GSM Transceiver Design Optimization

Transceiver design is a tradeoff between several parameters that impact on the transceiver specifications. These parameters are also interrelated such that an increase in one parameter impacts on the possible values of the second parameter and these determine the specifications achievable. This work presents the design of a GSM transceiver system and presents that achieved results in comparison to the ETSI GSM specifications. The parameters were all subjected to the same percentage variation and Matlab software was used to develop algorithms for determining the variations and interrelationships between the parameters .One key criteria in transceiver design is the Noise figure and the results show that the frontend comprising of the Duplexer, LNA, the Mixer has the greatest impact on the transceiver design while the power amplifier noise figures have very minimal effect of the overall system noise figure. It also shows the power amplifier as the unit that consumes the most power. From the results, several power saving techniques such as sleep modes targeted at the Power amplifiers can be implemented without having any significant effect on the transceiver speed, The results also show an inverse relationship between the overall system gain and the dynamic range of the transceiver such that to achieve a higher dynamic range, the system gain would have to be reduced. . This work enables an understanding of the relationships between the different parameters of the GSM transceiver desig

Development of a Bluetooth-Based Contactless Automated Attendance Capture System for Large Halls and Auditoriums

The g Attendance capture for large populations still remains a challenge for organizations such as Schools, Universities and Event organizers. This is due to the fact that the attendance capture process is sequential requiring individual identification and autentification process. This process usually takes up a lot of time and generates a lot of inconvenience for the attendees. This process is also subject to manipulations as the most common identification model involves the use of ID cards embedded with either RFIDs or identification methods to tie the user to the card. These cards can be given to third parties for the purpose of taking the attendance. This paper presents the development of a Bluetooth based system and a local identification system for the development of a contactless identification capture system for large halls. The system identifies the user using his fingerprint. When the identification is completed, the data is transmitted to a central data base using the Bluetooth transmission technology. This system will enable a contactless capturing of the attendance in large halls resulting in a system with a very high security level and no inconvenience for the attendees

An Evaluation of the Spatiotemporal Variation in the Degree of Saturation of Traffic at Signalised Roundabouts in a Typical Nigerian City

The degrees of saturation of traffic at the approaches to the two major signalised junctions, Fajuyi Roundabout, and Matthew Roundabout at Ado Ekiti, Nigeria, which are spaced at approximately 500m, were determined for the weekdays and weekend. In general, the results showed morning peaks at 7am-9am, evening peaks at 3pm-6pm and inter-peaks between these periods, especially around noon during weekdays at the roundabouts. There were mainly low-value peaks at 7am-9am and 3pm-5pm respectively on Saturday while the values on Sunday were mainly uniform; and the lowest. The most significant differences in the traffic flow at the two junctions were the congestion being experienced at Irona Street approach of Matthew Roundabout during weekdays, and the high degree of saturation of traffic between 12noon-5pm at the Ijigbo Street approach of the roundabout on Sunday. Even with this, there was relative similarity in the temporal variation of the degree of saturation of traffic at the two roundabouts, which was attributed to the similarity in their location, and thus traffic flow, as both are sited at the city centre. Other contributory factors include the short spacing and comparable land-use. Keywords: degree of saturation, signalised roundabout, traffic control lights, congestion, traffic strea

Activity Concentration of Gamma Emitting Natural Radionuclides in Building Materials

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. Keywords: Natural radionuclide, Building materials, absorbed dose, Radium equivalen

An Assessment of the Performance of Traffic Control Signals Installed at a Main Junction in Ado Ekiti, Nigeria

The traffic at one of the major isolated signalised junctions in Ado Ekiti, Nigeria was evaluated. Traffic counts were undertaken from 7am to 7pm on the approaches to the junction over a period of one week. Peak periods of traffic appeared to be 7am-10am and 3pm-6pm respectively. The maximum flow rate for the traffic streams was calculated from the geometric characteristics of the junction and the direction of the streams. Owing to non-marking of the lanes, the degree of saturation on each approach to the junction was calculated from the aggregation of such for the traffic streams. The results show that one of the approaches to the junction was mainly congested throughout the day, and therefore the existing traffic control signals were ineffective for the traffic at the approach. Keywords: traffic control signals, saturation, congestion, traffic stream, demand, capacit

Detection of rotavirus VP7 gene in helmeted guinea fowls and Japanese quails in Ogun state, Nigeria

Rotaviruses classified into groups A through H are important etiological agents of gastroenteritis in man and animal. In Nigeria vaccination of infants has continuously been carried out, however the disease is still a burden to the nation which remains one of the countries with the highest cases of rotavirus gastroenteritis. There are several evidence of interspecies cross transmission and reassortment among group A rotaviruses. However, few studies have focused on rotavirus in the avian species, thus the virus has only been reported in chickens from southwest Nigeria. Guinea fowls (Numidea meleagris) and Japanese quails (Coturnix corturnix japonica) serve as source of income to the rural house-hold where they are raised in backyards. A total of 100 fecal samples from Guinea fowls (50) and Japanese quails (50) from different locations in Ogun state were collected and analyzed using group A specific RT-PCR. Fecal samples were screened for rotavirus using VP7 primers. The virus was detected in pooled diarrheic fecal samples of both Guinea fowls and Japanese quails and also in non-diarrheic feces of Guinea fowls. Due to the close proximity at which different breeds of birds are raised in backyard poultry in Nigeria and the reassortment ability of the virus, there will continuously be an increase in the diversity of the virus. This is not leaving out a zoonotic transmission with subsequent contribution to vaccine failure in man. It is thus important to continually survey for the virus in man and animal. This study provides the first report of rotavirus in helmeted Guinea fowls and Japanese quails in Nigeria.Keywords: Guinea fowl, Japanese quail, Feces, Detection, Rotavirus, VP7 gen

Comparative Haemolymph Biochemical Properties of Giant African Land Snail (Archachatina marginata) from Nigeria

The Giant African Land Snails (GALS) is a very important micro livestock that is consumed widely within several regions in sub-Saharan Africa which differ in their vegetation types and climatic factors. Studies have shown that diet and stocking density influence properties of the snail haemolymph. This study examines the haemolymph biochemical properties of the land snail, (Archachatina marginata) from south-west (Ekiti, Lagos, Ogun, Ondo, Osun and Oyo). Organic (protein, lipids, glucose) and inorganic (Na, K, Ca, Cl, PO4) composition of snails’ haemolymph were determined by standard methods. Results showed that GALS from Oyo state had the highest lipids and glucose concentrations in the haemolymph while Ondo and Ekiti states recorded the least. Protein was the most abundant (33.83g/l-49.37g) organic substance while lipids were the least (23.93mg/dl-33-93mg/dl). There were significant differences (P<0.05) in the concentrations of inorganic substances in the haemolymph across the six states. Snails from Oyo state recorded significant higher (p<0.05) concentrations of Na+, Ca2+ and Cl- than those of other states. Also, Na+ and Cl- were the most common anions in snails’ haemolymph from the six states. This current study concluded that snails from Oyo state had better haemolymph biochemical properties than other south west states of Nigeria. DOI: 10.7176/JBAH/10-12-02 Publication date:June 30th 202

Drinking water quality assessment: lessons learnt from Ogun State, Nigeria

A drinking Water Quality Assessment survey was carried out in Ogun State Nigeria in 2009. The collected water samples were analysed in the laboratory to determine compliance with the Nigerian Standard for Drinking Water Quality (NSDWQ) and the WHO Guideline Values (WHO GLV). Results from the Study showed that high Coliform counts were recorded in many sampled sites

Factors affecting temperaments in Zebu and Friesian-Zebu crossbred cattle

The influence of breed, sex, season, age, liveweight and body condition on temperament scores was investigated. All variables, except age, had significant (P<0.05) effect on temperament. Progeny of crossbred dams had lower temperament than those of purebred Zebu dams. Female animals had higher temperament and so also were animals with better body condition. Temperament was lowest in the hot, dry season. Phenotypic correlations between measurements of temperament were positive and significant (P<0.05), with vigour of movement having the highest correlation with the overall temperament score. Liveweight was negatively correlated with temperament while there was a positive correlation between temperament and body condition. Regression equations for predicting overall temperament using vigour of movement are presented

Quality of sealed polythene water in Kaduna and Lagos

This study is a preliminary study to first of all establish a working basis for assessment of water quality. It involves an evaluation of randomly selected sample of twenty brands from different producers at three(3) interval of time within the sampling months ( i.e the three samples constitute a batch No. for that producer). Summarized results of the 3 samples for each producer were presented as a batch in the table I and II. Key parameters for physico-chemical analysis and bacteriological examination of the ‘Pure water’ samples were determined to find out the wholesomeness of the water. During the course of the study, visits were made to two of the producers to see their outfit production process and recognise potential pitfalls that might contaminate the ‘Pure water’ products