مقاله انگلیسی رایگان در مورد سیستم حسگر هوشمند فعال شده اینترنت اشیا – IEEE 2017

Nitrogen is an important nutrient for plants and is contained in the building blocks of life, such as in nucleotides, amino acids, and proteins [1]. The excessive use of fertilizers, urination due to animal farming, and industrial waste are the significant reasons for nitrate leaching in water [2-7]. Excessive nitrate can hamper aquatic life and can lead to algal blooms and eutrophication [8]. According to the US Environmental Protection Agency (EPA), the maximum allowable nitrate concentration in drinking water should be 44.2 ppm. Over this range of concentration it would be considered as contaminated water [9]. The concentration of nitrate fluctuatesin water, both spatially and temporally. It also depends on the season, weather conditions and the rainfall of any location. Currently, the regional council or local government collects water samples in a routine manner. This is done by expert staff at regular intervals to track the change of nitrate concentration [10]. However, data taken too seldom may not be adequate to measure the actual nitrate profile. There are conventional standard methods available for nitrate measurement, such as UV/Vis spectrometry, chromatography, HPLC and capillary electrophoresis. They are unsuitable for creating a large-scale Wireless Sensor Network (WSN) due to their massive instrumentation, bulky features, complex and sensitive measurement procedure; and above all they are costly. They also produce lots of chemical waste which might be harmful to the environment [11]. A wireless sensor network (WSN) consists of a number of dedicated sensor nodes with physical sensing and computing abilities, which can sense and monitor the surrounding physical parameters. A WSN has a lot of essential characteristics and a few constraints, such as limited energy and computational power. During the last decades, WSNs have been widely used in different applications related to water monitoring [12-14], forests [15, 16], industrial [17, 18], and agricultural [19-22] . Some researches were reported [23-25] to monitor the nitrate concentration through the WSN network [26]. Their limitation was that most of them are laboratory based and perform the real-time analysis in the laboratory only. Juan V. Capella et al. [24] reported in-line analysis of nitrate concentration in river water and emphasized the feasibility of development of wireless sensor networks based continuous monitoring.