetable maintained almost unaltered its original phenolic content (around 10 mg/g dried leaves). The unique exception is the blanched Ocimum gratissimum sample that showed a consistent increment of the total phenols, particularly of rosmarinic acid (from 6.1 to 29.8 mg/g dried leaves) with respect to the unprocessed vegetable