On Modeling Geometric Joint Sink Mobility with Delay-Tolerant Cluster-less Wireless Sensor Networks

Moving Sink (MS) in Wireless Sensor Networks (WSNs) has appeared as a blessing because it collects data directly from the nodes where the concept of relay nodes is becomes obsolete. There are, however, a few challenges to be taken care of, like data delay tolerance and trajectory of MS which is NP-hard. In our proposed scheme, we divide the square field in small squares. Middle point of the partitioned area is the sojourn location of the sink, and nodes around MS are in its transmission range, which send directly the sensed data in a delay-tolerant fashion. Two sinks are moving simultaneously; one inside and having four sojourn locations and other in outer trajectory having twelve sojourn locations. Introduction of the joint mobility enhances network life and ultimately throughput. As the MS comes under the NP-hard problem, we convert it into a geometric problem and define it as, Geometric Sink Movement (GSM). A set of linear programming equations has also been given in support of GSM which prolongs network life time

Assessment of Groundwater Quality in the Al Khatim and Remah Area of the United Arab Emirates

Groundwater constitutes an important part of the available water resources in arid areas. Knowledge of the quantitative and qualitative status of groundwater is a key aspect in optimal groundwater management. The chemical characteristics of groundwater in two neighboring areas (Remah and Al Khatim) have been used to identify the processes controlling groundwater chemistry in the sand aquifer of Abu Dhabi Emirate, United Arab Emirates. Furthermore, the suitability of the groundwater for agricultural purposes was assessed using a range of indices. Both areas showed elevated levels of nitrate, potassium and cadmium, indicating the impact of agricultural activities. The groundwater was found to be unfit for agricultural purposes as explained by the agricultural indices. Radon causes lung cancer when inhaled or ingested in higher concentration. The radioactive study of Radon-222 showed its concentration below the WHO permissible guidelines. However, considering that groundwater is the only available water source for irrigation, it will continue to be used for agriculture. This study therefore provides valuable technical support for farmers, decision makers and other stakeholders to develop strategies for sustainable groundwater development in the context of food security

Studies on the Measurement of Extractable and Mineralizable Nitrogen in Soil

The different potassium salts which are used for the extraction of inorganic nitrogen from soils contain variable and often high amounts of ammonium and nitrate nitrogen which could introduce an error in the analysis of low levels of soil inorganic nitrogen. The potassium salt solutions can be purified of ammonium nitrogen by increasing the pH to 11.0 with a solution of potassium hydroxide and then boiling and stirring for 15 minutes. The pH is then readjusted to pH 5.5 - 6.0 with a dilute acid. There is no simple method for the removal of nitrate nitrogen and therefore, it is suggested that a batch number with low nitrate nitrogen content be used for the extraction of soil. Different grades and batches of filter papers also contain variable amounts of ammonium and nitrate nitrogen which needs removing before use for the filtration of soil extracts. Ammonium and nitrate nitrogen can be removed from the filter papers by washing with 50 cm of 0.5 M potassium sulphate in 2 lots each of 25 cm3 , then rinsing twice with deionised water and drying for 4 hours at 7

On Energy Efficiency and Delay Minimization in Reactive Protocols in Wireless Multi-hop Networks

In Wireless Multi-hop Networks (WMhNs), routing protocols with energy efficient and delay reduction techniques are needed to fulfill users demands. In this paper, we present Linear Programming models (LP_models) to assess and enhance reactive routing protocols. To practically examine constraints of respective LP_models over reactive protocols, we select AODV, DSR and DYMO. It is deduced from analytical simulations of LP_models in MATLAB that quick route repair reduces routing latency and optimizations of retransmission attempts results efficient energy utilization. To provide quick repair, we enhance AODV and DSR. To practically examine the efficiency of enhanced protocols in different scenarios of WMhNs, we conduct simulations using NS- 2. From simulation results, enhanced DSR and AODV achieve efficient output by optimizing routing latencies and routing load in terms of retransmission attempts

HEER: Hybrid Energy Efficient Reactive Protocol for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) consist of numerous sensors which send sensed data to base station. Energy conservation is an important issue for sensor nodes as they have limited power.Many routing protocols have been proposed earlier for energy efficiency of both homogeneous and heterogeneous environments. We can prolong our stability and network lifetime by reducing our energy consumption. In this research paper, we propose a protocol designed for the characteristics of a reactive homogeneous WSNs, HEER (Hybrid Energy Efficient Reactive) protocol. In HEER, Cluster Head(CH) selection is based on the ratio of residual energy of node and average energy of network. Moreover, to conserve more energy, we introduce Hard Threshold (HT) and Soft Threshold (ST). Finally, simulations show that our protocol has not only prolonged the network lifetime but also significantly increased stability period.Comment: 2nd IEEE Saudi International Electronics, Communications and Photonics Conference (SIECPC 13), 2013, Riyadh, Saudi Arabi