Information Technology

The Sb-doped SnO, thin films have been developed for gas sensors applications. The mechanism of sensing is based on the absorption and desorption of gases on the films surface that change the electrical resistivity of the Jilms. ThinJilms of SnO2 were prepared on the glass slide substrates by spray pyrolysis method. The films in the range of 2000-5000 A are very sensitive to 0, and CO, and less sensitive to NI gas. The basic principles of the mechanism of action will be described in details.

The Mg concentration dependence of the performance of inverted type organic solar cells based on Mgdoped ZnO nanorod arrays and poly(3-hexylthiophene) (P3HT) has been investigated. The Mg dopants with various concentrations (0, 1, 3 and 5 at.%) were introduced during the hydrothermal growth of the ZnO nanorod arrays on fluorine-doped tin oxide (FTO) glass substrate. The P3HT was deposited onto Mg-doped ZnO nanorod arrays by spin coating technique, followed by deposition of Ag as anode using magnetron sputtering technique. The length and density of Mg-doped ZnO nanorods increased, whereas the diameter decreased with the Mg concentration. The short circuit current density (J sc) and open circuit voltage (V oc) improved with increasing of Mg concentration up to 3 at.%, which could be attributed to increased interfacial area for more efficient exciton dissociation and reduced charge recombination as a result of lower number of oxygen interstitials which act as electron traps in ZnO. However, the J sc and V oc started to decrease at Mg concentration of 5 at.%, mainly due to poor infiltration of P3HT into the high-density 5 at.% Mg-doped ZnO nanorod arrays and increase of Mg dopant-related trapping centers. The highest power conversion efficiency of 0.36 ± 0.02% was achieved at Mg doping concentration of 3 at.%, an enhancement of 225% as compared to that based on undoped ZnO nanorod arrays.

The Langmuir-Blodgett thin films of n-tetraphenyl porphine iron (III) chloride, n-tetraphenyl porphine manganese (III) chloride, n-tetrakis (4-methoxyphenyl) porphine cobalt (II) and n-octaethyl porphine cobalt (II) mixed with arachidic acid were used as sensing elements for optical detection of capsicum (chili) aroma. The sensing sensitivity of aroma was based on changes of optical absorption of the films taken at four wavelengths i.e. 646, 615, 601 and 585 nm. The responses of the films upon aroma exposure were fast and recoverable. The patterns of the absorption changes were able to distinguish three capsicum samples; dried capsicum annum, fresh capsicum annum and capsicum minimum.

Polymer light emitting device (PLED) based on blue polymeric material, poly(9,9-din -HexylFluorenyl-2,7-diyl), PHF was prepared using toluene as solvent in spin coating technique. The device with ITO/PHF/AI structure has a peak emission wavelength at 530 nm. This peak is considered green emission range. This paper reports, the used of tetrahydrofuran and benzene as solvents for fabrication of PLED to improved the peak emission spectrum of the device. It was found that the solvents were influenced the emission wavelength of the devices. The device using benzene solvent showed peak emission at 490 nm which is the blue emission range.

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The study of nonlinear optical properties of polymer nanocomposites has been given increasing attention due its application in laser, communication and data storage technology. There is a need to enhance the understanding of all photonics technologies. In the current work, PMMA-ZnO nanocomposites as foils and as thin films have been successfully prepared. Casting method and spin coating were used to prepare them respectively. Nanocomposites were prepared by mixing ZnO nanoparticles with polymethyl methacrylate (PMMA) as the polymer matrix. Different contents of ZnO nanoparticles were used as the filler in the nanocomposites. The absorbance spectra of the samples were obtained. The linear absorption coefficient was calculated. The nonlinear refractive index and nonlinear absorption coefficient were investigated using a single beam Z-scan technique. A Q-switched Nd-YAG pulsed laser (532 nm, 7 ns, 5 Hz) was used as a light source. Both thin film's and foil's samples showed peak absorption at 375 nm and increasing absorption with ZnO nanoparticles concentration. The nonlinear refractive index was in the order of 10-11 cm2/W for thin film samples and 10-12 cm2 /W for foil's samples with a negative sign. In contrast, the nonlinear absorption coefficient is in the order of 10-6 cm/W and 10-7 cm /W for thin film and foil respectively. The figures of merit W and T were calculated in order to evaluate the suitability of the samples as optical switching device .However; they unsatisfied the requirements of optical switching devices but they can be considered as an excellent candidate for optical limiting.

Universities and other educational institutions around the world are increasingly using e-learning technology to more efficiently and effectively deliver the education to their students. Successful implementation of e-learning system is determined by the acceptance of such system by students. Therefore, this study was undertaken to explore the factors that influence the intention of students to adopt e-learning of two institutions namely the Federal University Dutsinma (FUDMA) and the Umaru Musa Yar'adua University (UMYU), and the investigation was carried out by using UTAUT model. It was found that performance expectancy, effect expectancy and facilitation conditions are the important factors, that are influencing students' intention to adopt e-learning, and the results are contributory for the development of a strategy for implementing e-learning system at these universities. It was also found that both, the universities and students are capable of adopting e-learning system.

The susceptibility of three phenotypes of Village chickens to Newcastle Disease Virus (NDV) (Hertz 33/56 strain) was investigated at Modibbo Adama University poultry farm, Yola. Forty five (45) village chickens, made up of fifteen (15) each of Frizzle, Naked neck and Smooth feathered types were infected with NDV (Hertz 33/56 strain) through intraocular and intranasal routes and subsequently bled on day 0, 3, 7, 14 and 28 post infection. A morbidity rate of 100% and mortality rates of 58.3%, 41.7% and 75% for the frizzle, naked neck and smooth feathered types was observed respectively. The mean antibody titre of all the phenotypes before the infection was zero and naked neck started developing protective antibodies on day 7 post infection (PI). All the phenotypes, with the exception of the naked necks in the intraocular group, exhibited highest Geometric mean titre (GMT) of NDV HI antibodies on day 28 PI through both routes. The GMT in the control group remained low throughout the ex...

The study analyzed the information needs and accessibility of artisanal fisher folk in Benue State, Nigeria. Multistage sampling technique was used to select two fishing communities from each of the three agro-ecological zones in the study area. A structured questionnaire was used to collect primary data from 222 respondents. Descriptive statistics showed that artisanal fisher folk were mostly married male adults with low level of formal education, low income, and low use of modern technologies. The chi-square test revealed that there was a significant relationship between access to needed information and the output of the artisanal fisher folk at 1% level of significance. Logit regression test revealed that age, education and household size had significant effect on fisher folk access to needed fisheries information. Important areas of information need of the fisher folk were, sources of micro credit, modern fish capture methods and aqua-culture. It was recommended that adequate fi...