Terms Of Mixing Research Articles

Energy modeling of thermal energy storage (TES) using intelligent stream processing system

Thermal energy storage (TES) is the core element of renewable energy system (RES) and can considerably affect its overall efficiency. An effective thermal energy storage (TES) should enhance the stratification by restricting inlet mixing. In this paper, an experimental study is presented to evaluate the performance of thermal energy storage (TES). Discharging of the tank was conducted with different inlet flow rates to assess the effect of inlet mixing on thermal stratification. Results are quantified in terms of temperature distribution, MIX, and Richardson number and were visualized to predict the behavior of TES. In addition, the data parsing is done in live mode with ad-hoc built stream-processing data layer. Finally a methodology for time series prediction in the context of TES using high end LSTM network is framed. It was concluded that discharging rate of 800 l/h has the maximum mixing and thus the worst stratification, while prediction efficiency fell well within 5.2% of the error range.

Modeling Mixing in Stratified Heterogeneous Media: The Role of Water Velocity Discretization in Phase Space Formulation

Modeling solute transport in heterogeneous porous media faces two challenges: scale dependence of dispersion and reproducing mixing separately from spreading. Both are crucial since real applications may require km scales whereas reactions, often controlled by mixing, may occur at the pore scale. Methods have been developed in response to these challenges, but none has satisfactorily characterized both processes. In this paper, we propose a formulation based on the Water Mixing Approach extended to account for velocity variability. Velocity is taken as an independent variable, so that concentration depends on time, space and velocity. Therefore, we term the formulation the Multi-Advective Water Mixing Approach. A new mixing term between velocity classes emerges in this formulation. We test it on Poiseuille’s stratified flow using the Water Parcel method. Results show high accuracy of the formulation in both dispersion and mixing. Moreover, the mixing process exhibits Markovianity in space even though it is modeled in time.

Influence of Bioconvection and Thermal Radiation on MHD Williamson Nano Casson Fluid Flow with the Swimming of Gyrotactic Microorganisms Due to Porous Stretching Sheet

An analysis is performed for electrical MHD flow of Williamson Nano Casson fluid with heat transfer. The fluid is positioned toward a porous stretching sheet along with mass flux. The impact of chemical diffusion and nonlinear thermal Radiation are further discussed. A highly nonlinear partial differential equations presenting the Williamson Nano Casson fluid flow over permeable extending plate is transformed to ordinary differential equations through appropriate similarity transformation and solved them with a shooting method-using package ND-Solve on Mathematica. The ascendency of arising physical interpretation of thermo-physical parameter on energy field, highly concentration field and density field are perceived. The valuations are achieved graphically for numerous protuberant terms like non Newtonian Williamson parameter, bio convection, Peclet number, mixed convection Hartman number, Casson parameter, thermophoresis diffusion, bio convection Rayeigh number, Brownian motion and mixed convection terms. These diverse terms are applied on dimensionless velocity function, concentration function, temperature function and density of the motile microorganism and analyzed numerically in detail. It is detected that through rising the value of bio-convection and Peclet number, the microorganism field diminishing. Graphical diagrams are illustrating the consistency of the latest outcomes.

GLOBE: a contrastive learning-based framework for integrating single-cell transcriptome datasets.

Integration of single-cell transcriptome datasets from multiple sources plays an important role in investigating complex biological systems. The key to integration of transcriptome datasets is batch effect removal. Recent methods attempt to apply a contrastive learning strategy to correct batch effects. Despite their encouraging performance, the optimal contrastive learning framework for batch effect removal is still under exploration. We develop an improved contrastive learning-based batch correction framework, GLOBE. GLOBE defines adaptive translation transformations for each cell to guarantee the stability of approximating batch effects. To enhance the consistency of representations alignment, GLOBE utilizes a loss function that is both hardness-aware and consistency-aware to learn batch effect-invariant representations. Moreover, GLOBE computes batch-corrected gene matrix in a transparent approach to support diverse downstream analysis. Benchmarking results on a wide spectrum of datasets show that GLOBE outperforms other state-of-the-art methods in terms of robust batch mixing and superior conservation of biological signals. We further apply GLOBE to integrate two developing mouse neocortex datasets and show GLOBE succeeds in removing batch effects while preserving the contiguous structure of cells in raw data. Finally, a comprehensive study is conducted to validate the effectiveness of GLOBE.

Research on Methane Measurement and Interference Factors in Coal Mines.

The detection of methane has always been an important part of coal mine safety. In order to improve the methane measurement accuracy in coal mines and to determine the influence of environmental interference factors on the measurement results, we designed a spherical, experimental chamber simulating the on-site environment of an underground coal mine containing methane, in which various environmental interference factors can be superimposed. The simulation chamber can generate a uniform and controllable dust environment, a controllable methane environment with concentrations below that which would trigger an alarm, controllable humidity, and environments characterized by other interference factors. Based on computational simulations of the experimental chamber with varying dust-particle-concentration distributions using a single particle size, an optimal design for the chamber has been realized in terms of the rapid mixing of dust and the flow field. Finally, we constructed an underground methane concentration measurement system for coal mines and assessed the influences of different dust concentrations and relative humidity values on the performance of methane measurements, providing a means for improving the measurement accuracy of underground coal mine, spectral, absorption-type methane sensors.

Self-dual Maxwell-Chern-Simons solitons in a parity-invariant scenario

We present a self-dual parity-invariant U(1)×U(1) Maxwell-Chern-Simons scalar QED3. We show that the energy functional admits a Bogomol'nyi-type lower bound, whose saturation gives rise to first order self-duality equations. We perform a detailed analysis of this system, discussing its main features and exhibiting explicit numerical solutions corresponding to finite-energy topological vortices and non-topological solitons. The mixed Chern-Simons term plays an important role here, ensuring the main properties of the model and suggesting possible applications in condensed matter.

Hidden spin-orbital texture at the overline{{{Gamma }}}-located valence band maximum of a transition metal dichalcogenide semiconductor

Finding stimuli capable of driving an imbalance of spin-polarised electrons within a solid is the central challenge in the development of spintronic devices. However, without the aid of magnetism, routes towards this goal are highly constrained with only a few suitable pairings of compounds and driving mechanisms found to date. Here, through spin- and angle-resolved photoemission along with density functional theory, we establish how the p-derived bulk valence bands of semiconducting 1T-HfSe2 possess a local, ground-state spin texture spatially confined within each Se-sublayer due to strong sublayer-localised electric dipoles orientated along the c-axis. This hidden spin-polarisation manifests in a ‘coupled spin-orbital texture’ with in-equivalent contributions from the constituent p-orbitals. While the overall spin-orbital texture for each Se sublayer is in strict adherence to time-reversal symmetry (TRS), spin-orbital mixing terms with net polarisations at time-reversal invariant momenta are locally maintained. These apparent TRS-breaking contributions dominate, and can be selectively tuned between with a choice of linear light polarisation, facilitating the observation of pronounced spin-polarisations at the Brillouin zone centre for all kz. We discuss the implications for the generation of spin-polarised populations from 1T-structured transition metal dichalcogenides using a fixed energy, linearly polarised light source.

Reconciling LSND and Super-Kamiokande data through the dynamical Lorentz symmetry breaking in a four-Majorana fermion model

We propose a model of Majorana fermions with quartic self-couplings. These Majorana fermions acquire masses via a type II seesaw mechanism in which the physical eigenstates are identified as a light Majorana fermion and another heavy Majorana fermion. On a physical basis, the quartic self-couplings involve axial currents of these Majorana fermions, and also the interaction of the axial current for the light particle with the heavy particle one. We introduce two auxiliaries gauge fields in this model, and we study the stability conditions of the correspondent effective potential of the model. The ground state of the effective potential introduces two 4-vectors as scales of vacuum expected values, and consequently, the dynamical Lorentz symmetry breaking (DLSB) emerges in the model. We use the expansion of the effective action to calculate the effective Lagrangian up to second order in the auxiliary fields as fluctuations around the ground state. This mechanism generates dynamics for the auxiliary gauge fields, mixed mass terms, longitudinal propagation, and Chern-Simons term through radiative corrections. After the diagonalization, the two gauge fields gain masses through an analogous type II seesaw mechanism in which a gauge boson has a light mass, and the other one acquires a heavy mass. In this scenario of Lorentz symmetry breaking, we obtain the correspondent dispersion relations for the Majorana fermions and the gauge boson fields. Posteriorly, we analyze the neutrino's oscillations in the presence of a DLSB parameter, in the transition $\nu_{e} \rightarrow \nu_{\mu}$. We discuss the parameter space of this transition and show that the DLSB can conciliate the LSND and super-Kamiokande results.

Low Density Neutron Star Matter with Quantum Molecular Dynamics: The Role of Isovector Interactions

The effect of isospin-dependent nuclear forces on the inner crust of neutron stars is modeled within the framework of Quantum Molecular Dynamics (QMD). To successfully control the density dependence of the symmetry energy of neutron-star matter below nuclear saturation density, a mixed vector-isovector potential is introduced. This approach is inspired by the baryon density and isospin density-dependent repulsive Skyrme force of asymmetric nuclear matter. In isospin-asymmetric nuclear matter, the system shows nucleation, as nucleons are arranged into shapes resembling nuclear pasta. The dependence of clusterization in the system on the isospin properties is also explored by calculating two-point correlation functions. We show that, as compared to previous results that did not involve such mixed interaction terms, the energy symmetry slope L is successfully controlled by varying the corresponding coupling strength. Nevertheless, the effect of changing the slope of the nuclear symmetry energy L on the crust-core transition density does not seem significant. To the knowledge of the authors, this is the first implementation of such a coupling in a QMD model for isospin asymmetric matter, which is relevant to the inner crust of neutron and proto-neutron stars.

Building flexibility revenue in modeled future bulk power systems with varying levels of renewable energy

The buildings sector can provide important demand-side flexibility for the integration of renewable energy. With the changing power system and rapid advancement in building energy control technology, technology providers and demand response aggregators need to know what potential revenues could be obtained by providing grid services. We dispatch a normalized and parameterized model of building load shifting against marginal service prices from grid investment and operational models to produce a database of the capacity, energy, and ancillary service revenues (gross value of providing bulk power system services) for a marginal kilowatt-hour (kWh) of shiftable load. The database is geographically disaggregated, hourly, and parameterized so that flexibility value can be estimated for a wide range of building technologies. The database covers the contiguous United States under three 2030 grid scenarios. Given the high degree of uncertainty in such grid projections, the results are perhaps best interpreted in terms of regional climate and grid mixes and are thus potentially applicable in non-U.S. contexts. Upon analyzing the results, we find the monthly mean gross value of building load shifting is 0–38 cents/kWh-day and the daily gross value of shifting the highest-value hour each day can be up to 620 cents/kWh-day. The different revenues obtained by aggregating results in different ways, as well as observed regional and seasonal differences, suggest different building technologies and grid environments might call for demand response program designs and business models.

Relative Contributions of Sea Surface Temperature and Atmospheric Nonlinearities to ENSO Asymmetrical Rainfall Response

Abstract Here, we investigate the relative roles of atmospheric nonlinearities and asymmetrical sea surface temperature (SST) forcing in the El Niño–Southern Oscillation (ENSO) asymmetrical rainfall response. Applying a vertically integrated water vapor budget to the ERA5 reanalysis leads to a simple analytical equation for precipitation anomalies. This formulation reveals that ENSO rainfall anomalies are dominated by the linear component of the dynamical term (i.e., the anomalous moisture convergence due to the effect of circulation anomalies on climatological humidity). Nonlinearities in this term and the linear thermodynamical term (i.e., the effect of climatological circulation on humidity anomalies) both strengthen central Pacific rainfall anomalies for both ENSO phases. In contrast, the nonlinear term associated with the effect of anomalous divergence on anomalous moisture (i.e., the mixed term) weakens La Niña dry and strengthens El Niño wet anomalies, in particular during extreme El Niño events when it contributes to about 40% of the eastern Pacific wet anomalies. Overall, atmospheric nonlinearities directly account for ∼70% of the positively skewed ENSO rainfall distribution east of the date line, and ∼50% of the negatively skewed rainfall distribution in the western Pacific. The remaining ENSO rainfall asymmetries are attributable to the asymmetrical ENSO SST pattern. This asymmetrical SST pattern also has contributions from atmospheric nonlinearities through the Bjerknes feedback loop, in addition to those from oceanic nonlinearities. Our estimates are thus likely a lower bound of the contribution of atmospheric nonlinearities to the overall ENSO rainfall asymmetry.

Lax–Wendroff Schemes with Polynomial Extrapolation and Simplified Lax–Wendroff Schemes for Dispersive Waves: A Comparative Study

One of the features of Boussinesq-type models for dispersive wave propagation is the presence of mixed spatial/temporal derivatives in the partial differential system. This is a critical point in the design of the time marching strategy, as the cost of inverting the algebraic equations arising from the discretization of these mixed terms may result in a nonnegligible overhead. In this paper, we propose novel approaches based on the classical Lax–Wendroff (LW) strategy to achieve single-step high-order schemes in time. To reduce the cost of evaluating the complex correction terms arising in the Lax–Wendroff procedure for Boussinesq equations, we propose several simplified strategies which allow to reduce the computational time at fixed accuracy. To evaluate these qualities, we perform a spectral analysis to assess the dispersion and damping error. We then evaluate the schemes on several benchmarks involving dispersive propagation over flat and nonflat bathymetries, and perform numerical grid convergence studies on two of them. Our results show a potential for a CPU reduction between 35 and 40% to obtain accuracy levels comparable to those of the classical RK3 method.

Soft elastic tubular reactor: An unconventional bioreactor for high-solids operations

Many bioreactors for solid state (SSF) and high-solids load fermentations have been developed in order to obtain valuable bioproducts. In general, it is emphasized the necessity for design improvements in reactor mixing, heat transfer, and gaseous mass transfer. A soft-elastic tubular reactor (SETR) was built and its behavior in terms of aeration, mixing, and temperature control was evaluated. Although soft-elastic reactors have been explored for some time, this was the first time they were thoroughly investigated for fermentation use. Depending on the applied parameters, such as aeration, mixing rate, and media characteristics (liquid viscosity, solid, sludge), KLa ranged between 1 and 40 h−1, a well-mixed state was attained between 0.3 and 60 min, and the temperature reached operational stability within 20 min. Soybeans were fermented by Bacillus subtilis subsp. natto as a proof of concept (moisture content from 66 wt% up to 80 wt%). The proposed SETR demonstrated that temperature, mixing, and aeration could be modified to meet the needs of the process, and while more research is needed, it might be regarded as a new option for solid state or high-load substrate processes.

Triple ion beam irradiation of glass-ceramic materials for nuclear fusion technology

The analysis of the radiation damage associated with energetic neutrons is a key factor for the application of glass-ceramics as joining materials in nuclear fusion plants. Triple ion beam irradiation is, currently, the only way to emulate the displacement damage and the effects of transmutation products induced by high energy neutrons at elevated doses by producing a high level of displacements per atom (dpa) and implanting high concentrations of low solubility gases on the glass-ceramic microstructure. In this paper, we investigate calcia-alumina glass-ceramics in which the damage expected in the working conditions of a nuclear fusion plant were reproduced by simultaneous irradiation with Si, He and H ions at different temperatures. TEM analysis of irradiated calcia-alumina samples shows amorphization (due to the Si beam) and partial recrystallization of the irradiated portion and the formation of He bubbles/cavities. The irradiation temperature plays a prominent role in determining the induced damage in terms of recrystallization, phase mixing and bubble size, density and aggregation.

Mixing of Monoclonal Antibody Formulated Drug Substance Solutions in Square Disposable Vessels

Fill & finish manufacturing processes of biologics drug product involve multiple unit operations. In particular they often include a mixing step to reduce non-uniformities in fluids by eliminating gradients of concentration and pH may occur during freezing. This step should be conducted carefully to avoid any degradation of the protein under mechanical stress.This study was aimed at characterizing disposable vessels of square cross-section such as Levmixer® from Sartorius Stedim in terms of fluid dynamics and mixing in turbulent regime. The investigation included two tree large vessels (50, 200 & 650-l) and one 4-l vessel designed in house. For that purpose, the impact of stirrer speed, filling volume and duration of mixing on product quality attributes were studied, using a surrogate. Moreover, a scale-up rule, based on first principle, was established and allows prediction of the mixing time as a function of stirring speed and filling volume. A lab-scale test, using drug product, was performed at the same stress intensity but for a much longer duration than the commercial operation and did not reveal any trend to aggregation. Finally, based on the correlation, lab scale stress test and a single verification test at large scale, a design space within which the product can be processed without altering product quality was proposed

Dark magnetic dipole property in fermionic absorption by nucleus and electrons

The fermionic dark matter (DM) absorption by nucleus or electron targets provides a distinctive signal to search for sub-GeV DM. We consider a Dirac fermion DM charged under a dark gauge group and with the dark magnetic dipole operator. The DM field mixes with right-handed neutrino and interacts with the ordinary electromagnetic charge current via the kinetic mixing term of gauge fields. As a result, the incoming DM is absorbed and converted into neutrino in final state through the dipole-charge interaction. For the DM absorption by nucleus, the recoil energy spectrum exhibit a peak at {m}_{upchi}^2/2{m}_N for each isotope in the target. XENON1T can probe the DM mass above 27 MeV and the projected constraint on the inelastic DM-nucleon cross section becomes 10−49 cm2. CRESSTIII with lower energy threshold would be sensitive to the DM mass above 2 MeV. We also check that the contribution from the nuclear magnetic dipole is negligible for 131Xe target. The absorption of DM by bound electron target induces ionization signal and is sensitive to sub-MeV DM mass. The involvement of the ionization form factor spreads out the localized recoil energy. We show the future prospect for the constraint on the magnetic dipole coupling from the electron ionization of 131Xe.

Comparison of Procedures Performed and Costs between an Outsourced Dental Health Plan with Fee-For-Service Payment and an Evidence-Based, In-House Dental Health Service with Salaried Professionals

Aim: Evaluate the change in terms of levels and mixes of services rendered and costs resulting from the change from an outsourced dental health plan with fee-for-service payment to an in-house health service provided by salaried dentists. Method: We evaluated dental care services provided to almost 4,000 users (employees and their families) of a big company (Moinhos de Vento Hospital, Brazil). The analysis was divided into two periods of time: from January 2000 to December 2002, during which time the dental care provided to employees (and families) was outsourced to a dental plan which operates with an accredited network, and from March 2003 to June 2005, when the dental care was provided by an in-house dental care service with preventive and evidence-based dentistry guidelines. Economic data were collected, as well as the type and number of procedures performed. Results: There was a significant increase in the number of preventive and oral environment adequacy procedures performed by the in-house service in relation to the outsourced dental plan. There also was a significant decrease in the number of restorative procedures with the implementation of the in-house service. Expenses were reduced by 36%, while the number of procedures increased by 30% and customer satisfaction did not decrease with the adoption of the in-house service. Conclusion: An in-house service with evidence-based clinical protocols, as compared with an accredited network, decreased costs and also increased the number of procedures done, changed the profile of care for a less invasive dentistry and one more geared toward the causes of diseases, while still preserving the customers’ satisfaction.

Bangkok Street Food Vendors (SME) Business Continuity during COVID-19 Pandemic

Aims: This study aimed at capturing the perceptions of Bangkok street food vendors related to the business continuity of SMEs during the covid-19 pandemic.
 Study Design: The study design followed the 7 Ps of the service marketing model: product, price, place, promotion, process, physical evidence, and people related to street food. 
 Place and Duration of Study: The study took place in Bangkok, Thailand from Summer 2021 until Fall of 2021.
 Methodology: We included 200 participants (66 men, 124 women; age range 18-80 years) who were SME street food vendors, 40% of them were under 40 years old with 59% having no university education and 35% with a bachelor degree. Two-thirds of the vendors (86%) earned less than 500 USD a month.
 Results: In terms of product the vendors stuck to the favorites (mean 4.34 and SD 0.97) trying to maintain quality and quantity while keeping prices constant as much as possible (mean 4.35 and SD 0.89). The most effective promotion was the 50/50 government food substitute co-payment (mean 4.69 and SD 0.99). Place changed from sit-down restaurants to take-away (mean of 4.77 and SD 0.96) and home delivery via food delivery apps (FDA). Process changes due to social distancing included screens and fewer tables (mean of 4.51 and SD 0.65) The number one physical evidence was wearing face masks and sanitization (mean 4.03 and SD 0.82). People changed in terms of customer mix with fewer foreigners and local tourists (mean of 4.77 and SD 0.75) as well as fewer migrant workers and more government agents taking a closer look at street food hawkers.
 Conclusion: Street food hawkers adjusted all 7Ps of the marketing mix to assure business continuity during the covid-19 pandemic as discussed above. Moving to food delivery along with face masks and social distancing were the biggest changes. These predictors, however, would benefit from further work to validate reliability in Thailand, ASEAN, and worldwide.

Analysis of Indihome Provider Marketing Mix Factors on Consumer Subscription Satisfaction

It is the purpose of this study to examine the elements that influence consumer subscription satisfaction at PT Telkom Indonesia Karawang in terms of the marketing mix, which includes product, price, promotion, and place provider Indihome. The quantitative analytical method was employed in this investigation. The technique of creating a scale utilizing the Likert scale technique was used in this investigation. The researcher employed multiple regression analysis to analyze the data collected during the study. The sample size for this study was 50 people that took part in it. The findings revealed that product, price, promotion, and location all had an impact on consumer satisfaction with the Indihome provider at PT Telkom Indonesia Karawang in a partial and simultaneous manner. The researchers also discovered that the four independent factors had a combined influence on the fixed variable, which was customer satisfaction, of 76.6 percent.

An Operational Matrix Technique Based on Chebyshev Polynomials for Solving Mixed Volterra-Fredholm Delay Integro-Differential Equations of Variable-Order

In this work, an algorithm for finding numerical solutions of linear fractional delay-integro-differential equations (LFDIDEs) of variable-order (VO) is introduced. The operational matrices are used as discretization technique based on shifted Chebyshev polynomials (SCPs) of the first kind with the spectral collocation method. The proposed VO-LFDIDEs have multiterms of integer, fractional-order derivatives for delayed or nondelayed and mixed Volterra-Fredholm integral terms. The introduced model is a more general form of linear fractional VO pantograph, neutral, and mixed Fredholm–Volterra integro-differential equations with delay arguments. Caputo’s VO fractional derivative operator is used to generate the matrices of the derivative. Operational matrices are presented for all terms. The reliability and efficiency of the proposed scheme are demonstrated by some numerical experiments. Also, some examples are included to improve the validity and applicability of the techniques. Finally, comparisons between the proposed method and other methods were used to solve this kind of equation.