Search Results (12)

This study examines the effects of hailstorms on photovoltaic (PV) modules, focussing on damage mechanisms, testing standards, numerical simulations, damage detection techniques, and mitigation strategies. A comprehensive review of the recent literature (2017–2025), experimental results, and case studies is complemented by advanced simulation methods such as finite element analysis (FEA) and smoothed particle hydrodynamics (SPH). The research emphasises the crucial role of protective glass thickness, cell type, number of busbars, and quality of lamination in improving hail resistance. While international standards such as IEC 61215 specify test protocols, actual hail events often exceed these conditions, leading to glass breakage, micro-cracks, and electrical faults. Numerical simulations confirm that thicker glass and optimised module designs significantly reduce damage and power loss. Detection methods, including visual inspection, thermal imaging, electroluminescence, and AI-driven imaging, enable rapid identification of both visible and hidden damage. The study also addresses the financial risks associated with hail damage and emphasises the importance of insurance and preventative measures. Recommendations include the use of certified, robust modules, protective covers, optimised installation angles, and regular inspections to mitigate the effects of hail. Future research should develop lightweight, impact-resistant materials, improve simulation modelling to better reflect real-world hail conditions, and improve AI-based damage detection in conjunction with drone inspections. This integrated approach aims to improve the durability and reliability of PV modules in hail-prone regions and support the sustainable use of solar energy amidst increasing climatic challenges. Full article

Recent advances in prefabricated construction have enabled modular systems offering structural performance, rapid assembly, and design flexibility. Textile Ceramic Technology (TCT) integrates ceramic elements within a stainless-steel mesh, creating versatile architectural envelopes for façades, roofs, and pavements. This study investigates the integration of silicon photovoltaic (PV) modules into TCT to develop an industrialized Building-Integrated Photovoltaics (BIPV) system that maintains energy efficiency and visual coherence. Three full-scale solar brick prototypes are presented, detailing design objectives, experimental results, and conclusions. The first prototype demonstrated the feasibility of scaling small silicon PV units with good efficiency but limited aesthetic integration. The second embedded PV cells within ceramic bricks, improving aesthetics while maintaining electrical performance. Durability tests—including humidity, temperature cycling, wind, and hail impact—confirmed system stability, though structural reinforcement is needed for impact resistance. The third prototype outlines future work focusing on modularity and industrial scalability. Results confirm the technical viability of silicon PV integration in TCT, enabling active façades that generate renewable energy without compromising architectural freedom or aesthetics. This research advances industrialized, sustainable building envelopes that reduce environmental impact through distributed energy generation. Full article

For several years now, fruit-growers have increasingly often used pre-tensioned, pre-stressed concrete posts for supporting branches of fruit trees and suspending protective nets in order to limit damage to fruits caused by hail, wind, snow, heavy rainfall, insects and birds. Pre-tensioned, pre-stressed concrete posts most often have a trapezoidal cross-section, which is ideally suitable for mass production in a self-supporting non-dismantlable steel mould on a pre-stressing bed. Posts with 70 mm × 75 mm, 80 mm × 85 mm and 90 mm × 95 mm cross-sections are typically produced, whereas 100 mm × 120 mm and 130 mm × 140 mm posts are manufactured to order. Furthermore, it is proposed to produce hollow posts. Such posts are lighter than solid posts, but they require a more complicated production technology. This paper presents selected parts of a comparative computational–experimental analysis of solid and hollow posts. In the Building Structures Laboratory in the Building Structures Department at the Civil Engineering Faculty of the Wrocław University of Science and Technology, experimental tests of pre-stressed concrete orchard posts of 70 mm × 75 mm and 90 mm × 95 mm with solid and hollow cross-sections were carried out on a full scale. The theoretical analysis and research has shown that the resistance to bending, cracking resistance and rigidity of hollow posts (with their cross-sectional outline unchanged) will not significantly differ from those of the currently produced solid posts. At same time, material savings will be achieved. Therefore, the main task is to master the continuous moulding of hollow posts from dense plastic concrete with the simultaneous pulling out of the cores, producing longitudinal hollows in the posts. Full article

The use of composite materials in aerospace structures has led to significant weight reductions and improved performance. However, their behavior under low-energy impact remains a critical concern due to the potential initiation of barely visible damage. This study investigates the crack initiation mechanisms in composite airfoil profiles subjected to low-energy impact, simulating real-world scenarios such as hail or bird strikes. Two types of airfoil profiles were fabricated using bidirectional carbon fiber reinforced polymer (CFRP) with epoxy resin and tested under ASTM D7136 impact conditions. Tensile tests following ASTM D3039 were conducted to assess post-impact mechanical behavior. The damage patterns were analyzed using high-resolution microscopy and non-destructive inspection techniques. Results revealed that damage severity and propagation depend on impact energy levels and airfoil geometry, with SC(2)-0714 exhibiting better impact resistance than GOE777-IL. Microscopic analysis confirmed that delamination initiated at 45° fiber orientations, expanding along interlaminar regions, while airfoil curvature influenced the impact energy dissipation. Full article

Long-term reliability is crucial for the commercialization of semi-transparent photovoltaic panels based on Luminescent Solar Concentrators (LSCs). This study addresses key challenges such as photodegradation and hail resistance using glazed LSC prototypes functionalized with organic Lumogen F dyes. A pilot-scale batch of LSC prototypes (10 × 10 cm²) underwent extensive outdoor exposure tests following the IEC 62108 “10.15 Outdoor Exposure Test” to evaluate long-term stability under natural solar radiation. Continuous monitoring revealed that prototypes with Lumogen F Red 305 experienced a 29% efficiency drop initially, which stabilized over time, indicating potential long-term stability. In contrast, those with Lumogen F Violet 570 showed minimal degradation, with only a 9% efficiency reduction. Additionally, the hail resistance of LSC panels was tested using the IEC 62108 “10.9 Hail Impact Test”. Panels with varying glass thickness, tempering methods, and surface areas were subjected to impact from 25 mm hailstones launched at 22.4 ± 5% m/s. All samples remained undamaged, highlighting their excellent hail resistance, a critical feature for preserving performance despite potential surface damage. This study demonstrates that combining glazed lightguides with polyvinyl butyral improves photostability and provides a cost-effective alternative to expensive fluorophores, while ensuring compliance with hail resistance standards. Full article

Background: Antibiotic (AB) resistance is caused partly by overuse, varies by region, and is influenced by prescriber perspectives. This study sought to determine physicians’ knowledge and attitudes toward AB prescribing, particularly in the Hail region of Saudi Arabia. Methods: An interdisciplinary team created and validated an electronic questionnaire via the test–retest method that measured reliability and consistency. The 19 questions covered the following subjects: demographic information (7), experience with AB resistance in daily work (3), AB prescribing behavior (2), communication with patients regarding AB resistance (3), and prescribing practices (4). The revised questionnaire was prepared and distributed to physicians in the Hail region via multiple electronic communication channels. Inferences were drawn based on descriptive statistics and multivariate regression analysis. Results: The questionnaire responses of 202 participants were eligible for analysis. A total of 70 (34.80%) participants were general practitioners, 78 (38.12%) were engaged in daily work that was only mildly related to AB resistance, and 25 (12.37%) performed work that was substantially related to AB resistance. A total of 88 (43.56%) physicians believed that prescribing behavior contributed to the emergence of AB resistance, whereas 68 (33.66%) did not. Regarding exposure, 51 (25.24%) physicians reported encountering instances of AB resistance monthly, whereas 104 (51.48%) reported seeing cases of AB resistance very rarely. In terms of prescribing practices, 99 (49.0%) physicians prescribed ABs to patients daily and 73 (36.13%) weekly. Regarding AB-resistance-related communication with patients, 73 (36.13%) physicians frequently discussed AB resistance with patients suffering from infections, whereas 13 (6.4%) never discussed it with patients. Conclusion: General practitioners in the Hail region exhibited comprehensive awareness of the elements that contribute to AB resistance but only rarely communicated about the issue with their patients, presuming the latter to be oblivious to the science behind AB resistance. Our findings suggest that the features underlying practitioners’ AB prescribing behavior could be a powerful strategy for lowering AB resistance. Full article

Staphylococcus aureus (S. aureus) is a ubiquitous pathogen responsible for several severe infections. This study aimed to investigate the adhesive properties and antibiotic resistance among clinical S. aureus isolated from Hail Hospital Province, Kingdom of Saudi Arabia (KSA), using molecular approaches. This study was conducted according to the ethical committee at Hail’s guidelines on twenty-four S. aureus isolates. A polymerase chain reaction (PCR) was performed to identify genes encoding the β-lactamase resistance (blaZ), methicillin resistance (mecA), fluoroquinolone resistance (norA), nitric oxide reductase (norB), fibronectin (fnbA and fnbB), clumping factor (clfA) and intracellular adhesion factors (icaA and icaD). This qualitative study tested adhesion based on exopolysaccharide production on Congo red agar (CRA) medium and biofilm formation on polystyrene by S. aureus strains. Among 24 isolates, the cna and blaz were the most prevalent (70.8%), followed by norB (54.1%), clfA (50.0%), norA (41.6%), mecA and fnbB (37.5%) and fnbA (33.3%). The presence of icaA/icaD genes was demonstrated in almost all tested strains in comparison to the reference strain, S. aureus ATCC 43300. The phenotypic study of adhesion showed that all tested strains had moderate biofilm-forming capacity on polystyrene and represented different morphotypes on a CRA medium. Five strains among the twenty-four harbored the four genes of resistance to antibiotics (mecA, norA, norB and blaz). Considering the genes of adhesion (cna, clfA, fnbA and fnbB), these genes were present in 25% of the tested isolates. Regarding the adhesive properties, the clinical isolates of S. aureus formed biofilm on polystyrene, and only one strain (S17) produced exopolysaccharides on Congo red agar. All these results contribute to an understanding that the pathogenesis of clinical S. aureus isolates is due to their antibiotic resistance and adhesion to medical material. Full article

Background: Marketed fish and shellfish are a source of multidrug-resistant and biofilm-forming foodborne pathogenic microorganisms. Methods: Bacteria isolated from Sparus aurata and Penaeus indicus collected from a local market in Hail region (Saudi Arabia) were isolated on selective and chromogenic media and identified by using 16S RNA sequencing technique. The exoenzyme production and the antibiotic susceptibility patterns of all identified bacteria were also tested. All identified bacteria were tested for their ability to form biofilm by using both qualitative and quantitative assays. Results: Using 16S RNA sequencing method, eight genera were identified dominated by Vibrio (42.85%), Aeromonas (23.80%), and Photobacterium (9.52%). The dominant species were V. natrigens (23.8%) and A. veronii (23.80%). All the identified strains were able to produce several exoenzymes (amylases, gelatinase, haemolysins, lecithinase, DNase, lipase, and caseinase). All tested bacteria were multidrug-resistant with a high value of the multiple antibiotic index (MARI). The antibiotic resistance index (ARI) was about 0.542 for Vibrio spp. and 0.553 for Aeromonas spp. On Congo red agar, six morphotypes were obtained, and 33.33% were slime-positive bacteria. Almost all tested microorganisms were able to form a biofilm on glass tube. Using the crystal violet technique, the tested bacteria were able to form a biofilm on glass, plastic, and polystyrene abiotic surfaces with different magnitude. Conclusions: Our findings suggest that marketed S. aurata and P. indicus harbor various bacteria with human interest that are able to produce several related-virulence factors. Full article

The devastating nosocomial resistance is an on-going global concern. Surveillance of resistance is crucial for efficient patient care. This study was aimed to conduct a surveillance in four major Ha’il Hospitals from September to December 2020. Using a multipoint program, records of 621 non-duplicate Gram-negative cultures were tested across 21 drugs belonging to different categories. Major species were Klebsiella pneumoniae (n = 187, 30%), E. coli (n = 151, 24.5%), Pseudomonas aeruginosa, (n = 84, 13.6%), Acinetobacter baumannii (n = 82, 13.3%), and Proteus mirabilis (n = 46, 7%). Based on recent resistance classifications, A. baumanni, P. aeruginosa, and enteric bacteria were defined as pan-resistant, extremely resistant, and multi-drug resistant, respectively. A. baumannii (35%) and K. pneumoniae (23%) dominated among coinfections in SARS-CoV2 patients. The “other Gram-negative bacteria” (n = 77, 12.5%) from diverse sources showed unique species-specific resistance patterns, while sharing a common Gram-negative resistance profile. Among these, Providencia stuartii was reported for the first time in Ha’il. In addition, specimen source, age, and gender differences played significant roles in susceptibility. Overall infection rates were 30% in ICU, 17.5% in medical wards, and 13.5% in COVID-19 zones, mostly in male (59%) senior (54%) patients. In ICU, infections were caused by P. mirabilis (52%), A. baumannii (49%), P. aeruginosa (41%), K. pneumoniae (24%), and E. coli (21%), and most of the respiratory infections were caused by carbapenem-resistant A. baumannii and K. pneumoniae and UTI by K. pneumoniae and E. coli. While impressive IC, hospital performances, and alternative treatment options still exist, the spread of resistant Gram-negative bacteria is concerning especially in geriatric patients. The high selective SARS-CoV2 coinfection by A. baumannii and K. pneumoniae, unlike the low global rates, warrants further vertical studies. Attributes of resistances are multifactorial in Saudi Arabia because of its global partnership as the largest economic and pilgrimage hub with close social and cultural ties in the region, especially during conflicts and political unrests. However, introduction of advanced inter-laboratory networks for genome-based surveillances is expected to reduce nosocomial resistances. Full article

Carbon fiber-reinforced polymer (CFRP) laminates, a key composite material, are widely used in aircraft structures and are susceptible to low-velocity impact (LVI) damage from bird strikes, lightning strikes, hail impacts and other situations. Therefore, finding a method that repairs the damaged structure and detects the effect of these repairs under LVI is a very important goal. In this work, the repair effect of LVI damage in CFRP laminates repaired with patches of various sizes is investigated via experimental and numerical nonlinear Lamb wave analyses. An integrated numerical procedure that combines LVI with nonlinear Lamb wave detection is developed to predict the nonlinear Lamb wave behavior in LVI-damaged patch-repaired CFRP laminates. The CFRP laminate damage in the nonlinear Lamb wave simulation is evaluated based on relative acoustic nonlinearity parameters (RANPs). As a result, the integrated numerical procedure is validated with drop-weight impact tests and RAM-5000 SNAP nonlinear ultrasonic detection system. An optimal patch design is established via interpolation to optimize the absorbed energy, delamination surface area, second RANP and third RANP with different patch repair sizes. These parameters exhibit consistent curve fitting trends, indicating that they can be used as important indicators of impact damage. The optimal circular patch design with a radius of 2.5 r has better impact resistance behavior and repair performance. Full article

This paper analyzes the resistance to hail of external thermal insulation composite systems (ETICS), i.e., external thermal insulation of foamed polystyrene with the same finishing coat and various reinforcing mesh and base coats used to make the reinforced layer. The manuscript presents our own new method for assessing ETICS resistance to hail and test results obtained according to this method. The basic premise of the presented new research methodology is evaluation of the thermal insulation system surface damage and fracture toughness, in the function of hit velocity with a polyamide ball with a standardized diameter and weight. The results of hail resistance tests were compared with the values of hard body impact resistance obtained in the tests done according to ETAG 004. Results obtained by the new method help to evaluate precisely the resistance of thermal insulation sets to damage as a result of impact of heavy objects of permanent shape, with greater accuracy than the hard body impact test. They also confirmed that thermal insulation sets with dispersion adhesive in the reinforcement demonstrate greater resistance to damage as a result of hail impact than the sets with cement-based adhesives and that weight of the reinforcing mesh used in the system is not significant to affect the hail resistance. Full article

The impact of hail ice cubes on composite structures (such as solar cells) causes actual defects. This article presents a series of tests, in which solar cell modules were exposed to hail simulation testbed balls, allowing to assess the following: the impact energy, which causes the major defects in solar cells; the formed micro-cracks in the structure of solar cells, resulting in the loss of power generated by a solar cell; and the solar cell parameters necessary for modelling. In addition, this article presents a digital analysis of hail simulation. Information received from the digital analysis was used to optimize the structure of solar cells in order to improve its resistance properties. The aim of this study was to present a simple method for experimental hail simulation. The proposed hail impact estimation method can be successfully applied to study the influence of the mechanical–dynamic impact of photovoltaic (PV) modules of different structures on the technical characteristics of these modules (structural stability, power generation, etc.). The study showed that PV modules are subjected to an irreversible effect of the excitation force (i.e., micro-cracking) and it can reduce the generated power by 2.33% to 4.83%. Full article