Double Splitting Research Articles

Double Rabi splitting in methylene blue dye-Ag nanocavity

Abstract We demonstrate a double Rabi splitting totaling 348 meV in an Ag nanocavity embedding of methylene blue (MB) dye layer, which is ascribed to the equilibrium state of monomer and dimer coexistence in MB dye. At low dye concentration, the single-mode strong coupling between the monomer exciton in MB dye and the Ag nanocavity is observed. As the dye concentration is increased, three hybridized plexciton states are observed, indicating a double Rabi splitting (178 and 170 meV). Furthermore, the double anti-crossing behavior of the three hybrid states is observed by tuning the Ag nanocube size, which validates the multi-mode strong coupling regime. It shows clear evidence on the diverse exciton forms of dye molecules, both of which can interact with plasmonic nanocavity, effectively. Therefore, it provides a good candidate for realizing the multi-mode strong coupling.

The global context of land market liberalization in Ukraine: opportunities and risks for rural development

The article considers various global factors influencing rural development under the conditions of liberalization of the agricultural land market in Ukraine. The author assesses the impact of global processes and global capital on the development of national farms, income distribution, access to land resources, production processes and equitable development in this country. It is proved that globalization, leading to increased concentration of agri-food production and business and expanding the role of large transnationalized corporations, is primarily aimed at exploiting the country’s existing comparative advantages, rather than increasing them, and promotes, in many recipient countries, a model of double economy split in the technological and socio-economic dimensions into qualitatively heterogeneous sectors. The author concludes that although global factors of agricultural production may have a relatively positive impact in macroeconomic terms, the dominance of multinational (transnational) companies, large exporting companies and financially powerful sovereign welfare funds in the market may create risks and threats of crowding out Ukrainian farmers from the market and blocking the sustainable development of rural areas. At the same time, Ukraine's agricultural sector will be transformed into a raw-material link of global food production chains dominated by large transnationalized entities, and a kind of raw-material enclave of transnationalized production will be created within the Ukrainian economy. The article argues that in today's global economy, where cardinal transformations are taking place and uncertainty is growing, land will become an increasingly valuable asset, attractive not only to agricultural producers but also to land speculators and those who try to maintain the value of their assets under the conditions of growing global risks. Under such conditions, investment in land will not at all necessarily contribute to the development of agricultural production, because speculative capital in the face of widespread expectations of a long and significant upward trend in land prices will prevail over productive agricultural capital. In general, this might lead to a significant increase in the cost of agricultural production and food prices. The author proves that the liberalization of the land market leads to increased risks of transfer of the control over Ukraine’s land resources to foreigners (sovereign financial funds and major international corporations), given their dramatic advantage by available financial resources for land acquisition, compared to those possessed by Ukraine’s residents. The article substantiates a set of policy measures and national policy instruments necessary to minimize the risks associated with the introduction (in the context of globalization) of free purchase and sale of agricultural land, which comply with the regulation principles of the European Union.

Technical and environmental potentialities of recycled steel fiber reinforced concrete for structural applications

The use of recycled materials and industrial by-products as sustainable constituents of cement-based materials could be an environmentally and technically promising solution for application to structural elements. In the present work, the technical and environmental impact of using recycled steel fibers as an alternative to industrial steel fibers for concrete reinforcement was assessed at material level. Numerical simulations were performed to derive the post-cracking constitutive laws of the developed Recycled Steel Fiber Reinforced Concrete (RSFRC) and Industrial Steel Fiber Reinforced Concrete (ISFRC) by inverse analysis of experimental results obtained from three-point notched beam bending tests (3PNBBT), round panel tests supported in three points (RPT-3ps) and double edge wedge splitting tests (DEWST). These simulations were able of fitting with high accuracy the experimental results and consequently to derive the tensile stress-crack width relationships of RSFRC and ISFRC that was used to numerically simulate the bending response of a T-cross section steel RSFRC beam failing in shear.The environmental impact of the incorporation of RSF in concrete in comparison with ISFRC was evaluated using Life Cycle Assessment methodology. The reduction of the environmental impact of the production of RSFRC compared to ISFRC with the same concrete strength class is demonstrated.

Глобальний контекст лібералізації земельного ринку в Україні: можливості та ризики для сільського розвитку

The article considers various global factors influencing rural development under the conditions of liberalization of the agricultural land market in Ukraine. The author assesses the impact of global processes and global capital on the development of national farms, income distribution, access to land resources, production processes and equitable development in this country. It is proved that globalization, leading to increased concentration of agri-food production and business and expanding the role of large transnationalized corporations, is primarily aimed at exploiting the country’s existing comparative advantages, rather than increasing them, and promotes, in many recipient countries, a model of double economy split in the technological and socio-economic dimensions into qualitatively heterogeneous sectors. The author concludes that although global factors of agricultural production may have a relatively positive impact in macroeconomic terms, the dominance of multinational (transnational) companies, large exporting companies and financially powerful sovereign welfare funds in the market may create risks and threats of crowding out Ukrainian farmers from the market and blocking the sustainable development of rural areas. At the same time, Ukraine's agricultural sector will be transformed into a raw-material link of global food production chains dominated by large transnationalized entities, and a kind of raw-material enclave of transnationalized production will be created within the Ukrainian economy. The article argues that in today's global economy, where cardinal transformations are taking place and uncertainty is growing, land will become an increasingly valuable asset, attractive not only to agricultural producers but also to land speculators and those who try to maintain the value of their assets under the conditions of growing global risks. Under such conditions, investment in land will not at all necessarily contribute to the development of agricultural production, because speculative capital in the face of widespread expectations of a long and significant upward trend in land prices will prevail over productive agricultural capital. In general, this might lead to a significant increase in the cost of agricultural production and food prices. The author proves that the liberalization of the land market leads to increased risks of transfer of the control over Ukraine’s land resources to foreigners (sovereign financial funds and major international corporations), given their dramatic advantage by available financial resources for land acquisition, compared to those possessed by Ukraine’s residents. The article substantiates a set of policy measures and national policy instruments necessary to minimize the risks associated with the introduction (in the context of globalization) of free purchase and sale of agricultural land, which comply with the regulation principles of the European Union.

On the convergence theory of double K-weak splittings of type II.

Recently, Wang (2017) has introduced the K-nonnegative double splitting using the notion of matrices that leave a cone K ⊆ ℝn invariant and studied its convergence theory by generalizing the corresponding results for the nonnegative double splitting by Song and Song (2011). However, the convergence theory for K-weak regular and K-nonnegative double splittings of type II is not yet studied. In this article, we first introduce this class of splittings and then discuss the convergence theory for these sub-classes of matrices. We then obtain the comparison results for two double splittings of a K-monotone matrix. Most of these results are completely new even for K = mathbb{R}_ + ^n. The convergence behavior is discussed by performing numerical experiments for different matrices derived from the discretized Poisson equation.

Alternating stationary iterative methods based on double splittings

Matrix double splitting iterations are simple in implementation while solving real non-singular (rectangular) linear systems. In this paper, we present two Alternating Double Splitting (ADS) schemes formulated by two double splittings and then alternating the respective iterations. The convergence conditions are then discussed along with comparative analysis. The set of double splittings used in each ADS scheme induces a preconditioned system which helps in showing the convergence of the ADS schemes. We also show that the classes of matrices for which one ADS scheme is better than the other, are mutually exclusive. Numerical experiments confirm that the proposed ADS schemes have several computational advantages over the existing methods. Though the problems are considered in the rectangular matrix settings, the same problems are even new in non-singular matrix settings.

Structural optimization scheme for acoustic cloaking structures considering general surfaces

ABSTRACT The present study presents the application of a structural optimization scheme for a Double Split Hollow Sphere (DSHS) based acoustic cloaking structure for irregular surfaces. For acoustic wave cloaking, many scientific devices utilizing phase differences have been developed. Considering the irregular surfaces of objects to be concealed, acoustic wave reflections become complex with random phase differences and determinations of the involved geometric parameters of cloaking structures become impractical. To determine the geometric parameters of acoustic cloaking devices with DSHS systematically, the present study applies a structural optimization scheme. The present scheme computes and minimizes the differences between the acoustic pressures reflected from irregular surfaces and the reference acoustic pressures without irregular surfaces by optimizing the location and geometric parameters of the DSHS. To show the validity of the present scheme, structural optimization problems are solved for several three-dimensional problems with complex and irregular surfaces.

Single vs double anti-crossing in the strong coupling between surface plasmons and molecular excitons.

Strong coupling between surface plasmons and molecular excitons may lead to the formation of new hybrid states-polaritons-that are part light and part matter in character. A key signature of this strong coupling is an anti-crossing of the exciton and surface plasmon modes on a dispersion diagram. In a recent report on strong coupling between the plasmon modes of a small silver nano-rod and a molecular dye, it was shown that when the oscillator strength of the exciton is large enough, an additional anti-crossing feature may arise in the spectral region where the real part of the permittivity of the excitonic material is zero. However, the physics behind this double anti-crossing feature is still unclear. Here, we make use of extensive transfer matrix simulations to explore this phenomenon. We show that for low oscillator strengths of the excitonic resonance, there is a single anti-crossing arising from strong coupling between the surface plasmon and the excitonic resonance, which is associated with the formation of upper and lower plasmon-exciton polaritons. As the oscillator strength is increased, we find that a new mode emerges between these upper and lower polariton states and show that this new mode is an excitonic surface mode. Our study also features an exploration of the role played by the orientation of the excitonic dipole moment and the relationship between the modes we observe and the transverse and longitudinal resonances associated with the excitonic response. We also investigate why this type of double splitting is rarely observed in experiments.

Characterization tests for predicting the mechanical performance of SFRC floors: identification of fibre distribution and orientation effects

In the context of the evaluation of the load-bearing capacity of a steel fibre reinforced concrete (SFRC) elevated slab recently built in northern Italy, this paper presents the study addressing the effects of fibre distribution and orientation. An extensive experimental programme was carried out in a collaboration between Politecnico di Milano and Universitat Politècnica de Catalunya. The programme included mechanical tests on four shallow beams and six notched standard beams. Additionally, uniaxial tensile tests (UTTs), double edge wedge splitting tests (DEWSTs) and double punching tests (DPTs) on 192 drilled core samples extracted from the shallow beams were performed. Inductive tests, measuring the self-induction change that occurs when a SFRC sample is placed inside a coil, were performed on all samples subjected to DPTs to assess fibre distribution. This paper compares direct and indirect tensile tests for the definition of the FRC post-cracking constitutive law, highlighting advantages and disadvantages of each test type. A comparison between standard and non-standard mechanical tests is also presented. Mechanical and non-destructive tests on drilled core samples extracted in different directions and at different locations have allowed the evaluation of the effects of fibre distribution and fibre orientation which provide an estimation of the possibility of using these tests as simplified tests for production control.

Characterization tests for predicting the mechanical performance of SFRC floors: design considerations

The paper presents an experimental program carried out to check the load bearing capacity of a steel fibre reinforced concrete (SFRC) floor in northern Italy. The extensive mechanical characterization focused on the suitability of 3 non-standardized test methods for quality control and tensile constitutive curve assessment was performed, this consisting of: uniaxial tensile test (UTT), double edge wedge splitting test (DEWST) and double punching test (DPT) to characterize the post-cracking mechanical properties of the material. The joint experimental programme, carried out at the Politecnico di Milano and at the Universitat Politècnica de Catalunya, included the flexural characterization of four shallow beams (1.5 × 0.5 × 0.25 m3) and six standard notched beams (0.55 × 0.15 × 0.15 m3). All the samples were produced from the same batch and with the same SFRC mix which was applied for the floor. After that, 192 cores were drilled from the shallow beams and subjected to either UTTs, DEWSTs or DPTs. The stress level, the scatter and the constitutive curves derived from the non-standardized tests were identified and analysed. The calculated constitutive curves were used to predict the behaviour of the shallow beams.

Regularized iterative method for ill-posed linear systems based on matrix splitting

In this paper, the concept of matrix splitting is introduced to solve a large sparse ill-posed linear system via Tikhonov?s regularization. In the regularization process, we convert the ill-posed system to a well-posed system. The convergence of such a well-posed system is discussed by using different types of matrix splittings. Comparison analysis of both systems are studied by operating certain types of weak splittings. Further, we have extended the double splitting of [Song J. and Song Y, Calcolo 48(3), 245-260, 2011] to double weak splitting of type II for nonsingular symmetric matrices. In addition to that, some more comparison results are presented with the help of such weak double splittings of type I and type II.

On comparison results for $ K $-nonnegative double splittings of different $ K $-monotone matrices

<abstract> The comparison results for $ K $-double splittings of one $ K $-monotone matrix are established in the literatures. As comparison theorems between the spectral radii of different matrices are a useful tool for judging the efficiency of preconditioners, we propose some comparison results for $ K $-nonnegative double splittings of different $ K $-monotone matrices in this note. The obtained results generalize the previous ones. </abstract>

Equation-of-motion coupled-cluster theory for double electron attachment with spin-orbit coupling.

We report implementation of the equation-of-motion coupled-cluster (EOM-CC) method for double electron-attachment (DEA) with spin-orbit coupling (SOC) at the CC singles and doubles (CCSD) level using a closed-shell reference in this work. The DEA operator employed in this work contains two-particle and three-particle one-hole excitations, and SOC is included in post-Hartree-Fock treatment. Time-reversal symmetry and spatial symmetry are exploited to reduce computational cost. The EOM-DEA-CCSD method with SOC allows us to investigate SOC effects of systems with two-unpaired electrons. According to our results on atoms, double ionization potentials (DIPs), excitation energies (EEs), and SO splittings of low-lying states are calculated reliably using the EOM-DEA-CCSD method with SOC. Its accuracy is usually higher than that of EOM-CCSD for EEs or DIPs if the same target can be reached from single excitations by choosing a proper closed-shell reference. However, performance of the EOM-DEA-CCSD method with SOC on molecules is not as good as that for atoms. Bond lengths for the ground and the several lowest excited states of GaH, InH, and TlH are underestimated pronouncedly, although reasonable EEs are obtained, and splittings of the 3Σ- state from the π2 configuration are calculated to be too small with EOM-DEA-CCSD.

Double Split Rings as Extremely Small and Tuneable Antennas for Brain Implantable Wireless Medical Microsystems

Wireless intracranial implantable microsystems are believed to potentially innovate the management of brain disorders and the treatment of neurological diseases. The fundamental challenge in the development of the wireless implantable system is the attainment of miniature antennas achieving adequately high efficiency for signaling and wireless power transfer in the presence of the dissipative intracranial tissues. Here, we demonstrate and evaluate an effective approach that utilizes the coupled split rings to develop the miniature implantable antenna. With the proposed approach, the antenna size can be decreased to π × (3 × 1.5) × 1 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> which is less than 2% of the operating wavelength at 915 MHz, while the antenna maintains the gain of -25 dBi when placed 16 mm deep in the anatomical human head model. As a proof of concept, we developed RFID tags based on the proposed antenna and verified their performance with tissue mimicking liquid and in vivo experiment with rats. The measured maximum read range of the tags reaches 0.7 and 1.1 m when immersed 30 mm in the tissue mimicking liquid and implanted 6 mm in a rat's cranial cavity, respectively.

A note on double weak splittings of type II

ABSTRACT Iterative methods based on matrix splittings are useful tools in solving real large sparse linear systems. In this aspect, the type I double splitting approaches are straight forward from the formulation of the iteration scheme and its convergence theory is well established in the literature. However, if a double splitting is of type II, then the convergence of the iteration scheme seems not to be straight forward. In this paper, we develop convergence theory for type II double splittings to make the implementation quite simple. In this direction, we first introduce two new subclasses of double splittings and establish their convergence theory. Using this theory, we prove a new characterization of a monotone matrix. Finally, we apply our theoretical findings to the double splitting of an M-matrix in the Gauss–Seidel double SOR method to obtain a comparison result.

More on proper nonnegative splittings of rectangular matrices

&lt;abstract&gt; &lt;p&gt;In this paper, we further investigate the single proper nonnegative splittings and double proper nonnegative splittings of rectangular matrices. Two convergence theorems for the single proper nonnegative splitting of a semimonotone matrix are derived, and more comparison results for the spectral radii of matrices arising from the single proper nonnegative splittings and double proper nonnegative splittings of different rectangular matrices are presented. The obtained results generalize the previous ones, and it can be regarded as the useful supplement of the results in [Comput. Math. Appl., 67: 136–144, 2014] and [Results. Math., 71: 93–109, 2017].&lt;/p&gt; &lt;/abstract&gt;

Ultra-Broadband Polarization Conversion Meta-Surface and its Application in Polarization Converter and RCS Reduction

In this paper, an ultra-broadband and high-efficiency polarization conversion metasurface is presented in the terahertz region. The metasureface is similar to a sandwiched structure, which is composed of the top Double Split Ring Resonator (DSRR), an intermediate dielectric layer and a bottom metal layer. Both numerical simulation and theoretical calculation results demonstrate that the proposed metasurface can convert linearly co-polarized waves into cross-polarized waves in the frequency from 2.04 THz to 5.33 THz with a relative bandwidth of 89% and the polarization conversion ratio (PCR) is over 90%. Further simulation results show that the proposed metasurface is insensitive to the polarization angle, and the physical mechanism is revealed in detail by the surface current distribution. In addition, two different kinds of 2-bit coding metasurfaces are designed based on the Pancharatnam-Berry (PB) Phase. The simulated and calculated results show that the proposed PB-coding metasurface has excellent performance in flexibly controlling terahertz wave reflection and low Radar Cross Section (RCS). A 10dB RCS reduction can be achieved from 1.9 THz to 5.5 THz under normal incidence. It provides new degrees of freedom for studying terahertz wave manipulation and reducing RCS.

Detection of Water Quality using Defected Ground Double Split Ring Resonator

Water is an essential thing for life. Now days due to population growth and pollution, the quality of water is degraded. In this paper, a single element double split ring resonator (DSRR) has been presented as a sensor to detect the quality of water. Here, two square shape metallic split rings are designed along with the microstrip line. On the back side of the substrate, defected ground structure (DGS) is introduced. The resonant frequency of the resonator is 11.12 GHz. Quality of water is detected by the shift in S21 resonant frequency with the variation in transmission coefficient. This sensor can be used in our daily life to detect the quality of water and it may be useful in medical field also.

U-joint Double split O (UDO) shaped with split square metasurface absorber for X and ku band application

This paper reports, a metasurface absorber which is U-joint loaded Double Split O shaped with a square split patch at the center and Double Negative (DNG) property. The proposed absorber shows significant absorption for potential applications like radar signal absorption and satellite communication, remote sensing, RF shielding. The vertical U joint and split O mutually creates substantial resonance and expedite by the center square patch, to cover two consecutive X and Ku band absorption peaks at 11.56 GHz with 82.31%, 12.27 GHz with 98.91% and 14.19 GHz with 97.79%. Besides, balanced geometrical shape with insensitivity polarization for TE and TM mode wave propagation enhances the robustness and tunability of the structure. The absorption mechanism analyzed and discussed with the Finite Integration Technique (FIT). Characterization of S-parameter executed with an established method for dielectric property extraction and finally compared the proposed absorber with existing literature.

Bandwidth enhancement of five-port reflectometer-based ENG DSRR metamaterial for microwave imaging application

A five-Port Reflectometer (FPR) with the integration of ultra-wideband (UWB) Epsilon Negative (ENG) Double Split Ring Resonator (DSRR) metamaterial array is introduced in this paper for microwave imaging (MWI) application. The designed DSRR consists of two concentric rings with a split in each which are spatially rotated by 180°, formed an inverted structure to exhibit a wide negative epsilon bandwidth of 187 % (from 0.5 GHz to 15 GHz). The FPR is designed using a ring junction topology and semi-circularly curved inter-port transmission lines (TLs) which are placed between five equally spaced ports. Localizing the DSRR metamaterial in a periodic array of 5 × 4 at the ground plane of FPR lead to 79.79 % fractional bandwidth and reflection coefficient within the operating frequencies of 0.991 GHz–2.2576 GHz. Equivalent circuit model has been alluded with an intricate description of different array configurations of the metamaterial unit cell. Comparison of EM simulation and circuit simulation has been performed to validate the equivalent circuit model. It is found that the existence of stray capacitance, Cstray which is represented by the DSRR configurations, significantly influenced the resonant frequency and bandwidth of FPR. Measured results of the proposed design suits well with the simulations and prove higher efficacious applicability of the proposed design for microwave imaging application. A comparison of the reconstructed image also proves its suitability for the microwave imaging application.