Natural Weather Conditions Research Articles

Urban Emergency Evacuation Path Optimization Based on Uncertain Environments to Enhance Response for Symmetric and Asymmetric Evacuation Problems

Background: Serious secondary disasters caused by extreme natural weather conditions occur frequently, making it essential to establish a scientific and efficient modern emergency management system to maximize life-saving efforts. Methods: This study focuses on the uncertain environment of urban road networks and employs fuzzy theory to construct a 0–1 integer programming model for emergency evacuation paths that minimizes the average expected travel time. Results: We enhanced the neighborhood search strategy of the traditional ACO_time by incorporating the 2-opt and 3-opt perturbation mechanisms from the SA algorithm. Additionally, we utilized improved ant-volume and ant-perimeter models, along with their combinations, in the pheromone-updating mechanism of the basic ACO. The heuristic principles of the A* algorithm were integrated, introducing the joint influence of path and time into the heuristic function of the ACO algorithm. Conclusions: The IACO3 algorithm was tested on the Sioux Falls network and the Berlin Heisenheimer Center network. The computation time of the improved IACO3 algorithm was reduced by up to 20% compared to the original IACO3 algorithm in relation to the SA algorithm, with only a 4–5% increase in computation time compared to the ACO_time algorithm, which translates to an increase of merely 4–5 s. This demonstrates the superior solution efficiency of the IACO3 algorithm.

Improved Detection of Multi-Class Bad Traffic Signs Using Ensemble and Test Time Augmentation Based on Yolov5 Models

Various factors such as natural disasters, vandalism, weather, and environmental conditions can affect the physical state of traffic signs. The proposed model aims to improve detection of traffic signs affected by partial occlusion as a result of overgrown vegetation, displaced signs (those knocked down, bent), perforated signs (those damaged with holes), faded signs (color degradation), rusted signs (corroded surface), and de-faced signs (placing graffiti, etc., by vandals). This research aims to improve the detection of bad traffic signs using three approaches. In the first approach, Spiral Pooling Pyramid-Fast (SPPF) and C3TR modules are introduced to the architecture of Yolov5 models. SPPF helps provide a multi-scale representation of the input feature map by pooling at different scales, which is useful in improving the quality of feature maps and detecting bad traffic signs of various sizes and perspectives. The C3TR module uses convolutional layers to enhance local feature extraction and transformers to boost understanding of the global context. Secondly, we use predictions of Yolov5 as base models to implement a mean ensemble to improve performance. Thirdly, test time augmentation (TTA) is applied at test time by using scaling and flipping to improve accuracy. Some signs are generated using stable diffusion techniques to augment certain classes. We test the proposed models on the CCTSDB2021, TT100K, GTSDB, and GTSRD datasets to ensure generalization and use k-fold cross-validation to further evaluate the performance of the models. The proposed models outperform other state-of-the-art models in comparison.

Biodegradation Behaviour of the Composite Consisting of Polypropylene and Bauhinia Vahlii Fiber

AbstractThe current study focuses on the degradation rate of polypropylene (PP) and Bauhinia Vahlii (BV) fibers under soil burial and natural weathering conditions for 360 days. The BV‐PP composite was produced with varying BV fiber compositions (0, 10, 20, and 30 wt.%) and 3 % MAPP (Maleic Anhydride Grafted Polypropylene). In addition, MAPP is employed as a coupling agent to improve fiber‐matrix compatibility and promote degradation. The XRD examination shows that a 10 % BV‐PP composite has a crystallinity index of 52.05 %, which is higher than that of neat PP. The rate of biodegradability was investigated using weight loss and tensile properties. The largest degradation was seen in natural weathering conditions with 30 % composite showing the maximum weight loss of 3.8 % and loss in tensile strength and modulus of 16.76 % and 5.11 %, respectively. Simultaneously, no weight loss or drop in tensile characteristics was found in the case of neat PP over 360 days. The SEM images of soil burial show material deterioration, which may be aided by bacterial and fungal activity, whereas natural weathering conditions show a large crack, rougher fracture surface, and cavities, which are attributed to thermal stresses, changes in moisture content, and ultraviolet radiation, thereby promoting the degradation process.

Climatic fluctuations alter the preference of stingless bees (Apidae, Meliponini) towards food contaminated with acephate and glyphosate

The global decline of pollinators has become a major concern for the scientific community, policymakers, and the general public. Among the main drivers of diminishing bee populations is the widespread use of agrochemicals. To gain a comprehensive understanding of the foraging dynamics of bees at agrochemical-contaminated areas, it is essential to consider both environmental conditions and the specific foraging ecology of bee species. For the first time, we conducted a semi-field study to investigate whether stingless bees exhibit a preference for food contaminated with agrochemicals compared to non- contaminated food, under natural weather conditions. Colonies of Plebeia lucii Moure, 2004 were placed in a greenhouse and subjected to a preference test, where bees were given the freedom to choose between contaminated or non-contaminated food sources following a preliminary training period. Within the greenhouse, we placed feeders containing realistic concentrations of an insecticide (acephate: 2 mg a.i./L), a herbicide (glyphosate: 31.3 mg a.i./L), or a mixture of both, alongside non-contaminated food. Environmental variables (temperature, humidity, and light intensity) were monitored throughout the experiment. At higher temperatures, the foragers preferred food containing the mixture of both agrochemicals or uncontaminated food over the other treatments. At lower temperatures, by contrast, the bees preferred food laced with a single agrochemical (acephate or glyphosate) over uncontaminated food or the agrochemical mixture. Our findings indicate that agrochemical residues in nectar pose a significant threat to P. lucii colonies, as foragers do not actively avoid contaminated food, despite the detrimental effects of acephate and glyphosate on bees. Furthermore, we demonstrate that even minor, natural fluctuations in environmental conditions can alter the colony exposure risk. Despite the interplay between temperature and bees' preference for contaminated food, foragers consistently collected contaminated food containing both agrochemicals, whether isolated or in combination, throughout the whole experiment.

The degradation of poly(1-butene) extrudates subjected to artificial and natural aging

In this work, we examined the degradation behavior of isotactic poly(1-butene) (PB-1) under artificial aging and natural weathering conditions. PB-1 samples underwent accelerated aging through UV irradiation and natural weathering. Chemical and structural changes in the degraded samples were characterized using Fourier-transform infrared–attenuated total reflectance (FTIR–ATR) spectroscopy, surface analysis, and wide-angle X-ray scattering (WAXS). The mechanical properties were evaluated via tensile testing. FTIR–ATR analysis revealed the presence of carbonyl groups in the degraded samples, indicating oxidative degradation. Surface observations employing scanning electron microscopy (SEM) revealed the formation of surface cracks in both samples, with differing crack initiation mechanisms. The two aging methods affected the mechanical properties of the samples: artificial aging induced a gradual reduction in both tensile modulus and strength, whereas natural weathering engendered a marginal increment in modulus alongside diminished strength. Additionally, elongation-at-break value witnessed a marked decrease in both sample sets during the preliminary stages of degradation. This work employed accelerated time equivalent, obtained by juxtaposition of the values of carbonyl index during both artificial aging and natural weathering and their interpolation to determine the degradation rate and adequately to correlate the final properties of the aged PB-1. It was observed that surface morphology and mechanical attributes of degraded samples were subject to additional influences such as temperature, humidity, and precipitation during natural weathering. This research work provided significant insights into PB-1 degradation mechanisms and effect of different aging conditions on its performance.Graphical abstract

Robust Rain-Repellency and Droplet Bouncing Properties of Bauhinia Fresh and Aged Leaves Up to 6 Months.

Robust rain-repellent surfaces are useful in roofs, solar panels, windshields, etc. Herein, excellent rain-repellency and droplet bouncing properties of Bauhinia Variegata leaves are presented. They possess surface microbumps (l ∼ 13 μm, w ∼ 8 μm, h ∼ 3 μm), which in turn comprise nanoplatelets (l ∼ 741 nm, t ∼ 59 nm) and Wenzel roughness (r w) of ∼2.2. The leaf's surface energy was estimated to be 9.47 ± 0.03 mJ·m-2 by incorporating rw into the van Oss-Good-Chaudhary theory. The leaves exhibited static contact angle of 157 ± 1°, roll-off angle of 9 ± 1°, and contact angle hysteresis of 12 ± 4°, which retained as they aged up to 186 days in the natural weather and laboratory conditions. The water droplets (10 μL, 40 μL) bounced off for free-fall heights from 5 cm to ∼13 m (Weber no. 36 to ∼2990) and displayed robust rain-repellency (Weber no. ∼4500), similar to that of a lotus leaf. Also, Bauhinia leaves survived pressurized water jets (Weber no. ∼4240). Nevertheless, underwater hydrophobicity has been persistent only for up to 3 h when submerged in 20 cm (∼1.96 kPa gauge pressure) deep water, while lotus leaves retained for >7 h. Such robust Bauhinia leaf's nanoplatelets and wax chemistries can be replicated onto glass/metals for preparing rain-repellent surfaces.

Weather ageing effects on the long-term thermal conductivity and biological colonisation of thermal insulating mortars with EPS, cork and aerogel

The use of thermal insulation materials in the opaque walls is one of the best strategies toward the improvement of the thermal performance of the building envelope, thereby contributing to increase the energy efficiency of the built environment. In this context, an increasing number of studies are focusing on the development of mortars with enhanced thermal performance, i.e., thermal insulating mortars. However, considering the innovative character of these materials, reliable data on their long-term performance is still lacking, particularly concerning the thermal performance and suitability to refurbishment works. The aim of this paper is to evaluate the long-term thermal conductivity and biological colonisation of industrially produced and experimentally designed thermal mortars with EPS, cork and silica aerogel aggregates. The long-term performance of the mortars was assessed prior, during and after exposure to three accelerated ageing tests including elevated temperature, freeze–thaw cycles and high humidity levels. For each test, an empirical model (i.e., Arrhenius law, Peck model, and Coffin-Manson equation) was used to compute the acceleration factor, thus allowing to correlate the accelerated and natural ageing results and to estimate the degradation levels that would be obtained after 10 years of exposure to natural weather conditions. The results of the thermal conductivity show that a maximum increase of 10 % and 30 % can be obtained after ageing for the industrially produced and experimentally designed mortars, respectively. Moreover, all mortars were susceptible to mould growth, with the greatest biological colonisation levels obtained after the high moisture content ageing for the experimentally designed mortars.

Acute toxicity of petroleum asphalt seal coat leachates to Ceriodaphnia dubia is linked to polymer preservatives

Low-VOC waterborne asphalt-emulsion (AE) seal coat is considered more sustainable than solvent-based coal-tar emulsion seal coat because asphalt emulsions contain negligible amounts of carcinogenic PAHs and release fewer harmful volatile organic compounds. Yet, many low-VOC coatings leach water-soluble substances under outdoor conditions. To investigate the chemical composition of seal coat leachates, three AE formulations were cured under natural weathering conditions and exposed to simulated runoff over a 10-day field trial. Runoff was collected and concentrated using ion-exchange solid-phase extraction (SPE) and analyzed using gas chromatography/mass spectrometry (GC–MS). Leached compounds included hydrocarbons, esters, amines, siloxanes, plasticizers, biocides, polyethylene glycol (PEG) ethers, urethanes, and toluene diisocyanate (TDI). Glycol ethers comprised 29–97 % of the measured leachate mass. Two seal coat formulations contained isothiazolinone biocides, methylchloro- and methylisothiazolinone (CMIT/MIT; 0.5 mg/L in runoff), while a third seal coat formulation continuously leached TDI, a reactive polyurethane (PU) precursor (0.7 mg/L in runoff). Biocide-containing leachates showed acute toxicity to the freshwater water flea, Ceriodaphnia dubia after 48 h, while TDI-containing leachate showed no acute toxicity, suggesting that leachate toxicity was due to in-can polymer preservatives. As biocides are implicated in impaired reproductive signaling, these results support the use of alkaline pH to avoid biofouling and reinforce the goal of reducing and/or avoiding the use of biocides altogether, especially for environmentally friendly products.

Transforming oil palm trunk waste into high-performance lightweight materials

Addressing the growing demand for efficient sustainable materials, this study presents the development of a high-performance lightweight material utilizing oil palm trunk—a waste product from oil palm (Elaeis guineensis) cultivation. The proposed novel process involves polymer impregnation of sawn oil palm trunk under ambient conditions for 24-h soaking intervals, resulting in loadings of polymethyl methacrylate ranging from 0 wt% to 220 wt%. Subsequent polymerization at temperatures (90 and 103°C) commonly employed in the wood drying industry enhances the water resistance of the material, making it comparable to that of commercially available timber. Remarkably, the treated oil palm lumber attained a maximum density of approximately 450 kg/m3, making it a lightweight material. Furthermore, the impregnation process significantly improves the decay resistance of this product under natural weathering conditions. The treated oil palm lumber also displayed an increase of up to five times in the bending and compressive strength. Interestingly, a linear correlation between these enhanced properties and the density of this material was observed. This suggests the possibility of systematically producing the high-performance oil palm lumber through a simple and industry-accessible process.

Natural weathering effects on the surface morphological and physicochemical properties of radiation curable coatings in tropical climate

The purpose of this research is to discover the effects of natural weathering on palm oil-based and petrochemical-based film coatings. The film coatings were prepared using the radiation curing approach via cross-linking. Three palm oil-based resins with TiO2 nanoparticle loading were developed: EPOLA, EPOLA-OPV, and POBUA. The petrochemical-based coatings were also developed to compare the performance of natural and synthetic coatings. The coatings were exposed to natural weathering for up to 60 days at varied angles of 0°, 45°, and 90°. The effect of natural weathering conditions on the surface morphological, physiochemical, and also flexural characteristics of coatings, as well as the discoloration visual inspection and the growth of mould or fungus on the tested specimen, was studied. The results showed that natural weathering exposure induced severe discoloration and deterioration of the polymer network structure of the coatings due to photo-oxidation reaction and the presence of fungi. Overall, palm oil-based coatings deteriorate slower than petroleum-based coatings, especially at a 90° angle. This study indicated that bioresources-based palm oil has a significant potential for interior wood varnish applications due to its superior qualities over synthetic-based coatings.

A Mechanistic Action of Salicylic acid on Metabolic Profiling, Antioxidative Potential, and Growth Pattern of Amaranthus hybridus

This study has been conducted to investigate the effects of salicylic acid application on the growth and biomass of Amaranthus hybridus. The crop was grown in pots during July-August 2023, under natural weather conditions in the botanical garden of Banaras Hindu University, Varanasi. Different doses of SA (0.69 ppm – 13.8 ppm) was sprayed on the shoot of the plants. Compared to the control group, SA application at 0.69 ppm, 1.38 ppm, and 2.76 ppm showed increased growth and yield of the plants. SA applied at 1.38 ppm concentration, particularly, gave maximum increments in the length and biomass of the crop. SA application reduced the formation of oxidative stress markers (H2O2, SOR, MDA) by increasing the activities of antioxidants like SOD, POD, APX, total phenol, and proline. Salicylic acid treatment also increased the nutritive value of the crop by increasing the level of Ca, Mg, Fe, Zn, and protein, while reduced the levels of oxalic acid. The photosynthetic efficiency of the PSII was strengthened better with 1.38 ppm SA application by increasing chlorophyll content, allocation of absorbed light energy to drive the photochemical process, and quenching of the heat energy. The metabolic profiling via UHPLC-Q-TOF-MS/MS revealed increase in the number and proportion of secondary metabolites belonging to phenolic, alkaloids, terpenoid, flavonoids, betalains, and coumarins group by 240%, 127%, 37%, 182%, 83%, and 90% respectively. Hence, 1.38 ppm of SA has been considered as the suitable dose for spraying on Amaranthus hybridus for increased growth and biomass.

Penerapan Algoritma K-Means untuk Klasterisasi Produksi Budidaya Perikanan Provinsi Sulawesi Utara

Capture fisheries production is decreasing due to natural resources or weather conditions, so other resources are needed to support fisheries production. One alternative is to increase the production of aquaculture commodities through seawater, freshwater, or brackish water cultivation. Various potentials for developing aquaculture have been developed in various regions, including the North Sulawesi region. Grouping aquaculture commodity production according to container type is very important to maintain and increase aquaculture production. This research aims to cluster aquaculture production in the North Sulawesi area using the K-Means method using Euclidean, Manhattan, and Minkowsky distances. The results of the research obtained three clusters, namely the first cluster, the region with the highest production of pond container types, namely the Sitaro Islands, and for second cluster consisting of 13 regions that have variations in production ranging from low to high for the types of floating net containers and ponds, while third cluster is the region Bitung with moderate production for pond types. It is hoped that this research can help related agencies to create policies to increase the production potential of aquaculture.

Development of a Mini Weather Station Based on Rainboard and Android Applications in Cipageran Cimahi

Every airport necessitates a weather station to furnish crucial weather information for aircraft operations. However, not all airports possess adequate weather stations due to their high costs and susceptibility to damage. Consequently, both new and established small airports require weather stations. Thus, this study endeavors to develop affordable mini weather station equipment composed of cost-effective domestic components. Development and testing of this equipment tookplace in Cipageran Cimahi, representative of Indonesia's natural weather conditions. After conducting various tests, sufficient weather data was obtained, closely resembling actual weather station conditions. The hardware utilized comprises budget-friendly options such as Rainboard or Arduino Uno, paired with domestic component sensors. Data is displayed through Android-based applications and compared against calibration tools like "heles" and BMKG Info. While the sensor and calibration tool data exhibited symmetrical results, BMKG Info differed due to its broader coverage area, unlike the local weather measurements obtained by the sensors and calibration tools. Further refinement of this equipment can be achieved by employing superior sensor components and ensuring calibration.

Mainstreaming climate change in policy frameworks for community-based natural resource management in a semi-arid savannah environment: case study of Botswana

Community-based natural resource management (CBNRM) is a concept that was introduced in southern Africa back in the 1980s with the dual aim of biodiversity conservation and poverty reduction in communities endowed with natural resources. Community-based tourism (CBT), one of the major forms of CBNRM, depends on natural resources, particularly wildlife, and weather and climatic conditions. However, natural resources are under threat from climatic changes and other anthropogenic and natural disturbances. This calls for the need to interrogate the extent to which CBNRM initiatives mainstream climate change in their agenda. The main aim of this article is to assess the extent to which the climate change agenda has been mainstreamed into the policy framework of Botswana's CBNRM program. The specific objectives are to (1) document the impacts of climate change on CBNRM-related initiatives in Botswana; (2) determine the relationship between climate parameters (temperature and rainfall), extreme events (drought and extreme heat), and visitor trends in Botswana and the Okavango Delta; (3) establish a historical correlation between evolution of climate change policy and CBNRM policy and vice versa, policy initiatives, programs, strategies, and projects in Botswana; (4) explore the extent to which international, regional, national, and local climate policies mainstream CBNRM and tourism issues and vice versa; and (5) explore the challenges and opportunities related to climate change and CBNRM, with a particular focus on adaptation and mitigation initiatives. This study mostly used qualitative approaches (desktop review of policy documents and scholarly articles) as well as secondary quantitative data (time-series data) to explore the evolution of CBNRM in Botswana, providing an overview of its structure, policy initiatives, programs, and projects and how these correspond with climate change issues. A scoping review was conducted to identify relevant studies on the impacts of climate change on CBNRM initiatives published between 1992 and 2023. A total of 50 articles were identified to answer the following research question: What evidence is available regarding the impacts of climate change on CBNRM initiatives? The article further looks at how climate change–related extreme events, particularly drought, has affected tourism performance over the years. The article then zeros down on the effects of climate change on CBNRM initiatives and the challenges, threats, and opportunities, as well as the mitigation and adaptation strategies adopted by the CBNRM projects in Botswana. The findings indicate that climate change–induced events, particularly drought, have affected nature-based tourism products in Botswana. However, it was revealed that although there is no statistically significant correlation between drought and tourism performance, evidence from the literature reveals that drought has impacted tourism in Botswana. The findings from policy analysis indicate that the climate change agenda is woven into more recent key legal and policy documents on CBNRM, on one hand, while the climate change policy documents also include components that speak to CBNRM, on the other. This implies that the tourism sector can leverage these provisions to strengthen climate resilience through transformative adaptation and mitigation action.

Potentially Massive and Global Non-Pyrogenic Production of Condensed "Black" Carbon through Biomass Oxidation.

With the increased occurrences of wildfires worldwide, there has been an increase in scientific interest surrounding the chemistry of fire-derived "black" carbon (BC). Traditionally, wildfire research has assumed that condensed aromatic carbon (ConAC) is exclusively produced via combustion, and thus, ConAC is equated to BC. However, the lack of correlations between ConAC in soils or rivers and wildfire history suggests that ConAC may be produced non-pyrogenically. Here, we show quantitative evidence that this occurs during the oxidation of biomass with environmentally ubiquitous hydroxyl radicals. Pine wood boards exposed to iron nails and natural weather conditions for 12 years yielded a charcoal-like ConAC-rich material. ConAC was also produced during laboratory oxidations of pine, maple, and brown-rotted oak woods, as well as algae, corn root, and tree bark. Back-of-the-envelope calculations suggest that biomass oxidation could be producing massive non-pyrogenic ConAC fluxes to terrestrial and aquatic environments. These estimates (e.g., 163-182 Tg-ConAC/year to soils) are much higher than the estimated pyrogenic "BC" fluxes (e.g., 128 Tg-ConAC/year to soils) implying that environmental ConAC is primarily non-pyrogenic. This novel perspective suggests that wildfire research trajectories should shift to assessing non-pyrogenic ConAC sources and fluxes, developing new methods for quantifying true BC, and establishing a new view of ConAC as an intermediate species in the biogeochemical processing of biomass during soil humification, aquatic photochemistry, microbial degradation, or mineral-organic matter interactions. We also advise against using BC or pyrogenic carbon (pyC) terminologies for ConAC measured in environmental matrices, unless a pyrogenic source can be confidently assigned.

Assessment of color and contact angle changes in waterborne stained wood under natural weathering condition of South Korea’s summer climate

This study aimed to develop a waterborne stain (WBS) that protects against weathering and increases resistance of wood to fungi when exposed to heavy rainfall. The WBS was prepared using an antibacterial agent, insect repellent, and copper nanoparticle solution (CN) as a surface coating agent. The WBS was applied on larch and hemlock wood, and changes in color and wettability due to natural and artificial weathering were evaluated. A gray-blue spot developed on the untreated wood surface within 30 d of outdoor exposure, which then spread over the entire wood surface, and the wood eventually turned black. Resistance to fungi increased when CN alone was applied; however, the CN surface was oxidized and turned gray after 30 d and 90 d for larch and hemlock, respectively. The water contact angle was increased due to leaching. The application of CN followed by WBS prevented wood discoloration under ultraviolet light and the wood showed excellent weathering resistance capacity. The prevention of wood discoloration and resistance to fungi by CN were confirmed, which could guide the development of a paint that can prolong protection from weathering of wood exposed to heavy rainfall events.

The role of an Ascophyllum nodosum extract in lowering the environmental impact and improving nitrogen use efficiency in pasture systems under a reduced nitrogen regime

Nitrogen is a macronutrient that is applied in substantial amounts as a chemical fertiliser to conventional agricultural systems. However, loss of nitrogen from agricultural systems to the environment, in the form of gases (N2O) and leachate (NO3), is detrimental to the environment. As such, improving the nitrogen use efficiency (NUE) of crops is an essential component of sustainable agriculture. Biostimulants are a category of products that improve NUE when applied to crops and/or soil. Here, we examined the effects of PSI-362, an Ascophyllum nodosum biostimulant mixed with and applied on calcium ammonium nitrate (CAN) granules, on grass yield, quality traits, and environmental impacts in lysimeter trials under natural weather conditions. By using PSI-362, it was possible to reduce nitrogen application by 25% without a significant loss in yield compared to a conventional 100% N system. We also observed an increase in NUE under a 75% N with PSI-362 co-application fertilisation regime, and a significant increase in crude protein content compared to the 100% N fertilisation controls. Furthermore, this reduced nitrogen application also resulted in reduced nitrogen loss through leachate (NO3) and N2O to the atmosphere. The total NUE for PSI-362 + fertiliser granules ranged from 58.7% to 78.6% depending on the biostimulant dose, which was significantly better than the fertiliser alone. Our results showed that this biostimulant, which can easily be incorporated into conventional agronomic practices, allows for a more sustainable approach to pasture-based systems.

Innovation Activities to Reduce Food Losses and Food Waste in the Slovak Republic

Due to its dependence on natural resources and weather conditions, agriculture is widely acknowledged as one of the most vulnerable sectors when talking about climate change. Lower yields and productivity, droughts, and water shortages have had an impact on food security globally. The food system using agrochemicals, cattle breeding, processing storage, transportation, and trade contributes even more to global emissions. Incorporating sustainability in the production of diverse and healthy food as a systematic approach to the concept of food security is challenging for the future capacity reduction of ecological systems due to the degradation of natural resources and the rise in social and economic inequality. Regenerative agricultural production that ensures long-term food security and nutrition, as well as processing and trade are therefore essential currently to secure the cooperation of social and economic systems. The main goal of the presented scientific paper is to point out the serious challenge of today related to environmental food losses and food waste in the world and the Slovak Republic in particular.

AdvRain: Adversarial Raindrops to Attack Camera-Based Smart Vision Systems

Vision-based perception modules are increasingly deployed in many applications, especially autonomous vehicles and intelligent robots. These modules are being used to acquire information about the surroundings and identify obstacles. Hence, accurate detection and classification are essential to reach appropriate decisions and take appropriate and safe actions at all times. Current studies have demonstrated that “printed adversarial attacks”, known as physical adversarial attacks, can successfully mislead perception models such as object detectors and image classifiers. However, most of these physical attacks are based on noticeable and eye-catching patterns for generated perturbations making them identifiable/detectable by the human eye, in-field tests, or in test drives. In this paper, we propose a camera-based inconspicuous adversarial attack (AdvRain) capable of fooling camera-based perception systems over all objects of the same class. Unlike mask-based FakeWeather attacks that require access to the underlying computing hardware or image memory, our attack is based on emulating the effects of a natural weather condition (i.e., Raindrops) that can be printed on a translucent sticker, which is externally placed over the lens of a camera whenever an adversary plans to trigger an attack. Note, such perturbations are still inconspicuous in real-world deployments and their presence goes unnoticed due to their association with a natural phenomenon. To accomplish this, we develop an iterative process based on performing a random search aiming to identify critical positions to make sure that the performed transformation is adversarial for a target classifier. Our transformation is based on blurring predefined parts of the captured image corresponding to the areas covered by the raindrop. We achieve a drop in average model accuracy of more than 45% and 40% on VGG19 for ImageNet dataset and Resnet34 for Caltech-101 dataset, respectively, using only 20 raindrops.

A Micromechanical Modeling Approach for the Estimation of the Weathering-Induced Degradation of Wind Turbine Blades

Glass fiber reinforced polymers (GFRPs) are widely used as composite material for a variety of applications such as wind turbine blades (WTBs). During their operating time, these GFRP structures are exposed to natural weathering conditions, such as low and elevated temperatures, ultraviolet radiation, and moisture. These weathering phenomena influence the material’s mechanical properties due to material aging and the degradation of the composite’s mechanical properties. For a reliable lifetime assessment and the design of a repurposed application of WTBs, the quantification of GFRP’s degradation is required. For this reason, the aim of the current study is to numerically estimate the combined effects of weathering on the mechanical properties of GFRP. Therefore, the effective elastic properties of a unidirectional GFRP composite were determined considering representative volume elements. The required numerical modeling was performed using finite element analysis. The mechanical properties of glass fibers, epoxy resin and their relationship with individual natural aging phenomena were used based on the existing literature values. As a result of the micromechanical modeling, the change of temperature and moisture absorption have the highest effect on the elastic properties on the epoxy resin and thus also on the GFRP composite. The used numerical approach enables a preliminary estimation of environmental-based degradation phenomena of GFRP which can be used at an early stage of developments of composite structures, the reuse of composites or for planning experimental studies considering degradation of these composite materials.