Multiple Splitting Research Articles

A New Model to Simulate Local Market Power in a Multi-Area Electricity Market: Application to the European Case

The work presented in this article proposes an original method that models the medium-term market equilibrium under imperfect competition circumstances in multi-area electricity systems. It provides a system analysis considering multiple market splitting possibilities, where local market power may appear according to the status of the interconnections. As a result of new policies and regulations, power systems are increasingly integrating the existing electricity markets in unified frameworks. The integration of electricity markets poses highly challenging tasks due to the uncertainty that comes from the agents’ strategic behaviors which depend on multiple factors, for instance, the state of the interconnections. When it comes to modeling these effects, the purpose is to identify each strategy by using conjectured-price responses that depend on the different states of the system. Consequently, the problem becomes highly combinatorial, which heightens its size as well as its complexity. Therefore, the purpose of this work’s methodology is the reduction of the possible network configurations so as to ensure a computational tractability in the problem. In order to validate this methodology, it has been put to the test in a realistic and full-scale two-year operation planning model of the European electricity market that consists of a group of nine countries.

Possible orbital crossover in the ferromagnetic Kondo lattice compound CeAgSb2

Utilizing femtosecond time-resolved pump probe spectroscopy, we investigated the ultrafast quasiparticle dynamics of the ferromagnetic Kondo lattice compound ${\mathrm{CeAgSb}}_{2}$. The photoinduced reflectivity demonstrates a positive relaxation process connected with simple metal physics at room temperature, while an additional negative decay channel associated with Kondo screening effect can be recognized immediately with temperature decreasing. The temperature-dependent amplitude of the latter exhibits a kink at ${T}^{*}\ensuremath{\approx}$ 45 K, which is close to the energy scale of the first excited crystal field splitting Ce $4f$ level. We propose that an orbital crossover is responsible for this intriguing feature. The dominating $4f$ orbitals that participated in the Kodno $c\ensuremath{-}f$ hybridization varies from the ground state below ${T}^{*}$ to multiple crystal field splitting levels. In the meantime, the hybridization gap changes from 12.6 to 220.4 K correspondingly, which is also in agreement with the fluence-dependent measurements.

Evaluation of redox performance of silver and transition metal‐doped ternary ceria oxides for thermochemical splitting of CO2

Synthesis of Ce0.9M0.05Ag0.05O2-δ materials (where, M = Ni, Zn, Mn, Fe, Cu, Cr, Co, Zr) via coprecipitation of hydroxide method and examination of these materials toward multiple thermochemical CO2 splitting (CS) cycles is reported in this paper. Physical properties of the derived Ce0.9M0.05Ag0.05O2-δ materials were estimated by analyzing the calcined powder using a powder X-ray diffractometer (PXRD) and scanning electron microscope (SEM). The redox reactivity (RR) of each Ce0.9M0.05Ag0.05O2-δ material was also evaluated by conducting high-temperature thermogravimetric experiments. The inclusion of Ag as an active dopant has improved the RR of all the Ce0.9M0.05Ag0.05O2-δ materials as compared with the Ce0.9M0.1O2-δ materials. Among all the Ce0.9M0.05Ag0.05O2-δ materials, Zn5Ag5Ce material was capable of releasing highest amount of O2 84.1 μmol O2/g·cycle and the Cr5Ag5Ce material indicated maximum CO production (151.6 μmol CO/g·cycle). The uppermost CO/O2 molar ratio equal to 1.89 was observed in case of Cr5Ag5Ce material. The quantity of O2 released and CO produced by Cr5Ag5Ce material was superior as compared with CeO21 by 30.7 μmol O2/g·cycle and 62.8 μmol CO/g·cycle, respectively.

Multiple splitting of droplets using multi-furcating microfluidic channels.

Removing volumes from droplets is a challenging but critical step in many droplet-based applications. Geometry-mediated droplet splitting has the potential to reliably divide droplets and thus facilitate the implementation of this step. In this paper, we report the design of multi-furcating microfluidic channels for efficient droplet splitting. We studied the splitting regimes as the size of the mother droplets varied and investigated the dependence of the transition between splitting regimes on the capillary number and the dimensionless droplet length. We found that the results obtained with our device agreed with the reported dimensionless analysis law in T-junctions. We further investigated the effect of channel lengths on the volume allocation in branch channels and achieved droplet splitting with various splitting ratios. This study proposed an efficient on-demand droplet splitting method and the findings could potentially be applied in washing steps in droplet-based biological assays or assays that require aliquot.

Brittleness Logging Evaluation of Shihezi Formation in Yanchang Gas Field in Ordos Basin Based on Rock Mechanical Characteristics

Brittleness determines the effect of reservoir fracturing and is important for increasing the production of unconventional oil and gas. The reservoir of Yanchang gas field is characterized by low porosity, low permeability and strong heterogeneity, which make it difficult to produce industrial gas flow under natural conditions. Triaxial compression tests in sandstone samples of Shihezi formation in Yanchang gas field show that the main fracturing mode is multiple horizontal splitting, the main cracks are completely fractured, and the brittleness index ranges from 46.1% to 51.4%. After S-wave velocity model in the study area is established, the conversion relation of dynamic and static mechanical parameters could be obtained, that is,Es=0.4142Ed+10.769(R2=0.8387),and μs=1.1076 μd-0.068(R2=0.7366), according to which, the dynamic mechanics parameters calculated by well logging can be adjusted, and then the reservoir brittleness could be quantitatively evaluated. Combining with the brittleness index calculated by mineral component method, it can be concluded that the brittleness calculated by well logging is reliable and the brittleness of Shihezi formation in Yanchang gas field is high, which is beneficial for reservoir fracturing.

Operators with the Maurey–Pietsch multiple splitting property

Let n be a natural number, such that . As a simultaneous extension of the p-summing and multiple p-summing operators we introduce the class of all n-linear operators which are -summing, . If , are such that we introduce the class of the operators with the Maurey–Pietsch -splitting property as the multilinear analogue of the class of -mixing linear operators and, as particular classes, , . We introduce two new classes of multilinear operators both being the multilinear analogues of the class of r-nuclear operators, namely, the class of r-nuclear operators with respect to the -norm, and the class and prove that . By concrete examples, we show that, contrary to the linear case, when , in the multilinear case the inclusions , are not true, which is in contrast to a well-known result shown by us in another paper that.

How valid is Taylor dispersion formula in slugs?

How valid is Taylor dispersion formula in slugs?

Electromagnetically induced polarization grating

Based on electromagnetically induced transparency (EIT), we investigate an all-optical grating structure to realize polarization-dependent multiple beam splitting in the Raman-Nath limit. To optimize the grating performance, higher excited state [e.g., nS1/2 (n ≥ 6)] of ultracold 87Rb atoms is employed to construct a five-level Ξ-Λ system sharing one common populated ground state. A principal advantage of our proposed scheme is that the σ± components of a linearly polarized weak probe field can be decoupled and thus be independently diffracted with high efficiency in both one and two dimensions by exploiting different quasi-standing waves as the two strong coupling fields in the Ξ and Λ configurations. Such an all-optical polarization-sensitive operation could greatly enhance the tunability and capacity of all-optical multiplexing, interconnecting, and networking in free space for both classical and quantum applications.

Multiple-band light absorber via combining the fundamental mode and multiple splitting modes of the 3-order response of metamaterial resonator

We present a rather simple metamaterial design consisted of only a rectangle-shape patch structure with a very small air strip on it to realize triple-band absorption at terahertz frequency. Results prove that three narrow-band absorption peaks are obtained at frequencies of 0.94 THz, 2.44 THz, and 2.85 THz, and the average absorption rates of the three peaks are 97.00%. The resonance at 0.94 THz is attributed to the fundamental mode (or 1-order) response of the metamaterial, while the last two modes are due to the two splitting modes of the 3-order response. The parameter changes of the small air strip in the rectangle-shape patch structure have large influence on the absorption performance of the metamaterial, in particular of the last two modes. Importantly, quad-band absorption can be obtained by introducing one more air strip in the rectangle-shape patch structure. It is found that the first resonance peak is derived from the 1-order response, whereas the last three modes stem from the three splitting modes of the 3-order response of the metamaterial. The combination of the 1-order resonance and multiple splitting modes of the 3-order response provides new design method to realize multiple-band light absorbers.

Ho^3+-doped ZnO nano phosphor for low-threshold sharp red light emission at elevated temperatures

As an approach to design efficient visible luminescent material at nano scale, Ho3+ ion-doped single-phase zinc oxide (ZnO) nano phosphor to obtain red emission suitable for LED/laser applications is reported. Ho3+-doped ZnO nanoparticles with various concentrations of Ho3+ have been prepared by a simple solgel synthesis technique. Under the excitation of 488 nm, the photoluminescence emission spectra of the nano phosphor exhibit an intense emission with multiple and well-resolved narrow splitting peaking in the range from 640 to 667 nm, which is identified as the emission from the Ho3+ ion, corresponding to F55→I58 transition with multiple splitting due to the ZnO crystal field. The required excitation threshold for these emissions is, surprisingly, as low as 33.8 kW/cm2, and the narrow line width (FWHM<2 nm) is found to be persistent even at higher temperatures. Such sharp emission from Ho3+:ZnO nanoparticles could be used for lasing applications.

Speedy standing wave design and simulated moving bed splitting strategies for the separation of ternary mixtures with linear isotherms

Simulated Moving Bed (SMB) has advantages over batch chromatography in terms of productivity and solvent efficiency. However, SMB applications in large scale production are still limited because of the many design parameters that must be specified and the multiple splitting strategies that can be implemented. To overcome these barriers, this study extends the Speedy Standing Wave Design (SSWD) method of Weeden and Wang for binary linear systems to ternary linear adsorption systems. The dimensionless operating parameters, sorbent productivity, and solvent efficiency can be quickly calculated without process simulations. SSWD also gives an overview of the productivity and solvent efficiency as a function of two key dimensionless groups. This overview can be used for optimization of separation costs and for comparison of splitting strategies. The SSWD method was verified using rate model simulations for the separation of three amino acids. The simulated yields agree with the SSWD target yields within 1% for all components. The example was also used to illustrate the key design rules for ternary separations. High productivity and solvent efficiency can be achieved with a large difference in the retention factors of the heavy key and light key, which are the components that define the split of the feed between extract and raffinate products. For ternary ideal systems, solvent efficiency is inversely proportional to the largest difference in retention factors. For this reason, minimizing the overall range of retention factors can significantly improve the solvent efficiency and product concentration without sacrificing productivity. If more than one SMB is needed, the easiest split should be done first for higher productivity, solvent efficiency, and product concentration. In the example case study, both the productivity and solvent efficiency were about an order of magnitude higher when the easiest split was done in the first ring. The SSWD method can be used to design a wide array of multi-component separations with high yield, productivity, and solvent efficiency.

Experimental investigation and modeling of dynamic thermomechanical behavior of 4-harness satin weave carbon/epoxy composites

Theoretical and experimental studies on the compressive mechanical behavior of 4-harness satin weave carbon/epoxy composite laminates under in-plane loading are conducted over the temperature range of 298–473 K and the strain rate range of 0.001–1700/s in this article. The stress–strain curves of 4-harness satin weave composites are obtained at different strain rates and temperatures, and key mechanical properties of the material are determined. The deformation mechanism and failure morphology of the samples are observed and analyzed by scanning electron microscope (SEM) micrographs. The results show that the uniaxial compressive mechanical properties of 4-harness satin weave composites are strongly dependent on the temperature but are weakly sensitive to strain rate. The peak stress and elastic modulus of the material have the trend of decrease with the increasing of temperature, and the decreasing trend can be expressed as the functional relationship of temperature shift factor. In addition, SEM observations show that the quasi-static failure mode of 4-harness satin weave composites is shear failure along the diagonal lines of the specimens, while the dynamic failure modes of the material are multiple delaminations and longitudinal splitting, and with the increasing of temperature, its longitudinal splitting is more serious, but the delamination is relatively reduced. A constitutive model with thermomechanical coupling effects is proposed based on the experimental results and the increment theory of elastic–plastic mechanics. The experimental verification and numerical analysis show that the model is shown to be able to predict the finite deformation behavior of 4-harness satin weave composites over a wide range of temperatures.

Analyzing and correcting the scatter in measurement of time-delays between fast and slow shear-waves with near-field earthquakes

The relationship between the variations of shear-wave splitting parameters and the preparation or occurrence of earthquakes has been one of the most interesting scientific problems in shear-wave research. It has not been possible to establish a physical correlation between the variation of the shear-wave time-delays and the change of stress during an earthquake, which can be confirmed by the vast majority of observations owing to the large scatter in the complete set of time-delay measurements of shear-waves. Therefore, it is necessary to analyze the cause of the scatter of the time-delays between fast and slow shear-waves in near-field seismic records and to identify a method to reduce the scatter of time-delays. Scatter in the measurement of the fast and slow shear waves may arise from the anisotropic structure and complexity of the medium under the observation station. It may also originate from the data processing procedure. To determine the source of the scatter in the measurement of shear-waves time-delays, we first need to identify the scatter, and distinguish its effects from the actual three-component seismic shear-wave records or measurements of the shear-wave parameters. This study is based on single station near-field seismic data from the KHZ station in northern South Island, New Zealand, from January 2013 to January 2017. It uses the visualization method to process the shear-wave data and measure the shear-wave splitting parameter of the seismic event in the shear-wave window of the KHZ station. It assumes that the physical properties and structure of the medium under the observation station are basically stable. The frequency filtering and distance normalization factors used to process the shear-wave, which lead to scatter in the measurements of the shear-wave time-delays, are compared one by one. In addition, the “false scatter” phenomenon, which may be caused by the multiple splits resulting from the anisotropic stratification of the medium under the observation station, is analyzed. Conclusions and suggestions for correcting the scatter in the measurement of shear-waves are proposed as follow: (1) the selection of the filter window directly affects whether the filtered observation data retain the waveform and amplitude characteristics of the shear-wave. If the main frequency of the shear-wave in the observation window is used as the main reference for the selection of the filter band, the obtained measurement of the shear-wave splitting parameter is more stable when the majority of the main frequency component is retained and there is less interference from the other frequencies. (2) The use of the whole source distance in the path normalization of shear-wave is another prominent factor in the scatter of the shear-wave time-delays. This is unreasonable in many cases because the source distance is often greater than the actual length that the split shear-wave propagates in an anisotropic medium. This “excessive” normalization causes all the time-delays between fast and slow shear-waves in the observed window to decrease with increasing source distance. (3) The actual path length of the seismic shear-wave through the anisotropic medium, that is, the “effective source distance,” should be the path length used in normalizing the time-delay. The depth of the interface where shear-wave splitting occurs should be determined by correcting the “excessive” normalization of the shear wave time-delays when there is no significant seismic activity near the observation station. The lower interface depth of the anisotropic medium under the KHZ station, by the near-field shear-wave data, is 37 km. (4) After correcting the scatter of the time-delays, the shear-wave multiple splitting phenomenon caused by the anisotropic stratification of the medium under the observation station is identified. From the “shear wave pairs” in the multiple splitting of the shear-wave data, it can be determined that there are other layers in the anisotropic medium below the KHZ station, and the corresponding depths of the interface are 15 and 27 km, respectively. (5) Normalized time-delay results from the KHZ station shows that before the 7.8 magnitude earthquake that occurred on November 13, 2016 at a distance of 50 km, the time-delays became increasingly large for a few months, and quickly decreased after the earthquake. It is a strong indicator of the stress accumulated and released in the anisotropic medium near the observation station before and after larger earthquakes. This aspect is expected to become an observable precursor of earthquakes.

Possible low spin state of Fe ions in HoBaFe4O7

Effective magnetic moment of YBaFe4O7-δ (YBFO) and HoBaZn3GaO7 is obtained as 4.88 μB (/magnetic atom) and 10 μB (/magnetic atom), respectively from magnetic susceptibility. Nevertheless that of HoBaFe4O7 (HBFO) is almost half magnitude (2.77 μB/magnetic atom) than simply summed up the former two effective moments, although magnetic interaction between Ho and Fe ions is absent. The small effective moment of HBFO suggests different spin state in comparison with YBFO. Taking consideration of our recent neutron inelastic scattering result of HBFO, the small effective moment of HBFO is considered by low spin state of Fe ions. Low spin state is hardly expected in cubic system of Fe ions usually, but low spin state is considered to be realized in HBFO due to spin multiple splitting by dynamical Jahn-Teller effect.

A new validity index of feature subset for evaluating the dimensionality reduction algorithms

A critical aspect of dimensionality reduction is to assess the quality of selected (or produced) feature subsets properly. Feature subset assessment in machine learning refers to split a given feature subset into a training set, which is used to estimate the parameters of a classification model, and a test set used to estimate the predictive performance of the model. Then, averaging the results of multiple splitting (i.e., Cross-Validation, CV) is commonly used to decrease the variance of the estimator. But in practice, CV scheme is very computationally expensive. In this paper, we propose a new statistics index method called LW-index for evaluation of feature subset and dimensionality reduction algorithms in general. The proposed method is a type of “classical statistics” approach that uses the feature subset to compute an empirical estimate of the quality of feature subset. A large number of performance comparisons with the machine learning approach conducted on fourteen benchmark collections show that the proposed LW-index is highly correlated with the external indices (i.e., MacroF1, MicroF1) of SVM and Centroid-Based Classifier (CBC) trained by five-fold CV scheme. Furthermore, the experimental results indicate that LW-index has the same performance as the traditional CV scheme for evaluating the dimensionality reduction algorithms and it is more efficient than the traditional methodology. Therefore, one contribution of this paper is to present an alternative methodology, based on an internal index typically used in the unsupervised learning context, that is computationally cheaper than the traditional CV methodology. Another contribution is to propose a new internal index that behaves better than other similar indices widely used in clustering and shows high correlation with the results obtained by the traditional methodology.

A Selective Linearization Method For Multiblock Convex Optimization

We consider the problem of minimizing a sum of several convex nonsmooth functions. We introduce a new algorithm called the selective linearization method, which iteratively linearizes all but one of the functions and employs simple proximal steps. The algorithm is a form of multiple operator splitting in which the order of processing partial functions is not fixed, but rather determined in the course of calculations. Global convergence is proved and estimates of the convergence rate are derived. Specifically, the number of iterations needed to achieve solution accuracy $\varepsilon$ is of order $\mathcal{O}(\ln(1/\varepsilon)/\varepsilon)$.

Particle-induced morphological modification of Al alloy equiaxed dendrites revealed by sub-second in situ microtomography

The study of dendritic growth is a challenging topic at the heart of intense research in material science. Understanding such processes is of prime importance as it helps predicting the final microstructure governing material properties. In the specific case of the design of metal-matrix nanocomposites (MMNCs), the addition of nano-sized particles inside the metallic melt increases the complexity as their influence on the growth morphology of dendrites is not yet fully understood. In the present experimental study, we use in situ X-ray tomography imaging with very high temporal resolution (0.35 s per 3D image) coupled with in situ ultrasonic melt homogenisation to record, in 3D and real time, the free growth at high cooling rates (∼2 K s−1) of equiaxed dendrites in an aluminium-based alloy (AA6082) containing Y2O3 nanoparticles. The careful 3D analysis of the dendrite morphologies as well as their solidification dynamics reveals that in the case of well-dispersed particles, dendrite equiaxed growth occurs through complex hyper-branched morphologies. Such behaviour is believed to arise from particle-induced modification of the solidification processes at the origin of multiple splitting, branching and curving mechanisms of the dendrite arms. These results shed light on long-standing empirical and modelling statements and open new ways for direct investigation of equiaxed growth in metallic alloys and composites.

Quantitative structure–activity relationships (QSARs) and pharmacophore modeling for human African trypanosomiasis (HAT) activity of pyridyl benzamides and 3-(oxazolo[4,5-b]pyridin-2-yl)anilides

In the present work, quantitative structure–activity relationship and pharmacophore modeling analysis were performed for human African trypanosomiasis healing activity of pyridyl benzamides (dataset-1) and 3-(oxazolo[4,5-b]pyridin-2-yl)anilides (dataset-2). For quantitative structure–activity relationship analysis, a pool of descriptors (mono-dimensional to three-dimensional) was generated, followed by descriptor reduction using objective and subjective feature selection. Multiple splitting was employed for the generation of multiple quantitative structure–activity relationship models to get maximum information about the descriptors that have correlation with the HAT activity of pyridyl benzamides and 3-(oxazolo[4,5-b]pyridin-2-yl)anilides. The genetic algorithm-multilinear regression quantitative structure–activity relationship models have excellent statistical robustness with good external predictive ability. The pharmacophore model and quantitative structure–activity relationship analyses furnished complementary and consensus results to each other.

CRISPR-PCS: a powerful new approach to inducing multiple chromosome splitting in Saccharomyces cerevisiae.

PCR-mediated chromosome splitting (PCS) was developed in the yeast Saccharomyces cerevisiae. It is based on homologous recombination and enables division of a chromosome at any point to form two derived and functional chromosomes. However, because of low homologous recombination activity, PCS is limited to a single site at a time, which makes the splitting of multiple loci laborious and time-consuming. Here we have developed a highly efficient and versatile chromosome engineering technology named CRISPR-PCS that integrates PCS with the novel genome editing CRISPR/Cas9 system. This integration allows PCS to utilize induced double strand breaks to activate homologous recombination. CRISPR-PCS enhances the efficiency of chromosome splitting approximately 200-fold and enables generation of simultaneous multiple chromosome splits. We propose that CRISPR-PCS will be a powerful tool for breeding novel yeast strains with desirable traits for specific industrial applications and for investigating genome function.

A 40 GHz‐100 GBPS wireless access network system based on all optical transformation and photoelectric direct detection

ABSTRACTA 40 GHz coordinated multi‐point radio over fiber (40 GHz ‐CoMP‐ROF) transmission system based on 16‐quadrature amplitude modulation (QAM) and optical orthogonal frequency division multiplexing (OOFDM) and 2 × 2 multiple input multiple output (16QAM‐OOFDM‐2x2MIMO) and photoelectric direct detection is proposed and proved by theoretical derivation. Duo to the QAM and OOFDM and multiple input multiple output (MIMO) and optical orthogonal polarization splitting combining (OOPSC) and excellent algorithm, the rate of the wireless access system is up to 100Gpbs. The designed system is simulated and tested by OptiSystem which is a set of professional simulation software for communication. And then, electrical spectrum, optical spectrum, constellation diagram, clear eye diagram and good bit error rate (BER) of the wired downlink signal and the wireless downlink signal are obtained respectively. Because of the photoelectric direct detection, the complexity of the base station (BS) is simplified. Thanks to the all optical transformation and photonic multiple doubling frequency technique, the cost of the local oscillator with ultra‐high frequency is greatly reduced at the BS. Owing to the coordinated multi‐point (CoMP) technique, ultra‐high speed wireless transmitting between the mobile station and the BS can become a reality on the edge of the cell. Compared with recent schemes, the outlays of center station and base‐station are greatly decreased. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2194–2202, 2016