Contours In Space Research Articles

Investigation of leachate infiltration on groundwater using georesistivity and natural electric field method around Ojoou-Olayanju’s dumpsite, Ada, southwestern Nigeria

The investigation of groundwater within the dumpsite environment is highly important in geophysical study. This is because the extent of interaction between the aquiferous medium and the contaminated zone could pose a serious threat to the end users especially humans when consumed. This research aimed at investigating leachate infiltration and its potential influence on groundwater at Ojoou Olayanju's Dumpsite using combining geo-resistivity and natural electric field (NEF) methods. In this study, five dipole-dipole and five NEF measurements were obtained using the Omega resistivity meters and PQWT-150 equipment respectively. The dipole-dipole method was deployed to obtain a 2D near-surface pseudo-section, and the NEF method was used to obtain the frequency curve and profile maps of electric potential difference. The dipoledipole results revealed the lateral variation in the resistivity along the traverses, suggesting that the materials within this near-surface are heterogeneous, and the closely spaced contours' varying gradients indicate fracture, which would facilitate potential leachate filtration. The NEF results revealed curves, and a subsurface image with respect to depth and profile distance. The points of convergence signals on the frequency model correspond to a medium with low resistivity on the profile map. The conductive medium is seen as being saturated with leachate, which suggests that very large portion of the study area around the dumpsite has been contaminated by leachate. Conclusively, it was revealed that leachate filtration is evidence especially at the topsoil and due to the presence of fractured zones, the groundwater quality is at risk of contamination by continuous filtration of leachate

CEDFlow: Latent Contour Enhancement for Dark Optical Flow Estimation

Accurately computing optical flow in low-contrast and noisy dark images is challenging, especially when contour information is degraded or difficult to extract. This paper proposes CEDFlow, a latent space contour enhancement for estimating optical flow in dark environments. By leveraging spatial frequency feature decomposition, CEDFlow effectively encodes local and global motion features. Importantly, we introduce the 2nd-order Gaussian difference operation to select salient contour features in the latent space precisely. It is specifically designed for large-scale contour components essential in dark optical flow estimation. Experimental results on the FCDN and VBOF datasets demonstrate that CEDFlow outperforms state-of-the-art methods in terms of the EPE index and produces more accurate and robust flow estimation. Our code is available at: https://github.com/xautstuzfy.

Doxycycline Sclerodesis-"Rhinodesis"-for Enhanced Soft Tissue Adhesion in Rhinoplasty: A Preliminary Study.

The use of doxycycline as a sclerosing agent is well-established. Given the clinical efficacy of doxycycline sclerosant therapy, we embarked upon a study to evaluate the efficacy of small-volume liquified doxycycline particularly in thick skinned rhinoplasty patients to promote re-adhesion of the nasal skin-soft tissue envelope (SSTE) thereby minimizing surgical dead space and enhancing surface contour, to improve the eventual outcome of surgery.We present two clinical case series using rhinodesis. All patients were treated with the same rhinodesis protocol that included conventional splinting and taping. The first series consisted of 102 consecutive primary rhinoplasties with medium to thick nasal skin treated via open rhinoplasty. Doxycycline solution at a concentration of 20 mg/mL was applied beneath the skin flap using a 14-gauge angiocath inserted through small gaps in the marginal suture line following closure, retained for 2 to 3 minutes, and then expressed from the dead space. Firm manual compression of the SSTE was maintained for at least 1 additional minute, and the splint was then applied. The second series consisted of 25 thick-skinned primary rhinoplasties that were also treated with open rhinoplasty using the same rhinodesis protocol. However, the second group was evaluated with serial postoperative ultrasonography to characterize the soft-tissue response to rhinodesis, particularly within the tip and supra-tip regions.Results revealed enhanced skin adherence in nearly all patients when compared to traditional taping and splinting alone. Ultrasonic examination demonstrated enhanced adherence of the subcutaneous tissue to the nasal framework and suggests that rhinodesis is effective at minimizing dead space in majority of thick-skinned rhinoplasty patients. No complications were observed. Doxycycline can be used easily and safely to seal the surgical dead space post-rhinoplasty and minimize degradation of nasal contour with excellent outcome.

Расчет поливной нормы при капельном орошении древесно-плодовых культур в садовых насаждениях

Purpose: to develop the methodology for calculating irrigation rate for drip irrigation of tree-fruit crops, ensuring the formation of moistened soil contours in soil space with the required geometric and moisture parameters. Materials and methods. The empirical basis for the methodology development was the materials of the author's research devoted to determining the geometric dimensions (parameters) of soil moisture contours. The working hypothesis of the study involved determining the water supply rate for one emitter, one tree-fruit plant and a number of crops in the plantation, with further determining drip irrigation rate per unit area of drip-irrigated agricultural land, taking into account the number of drip micro-water outlets located on it. Results and discussion. When determining the geometric parameters of moisture contours and water supply rate, the main soil and technological parameters of drip irrigation and contour formation (physical clay content in soil, its lowest moisture capacity and bulk density, levels of pre-irrigation and after-irrigation soil moisture, specified depth soil profile moistening and dripper consumption) were considered as influence factors. The dependencies obtained by the author make it possible to determine the linear, areal and volumetric dimensions of local moisture contours and water supply rate, which, under appropriate conditions of drip irrigation, ensures the formation of a local, initially formed moisture contour with the required soil wetting depth in the soil layer. A study of the proposed methodology showed a deviation of the predicted parameters from the experimental soil moisture contours within ±10.0 %. Conclusions. A methodology allowing determining the irrigation rate for drip irrigation of agricultural land as the sum of the water supply rates of all drip water outlets irrigating 1 hectare of agricultural land with practical accuracy has been developed.

Расчет поливной нормы при капельном орошении древесно-плодовых культур в садовых насаждениях

Purpose: to develop the methodology for calculating irrigation rate for drip irrigation of tree-fruit crops, ensuring the formation of moistened soil contours in soil space with the required geometric and moisture parameters. Materials and methods. The empirical basis for the methodology development was the materials of the author's research devoted to determining the geometric dimensions (parameters) of soil moisture contours. The working hypothesis of the study involved determining the water supply rate for one emitter, one tree-fruit plant and a number of crops in the plantation, with further determining drip irrigation rate per unit area of drip-irrigated agricultural land, taking into account the number of drip micro-water outlets located on it. Results and discussion. When determining the geometric parameters of moisture contours and water supply rate, the main soil and technological parameters of drip irrigation and contour formation (physical clay content in soil, its lowest moisture capacity and bulk density, levels of pre-irrigation and after-irrigation soil moisture, specified depth soil profile moistening and dripper consumption) were considered as influence factors. The dependencies obtained by the author make it possible to determine the linear, areal and volumetric dimensions of local moisture contours and water supply rate, which, under appropriate conditions of drip irrigation, ensures the formation of a local, initially formed moisture contour with the required soil wetting depth in the soil layer. A study of the proposed methodology showed a deviation of the predicted parameters from the experimental soil moisture contours within ±10.0 %. Conclusions. A methodology allowing determining the irrigation rate for drip irrigation of agricultural land as the sum of the water supply rates of all drip water outlets irrigating 1 hectare of agricultural land with practical accuracy has been developed.

The ‘health workforce crisis’ and ‘the medical manpower problem’: New term, old problems.

The recent, but overdue, publication of the NHS Long Term Workforce Plan marks a welcome investment in the future sustainability of the service. The Plan includes a near doubling of medical and nursing school places, a proposed shortening of medical degrees, growth in ‘new roles’ including associates and apprentices, reduced overseas recruitment of staff and efforts to boost productivity and retention. While the plan was greeted with enthusiasm by many, criticisms were also numerous. This short opinion piece does not aim to add to the critique, but instead presents an argument for why, in trying to understand the persistence of the ‘health workforce crisis’ across the world, we might usefully think back seven decades to international efforts to address the ‘medical manpower problem’. Here, the manpower concept offers a hugely useful heuristic to think through the contours of time, space and resources that characterise(d) efforts to forecast and anticipate future health needs and, therefore, staff and resourcing. Geographers, I argue, should have far more to say about these conceptual continuities in modes and means of problematisation, as well as their consequences.

Soft x-ray photoelectron momentum microscope for multimodal valence band stereography

The photoelectron momentum microscope (PMM) in operation at BL6U, an undulator-based soft x-ray beamline at the UVSOR Synchrotron Facility, offers a new approach for μm-scale momentum-resolved photoelectron spectroscopy (MRPES). A key feature of the PMM is that it can very effectively reduce radiation-induced damage by directly projecting a single photoelectron constant energy contour in reciprocal space with a radius of a few Å−1 or real space with a radius of a few 100 μm onto a two-dimensional detector. This approach was applied to three-dimensional valence band structure E(k) and E(r) measurements (“stereography”) as functions of photon energy (hν), its polarization (e), detection position (r), and temperature (T). In this study, we described some examples of possible measurement techniques using a soft x-ray PMM. We successfully applied this stereography technique to μm-scale MRPES to selectively visualize the single-domain band structure of twinned face-centered-cubic Ir thin films grown on Al2O3(0001) substrates. The photon energy dependence of the photoelectron intensity on the Au(111) surface state was measured in detail within the bulk Fermi surface. By changing the temperature of 1T-TaS2, we clarified the variations in the valence band dispersion associated with chiral charge-density-wave phase transitions. Finally, PMMs for valence band stereography with various electron analyzers were compared, and the advantages of each were discussed.

Navigation-Oriented Topological Model Construction Algorithm for Complex Indoor Space

Indoor space information is the basis of indoor location services such as indoor navigation, path planning, emergency evacuation, etc. Focusing on indoor navigation needs, this paper proposes a fast construction algorithm for a complex indoor space topology model based on disjoint set for the problem of lacking polygon description and topological relationship expression of indoor space entity objects in building plan drawings. Firstly, the Tarjan algorithm is used for identifying the hanging edges existing in the indoor space. Secondly, each edge is stored as two different edges belonging to two adjacent polygons that share the edge. A ring structure is introduced to judge the geometric position of walls, and then an efficient disjoint set algorithm is used to perform set merging. After that, disjoint set is queried to obtain all indoor space contours and external boundary contours, thereby the complete indoor space topological relationship at multiple levels is established. Finally, the connectivity theory of graph is used for solving the problem of a complex isolated polygon in topology information generation. The experimental results show that the proposed algorithm has generality to efficiently complete the automatic construction of a topological model for complex scenarios, and effectively acquire and organize indoor space information, thus providing a good spatial cognition mode for indoor navigation.

Real-space observation of ultraconfined in-plane anisotropic acoustic terahertz plasmon polaritons.

Thin layers of in-plane anisotropic materials can support ultraconfined polaritons, whose wavelengths depend on the propagation direction. Such polaritons hold potential for the exploration of fundamental material properties and the development of novel nanophotonic devices. However, the real-space observation of ultraconfined in-plane anisotropic plasmon polaritons (PPs)-which exist in much broader spectral ranges than phonon polaritons-has been elusive. Here we apply terahertz nanoscopy to image in-plane anisotropic low-energy PPs in monoclinic Ag2Te platelets. The hybridization of the PPs with their mirror image-by placing the platelets above a Au layer-increases the direction-dependent relative polariton propagation length and the directional polariton confinement. This allows for verifying a linear dispersion and elliptical isofrequency contour in momentum space, revealing in-plane anisotropic acoustic terahertz PPs. Our work shows high-symmetry (elliptical) polaritons on low-symmetry (monoclinic) crystals and demonstrates the use of terahertz PPs for local measurements of anisotropic charge carrier masses and damping.

Copolymerization Reactivity Ratio Inference: Determining Confidence Contours in Parameter Space via a Bayesian Hierarchical Approach

AbstractConfidence contours in parameter space are a helpful tool to compare and classify determined estimators. For more intricate parameter estimations of nonlinear nature or complex error structures, the procedure of determining confidence contours is a statistically complex task. For polymer chemists, such particular cases are encountered in determination of reactivity ratios in copolymerization. Hereby, determination of reactivity ratios in copolymerization requires nonlinear parameter estimation. Additionally, data may possess (possibly correlated) errors in both dependent and independent variables. A common approach for such nonlinear estimations is the error‐in‐variables model yielding statistically unbiased estimators. Regarding reactivity ratios, to date published procedures neglect the non‐Gaussian structure of the error estimates that is a consequence of the nonlinearity of the model. In this publication, this issue is addressed by employing a Bayesian hierarchical model, which correctly propagates the errors of all variables. The statistical procedure is discussed in chemist friendly language to encourage confident usage of the tool. The approach is based on a Python program requiring minimal installation effort. A detailed manual of the code is included in the appendix of this work, in an effort to make this procedure available to all interested polymer chemists.

ОПРЕДЕЛЕНИЕ ПОЛИВНОЙ НОРМЫ ДЛЯ ФОРМИРОВАНИЯ ПЕРВИЧНОГО ЛОКАЛЬНОГО КОНТУРА КАПЕЛЬНО-УВЛАЖНЕННОЙ ПОЧВЫ

Purpose: development of methodology for determining the irrigation rate value, which ensures the formation of a primary local contour of moistened soil in the soil space under drip irrigation with one emitter. Materials and methods. The methodological and factual basis of the development were materials and empirical dependencies obtained from the data of author's field studies of local moisture contours formed under various soil conditions with above-surface and surface drip irrigation. Results and discussion. The analysis and evaluation of known approaches to the calculation of irrigation rates for drip irrigation of plants is carried out, the direction of the development of the methodology is determined. Based on materials of field and office studies, 11 contour profiles of drip-moistened soil formed under various soil and technological conditions of drip irrigation were obtained. Soil conditions are characterized by a wide range of changes in their parameters: the content of physical clay is from 20.8 to 74.6 % of the dry soil mass (DSM), the lowest moisture capacity is from 16.9 to 32.2 % of DSM, the level of additional irrigation moisture is from 60 to 70 % of the lowest moisture capacity. Moisture contours were formed with an average soil moisture content of 90 % of the lowest moisture capacity. Empirical dependencies for determining the maximum and average radius (diameter) of moisture contours at given depths of the moistened soil layer, which make it possible to predict the volumes of moisture contours are obtained. The dependence and a method for calculating the irrigation rate value, which ensures the formation of a moisture contour of a given depth and a given level of soil moisture, are obtained for a wide range of granulometric and water-physical characteristics of soils. Conclusion. A method for calculating the irrigation rate required for the formation of a local moisture contour in soil space with specified dimensional and moisture parameters during irrigation water delivery by one drip micro emitter is proposed.

A grey zone: The contours of outer space armed conflict and South Africa’s national interests

ABSTRACT The prospect of extra-terrestrial (outer space) armed conflict between major powers is a real possibility. As early as 1966, an Outer Space Treaty was signed by over 100 countries in response to such a possibility. In 2019, NATO declared outer space a new potential war zone or military operational domain alongside air, land, sea, and cyberspace. This new war zone is mainly a strategic frontier, exclusively dominated by a few global superpowers. It would be naive to think that global superpowers’ wars fought in outer space will not have a detrimental socio-economic effect on non-participating countries. On the contrary, an outer space war will have dire consequences for the developing world, such as South Africa. This article is descriptive and explanatory in nature and analyses the potential risks of a twenty-first-century space war to South Africa's national security. It provides a deeper understanding by contextualising the international legal regulation of the military use of space, the use of force against the architecture of space resources, technological advances in satellite systems and weapons, the current geopolitical tensions between the major superpowers related to space and highlights South Africa's international relations with some of these global superpowers.

Stringy ER = EPR

The ER = EPR correspondence relates a superposition of entangled, disconnected spacetimes to a connected spacetime with an Einstein-Rosen bridge. We construct examples in which both sides may be described by weakly-coupled string theory. The relation between them is given by a Lorentzian continuation of the FZZ duality of the two-dimensional Euclidean black hole CFT in one example, and in another example by continuation of a similar duality that we propose for the asymptotic Euclidean AdS3 black hole. This gives a microscopic understanding of ER = EPR: one has a worldsheet duality between string theory in a connected, eternal black hole, and in a superposition of disconnected geometries in an entangled state. The disconnected description includes a condensate of entangled folded strings emanating from a strong-coupling region in place of a bifurcation point. Our construction relies on a Lorentzian interpretation of Euclidean time winding operators via angular quantization, as well as some lesser known worldsheet string theories, such as perturbation theory around a thermofield-double state, which we define using Schwinger-Keldysh contours in target space.

Is the Nicolai map unique?

The Nicolai map is a field transformation that relates supersymmetric theories at finite couplings g with the free theory at g = 0. It is obtained via an ordered exponential of the coupling flow operator integrated from 0 to g. Allowing multiple couplings, we find that the map in general depends on the chosen integration contour in coupling space. This induces a large functional freedom in the construction of the Nicolai map, which cancels in all correlator computations. Under a certain condition on the coupling flow operator the ambiguity disappears, and the power-series expansion for the map collapses to a linear function in the coupling. A special role is played by topological (theta) couplings, which do not affect perturbative correlation functions but also alter the Nicolai map. We demonstate that for certain ‘magical’ theta values the uniqueness condition holds, providing an exact map polynomial in the fields and independent of the integration contour. This feature is related to critical points of the Nicolai map and the existence of ‘instantons’. As a toy model, we work with mathcal{N} = 1 supersymmetric quantum mechanics. For a cubic superpotential and a theta term, we explicitly compute the one-, two- and three-point correlation function to one-loop order employing a graphical representation of the (inverse) Nicolai map in terms of tree diagrams, confirming the cancellation of theta dependence. Comparison of Nicolai and conventional Feynman perturbation theory nontrivially yields complete agreement, but only after adding all (1PI and 1PR) contributions.

Robust Image Hashing Combining 3D Space Contour and Vector Angle Features

AbstractIn this paper, an image hashing scheme combining 3D space contour (TDSC) features with vector angle (VA) features is proposed. The proposed algorithm extracts the 3D contours of the local component variation features of the image and the expression changes of the local component of the image in the form of a 3D VA to improve the performance. First, the gray component of the color image is used to construct a 3D space and the contour change features of the local component of the gray image are extracted using multi-perspectives. Then, the opposite color component and the brightness component Y of the YCbCr color space are extracted from the input image. The angular features of several image components are, respectively, extracted in the 3D space. Finally, the TDSC features are combined with the VA features to obtain image hashing. The simulations demonstrate and validate that the proposed image hashing scheme not only has better classification performance compared with the other image hashing techniques but is also equipped with the performance of tamper localization.

Advanced Intelligent Big Data Analytic-Based Automated Layout for Environmental Design Intelligent Sensor Networks

In this paper, through the in-depth study of advanced intelligent extensive data analysis and the design of the model of the environment design automatic layout intelligent sensor network, we realize the environment design intuitive layout smart sensor network based on advanced thoughtful and extensive data analysis. According to the non-beacon-enabling CSMA/CA algorithm of the MAC layer of a single node in intelligent sensor network, the analysis model of the node MAC layer of the innovative sensor network based on the Markov chain is established. The mathematical calculation method of node MAC layer delay is obtained through the analysis and calculation of nodes’ Markov state transfer process in this model. By analyzing the internal composition of design grooming, data support, analysis modeling, and platform in environmental design big data and the relationship between each part, the industrial extensive data analysis modeling method system is formed based on the CRISP-DM model, based on which the demand analysis of the industrial comprehensive data analysis modeling platform is carried out, and the overall architecture of the platform is formed; this paper proposes an automatic layout algorithm based on strategy iteration for each. Each type of environment design is modeled, and the layout scheme is sequentially generated. The applicability, aesthetics, and comfort are considered, but the design information provided by the space contour can be regarded to develop a reasonable layout scheme. The experimental results show the rationality and versatility of the automatic layout schemes, proving the practicality and time-saving nature of the work.

Automated 3D Whole-Heart Mesh Reconstruction From 2D Cine MR Slices Using Statistical Shape Model.

Cardiac magnetic resonance (CMR) imaging is the one of the gold standard imaging modalities for the diagnosis and characterization of cardiovascular diseases. The clinical cine protocol of the CMR typically generates high-resolution 2D images of heart tissues in a finite number of separated and independent 2D planes, which are appropriate for the 3D reconstruction of biventricular heart surfaces. However, they are usually inadequate for the whole-heart reconstruction, specifically for both atria. In this regard, the paper presents a novel approach for automated patient-specific 3D whole-heart mesh reconstruction from limited number of 2D cine CMR slices with the help of a statistical shape model (SSM). After extracting the heart contours from 2D cine slices, the SSM is first optimally fitted over the sparse heart contours in 3D space to provide the initial representation of the 3D whole-heart mesh, which is further deformed to minimize the distance from the heart contours for generating the final reconstructed mesh. The reconstruction performance of the proposed approach is evaluated on a cohort of 30 subjects randomly selected from the UK Biobank study, demonstrating the generation of high-quality 3D whole-heart meshes with average contours to surface distance less than the underlying image resolution and the clinical metrics within acceptable ranges reported in previous literature. Clinical Relevance- Automated patient-specific 3D whole-heart mesh reconstruction has numerous applications in car-diac diagnosis and multimodal visualization, including treatment planning, virtual surgery, and biomedical simulations.

Enhanced Automatic Identification of Urban Community Green Space Based on Semantic Segmentation

At the neighborhood scale, recognizing urban community green space (UCGS) is important for residential living condition assessment and urban planning. However, current studies have embodied two key issues. Firstly, existing studies have focused on large geographic scales, mixing urban and rural areas, neglecting the accuracy of green space contours at fine geographic scales. Secondly, the green spaces covered by shadows often suffer misclassification. To address these issues, we created a neighborhood-scale urban community green space (UCGS) dataset and proposed a segmentation decoder for HRNet backbone with two auxiliary decoders. Our proposed model adds two additional branches to the low-resolution representations to improve their discriminative ability, thus enhancing the overall performance when the high- and low-resolution representations are fused. To evaluate the performance of the model, we tested it on a dataset that includes satellite images of Shanghai, China. The model outperformed the other nine models in UCGS extraction, with a precision of 83.01, recall of 85.69, IoU of 72.91, F1-score of 84.33, and OA of 89.31. Our model also improved the integrity of the identification of shaded green spaces over HRNetV2. The proposed method could offer a useful tool for efficient UCGS detection and mapping in urban planning.

Flutter of a finite rectangular Wing’D mill in pitch and heave

Exact solutions of flutter are explored for a mode suitable for an oscillating 2D hydrofoil version of the summarised FlutterWing windpump which radically surpasses the old rotary fanpump. The imaginary part G of the 1D Theodorsen wake lift factor T rises singularly from the steady to allow 1D pure pitch flutter around the leading edge at low frequency. But its logarithmic infinite negative pitch damping by the shed vorticity is capped by the log of the 2D span. The downwash of an oscillating trailing (tip) vortex is reduced by a function of the reduced frequency based on spanwise distance. Its lag damps pitch and further raises the pitch unstable aspect ratio A to above 36. All binary pitch & heave neutral flutter frequency contours in (inertia, imbalance) space still pass through a nexus of the same total pitch inertia and imbalance as the corrected virtual mass concentrated at ¾ chord, a very high total in water. The internal bound windwise vortex from ¼ chord to trailing edge reduces as A−2 the 1D lift slope at all frequencies. It expands the 1D T = ½ double root of high frequency elliptical contours kissing the low frequency limit line at the nexus to make them dip below the line to the right of the nexus as hyperbolae with the nexal ray as left asymptote. Thus low A discovers a new wedge of high frequency binary flutter with real mass moments less than the virtual, as in water.

Emergence of Fermi arcs due to magnetic splitting in an antiferromagnet.

The Fermi surface plays an important role in controlling the electronic, transport and thermodynamic properties of materials. As the Fermi surface consists of closed contours in the momentum space for well-defined energy bands, disconnected sections known as Fermi arcs can be signatures of unusual electronic states, such as a pseudogap1. Another way to obtain Fermi arcs is to break either the time-reversal symmetry2 or the inversion symmetry3 of a three-dimensional Dirac semimetal, which results in formation of pairs of Weyl nodes that have opposite chirality4, and their projections are connected by Fermi arcs at the bulk boundary3,5-12. Here, we present experimental evidence that pairs of hole- and electron-like Fermi arcs emerge below the Neel temperature (TN) in the antiferromagnetic state of cubic NdBi due to a new magnetic splitting effect. The observed magnetic splitting is unusual, as it creates bands of opposing curvature, which change with temperature and follow the antiferromagnetic order parameter. This is different from previous theoretically considered13,14 and experimentally reported cases15,16 of magnetic splitting, such as traditional Zeeman and Rashba, in which the curvature of the bands is preserved. Therefore, our findings demonstrate a type of magnetic band splitting in the presence of a long-range antiferromagnetic order that is not readily explained by existing theoretical ideas.