Relative Depth Research Articles

Monitoring for relative effect of corrosive environmental factor on corrosion rate for steel structural details

It is necessary to examine the corrosion durability of a steel structure based on its local corrosive environmental conditions since its corrosion deterioration could appear locally, depending on the installation environment or structural details. In this study, therefore, test specimens with various structural details were fabricated to evaluate the relationship between the corrosive environmental factors and relative corrosion rates, and outdoor exposure tests were conducted on the distinguishing area with and without airborne chloride. For this, the temperature, relative humidity, corrosion current, time of wetness (TOW), and surface chloride were measured as corrosive environmental factors for the outdoor exposure test site and test specimens, and their relative corrosion rates were also examined using monitoring steel plates (MSP) as their mean corrosion depths. From the outdoor exposure test results, their mean corrosion depths exposed to the same environment were shown to be affected by their angles of the structural details. The relative mean corrosion depth varying due to the structural details was shown to be affected by the TOW and surface chloride.

Dynamic time warping to quantify age distortion in firn cores impacted by melt processes

Abstract As warming intensifies across the Greenland ice sheet, an increasing number of shallow coring and radar studies are targeting the melt-impacted firn column to investigate meltwater processes. Highly inhomogeneous infiltration and refreezing, however, redistributes mass, distorting age–depth relationships and confounding comparisons between different cores. Here, we utilize a dynamic time warping algorithm for time series alignment to investigate and quantify the heterogeneous impact of melt processes on nine closely spaced (within 50 m) firn core-density profiles. The 10 m cores were collected relatively high in Greenland's percolation zone, where melt alteration is minimal compared to lower elevation. Our analysis demonstrates the effectiveness of dynamic time warping as a tool for assessing heterogeneity between ice core records. We find that the optimal alignment of density profiles in the nine cores requires vertical stretching and compression of individual profiles, ranging from, on average, <1 to ~16% of the core lengths. We identified four depth zones of mass redistribution that appear to coincide with observed ice layers. Further, ~75% of density measurements from each core do not align with an age model-derived density profile that assumes no mass redistribution of meltwater, indicating the pervasive impact of melt processes.

Slurry Activation for Enhanced Surface Redox Reactions in CMP

A novel add-on hardware device is placed near the point of slurry dispense that can instantaneously activate slurry performance during polishing via megasonic irradiation. This new technology (Flucto-CMP® is able to overcome the inherent polisher-slurry weaknesses such as wafer-level defects, process vibrations, cost of ownership, slurry waste, remval rate (RR), and RR selectivity. Flucto-CMP® has been successfully applied to various types of CMP slurries resulting in significant increases in the removal rates of copper, SiC, borosilicate hard mask, ILD, TiN, and silicon carbide through chemical alteration of the passivation layer needed for material removal. Specifically, for copper CMP, using Flucto-CMP®, we see an up to 31% boost in RR which is well correlated with the amount of reactive oxidizing species generated through irradiation as well as the measured relative indentation depth of the passivation layer. In addition to boosts in RR, for copper, we see a 50X drop in the variance of shear force and a 5X drop in the variance of normal force when Flucto-CMP® is used. This dramatic reduction in process vibration for copper soft-landing processes ought to reduce wafer-level defects. Much greater rate improvements are observed when polishing SiC, and borosilicate hard masks.

Experimental Study of the Hydrodynamics of an Open Channel with Algae Attached to the Side Wall

The construction of large-scale water diversion projects has effectively alleviated the current situation of the uneven distribution of water resources in China. However, due to the siltation of very fine sediment and organic matter on the side wall of an open channel, and the slow velocity of the side wall flow field, it is easy for epipelic algae to be produced, which affects water quality. Because prototype observation cannot be used to predict the series of flow in real time, and the calculation of the mathematical model is affected by parameter limitations, these two methods often cannot truly reflect the hydrodynamic characteristics of an open channel with epipelic algae. Therefore, by referring to the design parameters of the water diversion project channel, this study took the epipelic algae growing on the side wall of an open channel as the research object and used the scale of 1:30 to carry out a generalized flume experiment. Through the analysis of the physical characteristics of the prototype sample, and the simulation of the cohesive force between the oblique side wall and the epipelic algae, multi-group and multi-series hydrodynamic tests were carried out. The velocity distribution law and flow field distribution law were analyzed. The research results show that the presence of epipelic algae has a certain hindering effect on the flow velocity and significantly reduces the range of the peak velocity of the channel along the water depth. The position of the maximum velocity on the vertical line of the channel flow appears at the relative water depth of 0.6. In the case of small flow, the epipelic algae group only reduces the average flow rate of the channel by 5~6%; in the case of large flow, the effect of epipelic algae on the channel flow rate is minimal. This paper includes important scientific guiding significance and practical value for the regulation of water quantity and water quality safety, as well as the protection of long-distance projects.

Investigation of Constraint Effect and Fracture Mode for Mixed Mode Inclination Surface Crack in Infinite Plate Under Compression

Abstract The stress field, constraint effect, and fracture mode transition at crack tip of mixed mode I-II-III inclination surface crack under compression have been investigated. The effects of geometrical configurations (relative crack depth and aspect ratio), friction coefficient, and biaxial scale factor on stress intensity factor (KII and KIII) and in-plane constraint parameter T-stress are quantitatively studied, the stress field at different crack inclination angles under tension and compression are compared, the failure mode at special locations along crack front of inclination surface crack is analyzed according to the generalized maximum tangential stress criterion (GMTS). The relative crack depth has slight effect on stress intensity factor and T-stress, and aspect ratio has a significant effect on stress intensity factor and T-stress. The friction coefficient decreases the magnitude of stress intensity factor and increases the magnitude of T-stress, the greater the crack inclination angle is, the more pronounced the effect is when crack inclination angle greater than 30 deg. The stress distribution around crack tip under tension and compression is completely different. At free surface, the crack will failure in-plane shear mode II sliding crack, and at the deepest part of crack, the crack will start as out-plane shear mode III tearing crack under compression.

Surface gravity wave interaction with a floating dock in the presence of a submerged composite wavy porous plate

A numerical model based on the multi-domain boundary element method is adopted to study surface gravity wave interaction with a finite floating dock in the presence of a submerged composite wavy porous plate in the two-dimensional Cartesian coordinate system. Physical parameters of interest such as reflection coefficient, transmission coefficient, dissipation coefficient, horizontal and vertical wave force coefficients of the wavy plate, vertical force and moment coefficients about the centre of the dock are calculated. The influence of structural parameters such as the number of ripple wavelengths, relative ripple amplitude, structural porosity and relative submergence depth of wavy plate, relative space between the plate and dock are computed and studied. An insight into the comparison of various types of plates such as flat plate, wavy plate and composite wavy plate is also presented. The study reveals that the mitigation of wave force on the dock is significant due to a wavy porous plate. Besides, the study exhibits that placing the wavy porous plate at a finite distance from the floating dock has a significant role in dissipating incident wave energy compared to that placing the submerged plate below the dock. Bragg reflection occurs due to the presence of the submerged wavy plate, which diminishes with an increase in structural porosity and depth of submergence of the wavy plate.

Blur aware metric depth estimation with multi-focus plenoptic cameras

While a traditional camera only captures one point of view of a scene, a plenoptic or light-field camera, is able to capture spatial and angular information in a single snapshot, enabling depth estimation from a single acquisition. In this paper, we present a new metric depth estimation algorithm using only raw images from a multi-focus plenoptic camera. The proposed approach is especially suited for the multi-focus configuration where several micro-lenses with different focal lengths are used. The main goal of our blur aware depth estimation (BLADE) approach is to improve disparity estimation for defocus stereo images by integrating both correspondence and defocus cues. We thus leverage blur information where it was previously considered a drawback. We explicitly derive an inverse projection model including the defocus blur providing depth estimates up to a scale factor. A method to calibrate the inverse model is then proposed. We thus take into account depth scaling to achieve precise and accurate metric depth estimates. Our results show that introducing defocus cues improves the depth estimation. We demonstrate the effectiveness of our framework and depth scaling calibration on relative depth estimation setups and on real-world 3D complex scenes with ground truth acquired with a 3D lidar scanner.

Modeling of discharge in compound open channels with convergent and divergent floodplains using soft computing methods

Abstract In this research, the estimation of discharge in compound open channels with convergent and divergent floodplains using soft computing methods, including the neural fuzzy group method of data handling (NF-GMDH), support vector regression (SVR), and M5 tree algorithm were performed. For this purpose, the geometric and hydraulic characteristics of the flow, including relative roughness (ff), relative area (Ar), relative hydraulic radius (Rr), relative dimension of the flow aspects (δ*), relative width (β), relative flow depth (Dr), relative longitudinal distance (Xr), convergent or divergent angle (θ) of the floodplain and longitudinal slope (So) of the bed were used as input variables and discharge was considered as the target (output) variable. The results showed that the statistical indices of the NF-GMDH in the testing stage are RMSENF-GMDH = 0.004, R2NF-GMDH = 0.923 and in the same stage for SVR are RMSESVR= 0.002 and R2SVR = 0.941 and finally for M5 tree algorithm are RMSEM5 = 0.002, R2M5= 0.931. The evaluation of the structure of the M5 tree algorithm showed that the most effective parameters are ff, Dr, Rr, δ*, and θ which confirm the important parameters specified by MARS, GMDH, and GEP algorithms used by previous researchers.

Experimental study of a hydraulic model of the side inlet and outlet of a pumped storage power station

Inlets/outlets have bi-directional characteristics and complex structures, which have important implications for practical operational safety and efficiency. In this paper, the hydraulic characteristics of the lateral inlet/outlet of a pumped storage power station are studied by means of model tests. The flow velocity distribution at the leading edge of the inlet/outlet orifice and the barrage section is more uniform, and the flow velocity distribution at the left, middle, and right of each orifice is the same. The formation of swirl is related to the relative submergence depth s/d and the Froude number Fr, with the inlet/outlet Fr< 0.23, relative submergence depth s/d> 0.5 and it has no harmful eddies.

Role of crack offset and loading condition on fracture behavior of wire specimen

Accurate stress intensity factor (SIF) solutions for cylindrical specimens with varied wire aspect ratios, crack aspect ratio, relative crack depth and crack offset are required to evaluate the fracture toughness of high strength yet brittle rods, cables, fibres and wire specimens. The mode I geometric factor (GF) solutions of various crack configurations in a cylindrical fracture specimen in tension have been determined using linear elastic fracture mechanics in earlier studies. In the present study, finite element analysis (FEA) was used to compute these as a function crack offset and wire aspect ratios for two different boundary conditions-constrained and unconstrained. In constrained loading condition, the GF was seen to decrease significantly with crack offset for wires at lower aspect ratio in all the 3 crack curvatures – concave, straight and convex. GF stabilized as the wire aspect ratio was increased beyond 40. In unconstrained loading the GF values were independent of the wire aspect ratio and crack offset for the 3 crack curvatures.

Effects of blade-tip squealer geometry on the working performance of a helico-axial multi-phase pump

Tip-leakage flow occurs in the tip-clearance region of helico-axial multi-phase pumps, and this reduces their working performance. In this study, a structural modification, in the form of the inclusion of “squealers” on the impeller blade tips, was adopted to reduce the tip-leakage flow in a helico-axial multi-phase pump, thereby improving its working performance. Numerical simulations were conducted to examine the impact patterns of geometric parameters such as the depth, shape, and size of the squealer on the external characteristics and tip-leakage flow. The results of this study show that the presence of squealer tips has significant effect on the performance of a multi-phase pump. The depth of the squealer and the ratio of the squealer length to the blade-tip length were found to be the critical structural parameters of the squealer. There is an optimal value for the relative squealer depth, and this was found to be 9%. Larger ratios of squealer length to blade-tip length were also found to be more favorable for improving the performance of the multi-phase pump. The width and location of the squealer were found to have relatively low impacts on the performance of the multi-phase pump considered in this study. The presence of squealer reduced the tip-leakage flow rate and also alter the structure of the flow field in the impeller blade-tip region, changing the periodic distribution pattern of tip-leakage flow to some extent. The results of this study have important guiding significance for improving the performance of helico-axial multi-phase pumps.

Identification and relative depth estimation in natural images of single human body parts

Identification and relative depth estimation in natural images of single human body parts

Application of triangular duct in solar-assisted air-heating system with surface roughness: a numerical investigation.

The device called solar air heater (SAH) is used to collect and transfer solar-thermal energy to air that can further be used for space heating, drying, etc. The conventional air heater (solar-assisted) has poor performance, and with this work, an attempt has been made to improve its performance by providing surface roughness over the heated surface. The roughness employed over the surface has an elliptical cavity, and its distribution over the heated surface is defined with the three parameters (dimensionless): relative flow-wise distance (ranging from 6 to 14), relative cavity depth (ranging from 0.016 to 0.038), and relative crosswise distance (ranging from 6 to 14). A CFD code has been developed and validated with experimentation to do the parametric study for understanding the effect of the proposed surface roughness on the performance of the air heater. It is concluded that the proposed surface roughness promotes the local turbulence, flow separation, and strong vortices in the flow field resulting in comparatively higher thermal performance in the proposed air heater. But this higher thermal performance is achieved at the expense of higher-pressure loss in the passage. A substantial change in heat augmentation by 2.57 times (with 2.3 times higher pressure loss) which results in 1.75 times higher thermo-hydraulic performance has been noticed over conventional designs at a relative flow-wise distance of 10, relative cavity depth 0.038, and relative crosswise distance of 10.

Water surface profile prediction in non-prismatic compound channel using support vector machine (SVM)

The process of estimating the level of water surface in two-stage waterways is a crucial aspect in the design of flood control and diversion structures. Human activities carried out along the course of rivers, such as agricultural and construction operation, have the potential to modify the geometry of floodplains, leading to the formation of compound channels with non-prismatic floodplains, thus possibly exhibiting convergent, divergent, or skewed characteristics. In the current investigation, the Support Vector Machine (SVM) technique is employed to approximate the water surface profile of compound channels featuring narrowing floodplains. Some models are constructed by utilizing significant experimental data obtained from both contemporary and previous investigations. Water surface profiles in these channels can be estimated through the utilization of non-dimensional geometric and flow parameters, including: converging angle, width ratio, relative depth, aspect ratio, relative distance, and bed slope. The results of this study indicate that the SVM-generated water surface profile exhibits a high degree of concordance with both the empirical data and the findings from previous research, as evidenced by its R2 value of 0.99, RMSE value of 0.0199, and MAPE value of 1.263. The findings of this study based on statistical analysis demonstrate that the SVM model developed is dependable and suitable for applications in this particular domain, exhibiting superior performance in forecasting water surface profiles.

French-Rwandan Foreign Relations: Depth and Rebirth of Diplomatic Relations

Abstract This research examines France and Rwanda’s historical, current and future relations. The consequences of France’s past support for Rwanda’s pre-genocide regimes indirectly resulted in nearly one million deaths during the 1994 Genocide against the Tutsi. France’s role during the Rwandan Civil War (1990–1994) against the Rwanda Patriotic Front (RPF) significantly influenced how the post-genocide Rwandan government engaged with France. Since 1994, French-Rwandan relations experienced significant lows, with Rwanda forming closer ties with the United States, European Union and the United Kingdom. However, there have been improved relations under Nicolas Sarkozy and President Emmanuel Macron. Bilateral relations increased under Macron through his personal interests in restoring Rwandan-French relations. This research relies on interpretivist and triangulation methods from interview data collected during multiple fieldwork period to understand through a Neorealist theoretical framework how Rwandan government elites, responsible for the state’s foreign policy, perceptions and desired diplomatic relations with France since 1994.

In Support of Valerie Plumwood

&#x0D; &#x0D; &#x0D; This paper offers general support for what Valerie Plumwood’s paper is trying to achieve by supporting the rejection of each of her four “false laws of logic”: exportation, illegitimate replacement, commutation (aka. permutation) and disjunctive syllogism. We start by considering her general characterizations of entailment, beginning with her stated definition of entailment as the converse of deducibility. However, this applies to a wide range of relevant logics and so is not able to be used as a criterion for deciding what laws to include in a logic. In this context, we examine the two key differences between deduction from premises to conclusion and entailment from antecedent to consequent. We also consider her use of sufficiency as a general characterizing feature. We then discuss Plumwood’s syntactic criteria used to reject the first three of her false laws of logic and add the Relevance Condition in this context. We next consider semantic characterizing criteria for a logic. After making a case against using truth, we introduce Brady’s logic MC of meaning containment. We then examine the content semantics for MC and use it to reject all of Plumwood’s false laws of logic together with some others. We follow with the related Depth Relevance Condition, which is a syntactic cri- terion satisfied by MC. This clearly rejects the first three of these laws and many others, but not the fourth law. We conclude by giving our overall support for her general enterprise. &#x0D; &#x0D; &#x0D;

Wave forces and moments on concave and vertical front caissons supported on piles

ABSTRACT The present paper details the total wave-induced forces and moments on the circular cum parabola shape (CPS-PSB) and vertical front pile-supported breakwaters (VF-PSB) through a comprehensive experimental investigation under intermediate to deep water conditions. The model was subjected to the action of random waves with peak wave periods ranging from 1s to 2.6s. The total wave forces and moments were measured using a six-component force balance. VF-PSB experiences maximum wave force at lower submergence and the vertical force decreases exponentially as relative depth increases. In the case of CPS-PSB, the variation of vertical force with relative depth is similar to the energy loss. The horizontal wave forces on both PSB models decrease with their relative submergence as the wave exposure frontal area. The induced moments are higher for longer waves and higher submergence. CPS-PSB experiences lesser force and moment than VF-PSB.

Monocular polarized three-dimensional absolute depth reconstruction technology for multi-target scenes.

The traditional polarization three-dimensional (3D) imaging technology has limited applications in the field of vision because it can only obtain the relative depth information of the target. Based on the principle of polarization stereo vision, this study combines camera calibration with a monocular ranging model to achieve high-precision recovery of the target's absolute depth information in multi-target scenes. Meanwhile, an adaptive camera intrinsic matrix prediction method is proposed to overcome changes in the camera intrinsic matrix caused by focusing on fuzzy targets outside the depth of field in multi-target scenes, thereby realizing monocular polarized 3D absolute depth reconstruction under dynamic focusing of targets at different depths. Experimental results indicate that the recovery error of monocular polarized 3D absolute depth information for the clear target is less than 10%, and the detail error is only 0.19mm. Also, the precision of absolute depth reconstruction remains above 90% after dynamic focusing on the blurred target. The proposed monocular polarized 3D absolute depth reconstruction technology for multi-target scenes can broaden application scenarios of the polarization 3D imaging technology in the field of vision.

Calculation of internal-wave-driven instability and vortex shedding along a flat bottom

The instability and vortex shedding in the bottom boundary layer caused by internal solitary waves of depression propagating along a shallow pycnocline of a fluid are computed by finite-volume code in two dimensions. The calculated transition to instability agrees very well with laboratory experiments (Carret al.,Phys. Fluids, vol. 20, issue 6, 2008, 06603) but disagrees with existing computations that give a very conservative instability threshold. The instability boundary expressed by the amplitude depends on the depth$d$of the pycnocline divided by the water depth$H$, and decays by a factor of 2.2 when$d/H$is 0.21, and by a factor of 1.6 when$d/H$is 0.16, and the stratification Reynolds number increases by a factor of 32. The instability occurs at moderate amplitude at large scale. The calculated oscillatory bed shear stress is strong in the wave phase and increases with the scale. Its non-dimensional magnitude at stratification Reynolds number 650 000 is comparable to the turbulent stress that can be extracted from field measurements of internal solitary waves of similar nonlinearity, moving along a pycnocline of similar relative depth.

Ultra-peripheral collisions of charged hadrons in extensive air showers

We discuss the electromagnetic collisions of high energy protons, pions and kaons with atmospheric nuclei. In particular, we use the equivalent photon approximation to estimate (i) the diffractive collisions where the projectile scatters inelastically off a nucleus, and (ii) the usual radiative processes (bremsstrahlung, pair production and photonuclear interactions) of these charged hadrons in the air. We then include the processes in the simulator AIRES and study how they affect the longitudinal development of extensive air showers. For 109-11 GeV proton primaries we find that they introduce a very small reduction (below 1%) in the average value of both X max and ΔX max. At a given shower age (relative slant depth from X max), these electromagnetic processes slightly increase the number of charged particles at the shower maximum and reduce the number of muons when it is old, decreasing by 1% the muon-to-(γ + e) near the ground level.