Archives-December  

In this work, the natural radionuclide contents of some building materials widely used in Nigeria were measured by the means of gamma-ray spectrometry using Na(I)Tl detector. A total of 15 samples were assayed from different materials. The mean of 226Ra, 232Th and 40K concentrations determined are 30.35±8.69BqKg-1, 20.12±6.00 BqKg-1 and 241.95±76.31 BqKg-1 respectively. These values were lower than permissible global values except for potassium which is higher than that of global permissible value of 52.2, 41.0 and 230.0 (BqKg-1 ) respectively by UNSCEAR. The obtained mean absorbed dose rate for all the collected building materials samples is 39.90(nGgh-1). These results, along with the results of the estimated annual effective dose rates, radium equivalent (Raeq), external hazard index (Hex) are presented and they are found below the internationally accepted safe limits. It suffices to say therefore the analyzed samples could be used for building and construction purposes. It is safe to say that there is no threat pose to any users of the materials.

Zero crossing detection is the most common method for measuring the frequency or the period of a periodic signal. This paper presents a comparative study of various zero crossing detector techniques. The accuracy of measuring zero crossing for synchronizing power system control and instrumentation requires a diverse approach to minimize phase detection errors from signals corrupted with noise and extraneous signals. An approach to detect zero crossing with the use of opto coupler is detailed describe in the paper. The issues related to the previous approaches has been discussed along with their pros and cons.

The content of a kidney image can be expressed in terms of different features such as auto correlation, contrast, promenance, shade, dissimilarity, energy, entropy, homogeneity, maximum probability, variance, co-variance, correlation, inverse difference moment and inertia. Retrieval methods based on these features can be varied depending on how the feature values are combined. Many of the existing approaches assume linear relationships between different features, and also require users to assign weights to features for themselves. In this paper, we study the neural network-based image retrieval system. This approach allows the user to select an initial query image and incrementally search target images through training the images which are stored in the image database. The experimental results show that this approach provides better image retrieval performance than the existing linearly combining approach methods.

This paper empirically illustrates the extent of Job involvement of women employees working the banking sector of India. A sample of 267 women employees from diverse cadres of hierarchy of public and private banking sectors was used for the study. The study classifies the degree of involvement of women employees based on the four sub dimension of Job involvement viz. Response towards work, Expressions of being job involved, Sense of duty towards work and feelings about unfinished task and absenteeism. Regression analysis is used to comparatively highlight the difference that exists between the four sub dimensions of job involvement of the employees.

Natural environmental conditions of Iran and its geographical location that falls in the arid belt in one hand, and overuse of non renewable resources in the other hand, cause series of problems and conditions that brings the country into a rapid deterioration. the two main factors of degrdation are natural factors and human factors. Of major natural factors, three factors are notable: climatic, geomorphologic and morphologic. In this study to evaluate the desertification condition regarding to local conditions of the study area, two processes of water and wind erosion were selected and assessment of desertification condition was conducted Based on these processes, wheightening indicators and MEDALUS model. The results showed that Qs and NQts all responsible for much of sentiment delivery and erosion and as a result, desertification severity of these two geological units considered as severe and very severe.

Video restoration or old film restoration is challenging but sometimes necessary process. Line scratches in old videos appearas thin bright or dark lines which are roughly vertical and straight. We propose, Frame – By – Frame line scratch detection algorithm to detect scratches from old films. For false detection temporal algorithm is used. Some assumptions and hypothesis from old scratch removal strategies are eliminated from Frame-By-Frame line scratch detection algorithm so that variety of line scratches can be detected. Contrario methodology and local statistical estimation is used in combinatorial way for robustness. Using these technologies over detection and confusion creating areas are greatly reduced. Vertical structure in video can cause false detection but temporal filtering algorithm eliminates false detection by considering and analyzing unity of underlying scenes. We contribute for removal of scratches using pixel filling technique. This concept of detecting and eliminating line scratch from video contribute fine methods for video restoration.

A hydrocarbon well log (Onyia well), obtained from the Niger Delta region of Nigeria. Was analyzed. The equipment used –Shale shakers log chart, detectors etc and parameters-rate of penetration (ROP), weight on bits (WOB) and strokes per minute (SPM). All provided evidences of the benefits of mudlogging as an exploration tool. The shows, stains and fluorescence obtained from the lithological analyses of zones of interest, from the Mudlog, ie 7100-8,300ft of well, after through examination indicated that the lithologies reached. and in some cases the availability of hydrocarbon in the reached zones.

The primary objective was to evaluate if batch staining of malaria blood films results in false positive smears. False positive smears (>1%) may cause a serious underestimate of a drug’s or vaccine’s protective efficacy, as well as affect evaluation of diagnostics, estimates of malaria prevalence, and clinical management. Thick blood films may float from a glass slide during staining and adhere to other films if batch staining is used resulting in false positive readings. Venous blood in EDTA anticoagulant from malaria positive samples of ? 20 parasites per high power field and a true negative sample was utilized to make thick and thin smears. Two true negative smears were stained with Giemsa stain with eight positive smears in batch in Coplin jars for 10 minutes or overnight. Two control negatives were stained alone with the same batch of stain. Blinded microscopists read these slides using a rereading paradigm. Thick film loss was graded by gross appearance ranging from 0 (none) to 4+ (> ¾ loss). A total of 602 slides were evaluated in this study, of which 392 were true positives (65%) and 210 (35%) were true negatives. Of the true negatives, 110 were batch stained with true positives, and 100 were true negative controls stained alone. Of the initial readings, 11-20% were reported falsely positive. “Fishing” or cross-contamination was infrequently noted by one of the microscopists, but was uniformly present in these smears on reexamination. Of the true positive smears (high density), 1-3% were read falsely negative. On reexamination of these slides, the cause was found to be reporting of results from very poor quality smears. Thick film loss was clearly more severe for the positive slides with 10 minute versus overnight drying (means score 0.97 vs 1.97, p <0.001).

In this study, comparison between two controllers i.e. PID controller and fuzzy logic controller is done for the proposed dc-dc closed loop boost converter. The simulation, modeling and stability analysis of DC-DC Boost converter for Solar Electric system is done using space averaging technique in order to study its time domain, frequency domain and pole-zero domain analysis. A feedback controller for DC-DC boost converter is Designed to obtain constant output voltage of 24 V.A fuzzy logic controller is later used to control the output voltage of the boost converter. Simulation results show that fuzzy logic controlled boost converter has fast transient response, better steady-state response, and the proposed converter is less sensitive to load changes as compared to that of PID controller.

The aim of this paper is to examine the issue convergence of per capita income of North Africa countries to the per capita income level of countries in Southern Europe. We have applied tests of sigma-convergence and polynomial beta-convergence of Chatterji to assess convergence. We have applied the multiple endogenous breaks test advocated by Bai & Perron (2003) in order to evaluate the sigma-convergence hypothesis. According to our results, the process of sigma-convergence is not uniform over time. There exists a movement of convergence of per capita income of NA countries towards the income level of countries of Southern Europe during the period 1980-1984. The estimate of convergence clubs can refine the results for countries that have started catching up. This test rejects the hypothesis of beta-convergence on the whole period (1980-2007). If the model is estimated for each country, then there is a movement of beta-convergence only for Tunisia and Morocco on the period 1985-2000.On the other sub-periods, the assumption of divergence is accepted. The per capita income level of countries of Southern Europe does not seem to be a target toward which converge the countries of the NA region in the long term.