Surface Depth Research Articles

Surface layer method for analysis of slope stability using finite elements

This paper introduces a surface layer method for the analysis of slope stability using finite elements. When stability of a slope is calculated using the strength reduction method, the slope typically fails at local surface irregularities, which leads to numerical divergence that stops the calculation. It is then impossible to quantify the factor of safety for potentially dangerous landslides of larger dimensions. In this paper, a method is introduced in which a weightless elastic surface layer is applied at the surface, which aims to stabilize the surface of a numerical model during the strength reduction. A vertical cut through the surface layer then predefines the surface contour of the landslide, while the shape and depth of the slip surface along with the associated factor of safety is the output of the analysis. A typical use-case scenario is when the landslide shape is known a-priori (for example when analysing existing landslides). If it is not known, various landslide shapes can be tested by searching for an outline with the lowest factor of safety. This is similar to the limit equilibrium method, where a complete slip surface including its surface trace must be predefined. The proposed method was validated using parametric studies both in 2D and 3D; its importance is most pronounced in 3D where the surface morphology is highly complex. Practical application of this method is demonstrated by the back analysis of the Dobkovičky landslide, which occurred in 2013 during construction of the highway D8 in Czech Republic.

Analysis of risk factors of infection in diabetic foot patients.

This cross-sectional study assessed the risk factors for infection in 150 diabetic foot patients admitted to the Xiamen University Hospital between October 2020 and October 2022. Patients were categorised as infected (n = 80) or uninfected (n = 70) cohorts. The diabetic foot was evaluated using the American Diabetic Foot Grading system, whereas ulcers were categorised using Wagner's method. Analysed were patient-specific information, clinical data and risk factors including neuropathy, arterial disease and foot deformities. Our findings revealed no statistically significant differences between infected and uninfected cohorts concerning age, body mass index, gender, duration of diabetes or ankle-brachial index values (p > 0.05). However, infected group had a higher proportion of smokers and reduced socio-economic status (p < 0.05). Wagner grades indicated a greater severity in the infected group, with grade 3, grade 4 and grade 5 differing significantly (p < 0.05). Comparative analysis of ulcer characteristics revealed no statistically significant differences in ulcer surface area and depth, but the infected group had a higher prevalence of osteomyelitis and a greater number of ulcers (p > 0.05). Blood vessel complications, retinopathy, the presence of three or more ulcers, osteomyelitis and diabetic nephropathy were substantially more prevalent in the infected group, as determined by univariate analysis (p < 0.05). Subsequent multivariate logistic analysis revealed that patients with blood vessel complications, retinopathy, osteomyelitis, diabetic nephropathy and three or more ulcers were at increased risk for infection (p < 0.05). In addition, lifestyle factors, such as smoking, sedentary behaviour, inadequate foot hygiene, obesity and poor glycaemic control, were also associated with higher infection rates. A multivariate analysis of foot wound factors revealed that deeper, longer and recurrent lesions increased the likelihood of infection. Escherichia coli was the most frequently isolated bacterium from the infected group's bacterial culture, followed by Pseudomonas aeruginosa and Staphylococcus aureus. The study enhanced our comprehension of the multifactorial risk factors associated with infections in diabetic foot patients, highlighting the need for thorough clinical evaluation, lifestyle modification and vigilant infection control.

Bayesian estimation of parameters and uncertainty of a 3-D dipping fault using gravity anomalies

SUMMARY Many significant geophysical anomalies are generated by fault systems, and effectively estimating fault parameters is a key step to understand the characteristics of these field sources. In general, the 2-D dipping fault is frequently utilized to simplify the representation of fault geometry. However, this approach could lead to larger errors when comparing realistic scenarios with simplifications. In this study, we use a parametrized 3-D dipping model to represent fault systems and compute gravity anomalies using an analytic method in the wavenumber domain. To estimate the marginal distribution of the 3-D dipping fault parameters, we utilize the Bayesian theory that integrates the likelihood function and prior information. Subsequently, we use the Markov chain Monte Carlo sampling method to assess the marginal distribution of the parameters. Compared with other deterministic inversion approaches, our method provides an effective means of quantifying parameter uncertainty. We first use synthetic data to validate the effectiveness of the proposed method. The results demonstrate the efficiency of our method in revealing 3-D dipping fault parameters and evaluating their uncertainty. We subsequently apply our method to the Pudu River fault, located in Yunnan Province, China, to demonstrate its practical applicability. Two alternative realistic fault models referred the prior seismic profile have been proposed. The optimal parameters and uncertainty with the specific model have been estimated. The results show that the fault characteristics retrieved by our method deviate slightly from existing knowledge. Specifically, the estimated depth of the bottom surface is greater than that reported in previous studies. This could potentially offer us new perspectives on the geological evolution and structural attributes of this fault.

Internal structure of an active landslide based on ERT and DP data: New insights from the Hofermühle landslide observatory in Lower Austria

Slopes with clay-rich, deeply weathered soils, such as those present in the Flysch Zone of Lower Austria, are prone to landslide processes. Even though generally being of low magnitude and velocity, they can cause substantial economic losses and threaten settlements as well as infrastructure. Previous studies have demonstrated the importance of sub-surface information to further increase our understanding on landslide processes and triggers in different areas as well as to support any decision makers to determine any appropriate landslide mitigation measures. The combination of direct and indirect methods thereby has proven to be an adequate methodology, yet case studies are still needed to develop a universal strategy for the investigation of clay-rich landslides. In this study, we applied Electrical Resistivity Tomography (ERT) and Dynamic Probing Medium (DPM) to further investigate the complex Hofermühle landslide in the Flysch Zone of Lower Austria in order to improve our knowledge on sub-surface conditions. The focus is on the initially activated main landslide area, which has already formed earth-flow-like processes in the past. The methodology facilitated a representative characterization of the sub-surface. We were able to approximate the geometry and depth of slip surfaces, as well as the transition to bedrock, allowing us to delimit those parts of the slope which are likely to fail and, respectively be re-activated in the future. The results show that a range of thicknesses can be found in the investigated part of the Hofermühle landslide. In particular, near the surface, which has been altered by creep displacement and also by anthropogenic alteration, the resistivity is more variable compared to deeper, presumably less disturbed, layers. Furthermore, it is assumed that clay particles are transported with the surface runoff and deposited in the surroundings of the drainage channels, resulting in lower resistivity values and higher saturation at this locations. The location of the slip surface is interpreted to be on the surface of the bedrock, where there is a highly disturbed, clay-rich mass with no interbedded layers. Layers with lower resistivity directly above the bedrock indicate weathered material and remolding of materials during creep.

Multi-objective optimization of the subsurface residual stress field of TC4 alloy in machine hammer peening

Machine hammer peening (MHP) is a surface strengthening process by introducing residual compressive stress at the part's surface. Many indicators of residual stress, such as the surface residual compressive stress and depth of residual compressive stress, significantly impact the fatigue performance of parts and thus need to be optimized. The present study focuses on two main problems in multi-objective optimization of the subsurface residual stress field induced by MHP: the relationship between a specific residual stress field and a combination of impact velocity and indentation distribution and how to implement the MHP process that could produce such a combination. The latter problem was first addressed by a kinematic model of the MHP device, which can optimize the MHP device input parameters to achieve the target axial impact velocity. For the former problem, a finite element model was first established to simulate the residual stress field induced by MHP. Then, the response surface method was used to optimize the simulated residual stress field with multiple objectives. Based on the above two models, we can obtain the appropriate MHP parameters to induce a target subsurface residual stress field. A verification experiment was carried out, and the residual stress field obtained was relatively close to the theoretical one, with a deviation of 1.7 % for the depth of residual compressive stress and 13.8 % for the surface residual compressive stress.

Effect of Irrigation Water Quality and Wetting and Drying Cycles on the Release of Calcium and Magnesium in Two Soils of Different Textures

Abstract&#x0D; The study included two sites for two soils of different textures (Al-Mazara and Bashiqa) within Nineveh Governorate - Iraq. Soil samples were taken from the surface depth (30 cm) naturally by means of columns. The experiment was carried out by adding two types of water (river water and well water) to each column with a volume equivalent to The pore size, and alternating wetting and drying were done for ten cycles, and the period between one cycle and another was 10 days. Soil samples were analyzed after the first cycle, the fifth cycle, and the tenth cycle to find out the effect of the number of humidification cycles on the exchanged ions, the relative effectiveness, and the Gapon constant. The results indicated that the released amount of exchanged calcium ions in the soil of Bashiqa was higher than the amount released in the soil of the Al-Mazara, while the amount of magnesium ions released in the soil of Al-Mazara was higher than the amount released in the soil of Bashiqa and when using both types of water, while the relative effectiveness values for calcium, the values ​​were higher when wetting with well water, except for the first cycle in the soil of Al-Mazara and the tenth cycle in the soil of Al-Mazara and Bashiqa, while the relative effectiveness of magnesium in the two study soils, the values ​​were higher when wetting with well water and for all cycles except the fifth cycle in Bashiqa soil, while the Gapon constant for calcium in the two study soils had higher values ​​when wetting with river water in the fifth cycles, while in the first and tenth cycles the values ​​were higher when wetting with well water, except for the first cycle in Bashiqa soil, while the Gapon constant for magnesium in the two study soils, the values ​​were higher when wetting with well water and for all cycles except for the first and fifth cycle in Al-Mazara soil. Then the following kinetic equations were applied: zero order equation, first order equation, diffusion equation, Eluvich equation and power function equation, the power function equation was the best equation that describes the process of release calcium and magnesium ions in the study soil.

Delineation of Nubian sandstone aquifer using geophysical data around Nuweiba area, Sinai, Egypt

The Nubian sandstone aquifer (NSA) is defined by using 19 vertical electrical sounding (VES) stations, 201 gravity stations, which define the structures that control the configuration of the NSA, and 183 land magnetic stations, which define the lower surface of the NSA by determining the depth of the basement surface. In order to assess the top of the NSA, we collected and analyzed 19 deep VESes. The upper surface depth of the NSA spans from 707 to 1154 m, according to the interpretation results for various geophysical data. Additionally, the aquifer’s resistivities ranged from 30.2 to 477 Ω m, which indicates good groundwater quality. According to the interpretation of the gravity result, the study region is influenced by many structural characteristics of different trends, including northwest–southeast, northeast–southwest, and east–west trends. The upper surface depth of crystalline rocks (also known as basement rocks) is determined by three-dimensional magnetic modeling to range between 967 and 4122 m.

Comparison of the intraarticular osteotomy and the “window” osteotomy in the treatment of tibial plateau fracture involving depressed posterolateral fragments

ObjectivesThe methods of reduction of depressed posterolateral fragments in tibial plateau fracture through anterolateral approaches remain controversial. This paper aimed to compare the intraarticular osteotomy technique and the “window” osteotomy technique for the reduction of depressed posterolateral fragments through anterolateral approach.MethodFrom January 2015 to January 2022, we retrospectively reviewed the data on patients with tibial plateau fracture involving depressed posterolateral fragments treated with the intraarticular osteotomy or the “window” osteotomy. 40 patients underwent the intraarticular osteotomy were divided into group A, while 36 patients underwent the “window” osteotomy were divided into group B. The operative time, bone grafting volume, fracture healing time, complication, reduction quality and postoperative functional results were compared between the two groups.ResultsThe average follow-up duration was 16.6 ± 3.7 months. The average bone grafting volume for all patients in group B was essential larger than group A (p = 0.001). Compared to group B, patients in groups A had significantly shorter fracture healing time (p = 0.011). The depth of depressed articular surface, PSA and the radiographic evaluation at 2 days and 6 months after surgery in group A were significantly lower than group B (p<0.05). Based on the HSS knee-rating score, no significant difference in function results was found between the two groups (p>0.05). No significant difference was found in operation time and blood loss between the two groups (p>0.05).ConclusionThe intraarticular osteotomy could obtain satisfactory clinical results in tibial plateau fracture involving posterolateral fragments.

Unsupervised single-shot depth estimation using perceptual reconstruction

Real-time estimation of actual object depth is an essential module for various autonomous system tasks such as 3D reconstruction, scene understanding and condition assessment. During the last decade of machine learning, extensive deployment of deep learning methods to computer vision tasks has yielded approaches that succeed in achieving realistic depth synthesis out of a simple RGB modality. Most of these models are based on paired RGB-depth data and/or the availability of video sequences and stereo images. However, the lack of RGB-depth pairs, video sequences, or stereo images makes depth estimation a challenging task that needs to be explored in more detail. This study builds on recent advances in the field of generative neural networks in order to establish fully unsupervised single-shot depth estimation. Two generators for RGB-to-depth and depth-to-RGB transfer are implemented and simultaneously optimized using the Wasserstein-1 distance, a novel perceptual reconstruction term, and hand-crafted image filters. We comprehensively evaluate the models using a custom-generated industrial surface depth data set as well as the Texas 3D Face Recognition Database, the CelebAMask-HQ database of human portraits and the SURREAL dataset that records body depth. For each evaluation dataset, the proposed method shows a significant increase in depth accuracy compared to state-of-the-art single-image transfer methods.

Influence of manure and tillage on soil carbon and soil organic matter in silt loam soils of corn–soybean–forage systems

AbstractIntroductionAn increasing number of farms in Northeast Ohio are being managed under reduced or conservation tillage practices, while those under conventional or intensive tillage are decreasing. Additionally, the use of on‐site farm manure among the growers is commonplace. Therefore, it is important to understand how the various management practices of these farms are impacting soil health, soil carbon stocks and crop yields.Materials and MethodsThis on‐farm study takes place in the temperate climate of the midwestern United States on a silt loam soil. It focuses on the impact of tillage (mouldboard plough [MP], vertical/chisel tillage [VT] and no‐tillage [NT]) and fertilizer (manure included or not) management practices on soil properties. Twelve agriculture fields and two woodland sites, for reference, on Canfield silt loam soils were selected for assessment in this project. Corn (Zea mays L.)–soybean (Glycine max L.) rotations and mixed forage Hayfields were the crops considered. Crop yields at each farm along with soil organic matter (SOM), total carbon (TC), total nitrogen (TN), bulk density, pH, soil test phosphorus (P), potassium (K) and sulphur (S) were assessed at two depths, 0–15 and 15–30 cm. Results of the first 2 years of the study (2020 and 2021) are presented here.ResultsAt the surface soil depth (0–15 cm), TC content was not different among cultivated fields (36 Mg ha−1), but was significantly less than Hayfields, which had the same amount of TC as the wood sites (58 Mg ha−1). There was no significant difference in soil test P, K or S due to tillage. Analysis of variance revealed no statistical difference due to fertilizer. At the soil surface depth, principal component analysis, supported by analysis of similarities (ANOSIM), determined that measurements of TC, TN and SOM distinguished a difference in Hayfields compared to cultivated fields (R‐statistic = 0.33; p = 0.001), but little difference when the 15–30 cm soil depth was considered (R‐statistic = 0.17; p = 0.001). ANOSIM also determined a slightly significant (R‐statistic = 0.065; p = 0.031) difference in fertilizer at the deeper soil depth. Correlation analysis revealed a strong positive relationship between SOM and corn grain yield (r = 0.59) and TN and corn grain yield (r = 0.39).ConclusionsThere was no significant loss of TC among increasing tillage intensities possibly due to the inclusion of manure fertilizer in tilled fields even though there were only slight statistical differences between fields that utilized manure and those that did not. The use of manure was not detrimental in terms of soil test P for most farms, but should be used judiciously. Inclusion of perennial crops such as hay in rotation with crop production can improve TC and TN content. Finally, increasing SOM could potentially increase corn grain yield, but no causal relationship has been determined yet.

Quasiperiodic perturbations of Stokes waves: Secondary bifurcations and stability

We develop a numerical method to study eigenvalue problems for operators fundamental to Stokes wave and its stability in a 2D ideal fluid with a free surface and infinite depth. The method allows to determine the spectrum of the linearization operator of the quasiperiodic Babenko equation. We illustrate by providing new results for eigenvalues and eigenvectors near the limiting Stokes wave and identify new bifurcation point to double-period waves. An infinite number of such points is conjectured as the limiting Stokes wave is approached. The eigenvalue problem for stability is also considered. The method in [1] is extended to allow finding of quasiperiodic eigenfunctions by introducing the Fourier-Floquet-Hill (FFH) approach in canonical conformal variables. Our findings agree and extend existing results for the Benjamin-Feir, high-frequency and localized instabilities, see also Refs. [2]. The numerical method is matrix-free and is based on Krylov subspaces. All operators appearing in the problems are pseudospectral and employ the fast Fourier transform (FFT), thus enjoying the benefits of spectral accuracy and O(Nlog⁡N) numerical complexity.

Composition and sources of suspended particles in the Pacific Arctic region

During the 6th (2014) and 7th (2016) Chinese Arctic Expedition (CHINARE), samples of suspended particulate matter (SPM) were collected from both surface (depth: <1.0 m) and subsurface (depth: approximately between 10 and 150 m) waters over the northern shelf of the Bering Sea and in the western Arctic Ocean. To investigate the distribution and sources of organic matter in both the surface water and the vertical profile, the concentration and stable carbon isotopic composition of SPM, particulate organic carbon (POC), and particulate nitrogen (only in surface water samples) were determined, and some particle samples were selected for examination using scanning electron microscopy. Results showed apparent geographical partitioning and temporal variation in both the concentration and the composition of SPM. Higher SPM concentrations were observed in nearshore, shelf break, and sea ice edge areas; the distribution of POC concentration displayed a similar pattern, with higher values found from the northern part of the Bering Shelf to southern parts of the Chukchi Shelf. In surface water, SPM mainly comprised clay and detrital minerals with higher POC contents, lighter δ13C values, and higher POC/PN ratios, indicating organic matter predominantly derived from terrestrial sources in areas south of St. Lawrence Island and north of 73°N. The downward trend of heavier δ13C values, together with reduction in clay and detrital minerals, suggests that vertical transport of SPM is hindered by stratification, resulting in transport of terrestrial materials toward northern basin areas. In the Chukchi Slope and Canada Basin areas, extremely light δ13C values (as low as −33.41‰ PDB) were mainly observed at depths of 20–60 m, where the Polar Mixed Layer (PML) intersects with the Upper Halocline Layer (UHL). Under the condition of low sea ice extent in 2016, the POC-δ13C values were heavier in the PML than in the UHL in the Chukchi Slope and Canada Basin areas. These findings provide insights into the sources, transport, and fate of organic matter in the Pacific Arctic region, which have important implications for understanding the biogeochemical cycles and ecosystem dynamics in this remote and rapidly changing environment.

Enhanced static simulation process of caisson sinking using the coupled Euler-Lagrange method

Caisson sinking is a vital process in marine engineering, and accurate simulations are crucial for predicting and preventing potential accidents or failures. Current numerical simulations necessitate measured engineering parameters, constraining their applicability. This study utilized the coupled Euler-Lagrange (CEL) method to compute specific parameters. These parameters served as substitutes for the engineering measurement values to enhance the static simulation process for the incremental height sinking of caissons, thereby addressing the constraints set by engineering measurements. The CEL method was initially utilized to simulate a dynamic permeation process, generating a series of valuable parameters such as the degree of caisson sinking and mud surface depth at the cavity bottom. Using these parameters instead of engineering measured parameters, a stable state model for incremental height sinking of caissons was established, followed by a static analysis. The improved method was subsequently applied to simulate the construction process involving caisson sinking, demonstrating its feasibility. This enhanced static simulation provides a novel approach for examining the equilibrium state of caisson subsidence, eliminating the need to wait for the actual construction phase to be completed. The proposed method exhibits the critical advantage of favorable predictability, allowing for the anticipation of potential mishaps, such as abrupt subsidence, and supplying timely cautionary information to facilitate proactive measures, ultimately reducing the incidence of engineering accidents or failures.

Microstructure evolution of medium carbon steel during heat-assisted 3D ultrasonic vibration-assisted turning

Medium carbon steel is an excellent carbon structural steel, and is one of the most common materials for metal cutting. Little research has been done on the microstructural changes induced by thermal-force coupling. In this paper, a finite element simulation method based on the improved J-C model is used to predict the grain size, microstructure change depth and surface hardness of medium carbon steel surface induced by heat-assisted 3D-UVAT are studied. The numerical simulation results are compared with the experimental results, and the significant influence of turning conditions on them is analyzed. The results show that heat-assisted 3D-UVAT lowered the grain size of machined induced deformation zone. Numerical model foresees this case with a mean error of 9.4%. Microstructure and hardness measurements under different turning conditions show that the turning speed and feed rate contribute significantly to grain size and grain refinement layer depth in the area being machined.

Image processing based tactile tactical sensor development and sensitivity determination to extract the 3D surface topography of objects

Inspired by the tactile sensing abilities of humans, tactile tactical sensors are used in many areas from robotics to heavy industry, such as surface roughness determination, softness determination, and quality control, etc. in industry. In the first stage of this study, for the production of a tactile tactical sensor from the silicon family, the most suitable tactile tactical sensor mixing ratios were determined according to the purpose of use by making softness, drying time, strength, flexibility, and light transmittance depending on the mixing ratios. In the second stage, the surface roughness images of the samples with known dimensions were taken by using the tactical tactile sensor produced with the determined mixing ratio for the determination of sub-millimeter surface roughness, in the microscopic imaging setup. In the third stage, image processing software was made with the original algorithm created using the MATLAB program, and depth detection calibration from the image was performed. As a result of the experiments, it has been determined that tactical tactile sensors and image processing software provide realistic depth information with 2-micron sensitivity and can be used for surface roughness. Inspired by the tactile sensing abilities of humans, the tactile tactical sensors are used in many areas from robotics to heavy industry, such as surface roughness, softness determination, quality control, etc. in industry. It is needed for purposes. In this article, it is aimed to develop a tactile tactical sensor and imaging system for artificial intelligence-based detection of submillimeter surface roughness. The developed system consists of three stages; In the first stage, the production of silicone rubber, which forms the tactile tactical sensor, is emphasized. Silicone rubber is obtained by reacting three different chemical components, namely A, B and C. The varying ratios of these chemical components give us different characteristics such as softness, drying time, strength, flexibility and light transmittance. In order to achieve the best tactile feature for the sensor, the optimum mixing ratio of the silicone rubber components that make up the tactile tactical sensor was determined by the Taguchi method. In the second stage of the system, the tactical tactile sensor, produced with the ideal mixing ratio determined for the determination of sub-millimeter surface roughness, was used in the microscopic imaging mechanism, and surface roughness images of the samples with known dimensions were taken. In the third stage of the system, image processing software was made with the original algorithm created using the MATLAB program, and depth detection calibration from the image was performed. As a result of the experiments, it has been determined that tactical tactile sensors and image processing software provide realistic depth information with 2-micron sensitivity and can be used with high reliability in surface roughness. This study allowed the surface depths of images taken with the sensor to be calculated on a pixel basis. With this tactile sensor, which does not take up space and has high mobility, depth analysis of hard-to-reach surfaces can be done easily and precisely. In addition, the tactile sensor can be considered a very useful apparatus in robotics technology for providing the robot with a sense of touch.

Effect of Material Selection and Surface Texture on Tribological Properties of Key Friction Pairs in Water Hydraulic Axial Piston Pumps: A Review

A water hydraulic axial piston pump has become the preferred power component of environmentally friendly water hydraulic transmission systems, due to its advantages of a compact structure, high power density, and so on. The poor friction and wear performance in the water medium, especially under extreme conditions of high speed and high pressure, limit the engineering application of the water hydraulic axial piston pump. In this review, the research progress for key friction pair materials (such as special corrosion-resistant alloys, engineering plastics, and engineering ceramics) for water hydraulic axial piston pumps is, firstly, summarized. Secondly, inspired by nature, the processing methods, lubrication drag-reduction mechanism, and tribological properties of the biomimetic surface textures are discussed. The effects of the surface texture shape, equivalent diameter, depth, and arrangement on the pump’s tribological properties are reviewed in detail. Finally, the application status of, and problems with, surface texture technology in water hydraulic axial piston pumps are summarized. It is suggested that future studies should focus on the multi-field coupling lubrication anti-friction mechanism of the multi-type composite texture under extreme conditions and mixed lubrication; and the anti-wear performance of the texture coupled with a coating modification, to further promote the surface texture in the field of lubrication antifriction engineering applications.

Vertical changes in water depth and environmental variables drove the antibiotics and antibiotic resistomes distribution, and microbial food web structures in the estuary and marine ecosystems

The influence of vertical changes in water depth on emerging pollutants distribution and microbial food web remains elusive. We investigated the influence of vertical transition in water depth on the environmental variables, antibiotics and antibiotic resistomes, and microbial community structures in estuary and marine ecosystems (0–50 m). Stepwise multiple linear regression model showed that among investigated environmental variables, change in water salinity was the most influential factor dictating the fluoroquinolone and macrolides concentrations, while dissolved oxygen and turbidity were the key influencers of sulfonamides and beta-lactam concentrations, respectively. Bacterial and eukaryotic diversity and niche breadth significantly increased with the increasing water depth. Ecosystem food web structure at the bottom depths was more stable than at the middle and surface depths. At the surface depth, the top 5 keystone genera were Cryothecomonas, Syndiniales, Achromobacter, Pseudopirsonia, and Karlodinium. Whereas Eugregarinorida, Neptuniibacter, Mychonastes, Novel_Apicomplexa_Class_1, Aplanochytrium and Dietzia, Halodaphnea, Luminiphilus, Aplanochytrium, Maullinia dominated the top 5 genera at the middle and the bottom depth, respectively. Absolute abundance of antibiotic resistance genes (ARGs) was drastically increased at the surface depth compared with the middle and bottom depths. Abundance of the top 10 ARGs and mobile genetic elements (MGEs) detected including tnpA-05, aadA2-03, mexF, aadA1, intI-1(clinic), qacEdelta1-02, aadA-02, qacEdelta1-01, cmlA1-01, and aadA-01 were amplified at the surface depth. This study demonstrated that ARGs abundance was disproportionate to bacterial diversity, and anthropogenic disturbances, confinement, MGEs, and ecosystem stability play primary roles in the fate of ARGs. The findings of this study also implicate that vertical changes in the water depth on environmental conditions can influence antibiotic concentrations and microbial community dramatically.

Cool skin effect and warm skin phenomenon observed by shipboard radiometer in the Northwest Pacific

Sea surface temperature (SST) is an important variable in the study of ocean boundary layers and heat exchange. The accurate simulation and measurement of skin effects are vital to air–sea model processing and satellite SST retrieval. Shipboard measurements from eleven cruises in the Northwest Pacific between August 2015 and October 2018 were used to estimate the cool skin effect and compare model results. The temperature difference ΔT between the sea surface skin temperature (SSTskin), as measured by an infrared radiometer, and the sea surface depth temperature (SSTdepth) at around 4 meters showed a mean difference and a standard deviation of the same 0.2 K, with a total of 5-min 39909 measurements. Both daytime and nighttime ΔT values were compared to physical model simulations and were found to have relatively larger mean values. A set of new coefficients for an exponential parameterization of the cool skin effect was derived in the research area, which performed well in comparison to previous empirical models. In nighttime observations from two summer cruises, the reverse process of heat flux transfer from the air to the sea in the form of a warm skin was distinguished. There were 667 positive ΔT values out of the 1917 nighttime observations, with magnitudes ranging from around 0 to 0.3 K. A high proportion of the cases of the warm skin phenomenon occurred when the air was very humid and much warmer than the sea surface.

Geophysical investigations for the identification of subsurface features influencing mineralization zones

The numerous hydrothermal alteration zones and subsurface structures affecting the mineralized deposits of the Dungash region were identified using aeromagnetic data. The Center of Exploration Targeting (CET) approach and several filters, such as reduction-to-pole, Tilt derivative, First Vertical Derivative, Horizontal gradient map, Downward continuation, analytical signal methods, regional, and residual separation, were used to analyze the aeromagnetic data. The research region is impacted by several structural trends running in the N-S, E-W, NW-SE, and NE-SW directions, and these trends are strongly related to the gold mineralization and surrounding hydrothermal alteration zones. In the NW-SE direction, four alteration zones have been identified. The research region's northern and eastern regions have shallower basement relief, with depths of only approximately 100 m, and those depths show that the area is rootless. Conversely, the basement relief and surface depths are lower in the study region's western and southern regions. The routes taken by the ascending hydrothermal fluids can be seen as aeromagnetic lineaments at the hydrothermal alteration zones. Mineralization appears to be linked to structural lineaments, as evidenced by airborne magnetic data. For gold prospecting, the aeromagnetic technique seems to be the most effective and efficient geophysical method because gold is typically found in severely deformed shear zones and faults.

A scattering spectrometer for white light interferometry

White light interferometry is a non-contact method to measure surface topography. The depth profile of the surface is typically encoded in the spectrum of the reflected light, and a spectrometer is used to decode this signal. In this work, we demonstrate a new form of spectral interferometry, a subset of white light interferometry, in which the conventional spectrometer is replaced with an engineered scattering chip and a camera. The chip is created using laser direct writing to controllably embed scattering centres within a bulk silica substrate, forming a highly stable optical scattering element. Calibration of our device is straight-forward: we circumvent the need for spectral characterisation and computational extraction of the spectrum, and instead directly measure the relationship between surface depth and the white light speckle pattern. Using our technique, we demonstrate surface profile measurements with a resolution of 27 nm over a range of 0.5 mm. Our work provides a new route to the development of potentially compact and low-cost white light interferometers with implications for the measurement of distance, strain, temperature, pressure, and more.