System Partitioning Research Articles

Experimental quantification of spatial correlations in quantum dynamics

Correlations between different partitions of quantum systems play a central role in a variety of many-body quantum systems, and they have been studied exhaustively in experimental and theoretical research. Here, we investigate dynamical correlations in the time evolution of multiple parts of a composite quantum system. A rigorous measure to quantify correlations in quantum dynamics based on a full tomographic reconstruction of the quantum process has been introduced recently [Á. Rivas et al., New Journal of Physics, 17(6) 062001 (2015).]. In this work, we derive a lower bound for this correlation measure, which does not require full knowledge of the quantum dynamics. Furthermore we also extend the correlation measure to multipartite systems. We directly apply the developed methods to a trapped ion quantum information processor to experimentally characterize the correlations in quantum dynamics for two- and four-qubit systems. The method proposed and demonstrated in this work is scalable, platform-independent and applicable to other composite quantum systems and quantum information processing architectures. We apply the method to estimate spatial correlations in environmental noise processes, which are crucial for the performance of quantum error correction procedures.

Adaptive Meshing Based on the Multi-level Partition of Unity and Dynamic Particle Systems for Medical Image Datasets

Adaptive Meshing Based on the Multi-level Partition of Unity and Dynamic Particle Systems for Medical Image Datasets

Isospin effects in nuclear fragmentation of isotopic, isobaric, and isotonic reactions

Using the isospin-dependent quantum molecular dynamics (IQMD) model, a study on the fragmentation of isotopic, isobaric, and isotonic reacting partners is presented. The partitioning of the fragmenting system into gas (low density) and liquid (high density) phases in semicentral collisions of medium mass systems is investigated at various beam energies ranging between 100 and 400 MeV/nucleon. Our findings revealed a crossover of gas/liquid content with the beam energy and the energy where gas and liquid content become equal is labeled as cross-over energy. The influence of isospin degree of freedom (via nuclear symmetry energy, Coulomb potential, and nucleon-nucleon scattering cross section) on the cross-over energy is investigated in detail and our study revealed the dominant role of symmetry potential over the other two isospin effects. Our study also concludes that cross-over energy can act as a sensitive probe of density dependence of nuclear symmetry energy at suprasaturation densities.

Ultrafast dissipative spin-state dynamics triggered by x-ray pulse trains

Frontiers of attosecond science are constantly shifting, thus addressing more and more intricate effects with increasing resolution. Ultrashort pulses offer a practical way to prepare complex superpositions of quantum states, follow, and steer their dynamics. In this contribution, an ultrafast spin-flip process triggered by sub-femtosecond (fs) excitation and strong spin-orbit coupling between 2p core-excited states of a transition metal complex is investigated using density matrix-based time-dependent restricted active space configuration interaction theory. The effect of the nuclear vibrations is incorporated making use of an electronic system plus vibrational bath partitioning. The differences between isolated sub-fs pulses and pulse trains as well as influence of various pulse characteristics on the initiated dynamics are discussed. The effect under study can be potentially used for ultrafast clocking in sub-few fs experiments.

Sorghum radiation use efficiency and biomass partitioning in intercrop systems

The objective of intercropping is to improve resource efficiencies for land, water and radiation. Few studies have focused on the interactive effects of water stress on radiation use efficiency (RUE) in an intercrop system. The study determines the effect of intercropping sorghum with either cowpea or bottle gourd on RUE and biomass accumulation in response to water stress. This was assessed using a split-plot design with crop sequences sole sorghum, sole cowpea, and sole bottle gourd and intercrop systems sorghum–cowpea and sorghum–bottle gourd assigned as sub-plots arranged in randomised complete blocks within main plots, water regimes: full irrigation, deficit irrigation and rainfed. We quantified specific leaf area, leaf area index as well as biomass accumulation and partitioning. Extinction coefficient, intercepted photosynthetic active radiation (IPAR) and RUE for biomass (RUEb) and grain (RUEg) were also determined. Under rainfed conditions, intercropping with either cowpea (26%) or bottle gourd (62%) improved sorghum leaf area. A reduction in specific leaf area was observed for sorghum when it was intercropped with either cowpea (−20%) or bottle gourd (−19%). Under full irrigation, sorghum stems constituted a larger proportion (62%) of final biomass in comparison to sorghum under deficit irrigation (52%) and rainfed conditions (50%). Intercropping sorghum with either cowpea or bottle gourd improved IPAR (38%), RUEb (93%) and RUEg (11%) under rainfed conditions. This study showed that under water-limited conditions intercropping reduced sorghum stem mass and increased canopy size, radiation interception, and grain yield and improved RUE. In agreement with our proposition, water availability was closely associated with radiation use efficiency. Intercropping can be recommended for semi-arid environments since it improves RUE and sorghum biomass and grain yield.

Dynamic model development of enteric methane emission from goats based on energy balance measured in indirect open circuit respiration calorimeter

A dynamic model of methane (CH4) emission in goats was proposed and parameterized from energy balance experimental data. The model focused on dry matter intake and fat content of the diet as explanatory variables for CH4 emission. Experimental and literature data were used to develop the model. Then, data (n = 123) from five energy balance experiments were used to evaluate the model. The model was adequate to represent energy in milk, heat production and CH4 emissions. Residual analysis showed that most of the prediction errors were due to unexplained variations with small mean and slope bias (around zero with exception of CH4; <6%). The model tends to over-predict energy in CH4 at higher energy intake and, energy in milk and heat production at lower energy intake. Random bias was greater than 90%, signifying than more than 90% of the error was non-systematic indicating the mechanism in the model are properly represented. The model is a first step towards a mechanistic description of nutrient use by goats and, useful as a research tool for investigating energy partition in dairy goat systems. The model described in this study should be considered for preparation of enteric CH4 emissions inventories for goats.

Parity-time symmetry breaking in spin chains

We investigate nonequilibrium phase transitions in classical Heisenberg spin chains associated with spontaneous breaking of parity-time ($\mathcal{PT}$) symmetry of the system under the action of Slonczewski spin-transfer torque (STT) modeled by an applied \textit{imaginary} magnetic field. We reveal the STT-driven $\mathcal{PT}$ symmetry-breaking phase transition between the regimes of precessional and exponentially damped spin dynamics and show that its several properties can be derived from the distribution of zeros of the system's partition function, the approach first introduced by Yang and Lee for studying equilibrium phase transitions in Ising spin chains. The physical interpretation of imaginary magnetic field as describing the action of non-conservative forces opens the possibility of direct observations of Lee-Yang zeros in nonequilibrium physical systems.

A Discrete Multi-Objective Optimization Method for Hardware/Software Partitioning Problem Based on Cuckoo Search and Elite Strategy

This paper attempts to provide a desirable solution to hardware/software partitioning of the embedded system. For this purpose, the author developed a discrete multi-objective optimization method based on the cuckoo search (CS) algorithm (MODCS) and the elite strategy of stratification and congestion degree comparison. Then, the MODCS was compared with two other typical simulation algorithms. The results show that the MODCS is superior to typical optimization algorithms in terms of many indices, including diversity, stability and generational distance (GD) of optimal solution. The superiority is positively correlated with the number of modules. The findings shed new light on the bionic optimization of hardware/software partitioning.

First-order foreland cycles: Interplay of flexural tectonics, dynamic loading, and sedimentation

Foreland systems on overriding plates (i.e., retroarc settings) form through the deflection of the lithosphere in response to a combination of supra- and sublithospheric loads. Supracrustal loading by orogens leads to the partitioning of foreland systems into foredeep, forebulge, and back-bulge flexural provinces. Thrusting in the orogenic belt results in foredeep subsidence and forebulge uplift, and the reverse occurs as orogenic load is removed by erosion or extension. This pattern generates out-of-phase ('reciprocal') stratigraphies across the flexural hingeline that separates the foredeep from the forebulge. Coupled with flexural tectonics, accommodation is also modified by dynamic (sublithospheric) loading. The latter mechanism operates at larger, continental scales, with rates controlled by the velocity and the angle of subduction.The interplay of accommodation and sediment supply during the lifespan of a foreland system controls the long-term shift from underfilled to overfilled accommodation conditions, which defines the first-order foreland cycle. Predictable shifts in the balance between flexural tectonics and dynamic loading during the evolution of a foreland system allow the subdivision of the first-order foreland cycle into early and late stages dominated by flexural tectonics, separated by an intermediate stage dominated by system-wide dynamic subsidence. The early stage is defined by an underfilled foredeep that hosts a deep-water environment, and an exposed forebulge whose progradation and erosion generates the ‘forebulge unconformity' at the base of the first-order foreland sequence. Submergence of the forebulge during the intermediate stage establishes an interior seaway across the entire foreland system. The late stage marks a shift to a system-wide continental setting, which defines the overfilled phase of the foreland cycle.

Modulating the Partitioning of Microparticles in a Polyethylene Glycol (PEG)-Dextran (DEX) Aqueous Biphasic System by Surface Modification

Aqueous two-phase systems (ATPSs) or aqueous biphasic systems are useful for biological separation/preparation and cell micropatterning. Specifically, aqueous two-phase systems (ATPSs) are not harmful to cells or biomaterials; therefore, they have been used to partition and isolate these materials from others. In this study, we suggest chemically modifying the surface of target materials (micro/nanoparticles, for example) with polymers, such as polyethylene glycol and dextran, which are the same polymer solutes as those in the ATPS. As a simple model, we chemically coated polyethylene glycol or dextran to the surface of polystyrene magnetic particles and observed selective partitioning of the surface modified particles to the phase in which the same polymer solutes are dominant. This approach follows the principle “like dissolves like” and can be expanded to other aqueous biphasic or multiphasic systems while consuming fewer chemicals than the conventional modulation of hydrophobicities of solute polymers to control partitioning in aqueous biphasic or multiphasic systems.

Phase equilibrium and protein partitioning in aqueous two-phase systems containing imidazolium ionic liquids and surfactant at low voltage levels

In this paper, the binodal data of aqueous two-phase system (ATPS) containing imidazolium-based ionic liquids (chlorinated 1-ethyl-3-methylimidazole, [Emim]Cl), and a non-ionic surfactant (octylphenol polyethoxylene, Triton X-100) was obtained by means of the cloud point method in the temperature intervals T=(288.15–308.15) K. It was found that the [Emim]Cl/Triton X-100 ATPS was sensitive to temperature and had a long phase segregation time. Screening experiments of various additives showed that adding 7% of sodium dodecyl sulfate (SDS) to the total mass of surfactants (w/w) reduced the temperature sensitivity, and improved the phase separation rate of the system. The liquid-liquid equilibrium (LLE) data of [Emim]Cl/Triton X-100 ATPS without additive and containing 7% SDS at 298.15K was further studied according to the cloud point method. To further shorten the long phase disengagement time, a low-voltage alternating current (AC) electric field was added to the [Emim]Cl/surfactant ATPS. Through the optimization of AC electric field conditions (such as electric field type, frequency and duty ratio), a relatively fast and stable [Emim]Cl/surfactant ATPS was established. In 0.67V/cm field strength, 1000Hz frequency and 50% duty ratio of impulse waveform, the phase splitting time is shortened by 2–3 times. With and without electric field, protein partitioning of cytochrome c (Cyt-c), bovine serum albumin (BSA) and lysozyme (Lys) in [Emim]Cl/surfactant ATPS indicated that Cyt-c and BSA tended to distribute in the bottom phase, while Lys was inclined to distribute in the top phase. The application of the AC electric field can still decrease the phase separation time in the protein distribution process, and has no significant effect on the distribution behavior of proteins. Furthermore, Lys activity in the top phase of ATPS was significantly enhanced, which could be caused by the low concentration of Triton X-100 in the top phase based on the comparison of Lys fluorescence spectra analysis in aqueous solution, in the top phase and in the bottom phase of [Emim]Cl/surfactant ATPS.

Equilibrium data and thermodynamic studies of α-amylase partition in aqueous two-phase systems

Liquid-liquid equilibrium data (LLE) were obtained for aqueous two-phase systems (ATPS) composed of polyethylene glycol (average molar mass of 1500 g mol−1), sodium citrate/citric acid and water, at different pH (4.0, 5.0, 6.0 and 7.0) and temperatures T = (303.15 and 313.15) K. The thermodynamic study of the phase equilibrium was performed. The experimental results of the LLE were correlated using the UNIversal Functional Activity Coefficient (UNIFAC) model. The salting-out effect evaluated using the model of the effective excluded volume (EEV). Partitioning of the α-amylase (EC 3.2.1.1) was investigated as a function of pH, temperature, and tie line length (TLL). It was observed that the temperature had no influence on the formation of the biphasic region. Increments in pH value resulted in the raising of biphasic region. Isothermal titration calorimetry (ITC) assays was performed in order to deeply understanding the intermolecular interactions involved in the α-amylase partition and the driving forces that govern this process. It was measured the Gibbs free energy transfer (ΔtrG), transfer enthalpy variation (ΔtrH) and transfer entropy variation (ΔtrS) during the enzyme partition, as a function of the pH, temperature and TLL. For α-amylase partition, it was verified that at pH 4.0 the enzyme had a strong tendency to transfer to the polymer-rich phase. At pH 5.0 α-amylase showed affinity for the salt-rich bottom phase, while at pH 6.0, the partition coefficient of the enzyme increased as temperature was reduced to 303.15 K. The opposite behavior was noted for α-amylase at pH 7.0. Thermodynamic analysis based on isothermal titration microcalorimetry indicated the partition of α-amylase partition in the ATPS at pH 4.0 and 7.0 and 313.15 K was accompanied by endothermic heat and was entropically driven to the upper phase. Results of yield (95.373%) parameter indicated the applicability of ATPS for amylase purification.

Parallel Electromagnetic Transients Simulation with Shared Memory Architecture Computers

This paper proposes a graph-based matrix level partitioning methodology for parallel electromagnetic transient (EMT) simulation. By partitioning the graph associated with the admittance matrix, an efficient bordered block diagonal matrix form is obtained, which is particularly suitable for parallel implementation. Even without the presence of distributed transmission lines, fully automatic system partitioning and parallelization of the simulation are achieved. The parallelized algorithm is implemented on a shared memory computer and assessed using two scalable test cases. The first involves an underground cable with many distributed parameter cascaded sections. The second is an interconnection of multiple instances of the IEEE 14-bus system, where only lumped transmission-line models are used. The tests show that EMT simulation can be significantly accelerated. The scalability is tested with up to 64 cores.

The role of solvent and neutral organophosphorus extractant structure in their organization and association

The choice of organic solvent is known to impact metal ion partitioning in solvent extraction systems, although an understanding based on molecular interactions has been largely qualitative. To provide a more quantitative and molecular scale understanding of extractant and solvent association in liquid-liquid solvent extraction systems, molecular dynamics studies of binary extractant/solvent systems are conducted for several organophosphorus solvating extractants across a range of organic solvents. Classical molecular dynamics potentials for the extractants are optimized in pure phase simulations. These potentials are then validated with binary extractant/solvent solutions by comparison to experimental data for percent volume change on mixing and mixing enthalpies. Trends in association free energy, mixing enthalpy and deviations from ideal mixing volume are reported for each extractant and solvent binary mixture. Contributions to those properties depending on extractant and solvent molecular structure are investigated, including the relative enthalpic favorability of extractant solutions in toluene, diethyl ether or n-hexane. Inclusion of the ether group in diethyl ether lowered the enthalpy of mixing to a similar degree as reducing the alkane solvent chain length from n-dodecane to n-hexane owing to dipole-dipole interactions with the “head” and “tail” regions of the extractant molecules, which depend on extractant alkyl chain length. Despite similar percent volume changes on mixing with n-hexane or diethyl ether, extractant/toluene mixtures were significantly more enthalpically favorable with an enthalpy of mixing minimum controlled by stoichiometry rather than volume fraction, as observed for alkane solvents.

Ontology of Quantum Entangled States No Needs Philosophy

When we understand, usually philosophical debates disappear. In this brief paper, starting from some works, we argue that quantum entangled states could be considered as primitive. We analyze from a conceptual point of view this basic question: can the nature of quantum entangled states be interpreted ontologically or epistemologically? According to some works, the degrees of freedom (and the tool of quantum partitions) of quantum systems permit us to establish a possible classification between factorizable and entangled states. We suggest, that the of degree of freedom (or quantum partitions), even if mathematically justified introduces an epistemic element, not only in the systems but also in their classification. We retain, instead, that there are not two classes of quantum states, entangled and factorizable, but only a single class of states: the entangled states. In fact, the factorizable states become entangled for a different choice of their degrees of freedom (i.e. they are entangled with respect to other observables). In the same way, there are no partitions of quantum systems which have an ontologically superior status with respect to any other. For all these reasons, both mathematical tools utilize(i.e quantum partitions or degrees of freedom) are responsible for creating an improper classification of quantum systems. Finally, we argue that we cannot speak about a classification of quantum systems: all quantum states exhibit a uniquely objective nature, they are all entangled states. In this framework we think that Rovelli’s interpretation of QM based on the relational approach could be considered a good candidate to understand the nature of physical reality.

A Game Theoretical Randomized Method for Large-Scale Systems Partitioning

In this paper, a game theory-based partitioning algorithm for large-scale systems (LSS) is proposed. More specifically, a game over nodes is introduced in a model predictive control framework. The Shapley value of this game is used to rank the communication links of the control network based on their impact on the overall system performance. A randomized method to estimate the Shapley value of each node and also an efficient redistribution of the resulting value to the links involved are considered to relieve the combinatorial explosion issues related to LSS. Once the partitioning solution is obtained, a sensitivity analysis is proposed to give a measure of its performance. Likewise, a greedy fine tuning procedure is considered to increase the optimality of the partitioning results. The full Barcelona drinking water network is analyzed as a real LSS case study, showing the effectiveness of the proposed approach in comparison with other partitioning schemes available in the literature.

ETS-NOCV decomposition of the reaction force for double-proton transfer in formamide-derived systems

The analysis of the electronic-structure changes along IRC paths for double-proton-transfer reactions in the formamide dimer (R1), formamide–thioformamide system (R2), and the thioformamide dimer (R3) was performed based on the extended-transition-state natural orbitals for chemical valence (ETS-NOCV) partitioning of the reaction force, considering the intra-fragments strain and the inter-fragments interaction terms, and further—the electrostatic, Pauli-repulsion and orbital interaction components, with the latter being decomposed into the NOCV components. Two methods of the system partitioning into the fragments were considered (‘reactant perspective’/bond-formation, ‘product perspective’ / bond-breaking). In agreement with previous studies, the results indicate that the major changes in the electronic structure occur in the transition state region; the bond-breaking processes are, however, initiated already in the reactant region, prior to entering the TS region. The electrostatic contributions were identified as the main factor responsible for the increase in the activation barrier in the order R1 < R2 < R3.

REFORM OF PRIMARY HEALTH CARE IN RUSSIA

Explore the historical domestic experience of primary health care to the population of major cities, the establishment of this type of medical care as the main and the largest national healthcare system partition stages of the reform of primary health care to date, with a gradual transition to a system of health insurance in order to further increase the availability of and quality of care. Due to the recent modernization of the health system outpatient offices were equipped with modern innovative medical devices for the delivery of primary health care at a high level. In addition, historically proved the effectiveness of medical care at the district territorial principle, which defines and improves access to health care, with subsequent referral to narrow specialists (bibliography: 20 refs).

Mesoscopic-microscopic spatial stochastic simulation with automatic system partitioning.

The reaction-diffusion master equation (RDME) is a model that allows for efficient on-lattice simulation of spatially resolved stochastic chemical kinetics. Compared to off-lattice hard-sphere simulations with Brownian dynamics or Green's function reaction dynamics, the RDME can be orders of magnitude faster if the lattice spacing can be chosen coarse enough. However, strongly diffusion-controlled reactions mandate a very fine mesh resolution for acceptable accuracy. It is common that reactions in the same model differ in their degree of diffusion control and therefore require different degrees of mesh resolution. This renders mesoscopic simulation inefficient for systems with multiscale properties. Mesoscopic-microscopic hybrid methods address this problem by resolving the most challenging reactions with a microscale, off-lattice simulation. However, all methods to date require manual partitioning of a system, effectively limiting their usefulness as "black-box" simulation codes. In this paper, we propose a hybrid simulation algorithm with automatic system partitioning based on indirect a priori error estimates. We demonstrate the accuracy and efficiency of the method on models of diffusion-controlled networks in 3D.

A new memetic algorithm for mitigating tandem automated guided vehicle system partitioning problem

Automated Guided Vehicle System (AGVS) provides the flexibility and automation demanded by Flexible Manufacturing System (FMS). However, with the growing concern on responsible management of resource use, it is crucial to manage these vehicles in an efficient way in order reduces travel time and controls conflicts and congestions. This paper presents the development process of a new Memetic Algorithm (MA) for optimizing partitioning problem of tandem AGVS. MAs employ a Genetic Algorithm (GA), as a global search, and apply a local search to bring the solutions to a local optimum point. A new Tabu Search (TS) has been developed and combined with a GA to refine the newly generated individuals by GA. The aim of the proposed algorithm is to minimize the maximum workload of the system. After all, the performance of the proposed algorithm is evaluated using Matlab. This study also compared the objective function of the proposed MA with GA. The results showed that the TS, as a local search, significantly improves the objective function of the GA for different system sizes with large and small numbers of zone by 1.26 in average.