An educational tool for enhanced mobile e-Learning for technical higher education using mobile devices for augmented reality

In all dimensions of education and all subjects, Smartphones have turned out to be broadly acknowledged technology. It plays an essential task in advanced online education systems. Because of smart devices� effortlessness and extension property, it is getting to be mandatory for portable applications. This paper analyses the research on Smart Devices (SD) to incorporate visual simulation into e-learning. The researchers created an Augmented Reality (AR) platform for e-learners to expand the coursebook with graphics and virtual multimedia applications. This paper recommends a Mobile e-Learning (MeL) application termed �MeL app. The advanced MeL app methods have been tested using Mann-Whitney �U� Test in the lecture hall using real-time learners. The proposed MeL app planned to create the learning practice easier, focusing on e-learner�s requirements by encouraging e-learners and instructor relationships to maintain communicative development-based e-learning for Technical Higher Education (THE). Software engineering learners assess this proposed framework in THE. Future work in this investigation incorporates new highlights, testing the device in extreme situations, evaluating the instructive perspectives utilizing more significant and increasingly various understudy and beginner inhabitants, and at last, extending the application space

UDTN-RS : A new underwater delay tolerant network routing protocol for coastal patrol and surveillance

The Coastal Patrol and Surveillance Application (CPSA) is developed and deployed to detect, track and monitor water vessel traffic using automated devices. The latest advancements of marine technologies, including Automatic Underwater Vehicles, have encouraged the development of this type of applications. To facilitate their operations, installation of a Coastal Patrol and Surveillance Network (CPSN) is mandatory. One of the primary design objectives of this network is to deliver an adequate amount of data within an effective time frame. This is particularly essential for the detection of an intruder's vessel and its notification through the adverse underwater communication channels. Additionally, intermittent connectivity of the nodes remains another important obstacle to overcome to allow the smooth functioning of CPSA. Taking these objectives and obstacles into account, this work proposes a new protocol by ensembling forward error correction technique (namely Reed-Solomon codes or RS) in Underwater Delay Tolerant Network with probabilistic spraying technique (UDTN-Prob) routing protocol, named Underwater Delay Tolerant Protocol with RS (UDTN-RS). In addition, the existing binary packet spraying technique in UDTN-Prob is enhanced for supporting encoded packet exchange between the contacting nodes. A comprehensive simulation has been performed employing DEsign, Simulate, Emulate and Realize Test-beds (DESERT) underwater simulator along with World Ocean Simulation System (WOSS) package to receive a more realistic account of acoustic propagation for identifying the effectiveness of the proposed protocol. Three scenarios are considered during the simulation campaign, namely varying data transmission rate, varying area size, and a scenario focusing on estimating the overhead ratio. Conversely, for the first two scenarios, three metrics are taken into account: normalised packet delivery ratio, delay, and normalised throughput. The acquired results for these scenarios and metrics are compared to its ancestor, i.e., UDTN-Prob. The results suggest that the proposed UDTN-RS protocol can be considered as a suitable alternative to the existing protocols like UDTN-Prob, Epidemic, and others for sparse networks like CPSN

Pore size distribution in porous glass: fractal dimension obtained by calorimetry

By differential Scanning Calorimetry (DSC), at low heating rate and using a technique of fractionation, we have measured the equilibrium DSC signal (heat flow) $J_q^0$ of two families of porous glass saturated with water. The shape of the DSC peak obtained by these techniques is dependent on the sizes distribution of the pores. For porous glass with large pore size distribution, obtained by sol-gel technology, we show that in the domain of ice melting, the heat flow Jq is related to the melting temperature depression of the solvent, $\Delta T_{\rm m}$ , by the scaling law: $J_q^0\sim \Delta T_{\rm m}^{-(1+D)}$. We suggest that the exponent D is of the order of the fractal dimension of the backbone of the pore network and we discuss the influence of the variation of the melting enthalpy with the temperature on the value of this exponent. Similar D values were obtained from small angle neutron scattering and electronic energy transfer measurements on similar porous glass. The proposed scaling law is explained if one assumes that the pore size distribution is self similar. In porous glass obtained from mesomorphic copolymers, the pore size distribution is very sharp and therefore this law is not observed. One concludes that DSC, at low heating rate ($q\leq 2 ^\circ$C/min) is the most rapid and less expensive method for determining the pore distribution and the fractal exponent of a porous material

Melting of ice in porous glass: why water and solvents confined in small pores do not crystallize?

The melting of ice in porous glass having different distribution of pores sizes is analyzed in details. One shows that confined water crystallizes only partially and that an interface layer, between the ice crystallites and the surface of the pore, remains liquid. Properties of this non crystalline interface at low temperature is studied by NMR and DSC. Both methods lead to an interface thickness h of the order of 0.5 nm, this explains why water do not crystallize when the dimension of confinement is less than a critical length $d^{\ast }\sim 1$ nm. The variation of the melting enthalpy per gram of total amount of water with the confinement length is explained taking into account two effects: a) the presence of this layer of water at the interface and b) the linear variation of the melting enthalpy $\Delta H_{m}$ with the melting temperature Tm. From the data of the literature one draws the same conclusions concerning other solvents in similar porous materials. Also one points out the important role of the glass temperature Tg in preventing the crystallization of the liquids confined in small pores and/or between the crystallites and the surface of the pores

Freezing, melting and dynamics of supercooled water confined in porous glass

International audienceThe freezing, melting and dynamics of supercooled water at different hydration of controlled porous glass (CPG) with mean pore sizes 10 nm, 30 nm, 50 nm and 70 nm are studied using differential scanning calorimetry (DSC) and deuteruim nuclear magnetic resonance (2 H-NMR). For saturated samples, the melting tempertaure follows the Gibbs-Thomson relation despite a clear linear decrease of the melting enthalpy when the transition is shifted due to confinement. For partially filled porous glasses the crystalization and melting temperatures as well as enthalpy are lower than for the saturated samples. 2 H-NMR confirms the existence of a non-crystallizable part of water adsorbed on the surface of pores. At room temperature, spin-lattice relaxation rate (1/T1) is proportional to the inverse of the mean pore size indicating that the relaxation is governed by a surface limited process. At low tempertaure relaxation rate follows the Vogel-Fulcher-Tammann (VFT) relation

Supercooled nano-droplets of water confined in hydrophobic rubber

International audienceHydrophobic elastomers are capable of absorbing a small amount of water that forms droplets around hydrophilic sites. These systems allow the study of confinement effects by a hydrophobic environment on the dynamics and thermodynamic behaviour of water molecules. The freezing–melting properties and the dynamics of water inside nano-droplets in butyl rubber are affected, as revealed by differential scanning calorimetry (DSC) and deuterium nuclear magnetic resonance (2H-NMR). Upon cooling down, all water crystalizes with a bimodal droplet population (da = 3.4 nm and db = 4.4 nm) in a temperature range associated with the droplet size distribution. However, the melting temperature is not shifted according to the Gibbs–Thomson equation. The relative decrease of the 2H-NMR longitudinal magnetization is not a single exponential and, by inverse Laplace transformation, it was deduced to be bimodal in agreement with the DSC measurements (T1,a ∼ 10 ms and T1,b ∼ 200 ms). The deduced correlation time of molecular reorientation is longer than that of bulk water and the behaviour with temperature follows the Vogel-Fulcher-Tammann (VFT) equations with a changing fragility as the droplet size is reduced when reducing hydration