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In agriculture, automation of spraying has boosted farm productivity. As a result, the labor issue has been resolved. However, the situation is different in a nation like Pakistan. Automation in the agricultural sector is challenging in these arid regions because the most Pakistani farmers are struggling financially. Therefore, the wide use of the manually operated sprayer is still common in majority of the areas of Pakistan. Due to its affordability, design, and versatility, manually lever driven backpack sprayers are much sought after by small-scale farmers. Two types of sprays are utilized in Pakistani farms: fuel-operated pumps and hand-operated ones. The primary disadvantage of a hand-operated spray pump is that its user cannot use it continuously for longer than five to six hours. Due to fatigue, long working hours are impossible without integration of any other energy, but a gasoline-operated spray pump needs fuel, which is costly and difficult to find in remote areas. Therefore, the work represents the integration of renewable energy (solar power) and a manually operated mechanism to achieve sustainability with increased efficiency and reduced human efforts. It is observed from the results that around 2.5 times increased discharge was achieved, and time is reduced by 2.5 times. The proposed idea drives a solar powered multi-nozzle with pump, which sprays pesticide uniformly, along with environmental benefits. In result, pesticide sprayer reduces farmer fatigue and sprays at its highest pace in the shortest amount of time without requiring fuel.

In the majority of Internet of Things (IoT) applications, persistent and stable operation is a crucial requirement. While environmental energy-harvesting technologies can enhance IoT's persistence, they do not guarantee stability. Therefore, we aim to address the stability challenges in solar-powered IoT (SP-IoT) by employing wireless power transmission (WPT) through unmanned aerial vehicles (UAVs). This study focuses on determining the optimal charging mobility of drones for WPT to enhance the stability of nodes operating in a wide area network (WAN)-based SP-IoT environment. The proposed scheme identifies nodes with insufficient solar energy harvesting and defines the optimal charging mobility parameters (hovering position, hovering time, and moving path) to efficiently transmit the drone's energy to these nodes in a balanced manner. The experimental results confirm that the proposed scheme significantly improves the stability of solar-powered IoT nodes by optimally utilizing the limited energy of the drone. [ABSTRACT FROM AUTHOR]

Greenhouse technology is crucial for combating climate change and enhancing off-season produce and crop yield. Dust build-up on greenhouse roofs remains a significant problem, significantly reducing light transmission and affecting plant growth. Therefore, this study aims to classify dust build-up on greenhouse roofs and to address it by designing, manufacturing, operating, and evaluating a solar-powered cleaning robot system. Water and cement removal agent (CRA) with different mixing ratios were selected to clean the greenhouse roof. The initial findings demonstrate the greenhouse cover's ability to allow light to pass through can differentiate between different levels of dust accumulation. This study reveals that 88 %–93 % of transmittance levels indicate a clean roof, 82 %–87 % reveal minor dust accumulation, 81 %–75 % denote moderate dust accumulation, and below 75 % signify major dust accumulation. This increased the efficiency of the light intensity for minor dust roofs from 39,285 to 41,731 lux ((CRA) 1:3 water), moderate dust roofs from 36,777 to 39,383 lux ((CRA) 1:1 water), and major dust roofs from 30,585 to 35,525 lux (CRA). The results show a substantial improvement in light transmittance from 88 % to 93 % for clean roofs, compared to much lower levels for dust-accumulated roofs.

This paper presents an overall scheme of a long-endurance small solar-powered convertible unmanned aerial vehicle (CUAV) that operates tilt-rotor for multiple hover tasks. First, a solar/battery hybrid energy strategy was proposed to comprehensively meet the requirements of CUAVs with long endurance and multiple hovers. The particular ability of the solar-powered fixed-wing unmanned aerial vehicle (UAV), pure battery-powered CUAV, and the proposed long-endurance solar-powered CUAV with multiple cruises and hovers were comparatively analyzed from an energy standpoint. Second, a suitable conceptual design method and process for small solar-powered CUAV was given, and the robustness of the designed CUAV was using three performance metrics under nominal conditions. The approach was then applied to design a 6.5 kg CUAV, which was initially tested in flight. Finally, the performance and application potential of the designed CUAV was evaluated with operating conditions, mission requirements, energy input, and perpetual flight capability. [ABSTRACT FROM AUTHOR]

This article presents novel research on the utilization of a neural-network-based time control system for microwave oven heating of food items within a solar-powered vending machine. The research aims to explore the control of heating time for various food products, considering multiple variables. The neural network controller is calibrated through extensive experimentation, allowing it to accurately predict optimal heating times based on input parameters such as food type, weight, initial temperature, water content, and desired doneness level. The results demonstrate that the neural-network-controlled microwave oven achieves precise and desirable heating durations, mitigating the risk of overheating and ensuring superior food quality and taste. Moreover, the solar-powered vending machine showcases a commitment to sustainable energy sources, effectively reducing dependence on non-renewable energy and minimizing greenhouse gas emissions. To maintain food quality and freshness, a food refrigeration unit is integrated into the vending machine, employing load-balancing technology to control the refrigeration chamber's temperature effectively. Energy efficiency is prioritized in both the refrigeration unit and the microwave oven through intelligent algorithms and system optimization. The combination of a neural-network-controlled microwave oven, a solar-powered vending machine, and a food refrigeration unit introduces a novel and sustainable approach to food preparation and energy management. [ABSTRACT FROM AUTHOR]

In the majority of Internet of Things (IoT) applications, persistent and stable operation is a crucial requirement. While environmental energy-harvesting technologies can enhance IoT’s persistence, they do not guarantee stability. Therefore, we aim to address the stability challenges in solar-powered IoT (SP-IoT) by employing wireless power transmission (WPT) through unmanned aerial vehicles (UAVs). This study focuses on determining the optimal charging mobility of drones for WPT to enhance the stability of nodes operating in a wide area network (WAN)-based SP-IoT environment. The proposed scheme identifies nodes with insufficient solar energy harvesting and defines the optimal charging mobility parameters (hovering position, hovering time, and moving path) to efficiently transmit the drone’s energy to these nodes in a balanced manner. The experimental results confirm that the proposed scheme significantly improves the stability of solar-powered IoT nodes by optimally utilizing the limited energy of the drone.

In this paper, a performance evaluation of a developed Solar-Powered Vapor Absorption Refrigeration (VAR) System using the NH3-H2O solution as a working fluid is done. The cooling system has a total storage space of 0.038 m³ with the capacity to accommodate about 0.04 metric tonnes (40kg) of items, such as cool water and other drinks for human comfort, applicable in rural regions where electricity is unreliable or non-existent. A solar Photovoltaic (PV) panel of 300W, 40 W Direct Current (DC) heating element with a 20A solar controller was designed to power the developed cooling system. Measurements of important operational parameters such as the generator, ambient, evaporator, cabinet and condenser temperatures were studied and measured from the system. Performance evaluation of the system refrigerating capacity was determined in terms of its cooling performance (COP) and the system efficiency ratio (?) based on no load and on load conditions. The system, when tested, has COP of 0.1275 at an average cabinet temperature (Tr) of 9.0 °C against an average room temperature of 25.8 °C. Additionally, the system had an overall refrigerating efficiency ratio of 8.25. The performance test results revealed that the developed cooling system performed well in terms of temperature regulation for refrigeration purposes. [ABSTRACT FROM AUTHOR]

This article presents novel research on the utilization of a neural-network-based time control system for microwave oven heating of food items within a solar-powered vending machine. The research aims to explore the control of heating time for various food products, considering multiple variables. The neural network controller is calibrated through extensive experimentation, allowing it to accurately predict optimal heating times based on input parameters such as food type, weight, initial temperature, water content, and desired doneness level. The results demonstrate that the neural-network-controlled microwave oven achieves precise and desirable heating durations, mitigating the risk of overheating and ensuring superior food quality and taste. Moreover, the solar-powered vending machine showcases a commitment to sustainable energy sources, effectively reducing dependence on non-renewable energy and minimizing greenhouse gas emissions. To maintain food quality and freshness, a food refrigeration unit is integrated into the vending machine, employing load-balancing technology to control the refrigeration chamber’s temperature effectively. Energy efficiency is prioritized in both the refrigeration unit and the microwave oven through intelligent algorithms and system optimization. The combination of a neural-network-controlled microwave oven, a solar-powered vending machine, and a food refrigeration unit introduces a novel and sustainable approach to food preparation and energy management.

Solar power is a popular option for powering Unmanned Aerial Vehicles (UAVs) due to its ability to provide power for long-endurance flight. However, solar-powered UAVs face challenges, including operational reliability problems. To address their operational reliability issues, this paper proposes an automatic solar tracker system and tests two implementation strategies for controlling a tandem-winged and solar-powered UAV, developed by the Faculty of Mechanical and Aerospace Engineering, Institut Teknologi Bandung. Due to its unconventional configuration, a mathematical model for the UAV is developed to evaluate the vehicle’s dynamic characteristics. Based on these, three feedback control systems are designed, i.e., roll attitude control, a heading tracker, and a solar tracker. Two implementation strategies are proposed to combine the control systems, i.e., the mode-switching and the simultaneous tracking strategies. A series of simulations are then conducted to check the vehicle’s overall flight performance, as well as the gathering of solar energy. The mode-switching strategy was able to gather up to 13% more solar energy than the simultaneous strategy, which could only reach slightly above 2%. Mode-switching, however, resulted in a shorter range compared to the latter, due to the time spent in the charging mode, flying in a circular pattern.

This study utilized the Solar Powered Multi-Network Greenhouse through microcontrollers and IoT-based application to design an automated mushroom monitoring and management system. As mushrooms are more to suffer from increased temperature especially in tropical countries like the Philippines, this study develops an automated system where composition is controlled by a microcontroller and monitored by Arduino IDE. The greenhouse monitoring device used different highly-capable sensors, which provides accurate parameters used for monitoring systems and better control management for cultivation. The different possible solutions to control parameters and maintain stability value suitable for mushroom cultivation were addressed. Thus, the prototype went through series of trials and tests to ensure functionality and accuracy of the device. Likewise, performance testing was conducted for temperature, relative humidity, and light to control and monitor the needs of the mushroom. The results revealed that the device is accurate, functional and capable. The study suggests that the greenhouse could be improved by installing a CCTV for constant monitoring of the interior and exterior of the greenhouse. The greenhouse could also be considered to be situated in a more private place as well as improve some of the application features.

The amalgamation of high-sensitivity gas sensors with neural electrical stimulation technology stands as a compelling solution for eliciting behavioral responses in the presence of low-level hazardous gases. The utilization of battery-powered or coil-based configurations introduces spatiotemporal limitations, encompassing constrained experimental durations due to battery life or the necessity to confine subjects to specific locales for wireless power transmission. In this study, we present an advanced wireless neural modulator, meticulously engineered for behavioral intervention in unrestricted environments. This device integrates a solar-powered unit, gas sensor, brain stimulation signal management system, and a neurostimulation electrode. The solar energy utilization eliminates the necessity for battery replacements and local range limitations. The surface of the solar cells is treated with a superhydrophobic coating, enhancing performance in outdoor settings by mitigating surface contamination issues inherent in traditional solar cells. This innovation guarantees continuous, long-term, on-demand operational capacity, ensuring uninterrupted power supply to the system. Experimentation revealed shortened locomotor activity in mice, induced by stimulation of the periaqueductal gray (PAG) brain region, for up to thirty minutes. These results underscore the significant potential of our technology for spatially and temporally unrestricted neuromodulatory applications, offering a viable strategy to alleviate the detrimental effects of hazardous gas exposure on physiological functions. [Display omitted] ● Solar Flexibility: Solar energy allows for free movement outdoors, removing the limitations of fixed power sources. ● Durable Panels: Superhydrophobic coatings protect solar panels from dirt, keeping them efficient. ● Sensitive Gas Detection: Advanced sensors in the system detect low levels of harmful gases, helping prevent health risks. [ABSTRACT FROM AUTHOR]

Wireless sensor networks (WSNs) suffer not only from short lifetimes because of limited energy but also from an energy imbalance between the nodes close to the sink and the other nodes. To fundamentally resolve the issue of short lifetimes, recent studies have utilized environmental energy, such as solar power. Additionally, WSNs that employ energy-aware dynamic topology control are also being studied to address the energy imbalance. This paper proposes an improved collection tree protocol (CTP) scheme, called solar-CTP, that uses the two approaches of energy-harvesting and energy-aware topology control simultaneously. The proposed scheme is derived from the CTP scheme, which is a widely adopted data collection strategy designed for typical battery-based WSNs with a fixed sink. We tailor the CTP scheme for solar-powered WSNs operating with a mobile sink. Performance verification confirms that our scheme significantly reduces the number of blackout nodes compared to other CTP variants, thus increasing the amount of data collected by the sink.

The solar-powered Organic Rankine Cycle (ORC) could solve the energy crisis and achieve low emissions because it presents a high energy conversion efficiency for a low-temperature heat source, with little impact on the environment. This paper investigates a solar-powered ORC that applies a compound parabolic collector (CPC) and a thermal storage unit for collecting solar radiation and achieving the continuous system operation, respectively. According to the established mathematical model, the effects of thermodynamic parameters on system performance are analyzed. In addition, a multiobjective optimization is performed to find the optimal key parameters and obtaining the optimal system performance from both thermodynamic and economic perspectives by employing nondominated sorting genetic algorithm II (NSGA-II). The results reveal that increasing the turbine inlet pressure, thermal oil mass flow of vapor generator, and CPC and decreasing the cooling water temperature could improve system performance. The optimization results show that the optimum solution is obtained with an average net power output of 143.02 kW and a daily average exergy efficiency of 7.75% under the given conditions. The corresponding values of the selected decision variables—turbine inlet pressure, thermal oil mass flow of CPC, thermal oil mass flow of vapor generator, and terminal temperature difference of condenser—are 1,999.611 kPa, 12.00 kg·s−1 , 5.97 kg·s−1 , and 14.02 K, respectively. [ABSTRACT FROM AUTHOR]

Having an exciting array of applications, the scope of unmanned aerial vehicle (UAV) application could be far wider one if its flight endurance can be prolonged. Solar-powered UAV, promising notable prolongation in flight endurance, is drawing increasing attention in the industries’ recent research and development. This work arose from a Bachelor’s degree capstone project at Hong Kong Polytechnic University. The project aims to modify a 2-metre wingspan remote-controlled (RC) UAV available in the consumer market to be powered by a combination of solar and battery-stored power. The major objective is to greatly increase the flight endurance of the UAV by the power generated from the solar panels. The power system is first designed by selecting the suitable system architecture and then by selecting suitable components related to solar power. The flight control system is configured to conduct flight tests and validate the power system performance. Under fair experimental conditions with desirable weather conditions, the solar power system on the aircraft results in 22.5% savings in the use of battery-stored capacity. The decrease rate of battery voltage during the stable level flight of the solar-powered UAV built is also much slower than the same configuration without a solar-power system.

Extensive research efforts have been recently devoted to the development of self‐driven electrocatalytic water‐splitting systems to generate clean hydrogen chemical fuels. Currently, self‐driven electrocatalytic water‐splitting devices are powered by solar cells, which operate intermittently, or by aqueous batteries, which deliver stored electric power, leading to high operating costs and environmental pollution. Thus, a fully solar‐powered uninterrupted overall water‐splitting system is greatly desirable. Here, the solar cells, stable output voltage of 1.75 V Ni–Zn batteries, and high efficiency zinc–nickel–cobalt phosphide electrocatalysts are successfully assembled together to create a 24 h overall water‐splitting system. Specifically, the silicon‐based solar cells enable the charging of aqueous Ni–Zn batteries for energy storage as well as providing sufficient energy for electrocatalysis throughout the day; in addition, the high‐capacity Ni–Zn batteries offer a steady output voltage for overall water‐splitting at night. Such an uninterrupted solar‐to‐hydrogen system opens up exciting opportunities for the development and applications of renewable energy.A prototype uninterrupted overall water‐splitting system is successfully assembled by incorporating solar cells with stable output voltage of 1.75 V Ni–Zn batteries and high‐efficiency zinc–nickel–cobalt phosphide electrocatalysts. Such a novel concept of the uninterrupted solar‐to‐hydrogen system opens up exciting opportunities for the development and application of renewable energy. [ABSTRACT FROM AUTHOR]

Abstract Solar-powered water splitting is expected to be a promising route for sustainable hydrogen production. However, its wide implementation is hampered by expensive electrocatalysts and photovoltaic apparatus. Herein, we designed a low-cost overall water splitting system combining flexible catalyst electrodes and one novel organic solar cell. The flexible electrodes contain carbon fabric functionalized with nitrogen-doped carbon encased iron-cobalt bimetallic phosphide and sulfide nanohybrids as electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. The electrolyzer for overall water splitting can realize a current density of 10 mA cm−2 at a low cell voltage of 1.60 V and remain stable in long-time durability test in alkaline media. Moreover, when driven by one organic solar cell, our system yields a record high water-splitting current density of 7.5 mA cm−2 with a solar-to-hydrogen efficiency of 9.2%. The above results demonstrate its potential as a real-life solar-powered hydrogen production system. Graphical abstract fx1 Highlights • Our electrocatalysts obtains high activity and favourable durability in HER and OER. • Our electrolyzer displays a low cell voltage for overall water splitting. • Driven by one novel organic solar cell, our solar-powered hydrogen production system reached a record high efficiency. [ABSTRACT FROM AUTHOR]

Solar adsorption refrigeration has many advantages. However, solar radiation has a relatively low energy density and requires much time to heat an adsorbent bed. In addition, the coefficient of performance (COP) of an adsorption refrigeration system is relatively low. In this paper, a new solar adsorption refrigeration prototype, which uses a compound parabolic concentrator (CPC) adsorbent bed with activated carbon-methanol as the working pair, was proposed and built to shorten the cycle time and improve performance. Laboratory experiments were conducted to evaluate and compare its performance and characteristics to those of a conventional solar adsorption refrigeration system. The experimental results show that the speed of the temperature increase of the adsorbent bed was boosted by employing CPC collectors. Compared with a conventional refrigeration system, the desorption period of the new system was reduced by one-third over one cycle. The desorption rate of the adsorption refrigeration cycle was notably improved. By using the CPC collector in a solar adsorption refrigeration system, the COP increased by 27%. The experimental results also show that applying solar concentrating technology in adsorption refrigeration is a promising approach for improving solar adsorption refrigeration performance and achieving a fast and continuous refrigeration cycle. [ABSTRACT FROM AUTHOR]

In solar-powered wireless sensor networks (SP-WSNs), the best use of harvested energy is more important than minimizing energy consumption since energy can be supplied periodically. Meanwhile, as is well known, the reliability of the communication between sensor nodes is very limited due to the resource constraints of sensor nodes. In this paper, we propose an efficient forward error correction (FEC) scheme which can give solar-powered wireless sensor networks more reliable communication. First, the proposed scheme provides energy-adaptive operation for the best use of solar energy. It calculates the amount of surplus energy which can be used for extra operations and then determines the number of additional parity bits for FEC according to this amount of surplus energy. At the same time, it also provides a link quality model that is used to calculate the appropriate number of parity bits for error recovery required for the current data communication environment. Finally, by considering these two parity sizes, it is possible to determine the number of parity bits that can maximize the data reliability without affecting the blacking out of nodes. The evaluation of the performance of the approach was performed by comparing the amount of data collected at the sink node and the number of blackout nodes with other schemes.

Large-scale aerial sensing missions can greatly benefit from the perpetual endurance capability provided by high-performance low-altitude solar-powered unmanned aerial vehicles (UAVs). However, today these UAVs suffer from small payload capacity, low energetic margins, and high operational complexity. To tackle these problems, this paper presents four individual technical contributions and integrates them into an existing solar-poweredUAV system: First, a lightweight and power-efficient day/night-capable sensing system is discussed. Second, means to optimize the UAV platform to the specific payload and to thereby achieve sufficient energetic margins for day/night flight with payload are presented. Third, existing autonomous launch and landing functionality is extended for solar-powered UAVs. Fourth, as a main contribution an extended Kalman filter (EKF)-based autonomous thermal updraft tracking framework is developed. Its novelty is that it allows the end-to-end integration of the thermal-induced roll moment into the estimation process. It is assessed against unscentedKalman filter and particle filter methods in simulation and implemented on the aircraft's low-power autopilot. The complete system is verified during a 26 h search-and-rescue aerial sensing mock-up mission that represents the first-ever fully autonomous perpetual endurance flight of a small solar-powered UAV with a day/night-capable sensing payload. It also represents the first time that solar-electric propulsion and autonomous thermal updraft tracking are combined in flight. In contrast to previous work that has focused on the energetic feasibility of perpetual flight, the individual technical contributions of this paper are considered core functionality to guarantee ease-of-use, effectivity, and reliability in future multiday aerial sensing operations with small solar-powered UAVs. [ABSTRACT FROM AUTHOR]

The idea of self-sustaining air vehicles that excited engineers in the seventies has nowadays become a reality as proved by several initiatives worldwide. High altitude platforms, or Pseudo-satellites (HAPS), are unmanned vehicles that take advantage of weak stratospheric winds and solar energy to operate without interfering with current commercial aviation and with enough endurance to provide long-term services as satellites do. Target applications are communications, Earth observation, positioning and science among others. This paper reviews the major characteristics of stratospheric flight, where airplanes and airships will compete for best performance. The careful analysis of involved technologies and their trends allow budget models to shed light on the capabilities and limitations of each solution. Aerodynamics and aerostatics, structures and materials, propulsion, energy management, thermal control, flight management and ground infrastructures are the critical elements revisited to assess current status and expected short-term evolutions. Stratospheric airplanes require very light wing loading, which has been demonstrated to be feasible but currently limits their payload mass to few tenths of kilograms. On the other hand, airships need to be large and operationally complex but their potential to hover carrying hundreds of kilograms with reasonable power supply make them true pseudo-satellites with enormous commercial interest. This paper provides useful information on the relative importance of the technology evolutions, as well as on the selection of the proper platform for each application or set of payload requirements. The authors envisage prompt availability of both types of HAPS, aerodynamic and aerostatic, providing unprecedented services. [ABSTRACT FROM AUTHOR]

Background: Hearing loss is a barrier to speech and social and cognitive development. This can be especially pronounced in children living in low- and middle-income countries with limited resources. Aim: To determine the feasibility, durability and social impact of ComCare GLW solar-powered hearing aids provided for Vietnamese children with hearing impairment. Methods:A retrospective review of data from an international, multi-discipline humanitarian visit was performed. Hearing aids were given to 28 children enrolled at the Khoai Chau Functional Rehabilitation School, Hung Yen Province, Vietnam. Device inspection and observational assessments were performed by teachers using a modified Parents’ Evaluation of Aural/Oral Performance of Children and an Infant Hearing Program Amplification Benefit Questionnaire. Qualitative interviews were undertaken to assess the study aims. Results: Hearing aids were well tolerated for use during regular school hours. All units remained functional during the study period (12 months). Teachers noted increased student awareness and responsiveness to surrounding sounds, but the degree of response to amplification varied between children. There was no significant improvement in speech development as all subjects had prelingual deafness. Teachers felt confident in troubleshooting any potential device malfunction. Conclusions:A solar-powered hearing aid may be a viable option for children in low- and middle-income countries. This study demonstrates that device distribution, maintenance and function can be established in countries with limited resources, while providing feasibility data to support future studies investigating how similar devices may improve the quality of life of those with hearing loss. [ABSTRACT FROM AUTHOR]

We present the development process behind AtlantikSolar, a small 6.9 kg hand-launchable low-altitude solar-powered unmanned aerial vehicle (UAV) that recently completed an 81-hour continuous flight and thereby established a new flight endurance world record for all aircraft below 50 kg mass. The goal of our work is to increase the usability of such solar-powered robotic aircraft by maximizing their perpetual flight robustness to meteorological deteriorations such as clouds or winds. We present energetic system models and a design methodology, implement them in our publicly available conceptual design framework for perpetual flight-capable solar-powered UAVs, and finally apply the framework to the AtlantikSolar UAV. We present the detailed AtlantikSolar characteristics as a practical design example. Airframe, avionics, hardware, state estimation, and control method development for autonomous flight operations are described. Flight data are used to validate the conceptual design framework. Flight results from the continuous 81-hour and 2,338 km covered ground distance flight show that AtlantikSolar achieves 39% minimum state-of-charge, 6.8 h excess time and 6.2 h charge margin. These performance metrics are a significant improvement over previous solar-powered UAVs. A performance outlook shows that AtlantikSolar allows perpetual flight in a 6-month window around June 21 at mid-European latitudes, and that multi-day flights with small optical- or infrared-camera payloads are possible for the first time. The demonstrated performance represents the current state-of-the-art in solar-powered low-altitude perpetual flight performance. We conclude with lessons learned from the three-year AtlantikSolar UAV development process and with a sensitivity analysis that identifies the most promising technological areas for future solar-powered UAV performance improvements. [ABSTRACT FROM AUTHOR]

By utilizing mobile sinks in wireless sensor networks (WSNs), WSNs can be deployed in more challenging environments that cannot connect with the Internet, such as those that are isolated or dangerous, and can also achieve a balanced energy consumption among sensors which leads to prolonging the network lifetime. However, an additional overhead is required to check the current location of the sink in order for a node to transmit data to the mobile sink, and the size of the overhead is proportional to that of the network. Meanwhile, WSNs composed of solar-powered nodes have recently been actively studied for the perpetual operation of a network. This study addresses both of these research topics simultaneously, and proposes a method to support an efficient location service for a mobile sink utilizing the surplus energy of a solar-powered WSN. In this scheme, nodes that have a sufficient energy budget can constitute rings, and the nodes belonging to these rings (which are called ring nodes) maintain up-to-date location information on the mobile sink node and serve this information to the other sensor nodes. Because each ring node only uses surplus energy to serve location information, this does not affect the performance of a node’s general operations (e.g., sensing, processing, and data delivery). Moreover, because multiple rings can exist simultaneously in the proposed scheme, the overhead for acquiring the position information of the sink can be significantly reduced, and also hardly increases even if the network size becomes larger.

A node in a solar-powered wireless sensor network (WSN) collects energy when the sun shines and stores it in a battery or capacitor for use when no solar power is available, in particular at night. In our scheme, each tiny node in a WSN periodically determines its energy budget, which takes into account its residual energy, and its likely acquisition and consumption. If it expects to acquire more energy than it can store, the data which has it has sensed is aggregated with data from other nodes, compressed, and transmitted. Otherwise, the node continues to sense data, but turns off its wireless communication to reduce energy consumption. We compared several schemes by simulation. Our scheme reduced the number of nodes forced to black out due to lack of energy so that more data arrives at the sink node. [ABSTRACT FROM AUTHOR]

The purpose of this study is to advance wireless sensing technology for permanent installation in operational highway bridges for long-term automated health assessment. The work advances the design of a solar-powered wireless sensor network architecture that can be permanently deployed in harsh winter climates where limited solar energy and cold temperatures are normal operational conditions. To demonstrate the performance of the solar-powered wireless sensor network, it is installed on the multi-steel girder bridge carrying northbound I-275 traffic over Telegraph Road (Monroe, Michigan) in 2011; a unique design feature of the bridge is the use of pin and hanger connections to support the bridge main span. A dense network of strain gauges, accelerometers and thermometers are installed to acquire bridge responses of interest to the bridge manager including responses that would be affected by long-term bridge deterioration. The wireless monitoring system collects sensor data on a daily schedule and communicates the data to the Internet where it is stored in a curated data repository. Bridge response data in the repository are autonomously processed to extract truck load events using machine learning, compensate for environmental variations using nonlinear regression and to quantitatively assess anomalous bridge performance using statistical process control. [ABSTRACT FROM AUTHOR]

In a wireless sensor network (WSN) environment with frequent errors, forward error correction (FEC) is usually employed at the link layer to achieve reliable transmission. In the FEC scheme, the error correction rate varies depending on the length of parity used for the recovery of broken data. The longer the parity length, the higher the possible error correction rate. However, this also means that the energy consumption increases. Meanwhile, in a solar-powered WSN, the energy of each node can be periodically collected, but the amount of collected energy varies drastically depending on the harvesting environment, including factors such as the weather, season and time of day. Therefore, each node must control energy consumption according to the energy harvesting rate. The scheme proposed in this study executes this control by adaptively adjusting the parity length of FEC according to the given energy budget of a node for the next period. This means that the error recovery rate can be increased as much as possible without adversely affecting the blackout time. Simulation results show that the proposed scheme improves the amount of data collected from the entire network for each environment compared with previous schemes.

The design of the energy storage serving solar-powered LiBr-water absorption air-conditioning systems to meet 24-h a day operation is an important parameter that determines the performance of the system and optimizes its components. Introducing hybrid storage designs can improve system performance, reduce collector size, lower storage tank capacity, and hence make 24-h a day operating solar-powered LiBr-water absorption air-conditioning systems more feasible. Moreover, hybrid storage designs will ensure uninterrupted operation in case of maintenance for one of the storage tanks. This paper investigates four hybrid storage designs (heat and refrigerant storage, cold and refrigerant stfsorage, heat and cold storage, and heat, cold, and refrigerant storage) for a continuous operation (24 h a day) of solar-powered LiBr-water absorption air-conditioning. The study includes system description, features, and selection analysis for a constant cooling load of 5 kW in a typical family house in Dhahran City, Saudi Arabia. The results indicate that the hybrid cold and refrigerant storage system is the most suitable design for 24-h a day supply of the cooling effect. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]