Smart Collectors Research Articles

Thermal analysis on a novel natural convection flat plate collector with perforated tilted transparent insulation material parallel slats (TIM-PS) in Mediterranean climate

The purpose of this research is the evaluation of heat transfer by natural convection in an innovative flat plate solar collector operating in natural convection mode. The design consists of inclined, perforated slats of transparent insulation material installed between the absorber and the glass cover. Hourly climatic data on the four specific days of solstices and equinoxes was used to investigate the behavior of the novel collector design in the city of Monastir; Tunisia. A comprehensive process, ANSYS FLUENT, was implemented to properly evaluate the thermal performance of the collector. In order to obtain accurate thermal properties of the smart collector façade unit containing the TIM-PS to exploit in the simulation, a validated three-dimensional finite volume model developed using the CFD software was used to solve the conductive, convective and radiative heat transfer properties of the system. We have explored in depth the effect of optical characteristics of the TIM-PS on the collector performance. Present research focuses on the analysis of thermal efficiency profile of flat plate collector with innovative façade in comparison with conventional collector for different climatic conditions. The analysis indicated that innovative façade collector’s efficiency is highly influenced by solar intensity. It was found that TIM-PS façade can effectively reduce the convective heat losses through the front of collector. The simulation results show that perforated tilted TIM-PS offer better performance than conventional façade of collector during all the seasons of the year. Simulations performed for one year predict that with careful selection of the parallel slats properties, the new façade system can generate an efficiency up to 83% in June, 76% in September, 53% in March and 42% in December. The results of the thermal evaluation of this research will help guide the future development of this system, as we have demonstrated that the innovative façade collector can be used all year round. In conclusion, the TIM-PS have great potential and a very wide range of applications in the field of flat plate solar collector.

Open source IoT-based collection bin applied to local plastic recycling

Plastic waste is a major challenge for policy making; it has a terrible impact on the environment if it is not properly managed. In order to mitigate this issue, recycling industries have emerged with the associated logistics chain that also has an environmental impact, notably with the production of greenhouse gas. In addition to using energy to transform plastic waste into source material, energy is also wasted to transport it. In parallel to reducing plastic waste, it may be recycled at a very local scale, reducing transportation and allowing potential improvement of the collecting process. Assuming that local transformation of plastic waste is possible, this article describes the design, assembly, and setup of the hardware, system architecture, and software of collectors that may be used by these recycling units. The specificity of these collectors is that they produces on-line data related to the quantity of waste collected. Once implemented, a network of smart collectors should allow the reduction of travel to collect waste as it notifies when the collectors are full. It also produces data on the scale of a territory to optimize the supply chain related to plastic waste collection. This article presents the design and engineering aspects as well as limitations induced by technical choices, but also potential improvements for future developments.

Energy Efficient Machine Learning Technique for Smart Data Collection in Wireless Sensor Networks

Performance-centric automated system plays a vital role in next-generation wireless networks. With reduction in size and cost, sensor devices have led to envision a world of ubiquitous wireless sensor networks. Inherent behavior of resource-constrained sensors results in energy-consuming hot spots (such as communication overhead, severe packet collision, network congestion and packet loss) causing premature death of sensor nodes and entire network. In this paper, a novel ‘Monkey Tree Search-based Location-Aware Smart Collector (MTS_LASC)’ that exploits fauna inspired Monkey Tree Search (MTS) behavioral model is explored. The MTS_LASC is an extremely dynamic and fascinating phenomenon comprising distributed smart collectors and a centralized meta-heuristic MTS engine used for solving hard and complex problem. The distributed smart collector is embedded with a client MTS module. It is capable of analyzing, categorizing and aggregating data collected from sensors and disseminating them to the sink using fuzzy inference mechanism, whereas the centralized MTS engine exploits meta-heuristic search to facilitate comprehensive situation awareness through energy-efficient route among multiple paths for crucial decision making in Internet of Things-based applications. Simulation results reveal promising gains with higher delivery ratio by significantly reducing redundant packet transmission and maintaining fidelity through data aggregation. Performance analysis shows that MTS_LASC remains stable even in high traffic-constrained setup as energy degrades more slowly resulting in prolonged network lifetime. By improving the life prospects of the sensor network commendably, the proposed scheme reflects high potential on practical implementation.

Smart collectors: Control of the wettability and floatability of quartz with UV irradiation

Quartz is a hydrophilic mineral that usually associates with other ores. In this paper, the effect of UV stimuli on the wettability and floatability of quartz was studied. An azobenzene-containing surfactant was synthesized and its structure was identified by 1H NMR. We used UV–vis and 1H NMR spectra of the surfactant to study its photoisomerization. After UV irradiation of the surfactant molecular, the trans isomer concentration decreases and the cis isomer concentration increases; both the aromatic protons of the azobenzene moiety and aliphatic protons experience an upfield shift, indicating that the surfactant molecular isomerizes from the trans isomer to the cis form. We used contact angle measurements to demonstrate that UV irradiation decreases the hydrophobicity of the quartz and increases the adhesion tension of the surfactant on quartz. The results of flotation tests demonstrate that the azobenzene-containing surfactant has higher performances than alkyl amine salt, and UV irradiation improves the selectivity of the azobenzene-containing surfactant in the flotation of quartz. This study demonstrates that the azobenzene-containing surfactant can be used as a light-responsive collector for quartz in the flotation of phosphate ores.

Randomization-Based Intrusion Detection System for Advanced Metering Infrastructure*

Smart grid deployment initiatives have been witnessed in recent years. Smart grids provide bidirectional communication between meters and head-end systems through Advanced Metering Infrastructure (AMI). Recent studies highlight the threats targeting AMI. Despite the need for tailored Intrusion Detection Systems (IDSs) for smart grids, very limited progress has been made in this area. Unlike traditional networks, smart grids have their own unique challenges, such as limited computational power devices and potentially high deployment cost, that restrict the deployment options of intrusion detectors. We show that smart grids exhibit deterministic and predictable behavior that can be accurately modeled to detect intrusion. However, it can also be leveraged by the attackers to launch evasion attacks. To this end, in this article, we present a robust mutation-based intrusion detection system that makes the behavior unpredictable for the attacker while keeping it deterministic for the system. We model the AMI behavior using event logs collected at smart collectors, which in turn can be verified using the invariant specifications generated from the AMI behavior and mutable configuration. Event logs are modeled using fourth-order Markov chain and specifications are written in Linear Temporal Logic (LTL). To counter evasion and mimicry attacks, we propose a configuration randomization module. The approach provides robustness against evasion and mimicry attacks; however, we discuss that it still can be evaded to a certain extent. We validate our approach on a real-world dataset of thousands of meters collected at the AMI of a leading utility provider.

Simultaneous observation of gas phase and surface species in photocatalytic reactions on nanosize Au modified TiO 2: The next generation of DRIFTS systems

We have developed the next generation of photocatalytic testing to observe the gas-phase photocatalytic reactions in situ. It is based on modified Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) unit equipped with the Smart Collector system. We have employed UV diode coupled with fiber optics to illuminate the sample while simultaneous collecting the diffuse reflectance spectra. This method was applied to study the NO 2 photocatalytic conversion on nanosize gold modified TiO 2 samples. We have successfully demonstrated that both gas phase and surface adsorbed species can be identified and used to compare activities of various catalysts. We have found that gold nanoparticles have significantly increased the activity of the catalysts for both gas phase and liquid phase oxidation, resulting in more than quadrupling the NO 2 photocatalytic conversion in the gas phase.