Aims and Objectives: The aim of this study was to investigate the effect of exposure times of Coca Cola on enamel’s microhardness, mineral weight, and rate of calcium and phosphate ions discharging from it. Materials and Methods:... more
Aims and Objectives: The aim of this study was to investigate the effect of exposure times of Coca Cola on enamel’s microhardness, mineral weight, and rate of calcium and phosphate ions discharging from it. Materials and Methods: Thirty-two enamel blocks were randomly divided into four groups and exposed to 10mL of their respective solution daily for 7 days, with each group containing eight specimens: Group 1 (enamel blocks exposed to artificial saliva, control group), group 2 (enamel blocks exposed to Coca Cola for 5 minutes), group 3 (enamel blocks exposed to Coca Cola for 10 minutes), and group 4 (enamel blocks exposed to Coca Cola for 30 minutes). Microhardness data (Vickers hardness number [VHN]) and mineral weight were calculated at baseline (sound enamel) and postexposure to Coca Cola. Inductively coupled plasma–optical emission spectrometry (ICP-OES) was utilized to study calcium and phosphate ion percolation from enamel surfaces. Results: Decrease in VHN was directly proportional to exposure time for all experimental groups. Comparison of baseline and postexposure values between control and experimental groups was statistically significant (P < 0.05). Mineral weight of enamel blocks decreased as the exposure time increased for all experimental groups. ICP-OES analysis revealed linear relationship between release of calcium and phosphate ions at 5 and 10 minutes, but at 30 minutes, a decrease in concentration of both ions was observed. Conclusion: The microhardness and mineral weight of enamel decreased linearly with exposure time. The release of calcium and phosphate ions from enamel increased initially but gradually decreased as the exposure time increased.
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A comparative study of performance is conducted between two indoor positioning algorithms described in the Literature, the Vector and Ecolocation algorithms. Both use received signal strength (RSS) to implement a radio frequency... more
A comparative study of performance is conducted between two indoor positioning algorithms described in the Literature, the Vector and Ecolocation algorithms. Both use received signal strength (RSS) to implement a radio frequency fingerprinting technique. The experiment is conducted using commercial ray tracing software called Wireless Insite and Matlab. The Vector algorithm performs better than the Ecolocation algorithm, which suffers heavily from an ambiguity issue. For the Vector algorithm, the median position error was 2.79 m and 90% of errors were less than 5.72 m.
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Research Interests: Computer Science and MIMO
Group communication as an efficient communication mechanism, in recent years has become popular. This is due to the increase in group applications and services. Group communication ensures efficient delivery of packets from one source to... more
Group communication as an efficient communication mechanism, in recent years has become popular. This is due to the increase in group applications and services. Group communication ensures efficient delivery of packets from one source to multiple recipients or many sources to multiple recipients. Group key management in a wireless environment has been an interesting challenge with group communication because of insecure communication channel. The security and integrity of group communication in a wireless environment is a challenge. One of the challenges with group communication is the mobility of group members. Member mobility is a challenge when designing a group key management scheme. There have been several attempts that have been made to design a secure group key management for wireless environment. Not so many successful attempts have towards wireless mobile environments to explicitly address the various challenges with dynamic mobility issue between multiple networks. This research proposes a GKM scheme that tackles mobility in group communication. The protocol is analyzed to assess security and performance requirements. The size of the group variation, the mobility rate variation are carefully observed to determine the impact on the average of rekeying messages generated at every event and also 1-affects-n phenomenon. The results achieved, shows that the proposed protocol outperforms other popular solutions with less number of rekeying messages per event and also less number of affected members per event. Backward and Forward security are preserved for moving members.
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Millimeter-wave indoor propagation characteristics including path loss models and multipath delay spread values for systems using directional and omnidirectional antennas are presented. The performance of the four 5G candidate... more
Millimeter-wave indoor propagation characteristics including path loss models and multipath delay spread values for systems using directional and omnidirectional antennas are presented. The performance of the four 5G candidate frequencies, 28 GHz, 39 GHz, 60 GHz and 73 GHz, are investigated in line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios using published real time frequency measurements conducted in indoor environments. Comparisons are made against simulation data obtained from the 3D Ray Tracing Wireless InSite software over Tx-Rx separations of 1.5 m to 62 m. In addition, frequency-dependent electrical properties, such as conductivity-σ and permittivity-ε, of common building materials are incorporated in the simulation. Results show material type influences propagation behavior of mm-waves due to reflections, diffractions and penetrations of walls and objects (obstacles). It is also shown that while both, the received power and delay spread decrease with increasing frequency, the number of ray paths increases.
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Research Interests: Computer Science, Computer Architecture, Artificial Intelligence, Computational Complexity, RFID, and 12 moreComputational Modeling, Activity Recognition, RSS, Recurrent Neural Network, Sensors, Ambient Assisted Living, Recurrent Neural Networks, Smart Homes, Data Models, Senior Citizens, LSTM, and Artificial Neural Network
This paper examines the benefits and drawbacks of these services, reviewing differences in infrastructure, power requirements, sensing devices, and other factors. Technologies covered include Radio Frequency Identification, GSM, GPS,... more
This paper examines the benefits and drawbacks of these services, reviewing differences in infrastructure, power requirements, sensing devices, and other factors. Technologies covered include Radio Frequency Identification, GSM, GPS, A-GPS, Smart Antennas, Distributed Antenna Systems, Localization by Cell-ID, Localization by Prediction (Dead Reckoning method), Angle of Arrival (AOA), Localization by Finger Printing, Localization by Time of Arrival (TOA), Localization by Observed Time Difference of Arrival (TDOA), and Hybrid Localization-based AOA-TOA.
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Research Interests:
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A comparative study of performance is conducted between two indoor positioning algorithms described in the Literature, the Vector and Ecolocation algorithms. Both use received signal strength (RSS) to implement a radio frequency... more
A comparative study of performance is conducted between two indoor positioning algorithms described in the Literature, the Vector and Ecolocation algorithms. Both use received signal strength (RSS) to implement a radio frequency fingerprinting technique. The experiment is conducted using commercial ray tracing software called Wireless Insite and Matlab. The Vector algorithm performs better than the Ecolocation algorithm, which suffers heavily from an ambiguity issue. For the Vector algorithm, the median position error was 2.79 m and 90% of errors were less than 5.72 m.
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This paper outlines a study of the effect of changing the electrical properties of materials when applied in the Wireless InSite (WI) ray-tracing software. The study was performed at 60 GHz in an indoor propagation environment and... more
This paper outlines a study of the effect of changing the electrical properties of materials when applied in the Wireless InSite (WI) ray-tracing software. The study was performed at 60 GHz in an indoor propagation environment and supported by Line of Sight (LoS) and Non-LoS measurements data. The study also investigates other factors that may affect the WI sensitivity, including antenna dimensions, antenna pattern, and accuracy of the environment design. In the experiment, single and double reflections from concrete walls and wooden doors are analysed. Experimental results were compared to those obtained from simulation using the WI. It was found that materials selected from the literature should be similar to those of the environment under study in order to have accurate results. WI was found to have an acceptable performance provided certain conditions are met.
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Over the last decade, significant research effort has been devoted to enhance the isolation between multiple-input-multiple-output (MIMO) antenna elements. This has led to offer several solutions, which in terms of band calcifications may... more
Over the last decade, significant research effort has been devoted to enhance the isolation between multiple-input-multiple-output (MIMO) antenna elements. This has led to offer several solutions, which in terms of band calcifications may be categories as follows: narrow band, broadband and dual/triple band. Services that have been covered by the narrow band solutions include Long Term Evolution (LTE) 700–800 MHz, UMTS and WLAN 2.4, 5.2 and 5.8 GHz. Thus, within this chapter, a low profile printed crescent-shaped monopole MIMO diversity antenna for use in smart mobile devices is proposed. The mutual coupling is significantly mitigated by simply printing an I-shaped conductor over the ground place which is symmetrically placed between the two antenna elements. The proposed MIMO antenna exhibits a wideband frequency range from 1.8 to 2.6 GHz, equivalent to bandwidth of 54.5%, while simultaneously achieving an isolation of −14 dB. Moreover, the proposed antenna demonstrates nearly omni...
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SUMMARY RT-PCR and dot blot hybridization assays were successfully used for the detection of Olive latent virus 3 (OLV-3), a newly discovered olive-infecting virus belonging to the family Tymoviridae. To assess the geographical... more
SUMMARY RT-PCR and dot blot hybridization assays were successfully used for the detection of Olive latent virus 3 (OLV-3), a newly discovered olive-infecting virus belonging to the family Tymoviridae. To assess the geographical distribution of OLV-3, a total of 224 olive samples were collected from eight Mediterranean countries and tested by RT-PCR and dot blot hybridization. According to RT-PCR assay, OLV-3 was detected in all surveyed countries with an overall average infection of 30.4%, ranging from 17% (Portugal) to 56% (Turkey). In 12 of 68 samples (c. 20%) shown to be infected by RT-PCR, dot blot hybridization failed to detect the virus, possibly because of the low concentration of target RNA. Single strand conformation polymorphism (SSCP) analysis of the viral RNA dependent RNA polymerase (RdRp) domain, conducted on the 68 PCR amplicons from infected trees of different geographical origin, yielded eleven heterogeneous patterns. Computerassisted analysis of the RdRp nucleotide...
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The presence of Fig leaf mottle-associated virus 1 (FLMaV-1) and Fig leaf mottle-associated virus 2 (FLMaV-2) was investigated in fig orchards of six Mediterranean countries. A total of 415 samples coming from Albania, Algeria, Lebanon,... more
The presence of Fig leaf mottle-associated virus 1 (FLMaV-1) and Fig leaf mottle-associated virus 2 (FLMaV-2) was investigated in fig orchards of six Mediterranean countries. A total of 415 samples coming from Albania, Algeria, Lebanon, Syria, Tunisia and Italy were collected and tested by PCR, which detected the presence of at least one of the tested viruses in all surveyed countries. Except for Algeria and Syria, where FLMaV-1 was absent, both viruses were found in all surveyed countries with mean infection rates of 34% and 18.5% for FLMaV-1 and FLMaV-2, respectively. More than 7% of the samples were infected with both viruses. As ascertained by dsRNA analysis, 25 out of 65 samples (ca. 38.5%) showed visible bands in polyacrylamide gel electrophoresis. Single strand conformation pattern (SSCP) analysis of a portion of the viral HSP70 gene from figs of different geographical origin showed heterogeneous patterns for both viruses. The HSP70 gene variability was confirmed by sequence ...
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Research Interests:
Research Interests:
Research Interests:
Research Interests: Computer Science and MIMO
Aims and Objectives: The aim of this study was to investigate the effect of exposure times of Coca Cola on enamel’s microhardness, mineral weight, and rate of calcium and phosphate ions discharging from it. Materials and Methods:... more
Aims and Objectives: The aim of this study was to investigate the effect of exposure times of Coca Cola on enamel’s microhardness, mineral weight, and rate of calcium and phosphate ions discharging from it. Materials and Methods: Thirty-two enamel blocks were randomly divided into four groups and exposed to 10mL of their respective solution daily for 7 days, with each group containing eight specimens: Group 1 (enamel blocks exposed to artificial saliva, control group), group 2 (enamel blocks exposed to Coca Cola for 5 minutes), group 3 (enamel blocks exposed to Coca Cola for 10 minutes), and group 4 (enamel blocks exposed to Coca Cola for 30 minutes). Microhardness data (Vickers hardness number [VHN]) and mineral weight were calculated at baseline (sound enamel) and postexposure to Coca Cola. Inductively coupled plasma–optical emission spectrometry (ICP-OES) was utilized to study calcium and phosphate ion percolation from enamel surfaces. Results: Decrease in VHN was directly proportional to exposure time for all experimental groups. Comparison of baseline and postexposure values between control and experimental groups was statistically significant (P < 0.05). Mineral weight of enamel blocks decreased as the exposure time increased for all experimental groups. ICP-OES analysis revealed linear relationship between release of calcium and phosphate ions at 5 and 10 minutes, but at 30 minutes, a decrease in concentration of both ions was observed. Conclusion: The microhardness and mineral weight of enamel decreased linearly with exposure time. The release of calcium and phosphate ions from enamel increased initially but gradually decreased as the exposure time increased.
Research Interests:
Alternative healthcare solutions have been identified as a viable approach to ameliorate the increasing demand for telehealth and prompt healthcare delivery. Moreover, indoor ocalization using different technologies and approaches have... more
Alternative healthcare solutions have been identified as a viable approach to ameliorate the increasing demand for telehealth and prompt healthcare delivery. Moreover, indoor ocalization using different technologies and approaches have greatly contributed to alternative healthcare solutions. In this paper, a cost-effective, radio frequency identification (RFID)-based indoor location system that employs received signal strength (RSS) information of passive RFID tags is presented. The proposed system uses RFID tags placed at different positions on the target body. The mapping of the analysed data against a set of reference position datasets is used to accurately track the vertical and horizontal positioning of a patient within a confined space in real-time. The Euclidean distance model achieves an accuracy of 98% for all sampled activities. However, the accuracy of the activity recognition algorithm performs below the threshold performance for walking and standing, which is due to sim...
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A modified indoor path loss prediction model is presented, namely, effective wall loss model. The modified model is compared to other indoor path loss prediction models using simulation data and real‐time measurements. Different operating... more
A modified indoor path loss prediction model is presented, namely, effective wall loss model. The modified model is compared to other indoor path loss prediction models using simulation data and real‐time measurements. Different operating frequencies and antenna polarizations are considered to verify the observations. In the simulation part, effective wall loss model shows the best performance among other models as it outperforms 2 times the dual‐slope model, which is the second best performance. Similar observations were recorded from the experimental results. Linear attenuation and one‐slope models have similar behavior, the two models parameters show dependency on operating frequency and antenna polarization.