Real Outdoor Research Articles

Design, development, and analysis of modified concrete block integrated with thermal energy storage material for regulating indoor temperature

This study shows a comparative analysis of indoor thermal behavior of concrete block embedded with macroencapsulated phase change material with fins and without fins. Concrete blocks of similar dimensions were incorporated with square shape, rectangular shape, cylindrical shape, square shape with fins, rectangular shape with fins, and cylindrical shape with fins macroencapsulated phase change material. Pure paraffin wax (70 wt%) and raw coconut oil (30 wt%) are used as phase change material. Real outdoor testing of all the modified concrete block in comparison with conventional concrete block was conducted for continuous 96 h. Various indoor thermal comfort parameters such as peak temperature, thermal amplitude, and decrement factor were investigated. Additionally, thermographic images were also analysed to understand the effect of incorporating various shapes of macroencapsulated phase change material. Result shows maximum peak temperature reduction of 8.43 °C by concrete block integrated with cylindrical shape macrocapsule with fins. Also, concrete block integrated with cylindrical shape macrocapsule with fins shows highest reduction in indoor thermal amplitude of 26.54 % followed by cylindrical macroencapsulated phase change material without fins in comparison with reference concrete block. Lowest deviation in thermal amplitude shows by rectangular shape macrocapsule with fins. Reduction in decrement factor was also observed in modified concrete blocks in comparison with reference concrete block.

Ecological cleaning of PV panels by exploitation of dew water in Morocco

This work presents an ecological solution for cleaning of photovoltaic (PV) modules and a continuity of our first experience. It consists on using the dew water formed on the surface of the front glass. The study site is in Rabat city in the Northwest of Morocco, at the RDI (Research, Development and Innovation) Solar Energy Platform of ENS. In order to examine the effect of the angle change combined with the formation of dew water, and consequently on the cleaning of PV modules, systematic measurements of soiling ratio were made. The experiments were performed on glass plates that were exposed in real outdoor conditions. The soiling ratio was calculated by measuring the transmitted and received irradiance by the glass. At approximately sunrise, the subsequent permutation of the glass from the horizontal position to a 30° tilt angle promotes the dew droplets flow. The efficiency of cleaning is then investigated. A comparison of the soiling losses of fixed glass and variable glass with dew water flow was presented. It was found that the soiling losses for fixed glass averaged 9.3% during the exposure period while variable glass only marked 3.3%. In other words, the losses due to soiling for the fixed glass generate three times the losses compared to a variable glass with cleaning using dew water.

Ageing and seasonal effects on amorphous silicon photovoltaic modules in a Mediterranean climate

This contribution presents a field study in which the long-term behaviour of two a−Si photovoltaic plants is studied. Two grid-connected a−Si:H photovoltaic plants located in Valencia (Spain) have been monitored during their first eight years of operation under real outdoor conditions. A per-unit approach and an STC normalisation have been made to analyse and compare photovoltaic plants with differences in electrical characteristics. An averaging process of the filtered and normalised data produces a monthly averaged value that is used to evaluate the ageing and seasonal effects experienced by the two photovoltaic plants. An analysis of the variations in the per unit output power finds that a seasonal effect is superimposed on the long-term stabilisation process. The study concludes that the long-term average stabilisation factor is equal to 1,35% per year, with a seasonal effect that shows a sinusoidal variation with an average amplitude of the sinusoidal oscillation equal to 2,71% per year. An estimation of the energy yield is performed considering the different ageing approaches presented in the study. Using the factors obtained from the experimental values, the ageing and seasonal effects are modelized, and a linear and an exponential expression is proposed to fit the long-term behaviour of both a−Si photovoltaic plants. Results obtained with the statistical analysis are compared with the experimental data and it is found that the exponential behaviour matches the experimental values.

Simulation of fault detection in photovoltaic arrays

In solar systems, faults in the module and inverter occur in proportion to increased operating time. The identification of fault types and their effects is important information not only for manufacturers but also for investors, solar operators and researchers. Monitoring and diagnosing the condition of photovoltaic (PV) systems is becoming essential to maximize electric power generation, increase the reliability and lifetime of PV power plants. Any faults in the PV modules cause negative economic and safety impacts, reducing the performance of the system and making unwanted electric connections that can be dangerous for the user. In this paper have been classified all possible faults that happen in the PV system, and is presented to detect common PV array faults, such as open-circuit fault, line-to-line fault, ground fault, shading condition, degradation fault and bypass diode fault. In this studies examines the equivalent circuits of PV arrays with different topological configurations and fault conditions to evaluate the effects of these faults on the performance of a solar system, taking into account the influence of temperature and solar radiation. This work presents the validation of a simulated solar network by measuring the output curves of a low-power photovoltaic array system under real outdoor conditions. This method can be useful in future solar systems.

Experimental Investigation on Thermal Comfort of COVID-19 Nucleic Acid Sampling Staff in Hot and Humid Environment: A Pilot Study of University Students

The current situation of Coronavirus Disease 2019 (COVID-19) prevention and control coupled with the need to work in high-temperature harsh environments makes it necessary to ensure the health and efficiency of medical staff. An experimental outdoor work tent was set up and university students were used to study the thermal comfort of personnel wearing protective clothing in hot and humid environments. The experiment was carried out simultaneously through subjective and objective field tests and physiological tests of personnel. The wet bulb globe temperature (WBGT) index was investigated to divide the outdoor thermal environment into four working conditions: 21–23 °C, 23–25 °C, 25–27 °C and 27–29 °C. Under the different thermal environment intensities, the variations of physiological parameters of test personnel were monitored. The results showed that when WBGT was increased to 27–29 °C, 100% of the participants expected the external temperature to become cooler and the humidity to decrease after one hour. When the temperature was close to 30 °C and the relative humidity was close to 60%, it was necessary to take cooling measures to reduce the thermal stress of the participants. Moreover, relationships between subjective feelings and physiological parameters of the nucleic acid sampling personnel were obtained. Results also found that the forehead, chest and back were the highest skin temperature parts, so it is most effective to give priority to improving the thermal comfort of these three locations. As an early attempt to conduct the real outdoor experimental study on the thermal comfort of COVID-19 nucleic acid sampling staff, this study provided a theoretical basis for follow-up research to develop cooling strategies for protective clothing in hot and humid outdoor environments.

Outdoor Characterization of a Plasmonic Luminescent Solar Concentrator

Plasmonic luminescent solar concentrators (PLSCs) have been shown to enhance the optical performance and power conversion efficiency of LSCs, due to added plasmonic gain in the medium. Despite the promising outlook of a PLSC through plasmonic coupling, device characterization and performance have not been verified in the real outdoor conditions, with varying direct and diffuse solar irradiation. In this work, characterization of a PLSC device of dimensions 4.5 \(\times\) 4.5 \(\times\) 0.3 cm3 embedded with Lumogen Red 305 dye and plasmonic gain medium of gold core silver shell nano cuboids was carried out in outdoor conditions of Dublin, Ireland. Optimized PLSC device power output at different solar insolation was compared to a reference photovoltaic (PV) cell and an optimized luminescent solar concentrator (LSC) device. The effect of the solar disc position, solar insolation, PV cell surface temperature, diurnal, and seasonal variation on the performance of the PLSC device is studied. The key observation was that PLSC average power conversion efficiency was 1.4 times more than the PV cell in cloudy and diffuse solar conditions. The PLSC device performed 45% better than a PV cell in December than July, as December has higher diffuse solar irradiation. Even though the PLSC device absorbs only 31% and transmits 69% incident solar irradiation in the concerned visible range of 380–750 nm. The preliminary outdoor characterization on a small-scale PLSC establishes its viability in a diffuse to direct solar radiation ratio throughout the year as well as establishing its benefits for integration in buildings.

Autonomous Source Search for UAVs Using Gaussian Mixture Model-Based Infotaxis: Algorithm and Flight Experiments

Estimating and searching source information such as the location and release rate, called a source term, have many applications across environmental, medical, and security domains. The Bayesian inference framework is used to estimate the source term. Since the gas dispersion and its measurements in a turbulent environment are highly non-Gaussian and nonlinear, the particle filter, one of sequential Monte Carlo methods, is adopted in this article. For autonomous source term search in a turbulent environment, this article presents an information-theoretic search approach that combines a widely used Infotaxis approach with the Gaussian mixture model (GMM), termed as GMM-Infotaxis. The GMM is used to determine action candidates for the next best informative sampling position in a continuous domain by appropriately clustering possible source locations obtained from the particle filter. This facilitates a better trade-off between exploitation and exploration for autonomous source search. Through the outdoor experiments, on average, the estimation errors for localization and release rate of the source are reduced 74 and 73%, respectively, while the search time step of the mobile agent is decreased around 18%. Real outdoor flight experiments using a multirotor UAV in various experimental setups show the superior performance of the proposed approach compared with the original Infotaxis method.

‘Lines of Flight or Tethered Wings’?: A Deleuzian Analysis of Women-specific Adventure Skills Courses in the United Kingdom

In this article we examine women-specific adventure sport skills training courses in the UK utilising a feminist new materialist approach. Drawing on Gilles Deleuze and Félix Guattari's (1987) concepts of ‘assemblage’, ‘lines of territorialisation’, and ‘lines of flight’, we apply a new lens to ask: what type(s) of material-discursive assemblages are produced through human and non-human, discursive, and non-discursive intra-actions on women-specific adventure sport skills courses? To what extent do these courses enable participants to engage with an alternative praxis and ethics and to think, feel, practice, and become otherwise? Our Deleuzian reading showed that the affective capacity of these courses is currently limited by dominant understandings of these courses as bridges to the real outdoors and as primarily designed for women who lack the confidence to participate in mixed-gender environments. However, these courses also enabled productive lines of flight and alternative understandings and practices related to the self, the body, others, material objects, learning, movement, and physical activity to emerge. These were both characterised and supported by less instrumental and hierarchical flows of relations and an openness to not knowing.

Paris-CARLA-3D: A Real and Synthetic Outdoor Point Cloud Dataset for Challenging Tasks in 3D Mapping

Paris-CARLA-3D is a dataset of several dense colored point clouds of outdoor environments built by a mobile LiDAR and camera system. The data are composed of two sets with synthetic data from the open source CARLA simulator (700 million points) and real data acquired in the city of Paris (60 million points), hence the name Paris-CARLA-3D. One of the advantages of this dataset is to have simulated the same LiDAR and camera platform in the open source CARLA simulator as the one used to produce the real data. In addition, manual annotation of the classes using the semantic tags of CARLA was performed on the real data, allowing the testing of transfer methods from the synthetic to the real data. The objective of this dataset is to provide a challenging dataset to evaluate and improve methods on difficult vision tasks for the 3D mapping of outdoor environments: semantic segmentation, instance segmentation, and scene completion. For each task, we describe the evaluation protocol as well as the experiments carried out to establish a baseline.

Outdoor exposure approach in a harsh environment toward the study of corrosion aspects of primary solar reflectors

Corrosion is among the most observed phenomena that threaten the profitability of concentrated solar thermal power plants and constitutes a real risk factor for metallic materials. Solar reflectors are between the impacted materials by corrosion because they are composed of metallic reflective layers that can easily be oxidized in air. To avoid this, paint systems could be applied in the back of the reflective layers as a barrier, that prevents the diffusion of corrosive elements to the metal layer. Metallic structures that support those reflectors can also be easily corroded and are replaced with composite structures that are not affected by corrosion. However, the durability of the paint protection systems and the composite structures must be inspected to ensure their effectiveness in protecting solar mirrors against corrosion, since they are found in sites that are often characterized by arid conditions, which affects corrosion protection solutions. This work is devoted to study the corrosion aspects and the parameters that affect the resistance of the protection systems of glass solar mirrors and solar mirrors fixed on composite structures by the use of a real outdoor exposure facility on a coastal site. The results show the important role of the paint coating layers number on the protection against corrosion. Also, the role of edge protection and shape were highlighted. Solar mirrors fixed on composite structures show a weak resistance because of the degradation of the fixing glue which creates areas of retention of salts and moisture that cause an aggressive corrosion of the metal layers.

Analytical versus Metaheuristic Methods to Extract the Photovoltaic Cells and Panel Parameters

The parameters of the photovoltaic cells and panels are very important to forecast the power generated. There are a lot of methods to extract the parameters using analytical, metaheuristic, and hybrid algorithms. The comparison between the widely used analytical method and some of the best metaheuristic algorithms from the algorithm families is made for datasets from the specialized literature, using the following statistical tests: absolute error, root mean square error, and the coefficient of determination. The equivalent circuit and mathematical model considered is the single diode model. The result comparison shows that the metaheuristic algorithms have the best performance in almost all cases, and only for the genetic algorithm, there are poorer results for one chosen photovoltaic cell. The parameters of the photovoltaic cells and panels and also the current-voltage characteristic for real outdoor weather conditions are forecasted using the parameters calculated with the best method: one for analytical—the five-parameter analytical method—and one for the metaheuristic algorithms—hybrid successive discretization algorithm. Additionally, the genetic algorithm is used. The forecast current-voltage characteristic is compared with the one measured in real sunlight conditions, and the best results are obtained in the case of a hybrid successive discretization algorithm. The maximum power forecast using the calculated parameters with the five-parameter method is the best, and the error in comparison with the measured ones is 0.48%.

Stable Nonwetting Artificial Compound Eye with Low Adhesion.

Microlens arrays (MLAs) are the key components of miniaturized optical systems. To meet the stringent requirements for their application in humid environments, achieving waterproof properties in these objects is an urgent task. It is noteworthy that conventional methods of microlens production usually sacrifice optical performance for stable superhydrophobicity by increasing the surface roughness of the microlens. In this paper, a large area artificial compound eye (ACE) is efficiently fabricated by combining photolithography and inkjet printing. The added micropillars separated the outside droplet from the microlens, and the water droplet was afterward suspended on the top of micropillars. Furthermore, the micropillars enabled superhydrophobicity (at a contact angle above 150°) and low surface adhesion (at a sliding angle of ∼2.8°) of the microlens without affecting its optical performance. Furthermore, when released from the height of 1 and 2 cm, the droplets were fully detached from the surface without sticking. The surface of the ACE was shown to have relatively stable nonwettability due to a small spacing between the micropillars. This means that tuning the morphology and spacing between micropillars allows one to noticeably improve the surface nonwettability stability. Finally, the performance of the fabricated optical system was demonstrated in a water washing experiment. Therefore, the findings of present study may open up the prospects for significant advancement in superhydrophobicity of the optical systems without affecting their imaging performance for real outdoor applications.

Statistical inference attack against PHY-layer key extraction and countermeasures

The establishment of secure secret keys ahead of transmissions is one of the key issues in the field of information security. The security of traditional cryptographic secret key establishment mechanisms is seriously challenged by computing-intensive attacks, with the fast growth of high-performance computing. As an alternative, considerable efforts have been made to develop physical (PHY) layer security measures in recent years, such as link-signature-based (LSB) secret key extraction techniques. Those mechanisms have been believed secure, based on the fundamental assumption that wireless signals received at two locations are uncorrelated when separated by more than half a wavelength. However, this assumption does not hold in some circumstances under latest observations, rendering LSB key extraction mechanisms vulnerable to attacks. To address this problem, the formal theoretical analysis on channel correlations in both real indoor and outdoor environments is provided in this paper. Moreover, this paper proposes empirical statistical inference attacks (SIA) against LSB key extraction, whereby an adversary infers the signature of a target link. Consequently, the secret key extracted from that signature has been recovered by observing the surrounding links. In contrast to prior literature that assumes theoretical link-correlation models for the inference, our study does not make any assumption on link correlation. Instead, we employ machine learning (ML) methods for link inference based on empirically measured link signatures. We further propose a countermeasure against the SIAs, called forward-backward cooperative key extraction protocol with helpers (FBCH). In the FBCH, helpers (other trusted wireless nodes) are introduced to provide more randomness in the key extraction. Our experimental results have shown that the proposed inference methods are still quite effective even without making assumptions on link correlation. Furthermore, the effectiveness of the proposed FBCH protocol is validated by our experiment results.

Localization accuracy of a robot platform using indoor positioning methods in a realistic outdoor setting

Summary Precise localization and reliable navigation are of crucial importance in order to fully automatize tasks in agriculture using field robots in an outdoor environment. However, under certain conditions, absolute localization accuracy of outdoor positioning systems, mainly global navigation satellite systems (GNSS), might drop under a critical threshold. Thus, field robots must rely on indoor positioning methods such as laser scanners and adaptive Monte Carlo localization (AMCL) in order to maintain necessary localization accuracy. Here, the localization accuracy of the field robot “Mathilda” using such an indoor positioning method is evaluated in a realistic scenario, in this case, an outdoor laboratory with plant pots aligned in rows. For this, the positioning error of the robot was determined using a motion capture system. The results showed a mean absolute distance error over all positions of 198.9 mm and a mean angular error over all positions of 4.9°. Most likely, limitations by the differential drive system, the large pneumatic tires, and unsatisfactory path planning are responsible for this large deviation.

Performance analysis outcome of a 19‐MWp commercial solar photovoltaic plant with fixed‐tilt, adjustable‐tilt, and solar tracking configurations

AbstractPhotovoltaic (PV) plants are generally installed at optimum tilt angle for a location or using sun tracking for enhancing energy generation potential. The objective of the present study is to assess the practicability of these techniques for large commercial plants along with determining expected uncertainty in simulated energy yield estimation. In this study, performance analysis of a 19‐MWp (17‐MWac) PV plant is carried out which is installed in India with fixed‐tilt (FT), seasonal adjustable‐tilt (AT), and horizontal single‐axis solar tracking (HSAT) configurations. This study is the first‐time comparative power enhancement analysis of these three different configurations under real outdoor conditions for a single large scale power plant at one location. The operation and maintenance issues of these configurations are also analyzed. A reliability analysis of linear actuator of the industrial solar tracking system is carried out as the actuator is a critical part of the solar tracking system of the power plant. Major results of the study are annual performance ratio 79% (FT), capacity factors = 19% (FT), 20% (AT), and 22% (HSAT) respectively, final yields (Yf) = 4.58 h/day (FT), 4.85 h/day (AT), and 5.28 h/day (HSAT). The energy yield simulations are done on two widely used PV design software: PVSyst and PVSOL and results are analyzed in detail. The accuracy of predicted data is validated and found to be within acceptable limits of uncertainty. The results of this study are compared with previous studies.

Experimental and numerical analysis of solar still using Pyrex glass quantum dot in tropical climate

This study investigates the effect of using quantum dots (QDs) on the performance of solar still in the tropical climate of India. This article presents a new way to use QDs, which on absorbing solar energy increases water evaporation rate. Pyrex glass powder QDs are used in the solar still due to its high absorptivity value. An experimental setup of solar still with QD and without QD was developed, and a comparative analysis was conducted under the real outdoor environment in a tropical climate. The experimental results were also validated through mathematical modeling. The experiment was carried out by mixing Pyrex glass powder QDs with black paint and was coated on the basin and sidewalls of the solar still. Experiments were conducted for a depth of 0.02 m for solar still with QDs and without QDs. The results revealed that for 0.02 m of water depth and 1 m2 of basin area, the percentage increase in distillate output using Pyrex glass powder QDs is 29.36% experimentally and 29.94% theoretically. Furthermore, the net percentage increase in solar still efficiency by using Pyrex glass QDs is 74.74% experimentally and 61.03% theoretically. The study analyzed that all the experimental results are in good agreement with the theoretical analysis. The addition of Pyrex glass powder QDs and black paint mixture in the basin of solar still caused significant enhancement in the distillate output and solar still efficiency.

Biohybrid generators based on living plants and artificial leaves: influence of leaf motion and real wind outdoor energy harvesting

Plants translate wind energy into leaf fluttering and branch motion by reversible tissue deformation. Simultaneously, the outermost structure of the plant, i.e. the dielectric cuticula, and the inner ion-conductive tissue can be used to convert mechanical vibration energy, such as that produced during fluttering in the wind, into electricity by surface contact electrification and electrostatic induction. Constraining a tailored artificial leaf to a plant leaf can enhance oscillations and transient mechanical contacts and thereby increase the electricity outcome. We have studied the effects of wind-induced mechanical interactions between the leaf of a plant (Rhododendron) and a flexible silicone elastomer-based artificial leaf fixed at the petiole on power output and whether performance can be further tuned by altering the vibrational behavior of the artificial leaf. The latter is achieved by modifying a concentrated mass at the tip of the artificial leaf and observing plant-generated current and voltage signals under air flow. In this configuration, the plant-hybrid wind-energy converters can directly power light-emitting diodes and a temperature sensor. Detailed output analysis has revealed that, under all conditions, an increase in wind speed leads to nearly linearly increased voltages and currents. Accordingly, the cumulative sum energy reaches its highest values at the highest wind speed and resulting oscillations of the plant-artificial leaf system. The mass at the tip can, in most cases, be used to increase the voltage amplitude and frequency. Nevertheless, this behavior was found to depend on the individual configuration of the system, such as the leaf morphology. Analysis of these factors under controlled conditions is crucial for optimizing systems meant to operate in unstructured outdoor scenarios. We have established, in a first approach, that the artificial leaf-plant hybrid generator is capable of autonomously generating electricity outdoors under real outdoor wind conditions, even at a low average wind speed of only 1.9 m s−1.

P‐3.4: VR Scene Display of Emergencies in Snow Field

Avalanche scene simulation is an emergency method that can be used to experience panic in advance of emergencies and to respond to emergencies in medical treatment through virtual reality simulation. Therefore, for the emergencies of the avalanche of the Winter Olympics snow field, virtual reality simulation is of great significance.This article takes the Winter Olympics snow field as the main line to show the medical rescue simulation after the avalanche. The entire design relies on the Unity3D engine, and the final test.stage will use the HTC interactive device for 3D scene evolution testing. First, using Unity's own mountain processing software, based on the original terrain, on the whole, a realistic outdoor ski resort model can be realized. Secondly, based on the Unity3D software design, it is mainly to construct the 3D model of the snow mountain and the subsequent emergency rescue animation module. The entire project C # language used as the scripting language of the entire project. After the avalanche scenario, virtual emergency medical rescue be realized. Finally, regarding the formulation of emergency levels and different rescue measures taken at different levels, and make emergency medical emergency response basedon avalanche scenarios.

A cross‐linguistic study of spatial location descriptions in New Zealand English and Brazilian Portuguese natural language

AbstractHumans use spatial language on a daily basis, to describe locations, give directions, and ask for information about places. Better understanding of spatial language can assist in developing natural language interfaces and querying tools for GIS and web mapping. However, most previous studies focus on artificial, indoor situations. We conduct cross‐linguistic experiments to compare natural language relative location descriptions (e.g., the house beside the river) in New Zealand English (NZE) and Brazilian Portuguese (BP) using eight real outdoor locations to discover the differences that occur when people describe the same location in the two languages. Our results show that NZE uses a wider range of spatial relation terms (e.g., beside) and reference objects (e.g., river) than BP, that BP uses more projective spatial relation terms than NZE, which prefers directional terms, and that translation between spatial relation terms is context‐dependent.

An Interactive Tool for Simulation of Biological Models Into the Wastewater Treatment With Microalgae

This paper presents a novel simulation tool to understand and analyze biological models for wastewater treatment processes using microalgae. The models for this type of processes are very complex to be analyzed because of the very different phenomena, variables and parameters involved. The model already included in the tool has been validated at controlled conditions simulating outdoor ones, it being useful to simulate real outdoor cultures. The major contribution of the proposed tool is that these models can be easily and interactively simulated and compared. The tool allows simulating biological models only considering microalgae or including the microalgae-bacteria consortium. Moreover, the simulations can be done only using the solar radiation contribution or by adding the environmental and bacteria effects as cardinal terms. Furthermore, the effects of the wastewater properties or different microalgae strains can be evaluated. The interactive simulations can be performed for selected days as representative of the different year seasons that are already preloaded in the tool. However, the user can also load data from other locations to simulate the models under particular conditions.