Hard Surface Research Articles

OVERVIEW OF MECHANIZED CARE EQUIPMENT BY THE HOOVES OF CATTLE

The current conditions of keeping cattle in specialized industrial complexes and large farms often lead to traumatism of the hooves, which can ultimately lead to pathology of the limbs. This negatively affects the productivity of animals and, as a result, causes significant economic losses in the livestock sector. Several reasons have been identified that cause trauma to cattle limbs and lead to their pathology. Yes, hard surfaces, slotted floors, and conveyor-type conveyors for removing manure have a negative effect on the animals' hooves. Up to 40% of animals suffer from limb diseases when cows are tethered, while up to 90% in monoblock cowsheds of the untethered type. In dairy enterprises, among all mechanical injuries to cows, from 60% to 80% are limb diseases caused by trauma to the hooves and toes. In order to prevent and successfully treat horn diseases in cattle on specialized farms and dairy complexes, it is necessary to improve treatment methods, animal care rules, and methods of cleaning and trimming horn growth of hooves. Trimming and cleaning of hooves are quite time-consuming operations, which are among the mandatory measures for the prevention of diseases of the limbs of animals. This operation is performed 2-3 times a year. At the same time, the excess layer of horny growth is cut off, and the legs are given an optimal shape. This ensures uniform distribution of the load over the entire support surface of the limb. The used mechanical means for trimming hooves have some disadvantages. Such a large mass and the lack of regulation of cutting modes depending on the physical and mechanical properties of the horn growth do not contribute to high-quality processing of hooves. The review of systems and equipment for cutting hoof horn growth in cattle, especially cows, shows that this direction of research is relevant and promising. To increase the productivity of trimming hooves and ensure their natural geometric shape and the necessary roughness of the treated surface, it is advisable to conduct further research on the justification of structural and technological parameters and modes of operation of mechanical equipment for effective care of cattle hooves.

Effective elimination of bacteria on hard surfaces by the combined use of bacteriophages and chemical disinfectants.

In this study, we investigated whether the combination of bacteriophages and chemical disinfectants can enhance the efficacy of reducing bacterial contamination on hard surfaces in the clinical setting. We found that specific phages are active in chemical disinfectants and that the combined use of phages and chemical disinfectants was highly effective in reducing bacterial presence on hard surfaces. As a proof-of-concept, we demonstrated that adding specific phages directly to chemical disinfectants is an effective and cost-efficient strategy for clinical environment disinfection.

A critical review on the effect of various sustainable reinforcements on armor grade aluminum alloys

To deflect projectiles with kinetic energy by blunting them upon impact, armor with an exceptionally hard surface is required.In order to absorb and disperse the projectile's kinetic energy, the next material needs to be exceedingly tough and have a high work of fracture; hence, it needs to be metallic. To maximize the strength to weight ratio, it must also be composed of a versatile material, such as ceramic. Thus, the application requires a range of qualities, ranging from ceramic to metallic. Aluminum alloys (AAs) are sought-after materials for a variety of engineering and defense uses owing to their excellent low-temperature characteristics, good specific strength, and acceptable corrosion resistance. The main issues with AAs are poor heat tolerance and wear resistance, which makes them unsuitable for military applications owing to their heavy weight, which can exacerbate the deterioration of mechanical components and impair vehicle maneuverability and speed. This paper offers the possibility of modifying the properties of monolithic aluminum materials by adding reinforcement and replacing conventional particulates with low-cost wastes derived from agriculture and industry, which are rich in oxides and other debris, such as fly ash (FA) and rice husk ash (RHA). The result is the development of hybrid aluminum metal matrix composites, or HAMMCs, which combine the best features of both metals with a variety of sustainable inorganic and organic reinforcements that can enhance the mechanical and tribological performances by 40–62 % in comparison to the basic matrix. So, they can be tailored to meet the needs that make their performance superior compared to unreinforced AAs. Through a review of existing literature, this paper will provide an outline of the effect of various kinds of reinforcements on armor-grade aluminum alloys.

Using Smartphones to Innovate Laboratories in Introductory Physics Courses

The SmartPhysics project involved two higher education institutions, one in Italy and one in the US, with the aim of exploring the use of smartphones for laboratory experiments in introductory Physics courses. Here we present and discuss two experiments that were developed in the project: the pendulum experiment, consisting in the measurement of the gravitational constant using a proximity stopwatch, and the ‘bouncing ball’ experiment, aimed at measuring the energy lost inelastic collisions with a hard surface. Both experiments were tested with the students in the academic year 2021-22. Our results and didactical reflections contain suggestions for the use of smartphone-based experiments in university settings, in comparison with traditional experiments and considering the specificities of different contexts.

Factors determining changes in the network of marked hiking trails in the Sudetes

Hiking trails are a basic type of tourist infrastructure, which, on the one hand, make areas available for tourist traffic, and on the other hand, can contribute to the protection of the natural environment (if they are well designed and maintained). Owing to the variety of performed functions, their designation is determined by several factors: natural, technical, economic, social. Networks of trails change constantly. The aim of this article is to determine exactly what factors influence transformations within the hiking trail networks and what is their significance. To this end, three study areas in the Sudetes were analysed: one on the Polish side of the Sudetes–the Table (Stołowe) Mountains, and two on the Czech side–the rock town near the village of Sloup v Čechách and the central part of Zlatohorská vrchovina. An analysis of changes in the shape of the networks over time was carried out, as well as surveys of institutions that were responsible for or influenced these transformations. These areas are characterised by a significant level of changes in the trail network. Among the factors influencing these changes, the tourist attractiveness of the area, the resilience of the environment, the intensity of tourism traffic, the environmental transformations associated with it, the history of tourism development and land ownership changes should be considered the most important. At each stage of forming networks, the key factor should be tourists’ needs, including the desire to escape the urbanised environment. For this reason, trails should avoid roads with artificial (hard) surfaces and heavy automobile traffic.

Synthesis and Analysis of Novel Hyaluronic Acid-Based Dual Photocrosslinkable Tissue Adhesive: An In Vitro Study.

Background Tissue adhesives are mainly used for aiding in the attachment of adjacent tissues or to nearby hard tissue surfaces. They promote the natural healing processes of the tissues, especially for less painful closure, simple application, no need for sutures following surgery, and localized drug release. This study aimed to synthesize and assess the properties of hyaluronic acid (HA)-based, dual photocrosslinkable tissue adhesive. Materials and methodology N-hydroxysuccinimide (NHS), 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC), HA, and polymethylmethacrylate, which served as a photoinitiator, were combined to synthesize a tissue adhesive. The prepared formulation was characterized, and its biocompatibility was assessed. Results Surface morphology, mechanical properties, and biological properties of the HA adhesive were comparable to those of conventional fibrin glue. Scanning electron microscopy (SEM) analysis showed the average size of the molecules, 10-25 mm in diameter, and also showed a smooth and nonporous surface. The specimens experienced maximum compressive stress of 0.06 ± 0.02 MPa, compressive strain of 3.07 ± 2.02, and a compressive displacement at break of 3.04 ± 1.23 mm, with a maximum force of 2.33 ± 0.07 N at break. The cytotoxicity assay results for HA and fibrin glue are almost equal. Conclusion HA-based photocrosslinkable tissue adhesive could be a potential biomaterial in various applications in the field of medicine, especially in soft tissue management.

Adaptability of VisCalor versus bulk-fill composites using scanning electron microscope: an in-vitro study

Purpose To evaluate the marginal integrity of two types of bulk-fill composite resins in Class I box-shaped cavities. Materials and methods Forty extracted human sound molars were selected. The teeth were fixed with sticky wax to the base of plastic cylinder and the cylinder was filled with self-curing acrylic resin so that only root was embedded. Simple Class I box-shaped cavities were prepared using a fissure carbide bur with water spray and finished with fine-grained flame burs. The overall dimensions and depth of the cavities were standardized as follows: 4 mm length mesiodistally and 3 mm width buccolingually and up to 4 mm depth. All prepared cavities were bonded using Futurabond M+ one-step self-etch adhesive system. The teeth were randomly divided into two groups (n = 20 teeth each): group I: specimens were restored with VisCalor composite bulk-fill composite resin, which is heated before insertion using a VisCalor dispenser dental device. Group II: specimens were directly restored with X-tra fill bulk-fill composite resin without preheating. After curing, finishing and polishing were performed. Each group was subdivided into two subgroups a and b (n = 10) according to whether subjecting 500 thermocycling fluctuations or not. Each specimen was sectioned buccolingually through the center of the composite resin restoration in two halves, and then cleaned under running tap water and subjected to thorough ultrasonic cleaning to get rid of both soft and hard surface deposits. All sectional samples were fixated in cylindrical carriers, and a thin layer of gold was applied to the surfaces. The marginal adaptation of composite restorations and ultramorphology of adhesive bonds were analyzed at ×50, ×1000 magnification, with a scanning electron microscope. ×50 magnification was utilized to measure the length of margins free gap in enamel and dentin by Autodesk Auto CAD program and expressed in mm/percent. All data of measurements of the length of nongaped margins in enamel and dentin are collected, tabulated, and statistically analyzed. Results Group Ia (VisCalor bulk-fill not thermocycled), recorded the highest mean value of marginal free-gap with 10.26 ± 0.27 mm (93.31%), while group IIb (X-tra-fill bulk-fill thermocycled) recorded the lowest mean value in 7.90 ± 0.26 mm (73.04%) and the difference was statistically highly significant (P = 0.000). In general, group I recorded higher mean values of marginal free gap and adaptation in mm/percent than group II, and the difference was statistically highly significant at P value of 0.000 (9.86 ± 0.55 and 8.23 ± 0.39 mm and 89.15 ± 5.38 and 74.89 ± 3.69%, respectively). Bulk-fill restorations without thermocycling exhibited a higher mean value of marginal free gap and adaptation in mm/percent than the thermocycled one with a significant difference recorded at P value of 0.005. Conclusion Using preheated VisCalor bulk-fill composites could decrease the marginal gap formation improving the continuity at the tooth–restorative material interface than conventional bulk-fill restorations. On the other hand, thermocycling.

Use of an Impact Recording Device to Determine the Risk of Bruising in Packaged Potatoes

Handling potatoes individually or collectively in packages can create opportunities for potatoes to develop quality defects including blackspot and shatter bruise. Three trials were conducted to examine how handling packaged potatoes can influence the risk for physical damage including shatter and blackspot bruise. An impact recording device was used to record peak acceleration (max g-force) in common fresh market packaging options (boxes or bales) at four drop heights (15 to 91 cm) on to three different surface types. When boxed potatoes were dropped onto concrete or a plastic slip, the potatoes on the bottom of the box had the highest risk of damage (greater than 100 g-force). When drop heights were lowered, or when cushioning material was added to hard surfaces (e.g., wooden pallet on top of concrete floor), the risk for impact damage was decreased throughout the box. When palletizing boxed potatoes, the risk of bruise decreased after the first layer was stacked on the pallet. Drop heights need to be below 15 cm, especially when making the first layer in a palletized stack of packaged potatoes to reduce potential bruising. The risk of high peak accelerations was not seen in the dropped or stationary bales for any of the drop heights examined. This study provided information for educating personnel on handling packaged potatoes and determining situations in which robotic stacking equipment needs to be adjusted to lower drop heights of packaged potatoes.

Acoustic signal monitoring using audible cracking sounds for efficient in-situ crack detection in laser directed energy deposition of hard surfaces

Laser directed energy deposition (LDED) is a promising way for creating hard surfaces like ceramic-reinforced metal matrix composites (MMC), but it faces a significant challenge in identifying crack formation during the process. As an emerging solution, acoustic signal monitoring is easy to be integrated within the process, and significantly reduces the time needed to detect micro-cracks in as-built MMC surfaces. This study reports on cracking sounds produced while employing LDED with SiC particles on a stainless steel 316 L substrate, examining the sound characteristics across time and frequency domains. Different sound sources in LDED are analyzed in the frequency domain, specifying the suitable frequency range for crack monitoring. Interestingly, the in-process micro-cracking on the hard surfaces produces a distinct audible ‘ping’ sound typically ranging between 12000 and 16000 Hz. By recording this sound, an efficient approach is proposed to identify crack generation during the rapid cooling in the LDED process of hard materials.

Effects of the Surface Type on the Sprint Force–Velocity–Power Profile of Female Beach Handball Top-Level Players

Beach handball (BH) is characterized by high-intensity actions, such as accelerations and short rest times, in combination with long periods of low-intensity activity during a match. The purpose of this study was to establish a comparative analysis between the effect of a hard surface vs. sandy surface on the properties of the sprint Force–Velocity–Power Profile (FVP) of female beach handball top-level players. Fourteen female BH players participated in this research. A cross-sectional investigation was performed in order to evaluate the determining variables of the FVP profile for different surfaces. After a specific warm-up, two maximal 20–30 m sprints (4 min resting between trials) were performed in two conditions (hard surface and sand) within 10 min. The female BH players showed higher mean values for all the FVP profile variables (p < 0.001) on the hard surface compared to sand, in addition to lower values for the 5 m (ES = 2.29 to 3.89) and 20 m sprinting times (ES = 2.39 to 3.99) (p < 0.001). However, the decrease in the ratio of force over acceleration was not discriminant between the surfaces. Positive correlations were found for the speed variables (0.691–0.807, p < 0.01), as well as the Pmax (0.520, p = 0.035), between the surfaces. A prior knowledge of the FVP profile for hard–sandy surfaces could offer an important reference value about the sprint properties of this population, and be useful for evaluating the efficiency, as well as the effect on the sprint and gaming performance, of specifically oriented training programs based on those reference values.

Insights into the risk of COVID-19 infection in urban neighborhood and its environmental influence factors:A novel approach

Many studies have dealt with the relationship between the built environment and COVID-19 infection in isolation. However, the research approaches were often inadequate in accurately reflecting the risk of COVID-19 infection. Therefore, we aim to develop a novel approach to study the risk of COVID-19 infection and its Environmental Influence Factors (EIFs) at the neighborhood scale. We constructed a multi-agent model of the spatial environment of residential quarters, including models of behavior and COVID-19 infection dynamics, and established 24 experimental schemes based on the Prevention and Control Measures (PCMs) of zonal control, mask-wearing, and outing frequency to simulate and assess the infection risk. The results show that the areas of accessible wood, hard surfaces, and seating are high-risk sites for infection. Zonal control and mask-wearing are effective PCMs, and the EIFs we set all play significant roles in influencing infection risk. Our study provides insight into the effects of PCMs and EIFs related to COVID-19 infection and highlights that the novel approach not only reveals the levels of infection risk and its mechanisms but also detects the spatio-temporal characteristics of behaviors and infection. This novel approach, dealing with individuals, space, environment, behavior, PCMs, and COVID-19 infection dynamics in integration, overcomes the limitations of traditional methods that overlook the influences of the spatio-temporal dynamics of individual behaviors and their environmental factors. It offers theoretical support for designing healthy outdoor built environments and technical support for the PCMs of the epidemic.

Analysis of Structure and Function of Ladybird Leg and Subsequent Design and Fabrication of a Simplified Leg Structure for Robotic Applications.

Many insects are able to walk vertically or upside down on both hard and soft surfaces. In beetles such as the ladybird (Coccinella septempunctata), intermolecular forces between tarsal setae on the footpads of the insects make this movement possible. In prior work, adhesion structures made from polydimethylsiloxane (PDMS) that mimic the action of the tarsal setae have been developed. It is proposed that these adhesion structures could be attached to a simplified version of the leg of a ladybird and used in practical applications. For example, the leg structures could potentially be employed in small surveillance drones to enable attachment to surfaces during flights, in order to preserve battery power. Alternatively, the structures could be used in small robotic devices to enable walking on steeply inclined surfaces. In this program of work, the morphology and movement of the leg of a ladybird were closely studied using a 3D X-ray microscope and a high-speed microscope. The positions of the tendons that facilitated movement were identified. From this knowledge, a simplified leg structure using pin-joints was designed and then fabricated using 3-D printing. The PDMS adhesion structures were then attached to the leg structure. The tendons in the actual insect leg were replicated using thread. Typical detachment forces of about 4 N indicated that the simplified leg structure was, in principle, more than capable of supporting the weight of a small device and then detach successfully. Attachment/detachment movement operations were performed using a linear actuator and controlled remotely. Therefore, proof of concept has been demonstrated for the use of such a simplified ladybird leg structure for the attachment/detachment of small robotic devices to horizontal, inclined, or vertical surfaces.

A neoteric antibacterial ceria-silver nanozyme for abiotic surfaces

Community-associated and hospital-acquired infections caused by bacteria continue to yield major global challenges to human health. Bacterial contamination on abiotic surfaces is largely spread via high-touch surfaces and contemporary standard disinfection practices show limited efficacy, resulting in unsatisfactory therapeutic outcomes. New strategies that offer non-specific and broad protection are urgently needed. Herein, we report our novel ceria-silver nanozyme engineered at a molar ratio of 5:1 and with a higher trivalent (Ce3+) surface fraction. Our results reveal potent levels of surface catalytic activity on both wet and dry surfaces, with rapid, and complete eradication of Pseudomonas aeruginosa, Staphylococcus aureus, and methicillin resistant S. aureus, in both planktonic and biofilm form. Preferential electrostatic adherence of anionic bacteria to the cationic nanozyme surface leads to a catastrophic loss in both aerobic and anaerobic respiration, DNA damage, osmodysregulation, and finally, programmed bacterial lysis. Our data reveal several unique mechanistic avenues of synergistic ceria-Ag efficacy. Ag potentially increases the presence of Ce3+ sites at the ceria-Ag interface, thereby facilitating the formation of harmful H2O2, followed by likely permeation across the cell wall. Further, a weakened Ag-induced Ce–O bond may drive electron transfer from the Ec band to O2, thereby further facilitating the selective reduction of O2 toward H2O2 formation. Ag destabilizes the surface adsorption of molecular H2O2, potentially leading to higher concentrations of free H2O2 adjacent to bacteria. To this end, our results show that H2O2 and/or NO/NO2−/NO3− are the key liberators of antibacterial activity, with a limited immediate role being offered by nanozyme-induced ROS including O2•- and OH•, and likely other light-activated radicals. A mini-pilot proof-of-concept study performed in a pediatric dental clinic setting confirms residual, and continual nanozyme antibacterial efficacy over a 28-day period. These findings open a new approach to alleviate infections caused by bacteria for use on high-touch hard surfaces.

Ball lightning and unidentified flying objects (UFOs)

Descriptions of observations of large luminous objects (UFOs) are given. Particularly valuable is information about these objects obtained by pilots who saw them at close range. These objects are capable of flying at airplane speeds and emitting cone-shaped beams of light. Sometimes these rays break off before reaching the ground. When the beam hits a hard surface, it crumbles into “sparkles”. If there is close contact with a UFO, the aircraft's electronic equipment fails. Sometimes these objects “land” on the ground and take off, moving faster than the speed of sound. Objects remain invisible on the radar screen operating in the decimeter range. A hypothesis of the UFO device has been proposed. It is believed that UFO is an ensemble of ball lightning located in a common shell. The reason for the generation of cone beams of light is the synchrotron radiation of relativistic electrons that are part of the nuclei of ball lightning. Objects are capable of moving at supersonic speeds due to the emission of charged micro-clusters of water from their surface.

Coating-Free Superhydrophobic Hard Surfaces by Electric Discharge Machining with a Magnetic-Assisted Self-Assembly Sheet Electrode.

Artificial superhydrophobic surfaces hold significant potential in various domains, encompassing self-cleaning, droplet manipulation, microfluidics, and thermal management. Consequently, there is a burgeoning demand for cost-effective, mass-producible, and easily fabricated superhydrophobic surfaces for commercial and industrial applications. This research introduces an efficient, uncomplicated method for constructing hierarchical structures on hard substrates such as binderless tungsten carbide (WC) and glass substrates. The WC substrates were processed by using electrical discharge machining (EDM) with a magnetic-assisted self-assembly sheet electrode. The resultant surfaces comprised micropillars/microgrooves and diminutive craters formed by discharge and ablation, respectively. These surfaces exhibited superior hydrophobic properties, which can be attributed to the modified surface energy and surface texture construction. Our study indicates that a superhydrophobic surface can be achieved on a textured binderless WC. The maximum contact angle and minimum roll-off angle of the hierarchical structure induced by EDM with a magnetic-assisted self-assembly sheet electrode are about 158 and 5°, respectively. The advancing and receding angles are about 161° ± 2 and 157° ± 3, respectively, when the base is tilted at 3°. Furthermore, we have successfully replicated this superhydrophobic structured surface on glass substrates utilizing glass molding technology. This innovative approach to creating superhydrophobic surfaces on hard materials paves the way for the mass production of functional structures on other materials, such as metallic glass, titanium alloy, and mold steel. Most crucially, the proposed fabrication technique offers a straightforward, cost-effective route for creating functional surfaces, rendering it attractive for large-scale industrial production due to its considerable application prospects.

Green Exercise, Blue Spaces and Active Leisure Events: The Performance of New Participants is Associated With Their Response to Event Characteristics

Active leisure events (ALEs) promoting activity among non-traditional sporting participants are an increasingly important part of health interventions and social prescribing. Identifying characteristics of ALEs that encourage engagement are key for enhancing their efficacy. Models revealed first-time participants returned to parkrun more quickly if they were male, older, performed poorly, attended a larger event with more new adult participants, a hard surface type and with woodland and freshwater on its route. Interaction terms between performance and event characteristics revealed poor performing new participants were particularly influenced by event size and less influenced by woodland and freshwater suggesting that they might find it easier to hide at large events and feel less out of place. This highlights the importance not just of identifying characteristics of ALEs that influence return rates but also identifying interaction terms with performance so the behavior of target demographics can be better understood. Organisers of ALEs might want to consider prioritizing the use of routes that maximize exposure to woodland and freshwater and consider introducing additional strategies designed to make less fit participants feel that they belong.

Liquid Marbles and Drops on Superhydrophobic Surfaces: Interfacial Aspects and Dynamics of Formation: A Review.

Liquid marbles (LMs) are droplets encapsulated with powders presenting varied roughness and wettability. These LMs have garnered a lot of attention due to their dual properties of leakage-free and quick transport on both solid and liquid surfaces. These droplets are in a Cassie-Baxter wetting state sitting on both roughness and air pockets existing between particles. They are also reminiscent of the state of a drop on a superhydrophobic (SH) surface. In this review, LMs and bare droplets on SH surfaces are comparatively investigated in terms of two aspects: interfacial and dynamical. LMs present a fascinating class of soft matter due to their superior interfacial activity and their remarkable stability. Inherently hydrophobic powders form stable LMs by simple rolling; however, particles with defined morphologies and chemistries contribute to the varied stability of LMs. The factors contributing to this interesting robustness with respect to bare droplets are then identified by tests of stability such as evaporation and compression. Next, the dynamics of the impact of a drop on a hydrophobic powder bed to form LMs is studied vis-à̀-vis that of drop impact on flat surfaces. The knowledge from drop impact phenomena on flat surfaces is used to build and complement insights to that of drop impact on powder surfaces. The maximum spread of the drop is empirically understood in terms of dimensionless numbers, and their drawbacks are highlighted. Various stages of drop impact-spreading, retraction and rebound, splashing, and final outcome-are systematically explored on both solid and hard surfaces. The implications of crater formation and energy dissipations are discussed in the case of granular beds. While the drop impact on solid surfaces is extensively reviewed, deep interpretation of the drop impact on granular surfaces needs to be improved. Additionally, the applications of each step in the sequence of drop impact phenomena on both substrates are also identified. Next, the criterion for the formation of peculiar jammed LMs was examined. Finally, the challenges and possible future perspectives are envisaged.

Trapping and scattering of a multiflagellated bacterium by a hard surface.

Thiovulum majus, which is one of the fastest known bacteria, swims using hundreds of flagella. Unlike typical pusher cells, which swim in circular paths over hard surfaces, T. majus localize near hard boundaries by turning their flagella to exert a net force normal to the surface. To probe the torques that stabilize this hydrodynamically bound state, the trajectories of several thousand collisions between a T. majus cell and a wall of a quasi-two-dimensional microfluidic chamber are analyzed. Measuring the fraction of cells escaping the wall either to the left or to the right of the point of contact-and how this probability varies with incident angle and time spent in contact with the surface-maps the scattering dynamics onto a first passage problem. These measurements are compared to the prediction of a Fokker-Planck equationto fit the angular velocity of a cell in contact with a hard surface. This analysis reveals a bound state with a narrow basin of attraction in which cells orient their flagella normal to the surface. The escape angle predicted by matching these near field dynamics with the far-field hydrodynamics is consistent with observation. We discuss the significance of these results for the ecology of T. majus and their self-organization into active chiral crystals.

Overview of Predation by Birds, Cephalopods, Fish and Marine Mammals on Marine Benthic Amphipods

With about 8000 marine benthic species, the amphipod crustaceans form one of the richest animal groups of the worldwide Ocean. They have colonized a wide range of soft- and hard-bottom natural and artificial habitats extending from the intertidal to hadal zones. Moreover, they show a broad size spectrum, with numerous giant species exceeding 20 cm in length and some species smaller than 2 mm. When biofouling artificial hard surfaces, some tube-building species can form very dense populations comprising up to 100,000 individuals per square meter. Amphipods are important prey for fish and mammals. Along with cephalopod juveniles, they are also included in the trophic diet of shorebirds that consume amphipods mostly during the low tide on tidal flats. They display diel migration, which reinforces the predation by demersal fish in the suprabenthic zone just above the sea bed, as well as by pelagic fish in the water column. Despite their importance in terms of biodiversity and trophic transfer, no general overview is available on the role of benthic amphipods in marine ecosystem food webs. Various methods, including laboratory and field experiments, as well as the analysis of stomach contents and DNA extraction, have been used to identify the prey/predator trophic links. Based on an extensive literature review, this study discusses the role of marine benthic amphipods as potential food for higher trophic levels in natural and artificial hard-bottom communities created via the construction of offshore wind farms.

Modelling of Truck Tire–Rim Slip on Sandy Loam Using Advanced Computational Techniques

Vehicles often experience low tire pressures and high torques in off-road operations, making tire–rim slip likely. Tire–rim slip is undesirable relative rotation between the tire and rim, which, in this study, is measured by the relative tire–rim slip rate. There is little research on the effect of different terrains on tire–rim slip despite its significance for off-road driving; therefore, this topic was explored through Finite Element Analysis (FEA) simulations. An upland sandy loam soil was modelled and calibrated using Smoothed-Particle Hydrodynamics (SPH), and then a Regional Haul Drive (RHD) truck tire was simulated driving over this terrain, with a drawbar load added to increase drive torque. To examine their effects, five parameters were changed: tire–rim friction coefficient, longitudinal wheel speed, drawbar load, vertical load, and inflation pressure. The simulations showed that increasing the tire–rim friction coefficient and the inflation pressure decreased the tire–rim slip while increasing the vertical and drawbar loads increased the tire–rim slip. Varying the longitudinal wheel speed had no significant effect. Tire–rim slip was more likely to occur on the soil because it happened at lower drawbar loads on the soil than on the hard surface. These research results increased knowledge of tire–rim slip mechanics and provided a foundation for exploring tire–rim slip on other terrains, such as clays or sands.