Real Polarization Research Articles

President’s Column: SPE@Energy Transition

_ Editor’s Note: This is a summary of the October episode of the President’s vodcast. We encourage you to watch the episode to see the full conversation. In this vodcast, Houzé discusses his views on SPE and the energy transition. _ Last month, I presented a to-do list with five main topics: energy transition, finances, governance, membership, and quality. This month, I will discuss the first topic, energy transition. 1. SPE’s polarized views on energy transition As I mentioned last month, there are significant geographic contrasts within our industry and SPE regarding how the energy transition is perceived and developed. In some SPE venues and regions, energy transition is the dominant, if not the only subject, and the P in SPE is indeed a major obstacle for support, even from our traditional stakeholders. In other regions, stakeholders acknowledge the energy transition, but the situation is essentially business as usual. Major investments are underway to sustain production at current levels or even increase hydrocarbon production to record levels, with development plans spanning over several decades. Even in these regions, most, if not all, new projects are designed from the outset to have a low carbon footprint, including mitigating methane emissions. Energy transition is somehow factored in. So, there are very different narratives, which are reflected in a polite but real polarization within SPE—geographic and, occasionally, demographic. As an SPE President visiting many sections and stakeholders, the contrast is often striking. But we are engineers operating on the same planet, and there must be a single energy narrative that accounts for the reality of the energy transition in whatever form or definition this takes, locally or globally. To do this, we can try to assess in the most objective way possible how our license to operate may evolve in the short to medium term. I will start with something you may have seen many times: the three main energy transition scenarios presented by the International Energy Agency (IEA). These scenarios predict the climate impact by the end of the century based on current and predicted variables, including consumption, population, economics, and technologies. These are just models, but as the statistician George Box pointed out: “All models are wrong, but some are useful.” These IEA models are definitely useful (Fig. 1).

U²PNet: An Unsupervised Underwater Image-Restoration Network Using Polarization.

This article presents U 2PNet, a novel unsupervised underwater image restoration network using polarization for improving signal-to-noise ratio and image quality in underwater imaging environments. Traditional methods for underwater image restoration using polarization require specific cues or pairs of underwater polarization datasets, which limit their practical applications. Our proposed method requires only one mosaicked polarized image of the scene and does not require datasets for pretraining or specific cues. We design two subnetworks (T-net and B textsubscript ∞ -net) to accurately estimate the transmission map and background light, and unique nonreference loss functions to ensure effective restoration. Our experiments are based on an indoor polarization simulated dataset and a real polarization image dataset constructed from our underwater robotic platform equipped with polarization cameras. Experiment results demonstrate that our proposed method achieves state-of-the-art performance on both simulated and real underwater polarization images. The code and datasets will be available at https://github.com/polwork/U-2Pnet.

Electro-Coloring Mechanism of Aluminum Anodic Oxides in Tin-Based Electrolytes

A method for accurately determining the chemical composition of deposits at the bottom of pores during the electrocoloring (e-coloring) of aluminum anodic oxide (AAO) layers in tin-based solutions is developed. The aluminum samples were AC e-colored after DC sulfuric anodization. Free-standing, tin e-colored aluminum oxide film was obtained by selective dissolution of the metallic aluminum from the AAO in copper chloride solution to access the deposit directly at the bottom of the pore. This allowed us to conduct XPS analysis directly on the deposits at pore bottoms without any interference from the base material or insulating barrier layer. The results revealed the presence of a mixture of tin oxide and metal in the deposits, which were richer in oxide content. Furthermore, a cyclic voltammetry experiment mimicking real polarization conditions during AC conditions was optimized and used to gain a deeper understanding of the electrochemical reactions that occur during AC electrocoloring. The comparison of CV results in tin-free and tin-containing electrolytes indicated that the tin deposited during a cathodic cycle is oxidized in the anodic cycle. The formation of tin-based deposits radically changed the CV behavior. The XPS and cyclic voltammetry results consistently show that the deposits formed during e-coloring comprised a mixture of metallic and oxidic tin species richer in oxide content.

Synthesis, Characterization, Optical and Dielectric Properties of NiO and Zn‐Doped NiO Nanostructures: Toward Advanced Applications

In this current study, hydrothermal method was employed to synthesize distinct nanostructures: pure nickel oxide (NiO), Zn‐doped NiO, and NiO/ZnO composites. X‐ray diffraction (XRD) results confirmed NiO’s cubic structure, with sizes of 17.01 nm for pure NiO and 30.87 nm for composites. Scanning electron microscope (SEM) images revealed flowerlike morphologies, energy‐dispersive X‐ray spectroscopy (EDX) authenticated the elemental composition without any impurities. Ultraviolet–visible (UV‐Vis) spectroscopy demonstrated heightened absorption in doped and nanocomposite samples. The bandgap energy calculated using Tauc’s plot reduced from 2.95 to 2.55 eV with increase in zinc (Zn) content. In Fourier‐transform infrared (FTIR) characterization, the Ni–O stretching vibration appeared at 666.7 cm−1 in doped samples, while Zn–O stretching was evident at 586.03 cm−1. Photoluminescence analysis unveiled a strong peak at 470 nm (near band edge) and another at 665 nm (indicative of defects), exhibiting intensified signals in doped and nanocomposite samples due to a higher defect density. The dielectric constant showed increased values at low frequencies attributed to real and space charge polarization. Notably, the conductivity of Zn‐doped and nanocomposite samples displayed an upward trend with frequency due to a higher defect density. This study unveils insights into the intricate optical and electrical properties of these novel nanostructures, showcasing their potential in advanced energy storage applications.

지역별상대주택가격지수 개발에 관한 연구

Recently, in Korea, the polarization of real estate prices by region has deepened, causing social and economic problems. In particular, the government's expansion of taxation on owners of multiple homes to stabilize housing prices led to the exacerbation of the real estate price polarization between the metropolitan areas and local regions. As a methodology for monitoring this phenomenon of real estate price polarization by region, this study is based on 3 house transaction types for 4 house types targeting 17 cities and provinces and affiliated administrative districts, tentatively named 'Regional Relative House Price Index’. The purpose is to calculate the 'RRHPI' for observing trends in relative real estate prices by region at the national level, suggesting brand-new directions for conducting research related to the regional polarization phenomenon.

The double Gelfand–Cetlin system, invariance of polarization, and the Peter–Weyl theorem

The bundle map T⁎U(n)⟶U(n) provides a real polarization of the cotangent bundle T⁎U(n), and yields the geometric quantization Q1(T⁎U(n))=L2(U(n)). We use the Gelfand–Cetlin systems of Guillemin and Sternberg to show that T⁎U(n) has a different real polarization with geometric quantization Q2(T⁎U(n))=⨁αVα⊗Vα⁎, where the sum is over all dominant integral weights α of U(n). The Peter–Weyl theorem, which states that these two quantizations are isomorphic, may therefore be interpreted as an instance of “invariance of polarization” in geometric quantization.

Proton Exchange Membrane Fuel Cell Power Prediction Based on Ridge Regression and Convolutional Neural Network Data-Driven Model

Research on the power prediction of proton exchange membrane fuel cells (PEMFCs) has garnered considerable attention. Because mainstream computational-fluid-dynamics-based methods are time-consuming, this study aimed to design a data-driven method based on Ridge regression (Ridge) and convolutional neural network (CNN) algorithms that can efficiently predict PEMFC power under uncertain conditions in real-world scenarios and reduce the time consumption. The measured data from a PEMFC test bench (3 kW) were collected as the data source for the model. First, we adopted Ridge to eliminate abnormal samples. Second, we analyzed and selected the variables that have a significant effect on PEMFC power. Moreover, we optimized the model using batch normalization, dropout, Nadam, Swish, and Huber techniques. Finally, the performance of the model was evaluated by combining real datasets and real polarization curves. The experimental results demonstrate that the polarization curves predicted by the CNN-based model agree with the real curves, with a prediction accuracy of approximately 0.96, a prediction time of 1 μs, and an iteration period of less than 1 s per cycle. A comparative analysis shows that the CNN-based model prediction precision was superior to that of other mainstream machine learning algorithms. In real scenarios, the CNN-based model accurately predicts the power of PEMFC.

Joint Denoising-Demosaicking Network for Long-Wave Infrared Division-of-Focal-Plane Polarization Images with Mixed Noise Level Estimation.

Denoising and demosaicking long-wave infrared (LWIR) division-of-focal-plane (DoFP) polarization images are crucial for various vision applications. However, existing methods rely on the sequential application of individual denoising and demosaicking processes, which may result in the accumulation of errors produced by each process. To address this issue, we propose a joint denoising and demosaicking method for LWIR DoFP images based on a three-stage progressive deep convolutional neural network. To ensure the generalization ability of this network, it is essential to have adequate training data that closely resembles real data. Therefore, we model the complex noise sources that affect LWIR DoFP images as mixed Poisson-Additive-Stripe noise and construct a least-squares problem based on the polarization measurement redundancy error to estimate the parameters of this model on real images. Subsequently, the estimated noise parameters are used to generate training data that enables the network to learn accurate polarization image statistics and improve its generalization ability. The experimental results demonstrate the effectiveness of the proposed method in enhancing the image restoration performance on real LWIR DoFP polarization data.

Deformation Quantization via Toeplitz Operators on Geometric Quantization in Real Polarizations

In this paper, we study quantization on a compact integral symplectic manifold X with transversal real polarizations. In the case of complex polarizations, namely X is Kähler equipped with transversal complex polarizations $$T^{1, 0}X, T^{0, 1}X$$ , geometric quantization gives $$H^0(X, L^{\otimes k})$$ ’s. They are acted upon by $${\mathcal {C}}^\infty (X, {\mathbb {C}})$$ via Toeplitz operators as $$\hbar = \tfrac{1}{k} \rightarrow 0^+$$ , determining a deformation quantization $$({\mathcal {C}}^\infty (X, {\mathbb {C}})[[\hbar ]], \star )$$ of X. We investigate the real analogue to these, comparing deformation quantization, geometric quantization and Berezin-Toeplitz quantization. The techniques used are different from the complex case as distributional sections supported on Bohr-Sommerfeld fibres are involved. By switching the roles of the two real polarizations, we obtain Fourier-type transforms for both deformation quantization and geometric quantization, and they are compatible asymptotically as $$\hbar \rightarrow 0^+$$ . We also show that the asymptotic expansion of traces of Toeplitz operators realizes a trace map on deformation quantization.

Operad structures in geometric quantization of the moduli space of spatial polygons

The moduli space of spatial polygons is known as a symplectic manifold equipped with both Kähler and real polarizations. In this paper, associated to the Kähler and real polarizations, morphisms of operads $\mathsf{f}_{\mathsf{K}\ddot{\mathsf{a}}\mathsf{h}}$ and $\mathsf{f}_{\mathsf{re}}$ are constructed by using the quantum Hilbert spaces $\mathscr{H}_{\mathrm{K}\ddot{\mathrm{a}}\mathrm{h}}$ and $\mathscr{H}_\mathrm{re}$, respectively. Moreover, the relationship between the two morphisms of operads $\mathsf{f}_{\mathsf{K}\ddot{\mathsf{a}}\mathsf{h}}$ and $\mathsf{f}_{\mathsf{re}}$ is studied and then the equality $\dim \mathscr{H}_{\mathrm{K}\ddot{\mathrm{a}}\mathrm{h}} = \dim \mathscr{H}_\mathrm{re}$ is proved in general setting. This operadic framework is regarded as a development of the recurrence relation method by Kamiyama (2000) for proving $\dim \mathscr{H}_{\mathrm{K}\ddot{\mathrm{a}}\mathrm{h}} = \dim \mathscr{H}_\mathrm{re}$ in a special case.

Carbon monoxide-sensing of SnS nanoflakes induced by the electron-trapped polaron upon the substituted-lithium

Two-dimensional (2D) SnS with wrinkled lattice and strong oxidation resistance exhibits malleable talents and great potential for gas-sensing applications. But it suffers the inherent disadvantage of low sensitivity towards weakly polarized gases like CO. Herein, inspired by the unique atomic real polarization and orbital penetration of lithium, a distinct polarized configuration of 2D Li-substituted SnS is proposed for achieving a moderate CO adsorption-desorption dynamics at room temperature. The 2D nanoflakes of Li-SnS, synthesized via one-step solvothermal method, reveal highly sensitive and selective performances towards trace CO as low as 2 ppm at RT. Conducting with first-principles calculations, the substitutional doping of Li in SnS crystal is unveiled as the knob to modulate the electronic state of SnS. The enhanced electron-deficiency states and the local vibration modes of Li atoms, urge the coupling of electrons and longitudinal-optical phonons to form a polaron on each Li site. These polarons serve as efficient electron traps, and synergize with anharmonic local vibrations of Li atoms to form energy state fluctuation, promoting CO adsorption-desorption dynamics and carrier transport for the SnS system. This work provides novel perspectives for understanding the structure-electrical configurations of 2D materials and the microscopic mechanism of gas adsorption.

Lagrangian fields, Calabi functions, and local symplectic groupoids

A Lagrangian field on a symplectic manifold M is a family Λ={Λx|x∈M} of pointed Lagrangian submanifolds of M. This notion is a generalization of a real Lagrangian polarization for which each Λx is the leaf containing x. Two Lagrangian fields Λ and Λ˜ are called transversal if Λx intersects Λ˜x transversally at x for every x∈M. Two transversal Lagrangian fields determine an almost para-Kähler structure on M. We construct a local symplectic groupoid on a neighborhood of the zero section of T⁎M from two transversal Lagrangian fields on M. The Lagrangian manifold of n-cycles of this groupoid in (T⁎M)n has a generating function whose germ around the diagonal of Mn is given by the n-point cyclic Calabi function of a closed (1,1)-form on a neighborhood of the diagonal of M2 obtained from the symplectic form on M.

Fractal Properties of the Magnetic Polarity Scale in the Stochastic Hereditary αω-Dynamo Model

We study some fractal properties of the hereditary αω-dynamo model in the two-mode approximation. The phase variables of the model describe the temporal dynamics of the toroidal and poloidal components of the magnetic field. The hereditary operator of the quenching the α-effect by field helicity in numerical simulation is determined using the Riemann–Liouville fractional differentiation operator. The model also includes a stochastic term. The structure of this term corresponds to the effect of coherent structures from small-scale magnetic field and velocity modes. A difference scheme and a program code for numerical simulation have been developed and verified. A series of computational experiments with the model has been carried out. The Hausdorff dimension of the polarity scale in the model and the distribution of polarity intervals are calculated. It is shown that the Hausdorff dimension of the polarity scale is less than 1, i.e., this scale is a fractal. The numerical value of the dimension for some values of the control parameters is 0.87, which is consistent with the dimension of the real geomagnetic polarity scale. The distribution histogram of polarity intervals in the model has a pronounced power-law tail, which also agrees with the properties of real polarity scales.

A novel anisotropic saturation magnetization phenomenon in flexible Mn-doped BiFeO3 thin films for wearable device

Pure inorganic flexible thin film with anisotropic magnetism is crucial for high temperature flexible/wearable spintronic devices and magnetic sensors. Here, a pure inorganic flexible Mn-doped BiMn0.05Fe0.95O3 (BMFO) thin film with a novel anisotropic saturation magnetization phenomenon is demonstrated on (001)-oriented fluorophlogopite (F-Mica) single-crystalline substrates by sol–gel method. The results of XRD indicate that the intensity ratios of the (101) and (110) direction increases with the increase in thicknesses. And an obvious anisotropy behavior in magnetization was observed in the thicker flexible BMFO thin films, and the anisotropic magnetization is slowly weakened as the thickness decreases. Meanwhile, the saturation magnetization (Ms) of both in-plane and out-of-plane increases with the increase in the thickness. These results indicate that the thickness can modulate the anisotropic magnetism for the flexible BMFO thin films. The maximum value of (Ms-in-plane-Ms-out-of-plane) is obtained in the flexible BMFO sample with the thickness of 550 nm. Moreover, the real nonvolatile ferroelectric polarization with Pr = 58.22 μC/cm2 was obtained in the flexible BMFO sample with the thickness of 336 nm. These flexible BMFO thin films with anisotropic saturation magnetism, mechanical anti-fatigue characters and well ferroelectric properties are promising for the applications in high temperature flexible spintronics and magnetic sensors.

Image denoising and enhancement strategy based on polarization detection of space targets

Polarization detection of space targets is one of the most important research directions in the field of space target recognition. In view of the fact that there are problems such as strong background noise and inconspicuous details of contour features in the polarization image of space targets, an image denoising and enhancement strategy is proposed. To solve the problem of high intensity of Gaussian noise in degree of polarization (DoP) images, a denoising method named adaptive noise template prediction (ANTP) is proposed to eliminate the noise. Compared to the existing methods, the ANTP algorithm performs better at reducing noise and improving image quality. Aiming at the difficulty of separating the background noise from angle of polarization (AoP) images, a denoising method named gray analysis of local area (GALA) is proposed. Compared to traditional methods, the GALA algorithm can effectively extract the contour features of targets and improve the contrast of AoP images. An image fusion method based on discrete cosine transform and local spatial frequency (LSF) is used to fuse the denoised DoP image and AoP image. The experimental results of the simulated and real space target polarization detection confirm the effectiveness of our proposed strategy.

Corrosion Experimental Research on Local Damage of Epoxy-Coated Steel Bars in Concrete Under Marine Environment

Epoxy coating has been proven to protect steel bars from corrosion. However, the damage of epoxy coating is inevitable, and this may lead to more serious corrosion of steel bar. In order to study the corrosion resistance of steel bars with damaged epoxy coating, two groups of coating-damaged bar and one group of coating-intact rebar were designed, and six specimens were made. The influence of electrolyte concentration on the corrosion rate of steel bars was studied by setting different concentrations. After 30 days of accelerated corrosion, electrochemical data were recorded by the electrochemical workstation. The experimental result shows that the steel bars with coating damage have obvious polarization curve characteristics of corrosion, and corrosion resistance decreases obviously. According to the corrosion current and potential, the larger the damaged area of the coating, the faster will be the corrosion rate. According to the polarization curve data, the polarization resistance is modified, and the result is closer to the real polarization resistance value. The calculated corrosion rate shows that the corrosion rate of reinforcement is affected by both electrolyte concentration and coating damage area, and electrolyte concentration has a greater influence on the corrosion rate.

Berezin–Toeplitz quantization in real polarizations with toric singularities

On a compact Kahler manifold $X$, Toeplitz operators determine a deformation quantization $(\operatorname{C}^\infty(X, \mathbb{C})[[\hbar]], \star)$ with separation of variables [10] with respect to transversal complex polarizations $T^{1, 0}X, T^{0, 1}X$ as $\hbar \to 0^+$ [15]. The analogous statement is proved for compact symplectic manifolds with transversal non-singular real polarizations [13]. In this paper, we establish the analogous result for transversal singular real polarizations on compact toric symplectic manifolds $X$. Due to toric singularities, half-form correction and localization of our Toeplitz operators are essential. Via norm estimations, we show that these Toeplitz operators determine a star product on $X$ as $\hbar \to 0^+$.

Approximations to a generalized real ray-tracing method for heterogeneous anisotropic viscoelastic media

The real ray-tracing approach leads to an effective solution in the real space domain using a homogeneous ray velocity vector. However, it fails to yield solutions for quasi-S-waves, which suffer from triplications of the wavefronts. To address this challenging problem, a new real ray-tracing method and its two approximations are developed to solve the complex ray equation. The numerical results indicate that the new real ray-tracing method is superior to the common real ray-tracing method in the presence of triplications of the quasi-S-waves in the computation of ray velocity, ray attenuation, and ray quality factors, as well as the reflection and transmission coefficients in viscoelastic anisotropic media. Based on the assumptions of the real slowness direction and real polarization vectors, two new approximations of the new real ray-tracing method are developed for directly computing the homogeneous complex ray velocity vectors of three wave modes (qP, qS1, and qS2). These approximations significantly improve computational efficiency by avoiding the iterative process required by the new real ray-tracing method that is inherited from the common real ray-tracing method. The computational accuracies are verified through transversely isotropic and orthorhombic models with different strengths of attenuation and anisotropy. Incorporation of the new approximation into the shortest-path method turned out to be efficient and accurate for seismic ray tracing in heterogeneous viscoelastic and transversely isotropic media with a vertical axis of symmetry, even in the presence of strong attenuation and anisotropy.

High-fidelity and rapid cellular-level Mueller matrix imaging for tissue identification with unstained sections

Mueller matrix polarimetry is regarded as a promising technique in the field of biomedicine, especially for pathological diagnosis. However, the current studies on Mueller imaging of pathological sections are all at the tissue-level, and the cellular-level polarization information is difficult to obtain. To overcome this challenge, we first propose a cellular-level Mueller matrix imaging method for accurate quantitative identification of tissues in this study. Benefiting from the significant birefringent behavior of paraffin in unstained sections, the proposed method can locate the paraffin distribution areas of retardance images by involving Otsu's algorithm. Then, the real cellular-level polarization information (e.g., depolarization) is acquired. The efficiency of the proposed method was demonstrated on unstained rat tissue samples. The results showed that the obtained depolarization images are highly consistent with the stained microscopic images in terms of the morphology and arrangement of the tissues at cellular level. Finally, this method was preliminarily applied to the detection of human lung cancer tissue section, effectively realizing the quantitative differentiation of normal, inflamed, and malignant areas in unstained section. This study provides a possible approach for the rapid and accurate diagnosis of cancer.

Geometric quantization via cotangent models

In this article we give a universal model for geometric quantization associated to a real polarization given by an integrable system with non-degenerate singularities. This universal model goes one step further than the cotangent models in [13] by both considering singular orbits and adding to the cotangent models a model for the prequantum line bundle. These singularities are generic in the sense that are given by Morse-type functions and include elliptic, hyperbolic and focus-focus singularities. Examples of systems admitting such singularities are toric, semitoric and almost toric manifolds, as well as physical systems such as the coupling of harmonic oscillators, the spherical pendulum or the reduction of the Euler’s equations of the rigid body on \(T^*(SO(3))\) to a sphere. Our geometric quantization formulation coincides with the models given in [11] and [21] away from the singularities and corrects former models for hyperbolic and focus-focus singularities cancelling out the infinite dimensional contributions obtained by former approaches. The geometric quantization models provided here match the classical physical methods for mechanical systems such as the spherical pendulum as presented in [4]. Our cotangent models obey a local-to-global principle and can be glued to determine the geometric quantization of the global systems even if the global symplectic classification of the systems is not known in general.