Qualitative design and implementation of human-robot spatial interactions

Despite the large number of navigation algorithms available for mobile robots, in many social contexts they often exhibit inopportune motion behaviours in proximity of people, often with very "unnatural" movements due to the execution of segmented trajectories or the sudden activation of safety mechanisms (e.g., for obstacle avoidance). We argue that the reason of the problem is not only the difficulty of modelling human behaviours and generating opportune robot control policies, but also the way human-robot spatial interactions are represented and implemented. In this paper we propose a new methodology based on a qualitative representation of spatial interactions, which is both flexible and compact, adopting the well-defined and coherent formalization of Qualitative Trajectory Calculus (QTC). We show the potential of a QTC-based approach to abstract and design complex robot behaviours, where the desired robot's behaviour is represented together with its actual performance in one coherent approach, focusing on spatial interactions rather than pure navigation problems

Computationally efficient solutions for tracking people with a mobile robot: an experimental evaluation of Bayesian filters

Modern service robots will soon become an essential part of modern society. As they have to move and act in human environments, it is essential for them to be provided with a fast and reliable tracking system that localizes people in the neighbourhood. It is therefore important to select the most appropriate filter to estimate the position of these persons. This paper presents three efficient implementations of multisensor-human tracking based on different Bayesian estimators: Extended Kalman Filter (EKF), Unscented Kalman Filter (UKF) and Sampling Importance Resampling (SIR) particle filter. The system implemented on a mobile robot is explained, introducing the methods used to detect and estimate the position of multiple people. Then, the solutions based on the three filters are discussed in detail. Several real experiments are conducted to evaluate their performance, which is compared in terms of accuracy, robustness and execution time of the estimation. The results show that a solution based on the UKF can perform as good as particle filters and can be often a better choice when computational efficiency is a key issue

A bank of unscented Kalman filters for multimodal human perception with mobile service robots

A new generation of mobile service robots could be ready soon to operate in human environments if they can robustly estimate position and identity of surrounding people. Researchers in this field face a number of challenging problems, among which sensor uncertainties and real-time constraints. In this paper, we propose a novel and efficient solution for simultaneous tracking and recognition of people within the observation range of a mobile robot. Multisensor techniques for legs and face detection are fused in a robust probabilistic framework to height, clothes and face recognition algorithms. The system is based on an efficient bank of Unscented Kalman Filters that keeps a multi-hypothesis estimate of the person being tracked, including the case where the latter is unknown to the robot. Several experiments with real mobile robots are presented to validate the proposed approach. They show that our solutions can improve the robot's perception and recognition of humans, providing a useful contribution for the future application of service robotics

METAL RECOVERY FROM E-WASTE BY CLAYS AND ACTIVATED CARBON

The growing global population and industrialization are driving an increasing demand for essential resources, particularly in key sectors such as the transition to climate neutrality and the development of innovative technologies. In this context, waste from electrical and electronic equipment (WEEE) represents a significant source of valuable materials. E-waste comprises various types of materials, including critical raw materials, plastics, and precious metals, each with different composition and recovery potential. The strategic raw materials are of particular interest, infact they play a vital role in the development of technologies for climate neutrality, aerospace, and safety sectors. These materials can be recovered and refined from e-waste, providing an alternative to environmentally damaging conventional mining practices. However, a large percentage of e-waste materials are currently discarded or lost, resulting in the waste of valuable metals and resources. To mitigate the environmental impact of traditional mining, several innovative techniques for material recovery are being explored, including pyrometallurgical, hydrometallurgical, and biotechnological methods. Among these, hydrometallurgy offers several promising technologies for metal separation, with solid-liquid adsorption standing out due to its high recovery efficiency, rapid extraction time, and the large quantities of adsorbents that can be utilized. This study investigates the adsorption of metal ions from a complex leachate solution derived from the leaching of milled mobile phone printed circuit boards (PCBs). The solution was analysed via ICP-OES (Inductively Coupled Plasma – Optical Emission Spectroscopy) to determine its composition. The multi-ions leachate was then exposed to two different sorbents, clay and activated carbon, both in their pristine and modified forms, while maintaining a fixed sorbent/solution ratio. ICP-OES analysis of the post-treatment solution allowed for the calculation of uptake efficiency for the different metals contained in the waste. The findings indicate the different behaviour of the sorbents towards the various ions. All the sorbents show the same uptake efficiency (of 100 wt.%) towards tin, while a different affinity is shown towards the uptake of copper: the clay reaches 1 wt.% of efficiency, while the other sorbents exceed 50 wt.%. Additionally, a release experiment was conducted under acidic conditions (pH = 1) to assess the release efficiency of each sorbent. Given that the leachate solution exhibited an extremely high concentration of copper (90 wt.%), a modified experimental setup was proposed, incorporating an electrodeposition step prior to adsorption. This new step significantly reduced the copper concentration from 21.5 g/L down to 1.58 g/L, reducing the amount of metal ions present in the solution

High occurrence of Flavescence dorée phytoplasma early in the season on grapevines infected with grapevine yellows

Research NoteA survey for the presence of phytoplasmas associated with grapevine yellows in about 500 Italian vineyards was conducted from 1999 to 2004. Grapevines with the earliest symptoms were mostly infected with Flavescence dorée type C phytoplasma (FD-C). As the season advanced, a steady relative decrease in the occurrence of FD-C coincided with a clear relative increase in Bois noir phytoplasma. The relative occurrence of Flavescence dorée type D phytoplasma remained stable.

Structure–function relationship during the early and long-term hydration of one-part alkali-activated slag

Understanding the mechanisms controlling the early (fresh) and long-term (hardened) hydration of one-part alkali-activated slags (AAS) is key to extend their use as low CO2 substitutes for ordinary Portland cement (OPC). Their “just add water” use makes them easier and less hazardous to manipulate than the more studied two-part ones. This is due to the absence of liquid alkaline activators, which are environmentally and energy demanding. In this work, numerous experimental techniques have been linked to obtain a comprehensive physico-chemical characterization of a one-part AAS activated with Na2CO3 and Ca(OH)2 powders at several water to solid ratios (w/s). Calorimetry and pH/conductivity measurements describe the functioning of the activators immediately after contact with water. Early reactivity is characterized through in situ X-ray powder diffraction (XRPD) and small amplitude oscillatory shear (SAOS) rheology, which reveal a rapid precipitation of nanometric hydration products (nano-C-A-S-H), which results in a continuous increase in the paste cohesivity until setting. Moreover, SAOS shows that rejuvenating the paste by means of shearing (performed externally to the rheometer in this study) is enough to restore the initial cohesion (i.e., workability) for long time spans until setting occurs. The long-term hydration is characterized by ex situ XRPD on aged AAS pastes, in parallel with mechanical testing on AAS mortar. A correlation can be observed between the amount of nano-C-A-S-H and the increase in compressive strength. Overall, this formulation shows satisfactory fresh and solid properties, demonstrating suitability for low- and normal-strength applications

Stress detection using wearable physiological and sociometric sensors

Stress remains a significant social problem for individuals in modern societies. This paper presents a machine learning approach for the automatic detection of stress of people in a social situation by combining two sensor systems that capture physiological and social responses. We compare the performance using different classifiers including support vector machine, AdaBoost, and k-nearest neighbour. Our experimental results show that by combining the measurements from both sensor systems, we could accurately discriminate between stressful and neutral situations during a controlled Trier social stress test (TSST). Moreover, this paper assesses the discriminative ability of each sensor modality individually and considers their suitability for real time stress detection. Finally, we present an study of the most discriminative features for stress detection

Environmental sensitivity mapping to oil spill and response actions for shoreline and portuary zone of Imbituba, SC, Brazil

Environmental Sensitivity Index maps (ESI) have been produced for the shoreline of Imbituba, located in the southern coast of Santa Catarina State, Brazil, in the scales of 1:50,000 and 1:10,000. Adequate cleanup procedures were selected and indicated for each coastal segment identified, in accordance to expected oil behavior in each one. The study area comprises an important environmental protection area for right whales (Eubalaena glacialis) reproduction. The ESI maps include information for three main components: sensitive biological resources, human-uses resources and shoreline habitats. Data of biological resources and some human-use information were obtained from an integrated project named Environmental Sensitivity Index Maps of Santos Sedimentary Marine Basin. Shoreline habitats data were obtained in field survey. Methodology applied was that proposed by the Brazilian Environment Ministry (MMA), adapted from the National Oceanic and Atmosphere Administration (NOAA), with the aid of remote sensing and geographical information system (SIG). Twenty segments were identified in the study area, comprising 15 km of shoreline. Only 6 different ESI were identified, with the most representative in extension being the ESI 3 (dissipative exposed beaches)

Capture and Release Mechanism of Ni and La Ions via Solid/Liquid Process: Use of Polymer-Modified Clay and Activated Carbons

open6noThis study is a starting point for the development of an efficient method for rare earths (REs) and transition metals (TMs) recovery from waste electrical and electronic equipment (WEEE) via a hydrometallurgical process. The capture and release capability of mineral clays (STx) and activated carbons (AC), pristine and modified (STx-L6 and AC-L6) with a linear penta-ethylene-hexamine (L6), towards solutions representative of the process, are assessed in the lab-scale. The solids were contacted with synthetic mono-and bi-ionic solutions containing Ni(II) and La(III) in a liquid/solid adsorption process. Contacting experiments were carried out at room temperature for 90 min by fixing a La concentration at 19 mM and varying the Ni one in the range of 19–100 mM. The four solids were able to capture Ni(II) and La(III), both in single-and bi-ionic solutions; however, the presence of the polyamine always results in a large improvement in the capture capability of the pristine sorbents. For all the four solids, capture behaviour is ascribable to an adsorption or ion-sorbent interaction process, because no formation of aquo-and hydroxy-Ni or La can be formed. The polyamine, able to capture Ni ions via coordination, allowed to differentiate ion capture behaviour, thus bypassing the direct competition between Ni and La ions for the capture sites found in the pristine solids. Release values in the 30–100% range were found upon one-step treatment with concentrated HNO3 solution. However, also, in this case, different metals recovery was found depending on both the sorbent and the ions, suggesting a possible selective recovery.openCristiani C.; Bellotto M.; Dotelli G.; Stampino P.G.; Latorrata S.; Finocchio E.Cristiani, C.; Bellotto, M.; Dotelli, G.; Stampino, P. G.; Latorrata, S.; Finocchio, E