Volume 4 - Issue 3

Dielectric behavior of acetonitrile + n-Butyl alcohol binary mixtures at microwave frequency
A. P. Jogdand1, Dr. P. L. Kadam

Abstract: Values of dielectric constant (ɛ') and dielectric loss (ɛ") have been experimentally determined for binary liquid mixtures of acetonitrile + n-butyl alcohol at 10.75 GHz microwave frequencies at 300C and over the complete mole fraction range. The values of ɛ' and ɛ" have been used to evaluate the loss tangent ( tan ), molar polarization (P12), apparent polarization (P2) and a.c. conductivity ( p ).The results are discussed in terms of intermolecular interactions. The results are positive over the entire range of composition. Viscosity, density and refractive index measurement of pure liquid and binary liquid mixtures were carried out at 300C. The values of viscosity have been used to evaluate the activation energy (Ea). The surface tension has been experimentally determined for pure liquid and binary liquid mixtures at 300C.These parameters have been used to explain the formation of hydrogen bonding and formation of complex in the binary liquid mixtures.
Keywords: Binary mixture, Dielectric constant, dielectric loss, Molar polarization, Activation energy, Molecular interaction.

Matching User Preferences with Learning Objects in Model Based on Semantic Web Ontologies
Alwalid Bashier Gism Elseed Ahmed, Anas Ali Ballah Ali, Samani A. Talab

Abstract: The e-learning contained many educational resources are generally used in learning systems like Moodle, It's free open source software packages designed and flexible platform to create Learning Objects (LOs) and users' accounts. The author demonstrates how to use semantic web technologies to improve online learning environments and bridge the gap between learners and LOs. The ontological construction presented here helps formalize LOs context as a complex interplay of different learning-related elements and shows how we can use semantic annotation to interrelate diverse between learner and LOs. On top of this construction, the author implemented several feedback channels for educators to improve the delivery of future Web-based learning. The particular aim of this paper was to provide a solution based in the Moodle Platform. The main idea behind the approach presented here is that ontology which can not only be useful as a learning instrument but it can also be employed to assess students' skills. For it, each student is prompted to express his/her beliefs by building own discipline-related ontology through an application displayed in the interface of Moodle. This paper presents the ontology for an e-Learning System, which arranges metadata, and defines the relationships of metadata, which are about learning objects; belong to academic courses and user profiles. This ontology has been incorporated as a critical part of the proposed architecture. By this ontology, effective retrieval of learning content, customizing Learning Management System (LMS) is expected. Metadata used in this paper are based on current metadata standards. This ontology specified in human and machine-readable formats. In implementing it, several APIs were defined to manage the ontology. They were introduced into a typical LMS such as Moodle. Proposed ontology maps user preferences with learning content to satisfy learner requirements. These learning objects are presented to the learner based on ontological relationships. Hence it increases the usability and customizes the LMS. In conclusion, ontologies have a range of potential benefits and applications in further and higher education, including the sharing of information across e-learning systems, providing frameworks for learning object reuse, and enabling information between learner and system parts.
Keywords: Semantic Web, Ontologies, Moodle, E-learning.

Electron Transport Properties in Bulk ZnO and Zn1-xMgxO Materials
F. Nofeli, M. H. Tayarani, H. Arabshahi

Abstract: In this work, an investigation of the steady-state electron transport and low-field electron mobility characteristics of Wurtzite ZnO and Zn1_xMgxO are examined using the ensemble Monte Carlo model. The Monte Carlo calculations are carried out using a three-valley model for the systems under consideration. The following scattering mechanisms, i.e, impurity, polar optical phonon and acoustic phonon are included in the calculation. The maximum electron drift velocity that is obtained at room temperature for 1023 m-3 donor concentration is 2.36×107 cms-1 for ZnO in threshold field of 461 kV/cm. While the maximum electron drift velocity is1.65×107 cms-1 for Zn0.95Mg0.05O in threshold field 861 kV/cm. The maximum electron mobility for ZnO 886 cm2/V.s and for Zn1_xMgxO in variuos amount x=0.05, 0.1 and 0.2 is 304, 132 and 33 cm2/V.s respectively.It can be seen the peak drift velocity for bulk ZnO is 2.36×107 Cms-1,while for Zn1_xMgxO the peak drift velocity decreases due to increasing electron effective mass. The electron mobility of Zno is more than ZnMgo alloysat all temperatures becauseelectron mobility behavior dependence on effective mass and ionized impurity concentration.
Keywords: Electron Transport, Monte Carlo simulation, Wurtzite Zn1_xMgxO, Effective mass.

Color changes and dimensional stability in fir wood (Abies Borissi-regis Mattf.) Modified by heat treatment
Andromachi Mitani, Ioannis Barboutis

Abstract: It is widely accepted that heat treatment of wood ameliorates its dimensional stability and color evolution. This study has analyzed the effects of heat treatment in color changes and hygroscopic properties of fir wood (Abies Borissi-regis Mattf.), exposed at 200º C for 2, 3 and 4h. Dimensional stability and absorption were measured after 1 day and 3 days immersion in water of 20 º C ± 3 temperature. Color evolution and color changes were analyzed in three different directions using the CIE L*a*b* color space. The results showed that heat treatment resulted in a darkened color and an improvement in the dimensional stability of wood. The visual changes in color were more distinct after 4h treatment. The total color differences (ΔΕ) of the surface of wood substrates appear to be directly correlated with the treatment time. Swelling percentage of the samples was found to be affected by the thermal treatment intensity. The higher percentage of swelling decrease was recorded at approximately 19.61% in 4h treatment duration in a tangential direction whereas, the lowest percentage of 0.54% was derived from 3h treatment duration in a radial direction.
Keywords: Abies Borissi-regis Mattf., Color, Dimensional stability, Heat treatment.

A Novel Quantity based Weighted Association Rule Mining
S. P. Syed Ibrahim, J. Shanthalakshmi Revathy

Abstract: Classical association rule mining algorithm discovers frequent itemsets from transactional databases by considering the appearance of the itemset and not other utilities such as profit of an item or quantity in which items bought. But in transactional databases large quantity of items is purchased may lead to very high profit even though items appeared in few transactions. Therefore the quantity of the item is considered as the most important components, lack of which may lead to loss of information. Here binary attributes of the Item is considered for calculating item weight using link based model. This paper provides novel framework, Quantity Based Association Rule Mining (QBARM) algorithm, considers quantity and item weight.
Keywords: Association rule mining, Weight, Quantity.

Indoor Localization in Wireless Sensor Networks
Farhat M. A. Zargoun, Nesreen I. Ziedan, and Ibrahim M. Henawy, Muamer K. Masoud

Abstract:Popularity of ubiquitous computing increases the importance of location-aware applications, which increases the need for finding location of the user. In this paper, we present a novel localization method for indoor environments using Wi-Fi infrastructure. While localization using Wi-Fi is cost effective, handling the obstructions which are the main cause of signal propagation error in indoor environments is a challenging task. We address this problem in two levels, resulting in increased accuracy of localization. In the first level, we "localize" the residing area of user node in coarse granularity. Then, we use building layout to find the objects that attenuate the signal between the reference node and the coarse estimate of the location of user node. Using multi-wall propagation model, we apply corrections for all obstructions and find the location of user node. Empirical results based on experiments conducted in lab-scale, shows meter-level accuracy.