Toa

Completely GPS-free positioning systems for wireless, mobile, ad-hoc networks typically stress on
building a network-wide coordinate system. Such systems suffer from lack of mobility and high
computational overhead. On the other hand, specialized hardware in GPS-enabled nodes tends to
increase the solution cost. A number of GPS free position based routing algorithms have been studied by
the authors before proposing a new positioning framework in this paper. The proposed positioning
framework is characterized by using only a handful of GPS enabled nodes. Lower dependence on
specialized GPS hardware reduces the total cost of implementing the framework. A new location aided
routing protocol called Location Aided Cluster Based Energy-efficient Routing (LACBER) has been
proposed in the paper. Simulation results show that using the proposed positioning framework, LACBER
turns out to be efficient in lowering mean hop and hence in utilizing the limited energy of mobile nodes.

In the current scenario location estimation is a very challenging field in case of WSN, as the utility is very high in the WSN application with respect to various aspects. So, a simulation based survey is carried out in this paper using three mostly used range based techniques likely RSSI, TOA & AOA, where the nodes are assumed to be static at the time of computation of their respective locations and some reference nodes are also considered for helping the location calculation, whose coordinates are known prior to the computation and is stored in the sensor nodes database.

Abstract: GPS is a well-established technique for location-finding, but mobile phone-based methods are generally less expensive to implement, and can give reasonable accuracies. These techniques can thus be useful to network operators in providing services based on geographical ...

Abstract—The accuracy of indoor wireless localization systems can be substantially enhanced by map-awareness, i.e., by the knowledge of the map of the environment in which localization signals are acquired. In fact, this knowledge can be exploited to cancel out, at least to some extent, the signal degradation due to propagation through physical obstructions, i.e., to the so called non-line-of-sight bias. This result can be achieved by developing novel localization techniques that rely on proper map-aware statistical modelling of the measurements they process. In this manuscript a unified statistical model for the measurements acquired in map-aware localization systems based on time-of-arrival and received signal strength techniques is developed and its experimental validation is illustrated. Finally, the accuracy of the proposed map-aware model is assessed and compared with that offered by its map-unaware counterparts. Our numerical results show that, when the quality of acquired me...

Adsorption of U (VI) from aqueous solutions was investigated using magnetically assisted chemical separation (MACS) process. In the present study, Triocthylamine (TOA) functionalized magnetite nanoparticles (TOAFMNPs) were applied as a novel adsorbent for adsorption of U (VI) from aqueous solutions. The effects of initial pH, Triocthylamine to magnetite nanoparticles weight ratio, amount of adsorbent, stirring time and initial U(VI) concentration on U(VI) adsorption efficiency were investigated by batch experiments. The adsorption of U(VI) using this adsorbent was pH dependent, and the optimal pH was 5.5. In kinetics studies, the adsorption equilibrium can be reach within 20 min., and the experimental data were well fitted by the pseudo-second-order model. The highest value of U(VI) adsorption (93.8%) was achieved in optimum conditions. The Langmuir isotherm model correlates well with the U(VI) adsorption equilibrium data for the concentration range 10-80 mg/l. The maximum U(VI) ads...

Treatment of major depression, posttraumatic stress disorder and other psychopathologies with antidepressants can be associated with improvement of the cognitive deficits related to these disorders. Although the mechanisms of these effects are not completely elucidated, alterations in the extinction of aversive memories are believed to play a role in these psychopathologies. We have recently verified that female rats present low levels of extinction when submitted to the plus-maze discriminative avoidance task. In the present study, female rats were treated long term with clinically used antidepressants (fluoxetine, nortriptyline or mirtazapine) and subjected to the plus-maze discriminative avoidance task to evaluate learning, memory, extinction and anxiety-related behaviors as well as behavioral despair in the forced swimming test. All groups learned the task and exhibited retrieval. Chronic treatment with fluoxetine (but not with the other antidepressants tested) increased extinct...

Distribution of formic acid (methanoic acid) between water and tri octyl amine (TOA) dissolved in various alcohols (isoamyl alcohol, hexan-1-ol, octan-1-ol, nonan-1-ol, decan-1-ol) as diluents, as well as the extraction capacity of pure diluent alone have been studied at isothermal conditions. All measurements were carried out at 298.15 K. The difference between the physical extraction and reactive extraction was studied. The