Characteristics Of Layer Research Articles

Preparation of Octacalcium Phosphate Thin Film with Exposing Reactive Crystalline Plane in Biological Fluid.

Octacalcium phosphate (OCP) has been used as a bone replacement material due to its higher bone affinity. However, the mechanism of affinity has not been clarified. Since the 100 crystalline plane of OCP is closely involved in the biological reactions during osteogenesis, it is important to expose the 100 crystalline plane of OCP to the biological fluid to precisely measure the interfacial reactions. In this study, the OCP plate-like crystals were fixed on a conductive substrate in the form of single-particle deposition, and the thin films with exposing 100 crystalline planes were fabricated. Then, the characteristics of hydration layers in the OCP crystals were enhanced by the exposure of 100 crystalline planes through the thin film formation, and the bioreactivity was found to be associated with the swelling and dissolution of the hydration layer in the biological fluid. Specifically, the OCP crystals were deposited on the gold sensor by electrophoretic deposition (OCP/Au-1). The results showed that the OCP plate-like crystals were selectively deposited on the gold sensor by electrophoresis. Subsequently, it was found that the ultrasonication of OCP/Au-1 resulted in the formation of an OCP crystalline thin film (m-OCP/Au-1) with the single-particle thickness on the gold sensor with exposing 100 crystalline planes. Moreover, the FT-IR spectra of m-OCP/Au-1 showed that the structure of the phosphate ions was rearranged by ultrasonication in the hydration layer, resulting in the regulation of the layered nanostructures, promoting higher crystallinity. Furthermore, the XPS spectra of m-OCP/Au-1 indicated that the hydrogen phosphate ions in the hydration layer were exposed on the 100 crystalline plane of the topmost surface. The prepared m-OCP/Au-1 was stable in citrate buffer, whereas it showed very high reactivity in phosphate buffer as the hydration layer gradually dissolved after the swelling, which was measured by the QCM-D technique. Therefore, the OCP crystalline thin films in this study were found to have higher surface reactivity due to the enhanced exposure of the hydration layer, which is assumed to be the cause of their bone-regeneration-promoting effect (i.e., higher bone affinity). The films in this study were stable at gastric acid pH and dissolved at neutral pH, which could make them useful as the orally administered drug carrier.

‘You Can Really See the Pain in Their Eyes’: Stressors and Supports Affecting the Well-being of Homelessness Services Staff in Ireland During COVID-19

Despite their crucial roles, the well-being narratives of those working in homelessness services have frequently been overlooked in research and policy. This paper addresses that gap, presenting qualitative evidence from interviews with homelessness service workers in Cork, Ireland, during 2021 and 2022. We explore the multidimensional, layered character of service staff members’ well-being narratives, showing they are intimately connected to relationships with their own families, commitment to service users, fears about COVID-19, and their motivation to the social mission of their work: to support vulnerable people with multiple, interlinking needs. Our data reveals that stressors encountered in pre-COVID times, relating to burnout, emotional labour, inter-agency working, and career progression, were exacerbated due to government restrictions and new challenges encountered by service users. We focus on the period covering pandemic-related lockdowns in 2020 and 2021, and the immediate aftermath, to consider how those delivering crucial services coped, the informal and formal support they accessed, and the value of this support in their lives. Significantly, our analysis reflects upon the longer-term implications of these findings, contextualised against the backdrop of the housing crisis in Ireland, changing demographics of persons accessing homelessness services, and increased systemic and social pressures.

In vivo assessment of regional scleral stiffness by shear wave elastography and its association with choroid and retinal nerve fiber layer characteristics in high myopia.

To evaluate the posterior scleral stiffness of different regions in high myopic eyes and to explore its associations with macular choroidal and peripapillary retinal nerve fiber layer (pRNFL) thickness and vasculature. Thirty subjects with high myopic eyes and 30 subjects with low myopic eyes were included in this study. The elastic modulus of the macular and peripapillary sclera at the temporal, nasal, superior and inferior regions were determined via shear wave elastography (SWE). Optical coherence tomography and angiography (OCT/OCTA) centered on the fovea and optic disc was obtained by using a commercially available swept-source OCT/OCTA device. Built-in automated software was used to quantify macular subfovea choroidal vessel volume (SFCVV), macular subfovea choroidal thickness (SFCT) and pRNFL thickness. The SWE results demonstrated that high myopic eyes had significantly lower macular and peripapillary scleral elastic modulus than low myopic eyes (P < 0.001). The reduction in the elastic modulus was slightly greater in the temporal peripapillary region, followed by the superior peripapillary, inferior and nasal peripapillary regions (P > 0.05). The linear regression analysis demonstrated a significant association between the posterior scleral elastic modulus and SFCT and inferior pRNFL thickness (P < 0.001). High myopic eyes had weakened posterior scleral stiffness. The regional change in the elastic modulus was associated with the SFCT and inferior quadrant pRNFL thickness. This novel in vivo quantitative assessment of scleral stiffness via SWE may help to characterize the underlying pathologic mechanism of scleral biomechanics on choroid and pRNFL changes in high myopia. WHAT IS KNOWN : Previous studies reported significant choroid thickness and peripapillary nerve fiber layer thickness decrease in high myopia The scleral stiffness is weakened in myopic eyes WHAT IS NEW : Shear wave elastography (SWE) is a novel tool to detect posterior scleral biomechanics in myopic eyes in vivo Stiffness of the posterior sclera at macular and peripapillary regions is lower in high myopic than in low myopic eyes The posterior scleral stiffness is correlated with subfovea choroidal thickness and inferior quadrant peripapillary nerve fiber layer thickness.

Aerosol transport and associated boundary layer thermodynamics under contrasting synoptic conditions over a semiarid site.

Understanding the kinematics of aerosol horizontal transport and vertical mixing near the surface, within the atmospheric boundary layer (ABL), and in the overlying free troposphere (FT) is critical for various applications, including air quality and weather forecasting, aviation, road safety, and dispersion modeling. Empirical evidence of aerosol mixing processes within the ABL during synoptic-scale events over arid and semiarid regions (i.e., drylands) remains sparse. We explored how synoptic-scale weather systems impact aerosol mixing processes within the daytime ABL over a site located in a dryland. We used ground-based Doppler lidar measurements collected during three events: a cold-front passage, a fair-weather day, and a dryline passage over Lubbock, Texas. The measurements of backscatter and vertical velocity fields were obtained with temporal and vertical resolutions of 1s and 60m, respectively. Here, we documented observations of aerosol transport and mixing within the ABL and found that frontal passages are crucial for understanding ABL features and aerosol mixing processes. For example, our findings suggest that during a dryline passage yielding a water vapor mixing ratio drop of 10g kg-1, the boundary layer characteristics transition from being shallow and stratified throughout a stable, pre-dryline ABL aerosol regime (300m deep) to a deep and well-mixed structure within the post-dryline ABL (2200m deep) confirming a higher ABL depth growth rate (∼300mh-1) than under quiescent conditions (∼125mh-1). The results for the frontal case reported aerosol mixing via frontal lifting to an altitude of 1250m from the ground due to strong updrafts (>7ms-1). Additionally, Doppler lidar measurements helped to characterize the aerosol mixing and transport processes in dry regions under different weather conditions which yielded close correspondence with the observed variability in near-surface particulate matter (i.e., PM2.5) concentrations (e.g., increase in PM2.5 from 9μgm-3 to 27μgm-3 due to a cold front passage). The aerosol transport, along with the derived properties of the mean up- and downdraft observations and variance-based (both vertical velocity and aerosol backscatter) turbulence profiling helped explain how frontal airmass exchanges impact aerosol loading near the surface. The results obtained emphasize the need to consider the impact of synoptic-scale events over drylands in both observational and atmospheric modeling studies.

A review of gas-liquid flow characteristics of anode porous transport layer in proton exchange membrane electrolysis cell

A review of gas-liquid flow characteristics of anode porous transport layer in proton exchange membrane electrolysis cell

The structural, optical, topographical, and H2 sensing characteristics of a Zn-doped Fe2O3 thin layer deposited via DC & RF magnetron co-sputtering method

In this study, a Zn-doped iron oxide layer was deposited onto a microscope slide using the magnetron co-sputtering technique with direct current (DC) and radio frequency (RF) sources. We comprehensively characterized the resulting Zn-doped Fe2O3 thin layer, employing techniques such as XRD, Raman spectroscopy, UV–VIS spectrophotometry, SEM, EDX, & AFM. XRD examination showed the nanocrystalline structure in the thin layer under investigation. Based on recorded absorption data, the band gap energy value calculation resulted in a value of 2.23 eV for the thin film. Raman spectroscopy identified peaks possessing Raman shifts from 100 to 1400 cm−1. SEM investigation illustrated a consistently uniform thin film surface characteristic throughout the substrate. Additionally, the AFM study disclosed a small RMS roughness value, indicative of an unrough surface for the Zn: Fe2O3 thin layer. The Fe2O3 thin film doped with Zn employing a 30 W DC voltage demonstrated effective hydrogen sensing capability at 300 °C, achieving notable response and recovery time. This work presents a novel application of Zn-doped Fe2O3 thin films as highly sensitive and stable hydrogen sensors, tailored for high-temperature environments. The unique combination of nanocrystalline structure and Zn doping optimizes the material’s electronic properties, enhancing its responsiveness to hydrogen gas. This approach offers a scalable, cost-effective pathway for developing advanced sensor technologies suited to environmental monitoring, industrial safety, and hazardous gas detection, making it a valuable addition to the field of gas-sensing materials.

Coating Performance Prediction using a Modified Spin Coater and the Taguchi Technique for Solar Cells

Background: This paper presents a novel approach to enhance the efficiency of solar cells by employing a modified spin coating technique with a Zinc oxide (ZnO) solution. Spin coating, known for its ability to achieve uniform, thin coatings on flat to moderately curved surfaces, serves as the central method in this research. The study meticulously investigates various factors affecting the coating process, including the volume of the solution, spinning speed, and spinning duration. To optimize these factors effectively, the Taguchi approach is employed, aiming to achieve the desired ZnO layer thickness and uniformity. The experimental findings reveal that the most favorable results are obtained when implementing a 3-second spin cycle at a rapid spin speed of 2000 rpm while using a ZnO solution volume of 5 microliters. Furthermore, advanced techniques such as scanning electron microscopy (SEM) are harnessed to scrutinize the surface characteristics of the ZnO layer and its interaction with the solution. To gauge the quality of the coatings, the signal-tonoise ratio (SNR) main impact plot is thoughtfully utilized. Subsequent in-depth analysis, employing the analysis of variance (ANOVA) technique, delves into the intricate relationship between the experimental parameters and the response parameter. The research outcomes are nothing short of remarkable, showcasing that the modified spin coating technique significantly elevates the efficiency of coated solar cells, ultimately achieving an impressive efficiency rate of 5.4%. In summation, this study introduces a pioneering spin coating technique tailored for solar cell applications with ZnO solution, leading to substantial enhancements in efficiency. The thorough optimization of process parameters through the Taguchi technique, coupled with the comprehensive analysis of experimental results via ANOVA, not only advances the comprehension of the coating process but also paves the way for more efficient and sustainable solar cell applications in the future. Methods: The research systematically explored critical factors affecting the coating process for solar cells, optimizing the ZnO layer's thickness and uniformity. The ideal parameters identified were a 3-second spin cycle at 2000 rpm with a ZnO solution volume of 5 microliters. Quality assessment was done using the signal-to-noise ratio (SNR) main impact plot, and further analysis via ANOVA revealed intricate parameter relationships. These findings offer a precise and efficient method for improving solar cell coatings, promising enhanced efficiency in renewable energy production. Results: The research achieved a minimum film thickness of 4.2 micrometers and revealed a correlation between spinning speed and film thickness. Solar cell efficiency reached an impressive 5.4% post-ZnO coating. The modified spin coating device outperformed conventional methods, enhancing efficiency by 5% to 10%. These results signify a significant breakthrough in improving solar cell performance and hold promise for more efficient solar energy production. Conclusion: This research optimized the spin coating process to apply ZnO solution to solar cells, achieving the desired film thickness. Ideal parameters were found: 2000 rpm spinning speed, three seconds spinning duration, and four microliters of solution. This resulted in a minimum film thickness of 4.2 micrometers. Higher spinning speeds correlated with thinner films, as shown in a contour plot. Solar cell efficiency reached 5.4% after the ZnO coating. A redesigned spin coating device outperformed conventional methods, improving efficiency by 5% to 10%. This modified technique holds promise for more efficient solar panel production.

Адаптивные свойства сортов льна масличного по содержанию жира в семенах

The object of the research were nine varieties of oil flax of different ecological and geographical origin. The Yantar variety, included in the State Register of Breeding Achievements and approved for use in the Volga-Vyatka region, was sown as a standard. The experiments were laid on sod-podzolic medium loamy soil with the following agrochemical characteristics of the arable layer: humus content - low and medium, mobile phosphorus and potassium - from medium to very high; exchangeable soil acidity from strongly acidic to close to neutral. The most favorable abiotic conditions for the accumulation of fat in oil flax seeds were formed in 2024 (environmental conditions index Ij = 3.96). On average, over three years, oil flax varieties accumulated from 37.3 to 42.1% fat. None of the studied varieties exceeded the standard Yantar variety in this indicator. The Abacus variety was reliably inferior in fat content in seeds by 3.1% to the Yantar standard and by 2.7–4.8% to all other studied varieties, except for the Istok variety. The most plastic variety is RFN with a plasticity coefficient bi = 1.54. The most stable in fat content in seeds are the Abacus and Focus varieties with stability coefficients close to or equal to zero. Keywords: VARIETY, OIL FLAX, FAT CONTENT, ADAPTABILITY, ENVIRONMENTAL CONDITIONS INDEX, COEFFICIENT OF VARIATION, COEFFICIENT OF STABILITY, COEFFICIENT OF PLASTICITY, STRESS RESISTANCE, RANGE OF PRODUCTIVITY, GENETIC FLEXIBILITY

In English

In porous or disperse media, the temperature and interfacial behaviors of water and solutions could be strongly affected by confined space effects (CSE). The surface nature of solids could influence the interfacial phenomena including both CSE and cryoscopic effects caused by the colligative properties of solutions. Strong changes in the characteristics of adsorption liquid layers, especially in narrow pores, are also caused by decreasing solvent activity. Therefore, it is of interest to compare the behaviors of water and NaCl solutions under CSE caused by hydrophilic and hydrophobic sorbents. Here, hydrophobic (AM–1) and hydrophilic (A–300) fumed silicas are used as representatives of disperse sorbents with different surface structure and characterized by textural porosity. This porosity is caused by voids between nonporous nanoparticles (NPNP) forming aggregates, agglomerates of aggregates, and visible particles (supra-NP structures) in the powders of low bulk density. Initial materials and related treated systems with bound water and NaCl/water were studied using nitrogen adsorption, microscopy, X–ray diffraction, infrared spectroscopy, thermogravimetry, rheometry, nuclear magnetic resonance spectroscopy, and quantum chemistry. Water bound to fumed silicas with or without NaCl could be assigned to several types: weakly (WBW, frozen at 260 K &lt; T &lt; 273 K) and strongly (SBW, frozen at T &lt; 260 K) bound waters; weakly (WAW, chemical shift of dH = 0.5 – 2 ppm) and strongly (SAW, dH = 4 – 6 ppm) associated waters. WAW is not observed for A–300 systems. Additionally, in the systems with water/NaCl, there is frozen (immobile) water characterized by melting delay (T &gt; Tm) at 273 K &lt; T &lt; 287 K (metastable water, MSW). The MSW appearance may be explained by release (with certain kinetic delay) of water trapped in NaCl crystallites dissolved at T &gt; Tm = 273.15 K upon increasing amounts of liquid water with increasing temperature. The difference in the CSE in voids in hydrophobic and hydrophilic supra-NP structures onto bound water could be explained by the surface (–O)2Si(CH3)2 functionalities enhancing the clusterization of water bound to AM–1. As a whole, the difference in the surface nature of AM–1 and A–300 affects: (i) the NaCl crystallite size distributions; (ii) melting/crystallization temperatures of NaCl; (iii) viscosity and torque vs. shear rate (strain); (iv) temperature and interfacial behaviors of water alone and NaCl solutions at 215 – 287 K; and (v) effects of dispersion media influencing bound water. Obtained results are of interest not only from a theoretical point of view but also from a practical one since both silicas are used as components of composites containing water and NaCl (or other salts) in various practical applications in medicine, agriculture, etc.

IDENTIFICATION OF MOBILE DEVICES BY CORRELATION FEATURES OF THEIR SIGNAL SPECTRA

Context. The mass spread of Wi-Fi networks is facilitated by the simplicity of their deployment, high speed, universality, and convenience of use. The development and dissemination of these networks continue despite a number of shortcomings. One of the shortcomings is their vulnerability to various types of attacks, including those based on the forgery (imitation) of identification data. At the same time, there are physical layer characteristics, knowledge of which expands the understanding of the network’s state, can contribute to increasing the reliability of network subscriber identification, and thus prevent a number of attacks. This research is aimed at the theoretical and practical substantiation of the possibility of their application. Objective. The aim of the study is to assess the application of detailed analysis of signal spectra emitted by devices connected to wireless Wi-Fi networks for their identification. To achieve this goal, it is necessary to analyze the experimentally measured spectra of wireless devices connected to the Wi-Fi network and evaluate the possibility of using the spectrum for the identification of mobile devices. Method. This work proposes a method for processing the results of measuring the spectra of Wi-Fi device emissions by evaluating the asymmetry coefficient of the Wi-Fi device spectrum’s cross-correlation function. Mathematical modeling was used to assess the effectiveness of the method. Results. The research results show that the minimum value of the asymmetry coefficient when comparing the template with different positions of one’s own device, and large values of the asymmetry coefficient when comparing templates with foreign spectra. Therefore, this characteristic can also be used for the identification of Wi-Fi devices. Conclusions. The research results suggest the possibility of applying the proposed method for the identification of mobile devices, which will qualitatively complement existing security models with another feature for detecting unauthorized access.

Latitudinal influences on sound scattering layer characteristics in the Southwestern Indian Ocean: insights into oceanographic environmental interactions

Sound scattering layers (SSLs) are vital components of marine ecosystems, yet their morphometric and distributional characteristics remain understudied. This study investigates the SSL core in the southwestern Indian Ocean using a 38 kHz echosounder, focusing on its attributes across latitudinal gradients (20–4°S, 65°E) and three depth layers: epipelagic (0–100 m), intermediate (100–300 m), and mesopelagic (300–600 m). Our findings reveal the highest average acoustic values in the epipelagic layer (–72.9 dB), followed by the mesopelagic layer (–77.8 dB) and the intermediate layer (–82.5 dB). The SSL core was more prominent in northern latitudes (NLS) and showed greater depth variability in southern latitudes (SLS), with vertical profile peaks at 42.2 m and 431.1 m. In the NLS, the SSL core was longer (18,358 m &amp;gt; 6,788 m), thicker (13.8 m &amp;gt; 11.7 m), and more concentrated (aggregation index: 0.0053 m−1 &amp;gt; 0.004 m−1), as well as more dispersed from the center (inertia: 269.9 m² &amp;gt; 112.7 m²). Notably, depth and acoustic fluctuations were more pronounced over circadian cycles in the SLS than in the NLS. Multiple regression analysis revealed that oceanographic factors influencing acoustic values varied by depth, highlighting the complex interactions within SSL ecosystems. These insights enhance our understanding of SSL dynamics and their implications for long-term monitoring and climate influence assessment.

Effect of Diatomite Application on the Removal of Biogenic Pollutants in Rain Gardens

Due to its structure and properties, diatomite from a deposit in Jawornik Ruski (Subcarpathian Voivodeship) can be used as a sorbent in rain gardens. The purpose of the current research is to analyze how enriching the substrate used in a rain garden with diatomite can affect the removal of biogenic pollutants. This study was carried out under laboratory conditions using retention columns, two experimental columns with different contents of diatomite, and a control column without the addition of diatomite. Analyses of the materials used included studies of the characteristics of the rain garden layers (water permeability and granulometric analysis) and characterization of the diatomite (SEM images, oxide and phase composition, leachability, and BET). The effects of diatomite on pollutant removal were studied for NH4+, PO43−, NO3−. The results showed approximately 3-fold higher reductions in the concentration of NH4+ and PO43− in the columns with the addition of diatomite than in the control one (reduction in the concentration of NH4+ by 93 and 94% and of PO43− by 94 and 98% with the addition of 20 and 30% diatomite contents, respectively). The study results confirmed the possibility of removing contaminants using diatomite, thus reducing their entry into the aquatic environment.

МЕТОДОЛОГИЧЕСКИЕ ОСНОВЫ МАТЕРИАЛОВЕДЧЕСКОЙ ОЦЕНКИ КАЧЕСТВА СМАЗОЧНЫХ СРЕД ДЛЯ НАГРУЖЕННЫХ СОПРЯЖЕНИЙ МАШИН И МЕХАНИЗМОВ. Сообщение 2. Влияние состава смазочных сред на структурно-фазовое состояние зоны деформации металлических трибосопряжений и их антифрикционные свойства

The results of experimental studies of deformation and diffusion in the surface layers of metallic frictional couples, which form the experimental and theoretical basis of the materials science approach to the quality evaluation of lubricants, are presented. The concepts of the component’s role for the lubricating medium in the implementation of the plasticizing and strengthening triboeffect are formulated. Structural condition characteristics for the surface layers of copper alloys during friction on steel in the mode of boundary lubrication in surface-active lubricants, are described. The conditions for achieving minimum power losses of such tribosystems for friction and wear have been found. The greatest service life of tribounit in a lubricating medium containing surfactants is resulted from wear resistance increase of a copper alloy with a relative decrease in hardness and increased plasticity of its surface layer. At the same time, a decrease in hardness due to the plasticizing effect of surfactants occurs only in the near-surface deformed layer of tribomaterial, while in its deeper layers with no plasticization resulted from a lubricating medium effect, the mechanical characteristics of the antifriction alloy remain at the required high level. It is demonstrated that alloys with a single-phase structure of an α-solid solution and a wide concentration range of solubility of the alloying element in the solid state meet these requirements. It is found that such boundary conditions are provided by the presence of stationary macroscopic diffusion flows of alloying elements in the zone of contact deformation of a polycomponent tribomaterial. The role of local diffusion phenomena in quasispinodal phase transitions is indicated. Examples of the selective transfer phenomenon during friction in industrial lubricants, are given.

Oxidation temperature influence on the properties of oxide layers thermally grown on 4H-SiC by wet oxidation

Abstract Compositional characteristics of oxide layers thermally grown on top of 4H-SiC were investigated as a function oxidation temperature. For that, we followed the evolution of the oxide properties after different oxidation times. Different oxidation regimes were identified: an initial oxidation regime where a substoichiometric oxide is formed, followed by the conversion of this layer to SiO2. Oxidation temperature was revealed a key parameter to obtain stoichiometric SiO2, since in the lower temperature used in this work (900 oC), only substoichiometric layers were obtained. The results obtained also evidence a similar behavior between wet and dry SiC oxidation, suggesting a multi-step process in both cases.&amp;#xD;

A Study on the Manufacturing Characteristics of the Wall Layers of the Mural Painting in Josadang Shrine of Buseoksa Temple, Yeongju

This study scientifically investigated and analyzed the structure and materials of the earthen wall of the mural painting in Josadang Shrine of Buseoksa Temple to identify its manufacturing characteristics. The wall comprises three layers: the support layer, the middle layer, and the finishing layer. The clay used was weathered soil that was refined according to the functional requirements of each layer. Straw fibers were used as reinforcements in the base and intermediate layers, while hemp fibers were utilized in the finishing layer. The support layer has a thickness of 3–4 cm, with a porosity of 2.10% and a particle size distribution of 12.31% gravel, 41.60% sand, 29.87% silt, and 16.23% clay. The middle layer has a thickness of 1–2 cm, with a porosity of 2.17% and a particle size distribution of 5.96% gravel, 40.97% sand, 35.66% silt, and 17.40% clay. The finishing layer is approximately 6 mm thick and exhibits a porosity of 4.70% with a particle size distribution of 53.51% sand, 38.57% silt, and 7.92% clay. In summary, the support and middle layers were constructed with poorly graded particles to form a dense structure, enhancing durability, while the finishing layer was designed with a focus on smoothness and uniformity.

Seasonal Analysis of Planetary Boundary Layer and Turbulence in Warsaw, Poland Through Lidar and LES Simulations

We analyzed the planetary boundary layer (PBL) characteristics in Warsaw, Poland for a day of summer, autumn, winter, and spring of 2021 by integrating and comparing measured and simulated data. Using remote sensing lidar sensor data, the PBLH was calculated using wavelet covariance transform (WCT) and the gradient method (GM). Also, simulations of turbulent fluxes were performed utilizing the large eddy simulation (LES) from the Parallel Large Eddy Simulation Model (PALM) to better understand how turbulence and convection behave across different seasons in Warsaw. The PBLH diurnal cycles showed pronounced changes in their vertical structure as a function of the season: the winter heights were shallow (~0.7 km), while summer heights were deeper (~1.7 km). The spring and autumn presented transient characteristics of PBLH around 1.0 km. This study is crucial for enhancing urban air quality and climate modeling. The PBLH simulations from PALM showed agreement with the measured data, with an underestimation of approximately 10% in both methods. Through PALM, it was possible to observe that summer exhibited increased convection, enhanced mixing efficiency, and a deeper boundary layer compared to other seasons throughout the daily cycle. Winter has a lower sensible heat flux and little convection throughout the day. Spring and autumn showed intermediate characteristics. In this way, the effectiveness of the applicability of the PALM model to obtain flows within the PBL and their heights is highlighted, because correlations ranged from strong to very strong (r ≥ 0.70).

Numerical and Experimental Investigation of Boundary Layer of a High-Lift Low-Pressure Turbine Cascade Under Periodic Wakes With Different Flow Coefficients

Abstract This article investigates the boundary layer on the suction surface of a low-pressure turbine (LPT) subjected to upstream wakes with three different unsteady flow cases, characterized by the variation of flow coefficients. The unsteady behaviors of the boundary layer on the LPT suction surface are studied numerically and experimentally. The Reynolds number in the cascade is constant. Three flow coefficients are achieved by varying the bar speed, while the cascade's outlet velocity remains stable across the three test cases. The wake shapes under the three flow coefficients are captured by numerical simulation, and the instantaneous characteristics of the boundary layer are analyzed by hot-film test data and numerical results. The wake can be divided into a center and a tail, each with different effects on boundary layer multimode transitions. The wake center promotes the separation bubble breakdown, inducing wake-induced transition. Klebanoff streaks, formed by shear sheltering at the blade's leading edge, accelerate wake-induced transition by breaking down vortices in the interaction between the wake tail and the boundary layer. Under the three different flow coefficients, the wake shapes are different, resulting in a difference in the intensity and development of the Klebanoff streaks. The interactions among the Klebanoff streaks and roll-up vortices, the wake shapes, and the timing of Klebanoff streak involvement in the wake-induced transitions are important coupled factors. Additionally, the flow coefficient can change the factors, resulting in different wake-induced transitions, which should be considered in the design of high-lift LPTs.

Tailoring Ga‐Doped ZnO Thin Film Properties for Enhanced Optoelectric Device Performance: Argon Flow Rate Modulation and Dynamic Sputtering Geometry Analysis

The impact of dynamic sputtering geometry on the properties of ZnO: Ga (GZO) thin film nanomaterials is investigated by systematically varying Ar flow rates and substrate positions during the film growth. The structural, optical, and electrical characteristics of GZO layers, deposited from a ZnO: Ga (5.7 wt%) ceramic‐type sputtering target, are comprehensively evaluated to reveal the relationship between the sputtering geometry and material properties. The obtained electrical properties, comparatively high carrier mobility 11.3 × 101 cm2 V−1 s−1 and the lowest resistivity 1.13 × 10−3 Ω‐cm, together with a moderately high optoelectric figure of merit with the films prepared using around 6 sccm Ar‐flow rate (corresponding to around 4.92 mTorr Ar partial pressure) reveal distinct correlations between the sputtering conditions and thin film properties, providing insights into the optimization of sputtering parameters for tailored material synthesis required for advanced and emerging applications. The GZO thin film (prepared with the optimal setting of 6 sccm Ar flow rate) exhibits remarkable optoelectronic capabilities as a transport layer in solar cells, reaching peak efficiencies of 26.34% for CIGS, 14.142% for CdTe, and 24.289% for Cs2AgBiBr6 perovskite in SCAPS‐1D simulated models. This study advances sputtering techniques for precise engineering of functional nanomaterials with enhanced performance and versatility, contributing to material synthesis optimization for emerging applications.

Evaluation of Satellite-Derived Atmospheric Temperature and Humidity Profiles and Their Application as Precursors to Severe Convective Precipitation

This study evaluated the reliability of satellite-derived atmospheric temperature and humidity profiles derived from occultations of Fengyun-3D (FY-3D), the Constellation Observing System for Meteorology, Ionosphere, and Climate-2 (COSMIC-2), the Meteorological Operational Satellite program (METOP), and the microwave observations of NOAA Polar Orbital Environmental Satellites (POES) using various conventional sounding datasets from 2020 to 2021. Satellite-derived profiles were also used to explore the precursors of severe convective precipitations in terms of the atmospheric boundary layer (ABL) characteristics and convective parameters. It was found that the satellite-derived temperature profiles exhibited high accuracy, with RMSEs from 0.75 K to 2.68 K, generally increasing with the latitude and decreasing with the altitude. Among these satellite-derived profile sources, the COSMIC-2-derived temperature profiles showed the highest accuracy in the middle- and low-latitude regions, while the METOP series had the best performance in high-latitude regions. Comparatively, the satellite-derived relative humidity profiles had lower accuracy, with RMSEs from 13.72% to 24.73%, basically increasing with latitude. The METOP-derived humidity profiles were overall the most reliable among the different data sources. The ABL temperature and humidity structures from these satellite-derived profiles showed different characteristics between severe precipitation and non-precipitation regions and could reflect the evolution of ABL characteristics during a severe convective precipitation event. Furthermore, some convective parameters calculated from the satellite-derived profiles showed significant and rapid changes before the severe precipitation, indicating the feasibility of using satellite-derived temperature and humidity profiles as precursors to severe convective precipitation.

Field-based investigation of low adhesion leaf layers: Assessing layer initiation and environmental influences

Changing weather conditions are known to impact on adhesion at the railhead. However, the influence on actual leaf layer “seeding” (formation) and low adhesion has not been measured in the field. This paper presents findings from a field survey conducted in autumn 2023 on a narrow gauge railway in Wales, observing leaf layer initiation, development, and environmental influences on adhesion levels. Using friction testing, timelapse imagery, and chemical analysis, the study examines the impact of weather and layer characteristics on friction. Results show that moisture content in the layer has a significant impact on adhesion levels, with a linear relationship observed between moisture and friction. Leaf layer initiation and development were observed, with water playing a crucial role in layer formation. Chemical analysis revealed the presence of iron oxides and biopolymers in the leaf layers. The results give insight into the variation in adhesion levels in leaf layer that have been measured through indirect measures in the past.