A Survey on the Use of the Internet of Multimedia Things for Precision Agriculture and the Agrifood Sector

The Internet of Things (IoT) has already penetrated an ever-increasing array of daily aspects of life. IoTs bridge the analog and digital worlds in an unprecedented manner and degree by providing in situ sensing. Adding to the IoT the capability to collect interrelated multi-modal sensing, the use of the Internet of Multimedia Things (IoMTs) has recently been exhibited to significantly enhance the role of Information and Communication Technologies (ICT) in numerous applications, and most importantly in agrifood systems. In this work, we review key recent works in the conjunction of the three domains of IoMT, agrifood and precision agriculture and present open research directions.

In Situ Monitoring of Powder Bed Fusion Homogeneity in Electron Beam Melting

Increasing attention has been devoted in recent years to in situ sensing and monitoring of the electron beam melting process, ranging from seminal methods based on infrared imaging to novel methods based on backscattered electron detection. However, the range of available in situ monitoring capabilities and solutions is still quite limited compared to the wide number of studies and industrial toolkits in laser-based additive manufacturing processes. Some methods that are already industrially available in laser powder bed fusion systems, such as in situ detection of recoating errors, have not yet been investigated and tested in electron beam melting. Motivated by the attempt to fill this gap, we present a novel in situ monitoring methodology that can be easily implemented in industrial electron beam melting machines. The method is aimed at identifying local inhomogeneity and irregularities in the powder bed by means of layerwise image acquisition and processing, with no external illumination source apart from the light emitted by the hot material underneath the currently recoated layer. The results show that the proposed approach is suitable to detect powder bed anomalies, while also highlighting the link between the severity of in situ detected errors and the severity of resulting defects in the additively manufactured part.

Earth Observation Data-Driven Cropland Soil Monitoring: A Review

We conducted a systematic review and inventory of recent research achievements related to spaceborne and aerial Earth Observation (EO) data-driven monitoring in support of soil-related strategic goals for a three-year period (2019–2021). Scaling, resolution, data characteristics, and modelling approaches were summarized, after reviewing 46 peer-reviewed articles in international journals. Inherent limitations associated with an EO-based soil mapping approach that hinder its wider adoption were recognized and divided into four categories: (i) area covered and data to be shared; (ii) thresholds for bare soil detection; (iii) soil surface conditions; and (iv) infrastructure capabilities. Accordingly, we tried to redefine the meaning of what is expected in the next years for EO data-driven topsoil monitoring by performing a thorough analysis driven by the upcoming technological waves. The review concludes that the best practices for the advancement of an EO data-driven soil mapping include: (i) a further leverage of recent artificial intelligence techniques to achieve the desired representativeness and reliability; (ii) a continued effort to share harmonized labelled datasets; (iii) data fusion with in situ sensing systems; (iv) a continued effort to overcome the current limitations in terms of sensor resolution and processing limitations of this wealth of EO data; and (v) political and administrative issues (e.g., funding, sustainability). This paper may help to pave the way for further interdisciplinary research and multi-actor coordination activities and to generate EO-based benefits for policy and economy.

In-Situ Sensing of Underwater Gas Releases

The O&G industry has been producing hydrocarbons from subsea reservoirs for several decades. However, there is a technological gap in the ability to reliably detect and quantify dissolved gases within the water column. This technological gap has in turn led to a scientific gap in our ability to determine the subsurface origin of subsea fluid emissions. Gas releases are commonly found in the marine environment primarily because of naturally occurring seeps and occasionally due to Oil and Gas production activities. There is a need to be able to identify the gas composition and accurately characterize its source (i.e., ongoing microbial activity or thermogenic derived hydrocarbons). However, building a reliable solution which allows this differentiation between thermal and microbial sources in the underwater environment as well as the inference of their subsurface origin requires a multi-disciplinary subsurface workflow coupled comprehensive high-fidelity measurements at the seabed. As one of the front-end building blocks of any robust multi-disciplinary workflow, there is a need for development of an in-situ sensing and sampling capability which allows real-time assessment and geological characterization of the underwater emissions across the upstream industry, from exploration to abandonment. Such a capability would also be complementary to the geohazard and subsurface assessment practices e.g., by reducing lost rig time during interventions by allowing quick characterization of emissions that arise from natural seeps or LOPC (Loss of Primary Containment) events. This paper describes the maturation of a compact underwater in-situ sensing technology deployed from autonomous or tethered underwater vehicles and which enables measurements of gas constituents and their respective isotopes at the seabed.

Conductive Electrospun Nanofibers for Multifunctional Portable Devices

The need to perform in situ sensing measurements lead to the development of innovative and smart field-portable devices. The advantages of such systems are remarkable since they are mainly battery-powered, lightweight and easy to carry and keep. Moreover, field-portable devices are easy to use and are able to give fast sensing responses. In the last few years, many efforts have been made in the development of new performing systems and the advantageous use of nanofibrous materials was assessed. To this purpose, the electrospinning has been recognized as the most powerful and facile technique for generating uniform nanofibers with controlled dimension and morphology. When conductive polymers are electrospun, very interesting electrical properties can be obtained along with the well-known ones that are typical of nanofibers. Among these polymers, polyaniline has been extensively used. In this work, an innovative hybrid material based on polyaniline/polyvinyl acetate/graphene oxide nanofibers was developed and tested as a sensor toward the detection of contaminants in aqueous media. Nanofibers, in the form of a compact mat, were deposited onto a support with suitable electrical contacts. Measurements were performed exploiting the excellent electrical properties of the realized nanofibers in both direct and alternating currents. When a direct current was used, the change in the nanofibers’ resistance value was registered upon exposure to contaminated aqueous solutions and used to determine the presence or absence of contaminants, whereas when tests were performed with an alternating current, the quantitative determination of single species in contaminated solutions was also possible. In this way, by integrating the two different measurement methodologies, an opportunely designed multifunctional portable device will be developed for both qualitative and quantitative contaminants determinations.

An Unmanned Lighter-Than-Air Platform for Large Scale Land Monitoring

The concept and preliminary design of an unmanned lighter-than-air (LTA) platform instrumented with different remote sensing technologies is presented. The aim is to assess the feasibility of using a remotely controlled airship for the land monitoring of medium sized (up to 107 m2) urban or rural areas at relatively low altitudes (below 1000 m) and its potential convenience with respect to other standard remote and in-situ sensing systems. The proposal includes equipment for high-definition visual, thermal, and hyperspectral imaging as well as LiDAR scanning. The data collected from these different sources can be then combined to obtain geo-referenced products such as land use land cover (LULC), soil water content (SWC), land surface temperature (LSC), and leaf area index (LAI) maps, among others. The potential uses for diffuse structural health monitoring over built-up areas are discussed as well. Several mission typologies are considered.