Alessandro Pozzebon

On the displacement of marked pebbles on two coarse-clastic beaches during short fair-weather periods (Marina di Pisa and Portonovo, Italy)

The aim of the investigation was to define the mechanisms of sediment transport in the swash zone of microtidal coarse-clastic beaches in the very short term by evaluating the displacement rates of marked pebbles under low-energy wave conditions. Tests were performed at two sites (Marina di Pisa, Ligurian Sea, and Portonovo, central Adriatic Sea) to check the consistency of the data over a range of different grain sizes. Two recovery campaigns were carried out at both sites, one 6 h and the other 24 h after the injection. During the experiments wave action was at a minimum (wave heights never exceeded 0.3 m). The results show that 20% of pebbles ranging in diameter from 30–90 mm moved significantly (more than 0.5 m) already 6 h after the injection, with some tracers being lost (3%). After 24 h, 40% of the pebbles were significantly displaced and 10% were lost. The preferential downslope movement of tracers, which suggests that coarse sediment movement under low-energy conditions is mainly controlled by gravity processes enhanced by steep beachface slopes, represents the novelty of the results reported here. It would appear that swash processes on low-energy beaches cause a significant rate of pebble displacement through the destabilization induced by wave uprush and backwash. Despite the microtidal range, the position of the mean water level plays a major role in changing the beach level at which swash processes can actually trigger pebble movement. The results of this study show that considerable, and mostly seaward-directed, coarse sediment transport takes place even during short fair-weather periods.

An RFID Based System for the Underwater Tracking of Pebbles on Artificial Coarse Beaches

Coastal erosion represents one of the most significant environmental emergencies, due to the fact that it affects locations distributed all over the world, including tourist sites and urban centers. Several solutions have been studied during the last years, including the use of gravel beaches as shore protections against the effects of waves. These solutions seem to provide a good protection, but efficient studies on the movement of sediments are very difficult to be performed due to the absence of effective technical solutions. In this article we propose the use of RFID automatic identification technology to keep trace of single pebbles shifting on a gravel beach. The tracking operations are made possible in the sea as well as on the beach providing a tool to perform accurate and global studies on the dynamics of artificial coarse beaches for what concerns both its under and outside water sectors.

In situ abrasion of marked pebbles on two coarse-clastic beaches (Marina di Pisa, Italy)

In this paper pebbles marked by passive integrated transpon ders from two artificial coarse-grained beaches at Marina di Pisa (Tuscany, Italy) were analyzed in order to measure the in situ abra sion rate. The beaches (Cella 7 and Barbarossa) were set up in 2006 as a form of coastal protection. They are both composed of pebbles (30-to-90 mm diameter) and bounded longshore by huge groynes. They differ in length (250 m and 110 m respectively) and in the prese nce of an additional defense structure, a submerged breakwater 50 m off the coastline, at Cella 7. The aim of the study is to reckon the abrasion rate of individual pebbles and evaluate abrasion differen ces of pebbles released on Cella 7 and on Barbarossa. The RFID technology (Radio Frequency Identification) was used to track the pebbles due to its reliability and limited costs. The tracers were released on the beaches in March 2009 along closely-spaced crossshore transects. The recovery campaign was carried out in May 2009. A total of 127 pebbles was detected, 83 of which were recov ered. Huge beach reworking during the storms determined high burial rates and consequently the loss of a definite amount of tracers. The pebbles that were recovered showed a significant increase in roundness, in particular the tracers that were released on Bar barossa. The average pebble weight loss measured at Cella 7 was slightly lower, which means lower mobilization rate at this site rather than at Barbarossa. The resulting values are significant considering the short time frame of the research (two months) and the limited energy of the storms occurred during the experiment.

Near Field Communication and Health: Turning a Mobile Phone into an Interactive Multipurpose Assistant in Healthcare Scenarios

In this paper we discuss the introduction of the Near Field Communication (NFC) technology in the management of the assistance operations in the hospitals. NFC is a new short range communication system based on RFID technology.

RFID Under Water: Technical Issues and Applications

While RFID technology is nowadays very common in many commercial and industrial sectors, from items tracking to personal identification, few studies have dealt with the chance to use RFID systems in marine or fluvial environments for underwater monitoring operations. While the technical limitations for these scenarios can be in some cases insur‐ mountable, ad-hoc studies have proven that in some cases RFID technology can work even under water.

A 3D virtual tour of the Santa Maria della Scala Museum Complex in Siena, Italy, based on the use of Oculus Rift HMD

In this paper we present the realization of a 3D virtual museum tour through the use of paired full-panoramas, to be displayed using the Head-Mounted Display “Oculus Rift”. The paper analyzes in details every stage of the project, from the starting point, i.e. the collection of the required images, to the end, that is the creation of the tour itself. The proposed solution is conceived to be developed using off-the-shelf devices in order to be easily replicated in other contexts: in particular, image capture is performed using two paired GoPro Hero 3 cameras. While this solution can be applied in several different scenarios this paper focuses on the development of a virtual reproduction of the Santa Maria della Scala Museum Complex in Siena, Italy.

An Analysis of the Performances of Low Frequency Cylinder Glass Tags for the Underwater Tracking of Pebbles on a Natural Beach

In this paper we provide the results of a two months experimentation of Low Frequency RFID technology for the sediments tracking on a beach close to Ancona, Italy. For this experimentation, cylinder glass tags were used, modifying a previous solution based on the use of plastic disc tags. While the use of Low Frequency RFID as a technology to monitor the movements of sediments under and outside water on beaches subject to high coastal erosion phenomenons was already been tested before and described in previous papers, the use of glass tags was not introduced until this last experimentation due to the fragile nature of these devices that discouraged from their use. Anyway, their use was finally encouraged from the goods results obtained from laboratory test concerning their reading range and their ease of use. The results provided in this paper show that cylinder glass tags are probably the best solution for the tracking of pebbles movements.

Possible configurations and geometries of long range HF RFID antenna gates

In this article we discuss the realization of antenna gate structures for Inductively Coupled Passive HF RFID Systems. Antenna gates are currently used in several applications, from industrial tracking to access control: in these structures the identification process is realized with the use of more antennas disposed in a configuration that makes them similar to doors. Nowadays these structures can reach a maximum width of 1.50–1.60 meters due to the limitations deriving from the CEPT ERC Recommendation 70-03 annex 9 on electromagnetic emissions from electronic devices. Next to this, limitations also derive from the decrease of the electromagnetic field with the distance and from physical constrains due to the fact that the field strength is proportional to the dimensions of the antennas. The purpose of this article is to describe a possible optimum configuration of antennas allowing the detection of tags across a 2 meters wide gate reducing as much as possible its dimensions.

A Low Power IoT Sensor Node Architecture for Waste Management Within Smart Cities Context

This paper focuses on the realization of an Internet of Things (IoT) architecture to optimize waste management in the context of Smart Cities. In particular, a novel typology of sensor node based on the use of low cost and low power components is described. This node is provided with a single-chip microcontroller, a sensor able to measure the filling level of trash bins using ultrasounds and a data transmission module based on the LoRa LPWAN (Low Power Wide Area Network) technology. Together with the node, a minimal network architecture was designed, based on a LoRa gateway, with the purpose of testing the IoT node performances. Especially, the paper analyzes in detail the node architecture, focusing on the energy saving technologies and policies, with the purpose of extending the batteries lifetime by reducing power consumption, through hardware and software optimization. Tests on sensor and radio module effectiveness are also presented.

Architecture of a hydroelectrically powered wireless sensor node for underground environmental monitoring

This study describes a sensor node powered by an energy harvesting method based on the watermill principle. This method is suitable whenever a sensor node has to be deployed in the nearby of an underground water line, such as a drainage system or an aqueduct. The operating scenario for whom this solution has been developed and employed is a wireless sensor network for the monitoring of the environmental conditions of the so-called ‘Bottini’ in Siena, Italy. The ‘Bottini’ is a network of medieval aqueducts dug in the underground of the historic centre of the city, in which water still flows nowadays. Using the proposed energy harvesting system the sensor nodes are able to operate independently, minimising the maintenance and allowing the real-time monitoring of environmental parameters, thanks, in order to manage the preservation of this ancient site. The entire system is composed of three parts: the power generation system, the data acquisition system and the wireless transmission system. The whole architecture has been tested in the operating scenario, precisely in ‘Fontebranda’, one of the biggest fountains in the ‘Bottini’ network.