Fundamentals of technology diffusion and mobile phone case study

The fundamentals of technology diffusion are introduced in this paper. Mathematical and heuristic (loose) modeling are defined and illustrated with real data. Starting with the embryonic phase, diffusion undergoes growing and mature phases and ends in the aging phase. The cumulative adoption function (of time) denoting the total number of users of a certain product is the output of the diffusion model used to either predict future trends (e.g. sales) or estimate certain model parameters. Problems often encountered in mathematical modeling and analysis are presented. Some of these shortcomings can be alleviated through loose modeling. A case study of mobile telephone diffusion in Finland is presented to illustrate some of the modeling principles and analysis.     

Creating a Fit Between BPR and IT Infrastructure: A Proposed Framework for Effective Implementation

As business imperatives change and new high-capability information technologies (IT) appear, organizations recognize the need to remain at the forefront of change by reengineering their business processes and implementing enabling responsive IT infrastructures. However, experience in this context indicates a lack of comprehension of essential elements and their mutual relationships that can contribute to the success of business-process change-implementation efforts. This article proposes a framework for managing IT for effective business-process redesign (BPR) implementation. After establishing BPR principles, components, and the relationship of BPR to some organizational and technological approaches, it presents the role and benefits of IT in BPR. The article then discusses in detail the core elements of the framework. Its theme is that an IT infrastructure that covers issues of BPR strategy development, IT strategic alignment, IT infrastructure development, IT sourcing, legacy systems reengineering, IS integration, and IS function competence is essential and critical for effective implementation.     

Genetic algorithm model for shear capacity of RC beams reinforced with externally bonded FRP

A variety of on-site construction applications using FRP materials have been realized worldwide. However, this technology is currently at a stage where its future widespread implementation and competitiveness will depend on the development of reliable design guidelines based on sound engineering principles. This paper presents simple, yet improved, equations to calculate the shear capacity of FRP bonded-reinforced concrete beams based on the genetic algorithms (GAs) approach applied to 212 experimental data points available in the open literature. The performance of the proposed equations was compared to that of commonly used shear design methods, namely the ACI 440, Eurocode (EC2), the Matthys Model, Colotti model and the ISIS Canada guidelines. Results demonstrate that the proposed equations better agree with the available experimental data than the existing models investigated. Moreover, a sensitivity analysis was carried out to investigate the effect of the shear span-to-depth ratio on the shear capacity contributed by concrete, the ultimate effective strain in FRP sheets, and the ultimate effective stress in transverse rebars. Results indicate that the shear span-to-depth ratio has a significant effect on the shear behaviour of FRP bonded-reinforced concrete beams.     

Optimal Decay Rate for Unidimensional Thermoelastic Problem within the Green-Lindsay Model

In this article we consider the system of generalized thermoelasticity under Green–Lindsay model in one dimension with Dirichlet–Neumann boundary conditions. First, the roots of the characteristic polynomial are investigated by applying an approach based on the implicit function theorem. Then we prove the exponential decay of the associated energy and describe the optimal decay rate. The numerical calculation of the corresponding characteristic roots is done for different real materials. Then another approach based on Hurwitz criterion is applied to obtain the decay rate analytically. Finally, we present a discussion of the decay rate given by both approaches, as well as a comparison with already-existing results for Lord–Shulman and classical models of thermoelasticity.     

The effect of magnetic treatment on the physico-chemical and microbiological characteristics of hard waters

The main objective of this study was to investigate the effect of magnetic treatment on the physico-chemical and bacteriological characteristics of hard waters. The scaling power of tested waters was evaluated using the rapid controlled precipitation (RCP) method. Results showed that magnetic treatment affects calcium carbonate crystallization. The RCP tests confirmed that the scaling power of the magnetically treated water was inhibited. Experimental results also indicated a significant improvement in the bacteriological quality of the treated water. Average reductions of 2.02 log Total coliforms, 0.95 log Escherichia coli and 1.06 log Faecal streptococci were obtained.     

Long-term water quality monitoring of the Sejnane reservoir in northeast Tunisia

The Sejnane reservoir in northeast Tunisia provides drinking and irrigation water. Long-term water quality monitoring data including precipitation, evaporation, temperature, pH, conductivity, dissolved oxygen, turbidity, total suspended solids, major anions and cations, fluoride, BOD₅, NO₃ ⁻, NO₂ ⁻, NH₄ ⁺, P _tot, fecal coliform bacteria, boron and heavy metals (Fe, Zn, Cu, Ni, Pb, Cr and Cd) are reported. The appropriateness for irrigation was estimated by the SAR and Na percentage and the water quality assessed using the Canadian Water Quality Index as good to excellent, which confirmed its suitability for drinking, aquatic life and irrigation purposes.      

Chemical composition and antioxidant and radical‐scavenging activities of Periploca laevigata root bark extracts

BACKGROUND: The root powder of Periploca laevigata is used for preparing soft drinks and as an aromatic in Tunisia. The infusion or decoction of its root bark has widespread use in folk medicine. The plant is used to treat digestive disorders and hypertensive effects as well as other health problems. RESULTS: The antioxidant activities of extracts of P. laevigata root bark obtained with solvents of different polarity were investigated using assays of 1,1‐diphenyl‐2‐picrylhydrazyl radical‐scavenging activity, ferric‐reducing capacity, β‐carotene‐bleaching ability, hydroxyl radical‐scavenging activity and lipid peroxidation inhibition. The methanol extract, with the highest amount of total phenolics and flavonoids, showed the highest antioxidant activities in all assays, followed by the water extract. Gas chromatography/mass spectrometry was used to determine the composition of the water and methanol extracts. Thirty‐four compounds were identified in the methanol extract, with proflavine (516.2 g kg^?1 dry matter (DM)) and 4‐methoxysalicylaldehyde (198.3 g kg^?1 DM) being the most abundant. Sixteen compounds were identified in the water extract, of which 4‐hydroxy‐3‐methoxyphenethylene glycol (351.2 g kg^?1 DM) was the main component. CONCLUSION: As far as is known, this is the first report on the chemical composition and biological activities of phenolic extracts from P. laevigata. The results of the study indicate that the root bark of this plant might be a good candidate for further investigation in developing new antioxidants. Copyright © 2009 Society of Chemical Industry     

Mid infrared and fluorescence spectroscopies coupled with factorial discriminant analysis technique to identify sheep milk from different feeding systems

Mid infrared spectroscopy (MIR) combined with multivariate data analysis was used to discriminate between ewes milk samples according to their feeding systems (controls, ewes fed scotch bean and ewes fed soybean). The MIR spectra were scanned throughout the first 11 weeks of the lactation stage. When factorial discriminant analysis (FDA) with leave one-out cross-validation was applied, separately, to the three spectral regions in the MIR (i.e. 3000–2800, 1700–1500 and 1500–900 cm⁻¹), the classification rate was not satisfactory. Therefore, the first principal component (PCs) scores (corresponding to 3, 10 and 10 for, respectively, the 3000–2800, 1700–1500 and 1500–900 cm⁻¹) of the principal component analysis (PCA) extracted from each of the data sets were pooled (concatenated) into a single matrix and analysed by FDA. Correct classification amounting to 71.7% was obtained. Finally, the same procedure was applied to the MIR and fluorescence data sets and 98% of milk samples were found to be correctly classified. Milk samples belonging to control and soybean groups were 100% correctly classified. Regarding milk samples originating from the scotch bean group, only 2 out of 33 samples were misclassified. It was concluded that concatenation of the data sets collected from the two spectroscopic techniques is an efficient tool for authenticating milk samples according to their feeding systems, regardless of the lactation stage.     

Isolation and characterisation of trypsin from sardinelle (Sardinella aurita) viscera

BACKGROUND: In Tunisia, sardinelle (Sardinella aurita) catches totalled about 13 300 t in 2002. During processing, solid wastes including heads and viscera are generated, representing about 30% of the original raw material. Viscera, one of the most important by‐products of the fishing industry, are recognised as a potential source of digestive enzymes, especially proteases with high activity over a wide range of pH and temperature conditions. This paper describes the purification procedure and some biochemical characterisation of trypsin from S. aurita viscera. RESULTS: Trypsin from the viscera of sardinelle (S. aurita) was purified by fractionation with ammonium sulphate, Sephadex G‐75 gel filtration, Sepharose mono Q anion exchange chromatography, ultrafiltration and a second Sephadex G‐75 gel filtration, resulting in a 5.42‐fold increase in specific activity and 6.1% recovery. The molecular weight of the purified enzyme was estimated to be 24 kDa using size exclusion chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis. The purified enzyme showed esterase‐specific activity on N‐α‐benzoyl‐L ‐arginine ethyl ester (BAEE) that was four times greater than its amidase‐specific activity on N‐α‐benzoyl‐DL ‐arginine‐p‐nitroanilide (BAPNA). The optimal pH and temperature for enzyme activity were pH 8 and 55 °C respectively using BAEE as a substrate. The trypsin kinetic constants K_m and k_cat on BAPNA were 1.67 mmol L^?1 and 3.87 s^?1 respectively, while the catalytic efficiency k_cat/K_m was 2.31 s^?1 L mmol^?1. CONCLUSION: Trypsin was purified from sardinelle (S. aurita) viscera. Biochemical characterisation of S. aurita trypsin showed that this enzyme can be used as a possible biotechnological tool in the fish‐processing and food industries. Copyright © 2008 Society of Chemical Industry