Global maps of soil temperature

Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world\u27s major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

Fatigue performance of notched and hot-dip galvanized laser and mechanically cut S960 steel components considering local defects with the theory of critical distances

Abstract Experimental fatigue tests were performed for a S960 steel grade, including hot-dip galvanized (HDG) round base material specimens, and laser cut, and machined notched component-sized specimens made of t = 6 mm S960 ultra-high-strength steel (UHSS) plates. Cracking after the HDG was found to have a major influence on fatigue strength and thus reducing the effect of surface quality on the fatigue performance. Design guidelines for notched HDG components are proposed, and HDG with UHSSs was found suitable for structures with geometrical notches. Multiparametric TCD-based 4R method application was introduced, and it was found to be applicable for the fatigue strength assessment of structural details with initial cracks

Fatigue strength assessment of cut edges considering material strength and cutting quality

Abstract In the present study, statistical analysis for previously reported cut edge fatigue test results is performed. Experimental fatigue tests are conducted for machined, plasma, and fiber laser-cut S960 edges to verify the effect of yield strength and cut edge quality, and to study the effect of the cutting method on fatigue performance. Experimental fatigue tests were complemented with hardness and residual stress measurements and metallurgical analyses with electron backscatter diffraction (EBSD) to characterize cut edge fatigue properties and to verify statistical analysis findings. The results show that cut edges can be divided into high- and low-quality categories. On the basis of these high- and low-quality categories, material strength, and applied cutting methods, FAT classes and recommended fatigue design practices are proposed

Data related to the microstructural identification and analyzing the mechanical properties of maraging stainless steel 13Cr10Ni1.7Mo2Al0.4Mn0.4Si (commercially known as CX) processed by laser powder bed fusion method

Abstract The data available in this article presents the microstructural information achieved via scanning electron microscopy and electron backscatter diffraction to evaluate the microstructure of maraging stainless steel 13Cr10Ni1.7Mo2Al0.4Mn0.4Si, in its as-built and heat-treated conditions, fabricated by laser powder bed fusion. In addition, the statistical analysis of the defects is included to indicate the quality of the additively manufactured metal. Furthermore, true stress-logarithmic strain diagrams of the material with different types of post-processing are available, indicating the strain hardening behavior of the material. These diagrams were achieved via quasi-static tensile tests performed in conjunction with the digital image correlation technique. Finally, the sample designs, additive manufacturing parameters, and the heat treatment procedure carried out on the material are also available in this paper to guide future research and ensure the repeatability of the data in this data article and its linked research paper. The research paper investigates the effects of processing and post-processing parameters on the microstructure, surface quality, residual stress, and mechanical properties of 13Cr10Ni1.7Mo2Al0.4Mn0.4Si (conventionally known as CX developed by EOS GmbH) processed by laser powder bed fusion [1]

Effects of manufacturing parameters, heat treatment, and machining on the physical and mechanical properties of 13Cr10Ni1·7Mo2Al0·4Mn0·4Si steel processed by laser powder bed fusion

Abstract This study investigates the effects of build orientations, heat treatment, and mechanical machining (as processing and post-processing factors) on the microstructure, quasi-static mechanical properties, strain hardening, notch toughness, and residual stress of additive manufactured 13Cr10Ni1·7Mo2Al0·4Mn0·4Si maraging stainless steel, known commercially as CX. The material investigated in this research was processed using the laser powder bed fusion (L-PBF) method as the additive manufacturing process. The results show that stainless steel CX had an anisotropic behavior under quasi-static tensile loads in its as-built condition. However, heat treatment significantly increased the strength of the material and eliminated the anisotropy in the strength levels. In addition, building orientation did not significantly affect the microstructure, hardness, and notch toughness. Further, retained austenite proved to have a role in determining the ductility and strain hardening of CX. Finally, the heat treatment utilized in this study proved to be effective in improving the mechanical properties employing shorter times and lower temperatures compared to the treatments used in other studies from the literature

Rapid exponential elimination of free prostate-specific antigen contrasts the slow, capacity-limited elimination of PSA complexed to alpha 1-antichymotrypsin from serum

OBJECTIVES: To study the rates of elimination of total prostate-specific antigen (PSA-T), free PSA (PSA-F), and PSA complexed to alpha 1-antichymotrypsin (PSA-ACT) from blood after radical retropubic prostatectomy (RRP). METHODS: We obtained venous blood from 10 patients with prostate cancer who were undergoing RRP. We analyzed PSA-F and PSA-ACT and equimolar detection of both of these forms together (PSA-T) by using immunofluorometric assays. An attempt was made to fit the serum concentrations of PSA-F, PSA-ACT, and PSA-T for each patient to exponential curves by applying one- and two-compartment models for pharmacokinetic analysis. RESULTS: Manipulation of the prostate during RRP resulted in a 3- to 28-fold increase in PSA-F concentrations in serum. Removal of the prostate resulted in a rapid, biexponential elimination of PSA-F from serum, corresponding to a mean initial (alpha) half-life of 0.81 hours and a mean terminal (beta) half-life of 13.9 hours. Serum PSA-ACT concentrations decreased by 20% to 40% immediately after removal of the gland; the elimination after surgery was slow and nonexponential, corresponding to a mean rate of 0.8 ng/mL/day. The elimination of PSA-T reflects a combination of the elimination patterns for PSA-F and PSA-ACT. CONCLUSIONS: The main proportion of PSA-F is rapidly eliminated from serum, possibly by glomerular filtration. PSA-F released during surgery did not form complexes with ACT, as suggested by the lack of PSA-ACT elevation in serum. The size (approximately 90 kDa) and the extensive in vitro stability of the PSA-ACT complex prevents renal clearance. The nonexponential elimination of the PSA-ACT complex is evidence of a capacity-limited process (e.g., metabolic transformation)

Effects of notch-load-defect interactions on the local stress-strain fields and strain hardening of additively manufactured 18Ni300 steel

Abstract This study investigates the influence of geometrical notches on the local (true) stress-strain curves, deformations, and strain hardening behavior of maraging tool steel 18Ni300 processed via the laser powder-bed fusion method as an additive manufacturing approach. For this purpose, five types of specimens with different notch designs were manufactured; these samples were considered to study the effects of the notch stress concentration factor and the notch position on the material's mechanical response against the applied external load. Accordingly, using the digital image correlation technique, true stress-logarithmic strain curves were plotted and compared for various points in the vicinities of the notches while the specimens were subjected to quasi-static tensile loads. Further, the strain (work) hardening behavior of the material at each point was then evaluated and compared with other points by plotting their strain hardening diagrams from the first derivative of the stress-strain curves. The results showed that the strain hardening of the samples increased with the stress concentration factor (notch sharpness) while its ductility decreased accordingly. Furthermore, notch location and shape also showed determining roles in defining the material behavior. Ultimately, higher stress concentrations, internal positioning, and less gradual changes in geometric features (C-shaped notches compared to V-shaped ones) can result in higher defect sensitivity, more decrease in ductility, and more likely catastrophic failures in metals processed by additive manufacturing

Fatigue performance of stainless tool steel CX processed by laser powder bed fusion

Abstract This study investigates the fatigue performance of additively manufactured steel CX under uniaxial high cycle loading. The results show that surface quality was the most influential parameter that changed the fatigue behavior of the material, compared to combinations of building orientation and heat treatment as other fabrication parameters. Consequently, improving the surface quality from Ra = 3 μm–1 μm increased the fatigue limit from 170 MPa to 250 MPa. However, heat treatment did not significantly influence the fatigue performance of the material, although it increased the hardness of the material from 320 HV to 460 HV

Thermomechanical simulation of the heat-affected zones in welded ultra-high strength steels:microstructure and mechanical properties

Abstract Ultra-high strength steels (UHSS) have a determining role in construction and industry. Furthermore, welding as the primary joining process for steel has a similar role in promoting its applications. Therefore, welded UHSS have a vital role in related applications. However, due to their complex microstructures, these steels are more prone to harmful effects of welding heat input on the mechanical properties compared to mild steels. Thus, identifying the correlations between the microstructural transformations triggered by the heat input and the mechanical properties can lead to new insights and hindering the drawbacks. This study investigates the microstructures and mechanical properties of S960 (with a severe softening after welding) and S1100 (with a negligible decrease of the mechanical properties after welding) to understand the mechanisms behind the softening of welded UHSS. Microstructural analysis showed the formation of soft phases, e.g., ferrite and granular bainite, as the primary reason for the softening. Furthermore, tempered forms of martensite and bainite resulted in the simultaneous decrease of hardness and notch toughness. Finally, the applicabilities of two experimental approaches to predict hardness from microstructural constituents were evaluated for welded S960 and S1100 and proved to have relatively good reliability to detect their HAZ softened spots

Effect of temperature on the plastic flow and strain hardening of direct-quenched ultra-high strength steel S960MC

Abstract This study investigates the plastic deformation and hardening behavior of the direct-quenched ultra-high strength steel S960MC at various temperatures ranging from room temperature to 900 ℃. In this regard, the Hollomon and Voce equations are used to model the hardening behavior of the material at different temperatures. The suitability of each equation to predict the plastic flow of S960MC is evaluated based on the best resulted fit for the material. In addition, microstructural investigations are carried out to indicate the correlations between the microstructural changes, occurring in the range of room temperature to 900 ℃, and hardening behavior and governing parameters. The Hollomon approach showed deviations from the experimental results for room to intermediate temperatures; however, the Voce equation modeled the material’s strain hardening and flow behavior more successfully for the entire temperature range of room temperature–900 ℃. Additionally, there was a significant consistency between the Kocks-Mecking and Voce parameters. Dislocation interactions, dynamic strain aging, dynamic recrystallization, dynamic recovery, tempering (martensite decomposition), and austenite formation were the most influential microstructural features on the hardening behavior at various temperatures. The correlations between these microstructural features and hardening parameters were established satisfactorily for both the Hollomon and Voce approaches