Hard Surface Research Articles

Impact of Urban Surfaces on Microclimatic Conditions and Thermal Comfort in Burdur, Türkiye

Rapid urbanization worldwide offers numerous benefits but also introduces challenges, particularly concerning urban climate comfort, which affects the physical and social well-being in cities. This study examined the microclimatic characteristics of the Burç neighborhood in the historical core of Burdur city, using ENVI-Met models with temperature, relative humidity, wind and PET data collected over a 33,665 m2 area at 06:00, 09:00, 12:00, 15:00, 18:00 and 21:00 on 15 August 2023. The analysis revealed that thermal comfort decreases significantly from 09:00 onwards, especially on hard surfaces like asphalt, concrete and parquet, which lack vegetation and intensify heat retention. By contrast, green areas were found to enhance bioclimatic comfort by reducing perceived temperatures by up to 20% in shaded and vegetated zones. Based on these findings, it is recommended that urban areas reduce heat-absorbing materials, such as asphalt and concrete and prioritize green spaces in landscape planning to improve thermal comfort and create more sustainable urban environments.

Quantifying head and withers movement asymmetry in sound and naturally forelimb lame horses trotting on a circle on hard and soft surfaces.

Reliable lameness thresholds for vertical head displacement for trotting on a circular path and on different surfaces have yet to be defined. Withers movement in lame horses could help improve the diagnostic accuracy of sensor technology. To define head movement lameness threshold ranges and describe the relationship between head and withers movement during trotting under different circumstances in sound and forelimb lame horses. Retrospective analysis of clinical data and comparison with control group. Fifty-five sound and thirty-four naturally lame horses were trotted under field conditions on a hard surface on a straight line and on both directions on soft and hard surfaces. Movement asymmetry was analysed by measuring differences in displacement minima for head and withers using an inertial measurement unit sensor-based gait analysis system. Receiver operating characteristic (ROC) analysis was performed to define threshold ranges. Relationships between head and withers data were identified by calculating the correlation with linear regression analysis. Estimated lameness threshold values for vertical head movement asymmetry ranged from 11.5 to 12.5 mm. On both surfaces, a head movement asymmetry threshold range from 24.5 to 26.5 mm could be found for the circle. Lame horses showed significant correlations between head and withers movement on hard ground straight line (R2 0.714, p < 0.001) and inner leg lame horses on the lunge (R2 0.915, p < 0.001). Different sources of lameness were not distinguished. Radius and speed during lungeing could not be perfectly controlled. Inclusion in the sound group was based on a subjective examination by one clinician and in the lame group two clinicians subjectively determined inner and outer leg lameness creating an extra amount of uncertainty. Lameness thresholds for quantifying head movement asymmetry on the lunge were proposed. A significant correlation was observed between head and withers movement asymmetry under several conditions.

Thermal Comfort and Green Spaces: The Role of Temperature-Regulating Elements in Neighborhood Parks

According to current studies, the thermal effects of global warming will affect urban areas more intensely. In the face of this situation, strategies for the improvement and management of urban green spaces are becoming increasingly important in sustainable landscape design. These strategies promote social sustainability by positively affecting individuals’ physical and psychological well-being, taking into consideration ecological sustainability. Projections regarding global warming emphasize that the density of hardscapes and green spaces, the selection of plant species, and the distribution of plants considered within the scope of this study should be taken into account. This research was conducted in the Görükle neighborhood of Bursa, focusing on the role of temperature-regulating elements in 14 neighborhood parks. Systematic temperature measurements were carried out in the research area on the 10th, 20th, and 30th of July and August, specifically between 12:00 and 13:00, during peak temperature hours. The presence of parks that are close to each other and relatively far away from each other in the study area was seen as advantageous to filter the effects of plant differences in similar conditions. Furthermore, evaluating these various factors together highlights the multifaceted nature of thermal comfort. Designated temperature measurement points included three points (hard surfaces and hard surfaces surrounded by vegetation and planted green spaces) in each park. An analysis utilizing SPSS and the RayMan program revealed that parks with a softscape to hardscape ratio of approximately two to one experienced temperature reductions of 2.5 to 3 °C. Furthermore, the findings indicate that coniferous trees have a more significant impact on thermal comfort compared to deciduous trees. The significant differences identified in this study underscore essential considerations for urban design processes aimed at achieving sustainability.

Experimental Investigation Comparing Far-UVC (222 nm) and UVC (254 nm) for Inactivation of Bacteria on Hard and Fabric Surfaces

Experimental Investigation Comparing Far-UVC (222 nm) and UVC (254 nm) for Inactivation of Bacteria on Hard and Fabric Surfaces

TIG assisted surface modification of Ti-6Al-4V with B4C, SiC particles

This research article assesses the improved hardness and wear behaviour of Ti–6Al–4V (Titanium-6Aluminium-4Vanadium) ex-situ produced composite case on its surface by TIG Arcing. This method is recognized for its potential to modify the surface of various metallic substrates by carefully controlling the melting and solidification of the substrate using a significantly less expensive high density electric arc heat source of the widely used autogenous (without filler) gas tungsten arc welding (GTAW) process.The molten base and the hard particles in the applied coating through reinforcement led to the development of hard surface characteristics in the Ti-6Al-4V surface matrix. The hard particles that have been reinforced by using TIG arcing to develop a hard wear-resistant surface coating are boron carbide (B4C) and silicon carbide (SiC). The presence of hard particles on the surface of Ti64 has been verified by XRD Pattern and EDS examination. The effect of different reinforced particles on the wear behaviour as well as the hardness of the modified surface has been studied by comparing the Ti64 modified surface without reinforcement and the as-built Ti64 surface samples. Vickers micro hardness testing measures the hardness of the modified particulate surface composite and demonstrates a significant increase in hardness, ranging from 1.5 to 2 times that of the base metal and wear tests confirm that the surface-coated samples of B4C and SiC on the base metal, showed a reduction in wear rate of approximately 55% and 45% respectively, compared to the base metal.

Field evaluation of Yorkool ®, a long-lasting insecticidal net after 12 months of use in Seme, Kisumu County, Kenya

Background: Physical integrity and insecticidal efficacy of long-lasting insecticide-treated nets (LLINs) is influenced by the handling practices during use. This was an evaluation of Yorkool® pyrethroid-based LLINs after 12 months of use to determine the washing and drying practices, physical conditions and bio-efficacy. Methods: This was a cross-sectional household survey in an area where rectangular Yorkool® a pyrethroid LLINs were distributed during national mass net distribution campaign in 2021. Questionnaires were used for data collection and bioassay tests were done from thirty randomly selected nets. Results: 262 household heads were interviewed with their mean age being 46.9 years (SD 17.4 years) and level of education was mainly primary (70.2%). Most households (71.8%) had 1 to 2 sleeping spaces. The households had a total 468 LLINs with 95.1% having been washed at least once. About three-quarters (74.4%) of the LLINs had been washed using local bar soap, with 99.6 % having not been scrubbed on hard surface during washing and 72.1% were dried under a shade. Those evaluated for physical integrity and had at least one hole made up 77.8% of the nets and 57.2% were too torn and requiring replacement. Bio-efficacy test recorded a mean KD of 92% after 1 hour, and mean mortality of 86% after 24 hours. The nets that passed the WHO efficacy cut off for mortality (≥80%) after 24 hours were 83.3% and 70% passed the KD (≥95%) cut off after 1 hour. Conclusions: While more than a half of the Yorkool® LLINs needed replacement due to poor physical integrity after one year of use in the households, the bio-efficacy of the LLINs was relatively high with the mortality on vectors meeting the WHO threshold

A novel route of carburizing through microwave hybrid heating

Abstract Carburizing is a surface treatment process by diffusing carbon into the steel. These days, manufacturing industries demand highly efficient processes that consume low power. Microwave processing is a newly evolving process that consumes low power. This study proposes a novel route for carburizing mild steel (substrate) through experimental and simulation studies using a microwave heating. Charcoal powder was used as a susceptor to convert microwave energy into heat energy and to deposit carbon on the surface of the specimen. The mild steel specimens were exposed to the microwave power input of 900 W and 360 W for exposure time of 1500 s and 1980 s naming it as S2 and S3 respectively. The microstructural analysis of specimens S2 and S3 confirms the formation of pearlite structures at the surface. However, the amount of pearlite structure was significantly higher for the S3. The higher carbon content is confirmed through energy-dispersive x-ray spectroscopy (EDS) analysis of specimen S3. The average hardness of the S3 specimen was determined to be 220.8 HV, which shows an increase of 38.36% compared to the S1 (base metal). x-ray diffraction (XRD) results indicate the additional cementite peaks (Fe3C) and ferrite-confirming phase transformations for carburized samples. The wear analysis of S2 and S3 was conducted through pin-on-disk testing. The peak COF of 0.73 and 0.64 was observed for S2 and S3 respectively. The hard surface of S3 resists the penetration of the counter body to a greater extent due to the fine morphology of pearlite. From the FEM study, the maximum value of 7.96 × 10 3 (V/m) was determined at the center region for the electric field distribution in the microwave cavity, which is the optimum value for efficient heating. The maximum temperature of the mild steel obtained during the carburization process was 900 °C in 1800 s. The microwave carburizing process requires relatively less time than the conventional carburizing process which will save energy consumption.

Investigation of the detergency properties of mixtures of biocides and nonionic surfactants using a new simplified hard surface cleaning method

AbstractThe present study explores the cleaning efficacy of a set of nonionic surfactants (linear ethoxylated alcohol, secondary ethoxylated alcohols with 5, 7, and 9 ethoxy groups, glycoside surfactants, polyglycerol surfactants, and an ethoxylated sorbitan monolaurate) combined with cationic biocides—alkyl quaternary ammonium salts. A simple hard surface cleaning methodology was applied, which was shown to discriminate well between poor and good cleaning formulations. In addition to cleaning efficacy, surface aesthetics such as gloss and haze were evaluated together to assess surface streaking caused by a residual surfactant layer. The haziness determination turned out to be the key feature revealing the complex cleaning performance of multi‐component products.

The Acero perioperative skin bundle: An intuitive perioperative pressure injury prevention bundle

Over 40 million major surgeries are performed each year in the US, and perioperative care areas are a high-risk environment for the development of pressure injuries (PI). A unique set of challenges for the prevention of PI is faced during the perioperative period due to prolonged immobility and positioning on a relatively hard surface. The Acero Perioperative Skin Bundle (APSB) was developed to facilitate risk assessment and application of appropriate interventions at a 500+ bed safety-net, teaching hospital. Prior to the implementation of the bundle, there was a perioperative-acquired incidence of 1.9 %, accounting for 38 % of all hospital-acquired PI. In the 24-months following implementation of the bundle the hospital has maintained a perioperative-acquired PI incidence of 0 % (p = .0001). This quality improvement report demonstrates how the implementation of standardized risk assessment and application of evidence-based interventions was cost effective and significantly reduced PI acquired in perioperative care.

A contribution to research on the knapped lithic assemblage from the Late Neolithic site of Altheim in Lower Bavaria

The lithic artefacts from Altheim, being regarded as essential for the interpretation of the site, have for a verylong time attracted attention. Here we concentrate on the discoveries made during the excavation of sections of ditches in 2013-2020. Certain earlier observations were confirmed by the latest excavations, namely the high proportion of arrowheads among the flaked stone tools. A large number of the arrowheads were burnt. Many of them have broken tips, and all the analysed arrowheads with broken tips bear diagnostic impact fractures: stepterminating bending fractures or spin-off fractures specifically in the shape of small fractures on the edge between one surface of the arrowhead and the surface of the fracture of the tip. These suggest an angle of impact of the arrow into a hard surface of about 60°-70°. Broken and burnt arrowheads were found in the solid context of the structures. The context suggest that these arrowheads can be connected with conflict.

Application of the Raman fluorescence method to study the effects of chemical, physical and radiation factors on the mineralization of hard dental tissues

Objective. To study the effect of physical, chemical and radiation factors on the degree of mineralization of the hard dental tissues surface using spectroscopy. Materials and methods. The degree of mineralization of hard dental tissues was studied by the Raman spectroscopy using hardware-software complex InSpectrum M on the teeth removed according to clinical indications (in vitro): in varying degrees of moisture (dry and wet); before and after exposure to acid and remineralizing drug; before and after exposure to radiation Results. The data obtained demonstrated the difference in the indicators in dry (1801 [1800; 1802]) relative units, and moistened (591.5 [591; 592]) teeth. The mineralization of teeth according to Raman Intensity before exposure to citric acid, was (602 [601; 602]) rel. units, and after the exposure it was (152 [152; 153]) rel. units, after application of the cm-2 plate it was (423 [422; 423]) rel. units. The identified differences are reliable (p 0.001). Thus, it is confirmed that organic acids (citric acid) contribute to the enamel demineralization by more than two times, and the use of calcium-containing plates contributes to remineralization almost to the initial state. At the same time, there were no significant differences in the level of mineralization (according to the Raman method of fluorescence spectroscopy) in teeth before and after direct radiation exposure, regardless of dose (2 Gy, 70 Gy, 110 Gy) in any of the functional groups (incisors, canines, premolars, molars). Conclusions. 1. Raman-fluorescence spectroscopy has a high sensitivity and is capable of detecting mineralization, de- and re-mineralization of hard dental tissues. 2. It is recommended to determine the hard tooth tissues mineralization by Raman-fluorescence spectroscopy in a moistened rather than a dry form. 3. Organic acids contribute to the demineralization of enamel, and the use of calcium-containing plates promotes its remineralization. 4. Direct radiation exposure does not have a direct effect on the mineralization of the surface of the hard dental tissues. regardless of the dose applied in all functional groups (incisors, canines, premolars, molars), in all areas of the teeth (equator, cutting edge, gum border).

Gross and scanning electron microscopic features of the oral cavity (palate, tongue, and sublingual floor) of the Egyptian long-eared hedgehog (Hemiechinus auratus aegyptius)

The study was focused on the anatomical characteristics of the Egyptian long-eared hedgehog's oral cavity by using gross and scanning electron microscopic examinations. The upper lip had an elongated T-shaped snout-like structure. The hard palate had a triangular rostral part (which had a semicircular area and a caudal ridged area with the first 3 or 4 ridges) and a caudal part (which contained seven or eight slightly oblique ridges with raphae). The diamond-incisive papilla is flanked on both sides by a groove and a fissure. The hard palate surface had glandular openings and a microplicae system. The uneven, soft palate's surface had multiple grooves and folds with 12–16 Gemmal papillae. The Gemmal papillary surface had three to four taste pores with microplicae and glandular openings. The dorsal lingual surface had six filiform subtypes: pointed (on the tip, rostral border, and median apical region), triangular (on the lateral apical and circumvallate regions), bifurcated (on the median tip only), leaf-like (on the median body region), branched (on the lateral root region), and small pointed papillae (on the median root). There were two fungiform subtypes: ovals (on the rostral border and lateral region) and rounds (on the median apical region and body). The caudal root part had a triangular arrangement of three circumvallate papillae. In conclusion, the finding confirmed its oral cavity adaptation with its insectivorous feeding habits and Egyptian environment.Graphical

Impact of surface hydrophilicity on the ordering and transport properties of bicontinuous microemulsions.

Microemulsions (MEs) have many industrial applications, where recent developments have shown that MEs can be utilized for electrochemical applications, including potentially in redox flow batteries. However, understanding the structure and dynamics of these systems, including at a surface, is needed to direct and rationally control their electrochemical behavior. While bulk solution measurements have provided insight into their structure, their assembly at an interface also impacts the electron (to the electrode) and ion (across the surfactant) charge transfer processes in the system. To address this shortcoming, neutron reflectivity experiments and molecular simulations have been completed that document the near surface structure of a series of deuterated water (D2O)/polysorbate-20/toluene MEs on hydrophilic and amphiphilic surfaces. These results show that the microemulsions form complex layered structures near a hard electrode surface, where most layers are not purely one component. Decreasing the D2O concentration in the ME increases the number of and purity of the layers established on the solid surface. These lamellar-type layers transition from the surface to the bulk microemulsion as a series of mixed layers (i.e., containing oil, water, and surfactant) that are consistent with perforated lamellae. Additionally, these mixed lamellae appear to become more perforated with oil and water pathways on an amphiphilic surface. The purity and thickness of these layers will influence the accessibility of an electrode by redox active species, as well as ion transport required to satisfy the electroneutrality condition.

Ameliorating the sodium storage performance of hard carbon anode through rational modulation of binder

Hard carbon anodes have emerged as promising candidates for sodium-ion batteries due to their inherent advantages. Nevertheless, the surface imperfections in these materials often culminate in irreversible electrolyte consumption, fostering the development of a heterogeneous and fragile solid electrolyte interface (SEI), thereby compromising the initial Coulombic efficiency (ICE). Drawing inspiration from the catalytic potential of C=O (carbonyl) bonds in directing preferential salt reduction, we introduce a novel strategy that leverages the modulation of the binder, a long-term overlooked pivotal components in the electrode process. Specifically, Polymethyl methacrylate (PMMA), abundant in C=O groups, is partially substituted for PVDF, ensuring robust adhesion of the electrode material to the current collector while preserving superior mechanical properties. The accurate combination of two binders with delightful compatibility in the state-of-art electrode process, can promote a uniform formation of the SEI on the hard carbon surface enriched in inorganic components, which can ensure long-term interfacial stability and suppresses excessive solvent decomposition and facilitates Na+ transfer at the interface. Consequently, the initial Coulombic efficiency of the hard carbon anode with 70 %PMMA binder achieves 86 %, with prominent cycling stability (88 % capacity retention over 500 cycles) at a high current density of 1.2 A g−1. When paired with high loading cathodes to assemble the pouch cell, it also demonstrates stable operational scenarios.

Energy features of friction thermomechanical handling (FTMH) of steel products and the effect on the state of their surface structure

Abstract. Problem. The article deals with the influence of energy and power characteristics of frictional thermomechanical handling of steel products (FTMH) on the state of their surface. Goal. The goal of this work is to study the relationship between the energy and power parameters of steel FTMР and the strengthening result. Methodology. To achieve this goal, the following tasks were solved: fabrication of samples from 65G steel, preliminary hardening heat treatment of samples, hardening of the working surface of samples using FTMO, measurement of the components of the cutting force arising from FTMO using a dynamometer, analysis of the microstructure and microhardness of each sample, comparison of the microstructure, microhardness, and depth of hardening of the experimental samples, conclusions regarding the relationship between the effectiveness of hardening of samples during processing and the energy and power parameters of FTMH. Results. Changes in the structures and properties of samples made of steel, which is used for products requiring a hard and wearresistant surface under the influence of processing to form surfaces with altered properties, are shown. Originality. Measurements of the machining process at FTMH using a dynamometer were carried out and the circumferential (circular) cutting (machining) force was calculated, which made it possible to construct graphical dependencies that allow characterizing the surface hardening taking into account the thickness of the disk. It is shown that the microhardness of the surface of the prototypes was increased to 1300 kg/mm2, which is equivalent to 13000 MPa. Practical value. Recommendations on the optimal thickness of the hardening disk have been made, taking into account the results obtained. The research results can be used in production and research.

Imaging fermionic dark matter cores at the centre of galaxies

ABSTRACT Current images of the supermassive black hole (SMBH) candidates at the centre of our Galaxy and M87 have opened an unprecedented era for studying strong gravity and the nature of relativistic sources. Very-long-baseline interferometry data show images consistent with a central SMBH within General Relativity (GR). However, it is essential to consider whether other well-motivated dark compact objects within GR could produce similar images. Recent studies have shown that dark matter (DM) haloes modelled as self-gravitating systems of neutral fermions can harbour very dense fermionic cores at their centres, which can mimic the space–time features of a black hole (BH). Such dense, horizonless DM cores can satisfy the observational constraints: they can be supermassive and compact and lack a hard surface. We investigate whether such cores can produce similar observational signatures to those of BHs when illuminated by an accretion disc. We compute images and spectra of the fermion cores with a general-relativistic ray tracing technique, assuming the radiation originates from standard $\alpha$ discs, which are self-consistently solved within the current DM framework. Our simulated images possess a central brightness depression surrounded by a ring-like feature, resembling what is expected in the BH scenario. For Milky Way-like haloes, the central brightness depressions have diameters down to ${\sim} 35\, \mu \text{as}$ as measured from a distance of approximately $8\,$ kpc. Finally, we show that the DM cores do not possess photon rings, a key difference from the BH paradigm, which could help discriminate between the models.

Enhancing electric field intensity of interfacial electric double layer to improve properties of solid electrolyte interface for sodium-ion batteries

The electrical double layer (EDL) provides a critical area, where the specific adsorption on the electrode dominates the initial structure and chemical composition of the solid electrolyte interface (SEI) film. Therefore, the SEI can be optimized by adjusting the properties of the EDL. Here, we regulate the properties of EDL to optimize the composition and morphology of the SEI film on the hard carbon anode surface by adding NaF with small molecule structure. The preferential accumulation of NaF additives on the electrode surface enhances the electric field intensity and promotes electrolyte decomposition. That is, the formed SEI film rich in inorganic NaF and B-O components, can significantly improve the storage capacity of sodium ions in the hard carbon anode and accelerate the rapid transport of sodium ions. This strategy enables the cycling capacity to improve by 13.5 %, and maintain a stable capacity retention rate of 86.2 % at the rate of 1C after 500 cycles, thereby extending the lifespan and increasing the capacity of the rechargeable battery. The strategy that utilizing small molecule additives to enhance the electric field intensity of EDL provides a new approach to improve the performances of SEI film and battery performances.

Muscular Activation Levels of Subjects with Low Medial Longitudinal Arch During Single-Leg Squat and Single-Leg Balancing Exercises on Surfaces of Different Hardness.

The primary aim of this study is to examine the effect of the stiffness of rehabilitation material on muscle activation in individuals with low medial longitudinal arch. The secondary aim is to compare the effects of single-leg balancing and single-leg squat exercises on the activation of the muscles around the ankle in the same individuals. Twelve individuals with low medial longitudinal arch and 18 healthy control participants were included. Participants were asked to perform the single-leg balance and single-leg squat exercises on Theraband stability trainers of three different stiffness levels. Activation of the peroneus longus, peroneus brevis, tibialis anterior, medial and lateral gastrocnemius muscles during exercises was evaluated by surface electromyography. The single-leg balancing exercise performed on soft and very soft ground was more effective than single-leg squat in increasing the activation of the lateral gastrocnemius muscle in participants with a low medial longitudinal arch. It was determined that performing single-leg squat exercise on a very soft surface instead of hard ground caused more muscular activation in the peroneus brevis, tibialis anterior, and medial gastrocnemius in the same individuals. The exercise progression to be applied on different surfaces to increase the activation of the muscles around the ankle in individuals with a low medial longitudinal arch and in healthy individuals without a low medial longitudinal arch was different.

Effect of compound surface modification of shot peening and DLC coating on surface integrity and fatigue properties of gear steel 16Cr3NiWMoVNbE

We conducted a study on the surface compound modification of shot peening and pure carbon DLC coating to simultaneously meet the requirements of wear resistance and fatigue resistance of spline structure. The effects of surface compound modification were investigated on the surface morphology, residual stress profile, microstructure, and nano-indentation hardness of 16Cr3NiWMovNbE gear steel, and conducted a comparative study on fatigue performance. The results show that the surface compound modification inherits the surface morphology and compressive residual stress gradient of shot peening, while the surface residual stress is slightly smaller than that of shot peening. In addition, surface compound modification still reflects the characteristics of high hardness and high fracture resistance of DLC coatings. Under the bending load based on spline tooth root, compared to the original specimen, the fatigue life after shot peening, pure carbon DLC coating, and surface compound modification is increased by 3.68, 2.35, and 3.36 respectively. Although the compound modified surface still maintains the shot peening morphology with a increasing surface roughness and stress concentration coefficient, the 100 μm-depth compressive residual stress profile and the subgrain refinement layer introduced, as well as the hard surface layer with good load-bearing capacity, have played the role of fatigue strengthening.

Rethinking Human Factors in Obesity: Development of Simulation and Physical Test Models of Human Soft Tissue to Study Autoinjector Activation Performance.

Activation against a hard surface according to ISO 11608-1 is not always representative of device use on a soft injection site. A softer injection site - which is an anthropometric property found in obese patients - presents a distinct viscoelastic property which can lead to greater autoinjector activation forces that are not captured in standardized activation testing methodology. Soft tissue simulation and physical testing were developed at SHL to advance the development of autoinjectors, allowing for rigorous testing and challenging these in scenarios involving even the softest injection sites.