Linear Term Research Articles

A Decision Procedure for a Theory of Finite Sets with Finite Integer Intervals

In this paper we extend a decision procedure for the Boolean algebra of finite sets with cardinality constraints (ℒ |⋅| ) to a decision procedure for ℒ |⋅| extended with set terms denoting finite integer intervals (ℒ [] ). In ℒ [] interval limits can be integer linear terms including unbounded variables . These intervals are a useful extension because they allow to express non-trivial set operators such as the minimum and maximum of a set, still in a quantifier-free logic. Hence, by providing a decision procedure for ℒ [] it is possible to automatically reason about a new class of quantifier-free formulas. The decision procedure is implemented as part of the { log } (‘setlog’) tool. The paper includes a case study based on the elevator algorithm showing that { log } can automatically discharge all its invariance lemmas, some of which involve intervals.

Comprehensive Comparison of Bioactive N-Glycans among Seven Species of Livestock and Poultry Plasma Using a Relative Quantification Strategy.

Glycans have been proven to play special roles in keeping human health as a class of nutritional and bioactive ingredients in many food materials. However, their broad use in the food industry is hindered by the lack of comprehensive analytical methods for high-quality food glycomics studies and large-quantity raw materials for their production. This study focuses on structural identification and quantitative comparison of bioactive N-glycans in seven species of livestock and poultry plasma as potential natural glycan resources by a novel comprehensive relative quantification strategy based on stable isotope labeling with nondeuterated and deuterated 4-methyl-1-(2-hydrazino-2-oxoethyl)-pyridinium bromide (d0/d7-HMP) in combination with linkage-specific derivatization of sialic acid residues. Methodological validation of the method in terms of detection sensitivity, signal resolution, quantification linearity, precision, and accuracy on model neutral and complicated sialylated glycans demonstrated its advantages over the existing methods. Based on this method, a series of bioactive N-glycans were found in seven species of livestock and poultry plasma, and their differences in structure, abundance percentages, and relative contents of N-glycans were revealed, demonstrating their excellent applicability for comprehensive food glycomics analysis and great exploitation potential of these plasma samples as large-quantity raw materials in producing bioactive N-glycans for application in food and pharmaceutical industries.

Refractive Index-Modulated LSPR Sensing in 20–120 nm Gold and Silver Nanoparticles: A Simulation Study

Localized surface plasmon resonance (LSPR) based sensing has been a simple and cost-effective way to measure local refractive index changes. LSPR materials exhibit fascinating properties that have significant implications for various bio/chemical sensing applications. In many of these applications, the focus has traditionally been on analyzing the intensity of the reflected or transmitted signals in terms of the refractive index of the surrounding medium. However, limited simulation work is conducted on investigating the refractive index sensitivity of LSPR materials. Within this context, here we simulate the refractive index sensing properties of spherical gold (Au) and silver (Ag) nanoparticles ranging from 20–120 nm diameter within 1.0 to 1.50 refractive index units (RIU). After analyzing the peak optical efficiency and peak wavelength, we report the sensing performance of these materials in terms of sensitivity, linearity and material efficiency, which we refer to as the figure of merit (FOM). Overall, our observations have revealed greatest FOM values for the smallest sized nanoparticles, a FOM of 6.6 for 20 nm AuNPs and 11.9 for 20 nm AgNPs with refractive index of 1.

Nearly optimal fault-tolerant constrained tracking for multi-axis servo system via practical terminal sliding mode and adaptive dynamic programming

In this paper, a nearly optimal tracking control is proposed for n-links robotic manipulators subject to parameter uncertainties, time-profile failures, and input saturation constraints. Firstly, the practical terminal sliding-mode (PTSM) manifold with a linear additional term is proposed to combine the system states related to joint rotation, such that the controlled states quickly fall into a tiny neighborhood of the equilibrium once they reach the PTSM manifold. Secondly, a nearly optimal sliding-mode reaching law is designed by using the adaptive dynamic programming (ADP) technique. Benefiting from a non-quadratic positive defined mapping of the proposed performance index, which relates to the derivative of the sliding-mode function, reduced-order system dynamics can be constrained to a desired region. For the bounded actuator fault caused by various inducements such as the power supply fluctuation and the wear of parts, a radial basis function neural network (RBFNN) is introduced to compensate for this, and the input saturation constraints of the controlled plant are also compensated at the same time. Innovatively, the node weights of RBFNN are updated by the critic network of the ADP framework, such that the integrity of the proposed control strategy is improved. Simulations verify the main conclusions.

Analysis of a reactive porous separation effects on depollution and indoor air quality: Application of LBM-MRT to heat and mass transfers

The reduction of energy demand and the indoor air quality associated with energy demand are the main goals of thermal buildings. This work is devoted to the study of the effect of a reactive porous separation on the ventilation (cooling) and depollution capacity in a rectangular room ventilated by air displacement. The model is considered as a cavity heated on its right verticle wall and thermally isolated by the other three walls. A porous separation divides the room into two compartments. The system of equations was solved using the Lattice Boltzmann method with multiple relaxation times. The extended Darcy Brinkman-Forchheimer model was used to simulate the porous material. An additional linear term is added to the standard transport equations (material diffusion) to account for reaction effects, this term was derived from Arrhenius' law. Over a wide range of Richardson and Darcy numbers, the results of the computations show the influence of these parameters on the flow structure, making it possible to categorize the different convection phenomena (natural, forced and mixed). The most important point to note is that the addition of reaction (fixing reaction) improves indoor air quality and can achieve a 55 % reduction in air renewal time, thus saving on energy costs. However, this reactif effect has no influence on the thermal efficiency of the proposed model.

Stop comparing resummation methods

I argue that the consistency of any resummation method can be established if the method follows a power counting derived from a hierarchy of scales. I.e. whether it encodes a top-down effective field theory. This resolves much confusion over which resummation method to use once an approximation scheme is settled on. And if no hierarchy of scales exists, you should be wary about resumming. I give evidence from the study of phase transitions in thermal field theory, where adopting a consistent power-counting scheme and performing a strict perturbative expansion dissolves many common problems of such studies: gauge dependence, strong renormalization scale dependence, the Goldstone boson catastrophe, IR divergences, imaginary potentials, mirages (illusory barriers), perturbative breakdown, and linear terms.

On the global existence and analyticity of the mild solution for the fractional Porous medium equation

In this research article we focus on the study of existence of global solution for a three-dimensional fractional Porous medium equation. The main objectives of studying the fractional porous medium equation in the corresponding critical function spaces are to show the existence of unique global mild solution under the condition of small initial data. Applying Fourier transform methods gives an equivalent integral equation of the model equation. The linear and nonlinear terms are then estimated in the corresponding Lei and Lin spaces. Further, the analyticity of solution to the fractional Porous medium equation is also obtained.

An optimal wavelet transform grey multivariate convolution model to forecast electricity demand: a novel approach

PurposeFor some years now, Cameroon has seen a significant increase in its electricity demand, and this need is bound to grow within the next few years owing to the current economic growth and the ambitious projects underway. Therefore, one of the state's priorities is the mastery of electricity demand. In order to get there, it would be helpful to have reliable forecasting tools. This study proposes a novel version of the discrete grey multivariate convolution model (ODGMC(1,N)).Design/methodology/approachSpecifically, a linear corrective term is added to its structure, parameterisation is done in a way that is consistent to the modelling procedure and the cumulated forecasting function of ODGMC(1,N) is obtained through an iterative technique.FindingsResults show that ODGMC(1,N) is more stable and can extract the relationships between the system's input variables. To demonstrate and validate the superiority of ODGMC(1,N), a practical example drawn from the projection of electricity demand in Cameroon till 2030 is used. The findings reveal that the proposed model has a higher prediction precision, with 1.74% mean absolute percentage error and 132.16 root mean square error.Originality/valueThese interesting results are due to (1) the stability of ODGMC(1,N) resulting from a good adequacy between parameters estimation and their implementation, (2) the addition of a term that takes into account the linear impact of time t on the model's performance and (3) the removal of irrelevant information from input data by wavelet transform filtration. Thus, the suggested ODGMC is a robust predictive and monitoring tool for tracking the evolution of electricity needs.

Streaming Current for Surfaces Covered by Square and Hexagonal Monolayers of Spherical Particles.

The interface and particle contributions to the streaming current of flat substrates covered with ordered square or hexagonal monolayers of spherical particles were theoretically evaluated for particle coverage up to close packing. The exact numerical results were approximated using fitting functions that contain exponential and linear terms to account for hydrodynamic screening and charge convection from the particle surfaces exposed to external flow. According to our calculations, the streaming currents for the ordered and random particle arrangements differ within a typical experimental error. Thus, streaming-current measurements, supplemented with our fitting functions, can be conveniently used to evaluate the particle coverage without detailed knowledge of the particle distribution. Our results for equal interface and particle ζ-potentials indicate that roughness can reduce the streaming current by more than 30%, even in the limit of the small size of spherical roughness asperities.

Air conditioning load prediction based on hybrid data decomposition and non-parametric fusion model

Accurate prediction of air conditioning load is the pivotal problem of air conditioning optimization control, which is of great significance for reducing building energy consumption. In order to improve the prediction accuracy of air conditioning load, this paper proposes a load prediction method of air conditioning based on hybrid data decomposition (HRD) and non-parametric fusion model (NPFM). First, the historical load data is decomposed into linear term and nonlinear term by using HRD, which are employed to combine the temporal convolutional network (TCN) and long short term memory (LSTM) method to achieve the priori prediction of air conditioning load, and are regarded as the state transition equation. Secondly, the strong correlation index based on correlation screening is used as the observation parameter, and the nonlinear relationship between air conditioning load and real-time operating parameters of air conditioning equipment is mapped by back propagation (BP) neural network, which works as the observation equation, and forming a set of NPFM. Thirdly, the particle filter (PF) algorithm is introduced to correct the prior load prediction, suppress the noise disturbance, and realize the closed-loop control. Finally, the effectiveness of the proposed method is validated by two examples, and the results indicate that the proposed method can provide more accurate and robust air conditioning load prediction compared with existing methods.

End-to-end Standardization of Original Medicines when Determining Related Impurities

Introduction. For tablets “Malоben, 60 mg” and “Etmaben, 300 mg”, permission was received to conduct phase I clinical trials, so they required a full cycle of research and standardization.Aim. Development of a unified analytical procedure for the determination of related impurities in samples (RS, API, FPP) of Malоben and Ethmaben.Materials and methods. RSs were obtained at the Department of Organic Chemistry of the St. Petersburg State Chemical and Pharmaceutical University; the synthesis of APIs and the production of FPP were carried out on an industrial scale in pharmaceutical production. The studies were carried out on a Flexar liquid chromatograph (PerkinElmer, USA), equipped with a pump (formation of a gradient on the low-pressure side), an autosampler, a column thermostat, a UV detector and a chromatographic column Intersil® ODS-3V, 5 µm, 100 Å, 250 × 4, 6 (Phenomenex, Japan).Results and discussion. In the research, uniform optimal chromatographic conditions were selected using the HPLC method to determine the RP in RS, API and FPP of Maloben and Ethmaben. Column C18 250×4.6 mm, mobile phase 0.1% phosphoric acid and acetonitrile (gradient elution), flow rate 1 ml/min, sample volume 10 µl, UV detector (270 nm). They were validated in terms of specificity, linearity, detection limit, precision, robustness, and solution stability. Analytical concentration levels were selected for the formation of draft regulatory documents. Using the developed analytical technique, samples of RS, API and tablets of malоben and ethmaben were analyzed.Conclusion. A full cycle of research was carried out, an analytical methodology was developed and related impurities were identified in RS, API and FPP of Maloben and Ethmaben.

A strategy for deciphering the bioactive metabolites of Farfarae Flos by the inter-individual variability of the antitussive effect

Farfarae Flos is a commonly used traditional herb for the treatment of respiratory disorders. In this study, ultra-high-performance liquid chromatography coupled with time-of-flight mass spectrometry combined with the mass defect filter method was used for the qualitative analysis of Farfarae Flos metabolites in the lung tissues. Then a method for the simultaneous determination of 14 Farfarae Flos metabolites was developed and validated in terms of specificity, linearity, precision and accuracy, matrix effect and recovery. The method was applied to compare the lung tissue of Farfarae Flos treated mice, and 10 caffeoylquinic acid metabolites were higher in the mice with better antitussive effect. Further network pharmacology analysis and molecular docking results showed that these metabolites played an important role in the antitussive effect of Farfarae Flos. This study presented a novel strategy for deciphering the active compounds of herbal medicine by inter-individual variability of bioactivities.

Modeling the thermo-responsive behaviors of polydomain and monodomain nematic liquid crystal elastomers

Liquid crystal elastomers (LCEs) are polymeric materials that combine liquid crystal orientation and rubber elasticity. The mechanical responses of LCEs strongly depend on the nematic order and temperature. Developing a thermo-order-mechanical coupling model is important for the engineering applications of LCEs. In this work, we first synthesize both polydomain and monodomain LCEs. The shape change with temperature under a certain stress level is further characterized. In the theoretical part, the Landau–de Gennes model and neo-classical model are combined to construct the free energy density of LCEs. A linear term accounting for the effect of interior stress on nematic–isotropic transition is incorporated into the Landau–de Gennes free energy density, while a macro-order parameter is defined to describe the polydomain–monodomain transition for polydomain LCEs induced by the external force. Comparison between the model predictions and experimental results shows acceptably consistency for both polydomain and monodomain LCEs. Therefore, this work provides an efficient approach to predict the shape change of LCEs in various scenarios.

Quantum and anharmonic effects in non-adiabatic transition state theory.

Quantitative descriptions of non-adiabatic transition rates at intermediate temperatures are challenging due to the simultaneous importance of quantum and anharmonic effects. In this paper, the interplay between quantum effects-for motion across or along the seam of crossing-and anharmonicity in the seam potential is considered within the weak coupling limit. The well-known expression for quantized 1-D motion across the seam (i.e., tunneling) in the linear terms approximation is derived in the thermal domain using the Lagrangian formalism, which is then applied to the case when tunneling is distributed along the seam of crossing (treating motion along the seam classically). For high-frequency quantum modes, a vibrationally adiabatic (VA) approach is developed that introduces to the non-adiabatic rate constant a factor associated with high-frequency wavefunction overlap; this approach treats the high-frequency motion along the seam quantum mechanically. To test these methodologies, the reaction N2O ↔ N2 + O(3P) was chosen. CCSD(T)-F12b/cc-pVTZ-F12 explorations of the 3A'-1A' seam of N2O revealed that seam anharmonicity has a strong effect on the rate constant (a factor of ∼20 at 2000K). Several quantum effects were found to be significant at intermediate/lower temperatures, including the quantum N-N vibration that was coupled with seam anharmonicity using the VA approach. Finally, a 1-D approximation to non-adiabatic instanton theory is presented to estimate the validity limit of the linear terms model at low temperatures (∼250 K for N2O). We recommend that the assumptions built into many statistical theories for non-adiabatic reactions-harmonic behavior, classical motion, linear terms, and weak coupling-should be verified on a case-by-case basis.

Development of Liquid Chromatography-Mass Spectrometry (LC-MS) Method for Quantification of Broccoli Sulforaphane

Sulforaphane (SFN) is an isothiocyanate and the product of the hydrolysis of glucoraphanin (GRA) by myrosinase. Broccoli is one of the rich sources of GRA and thus SFN. SFN possess a wide range of bioactivities and is considered an anti-cancer phytochemical. Most of the current common methods used to quantify SFN are based on high-pressure liquid chromatography (HPLC) with diode array detection (DAD) — also known as HPLC-DAD. Although this technique has shown encouraging results, the detection of SFN by DAD is relatively weak and affected by high interference of sample matrices. Therefore, the aim of this study was to develop a liquid chromatography-mass spectrometry (LC-MS) method in which SFN is identified by molecular mass to give more accurate results. The developed method demonstrated a highly reproducible retention time (7.204 ± 0.008 min), producing a sharp, symmetrical and well-defined sulforaphane peak in standard and test samples. The most dominant ion of sulforaphane in the pure and test samples was 178 m/z ([M + H]+). In terms of linearity, the calibration curve had a coefficient of determination (R2) of 0.9963. The limit of detection of this method is 1.3 ng/mL, and the limit of quantification is 3.9 ng/mL, indicating high sensitivity. The uniformity of peak shape and retention time in both pure and test samples were the same suggesting excellent selectivity. Overall, the developed method showed promising results in identifying and quantifying broccoli SFN.

Development and optimization of methylcellulose-based edible coating using response surface methodology for improved quality management of ready-to-eat pomegranate arils

ABSTRACT In this study, the methylcellulose edible coating additives, namely, salicylic acid (SA) (1–2.5 mM), canola oil (0.05–0.1%) and tween-80 (0.05–0.1%) were optimized using RSM to improve quality management of pomegranate arils. The central composite design was used, and the response variables included mass loss (ML), total soluble solids (TSS), total phenolic content (TPC) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH scavenging activity). The results showed that ML was affected by the quadratic terms of canola oil, tween-80 and SA, whereas TSS was affected by the quadratic terms of canola oil and tween-80. The interaction of SA and canola oil showed a significant effect on TSS and TPC, whereas DPPH scavenging activity was affected by linear terms of SA and canola oil. The optimized conditions for the independent variables were 1.55 mM, 0.079% and 0.079% for SA, canola oil and tween-80, respectively. The predicted responses were consistent with experimental values, indicating the model accuracy and suitability.

Current Tracking and Circulating Current Suppression Super-Twisting Sliding Mode Control for Parallel Operation of EAST Fast Control Power Supply

To quickly output sufficient current for plasma excitation control, parallel operation of a structure of multiple branches is adopted in the Experimental Advanced Superconducting Tokamak (EAST) fast control power supply. During the process of parallel operation of multiple branches in engineering, a larger inductance current sharing reactor is used to suppress the circulating current for the branches, which reduces the dynamic response speed of the output current and increases economic costs. In order to achieve cost savings and improve the dynamic response speed of the output current, the parallel branch current model of the EAST fast control power supply is analyzed, and the current of each branch is reconstructed into two parts: the current flowing to the load end and the circulating current flowing to other branches. Without changing the circuit structure and increasing the additional complex communication system for each branch, observation of the current flowing to the load end from each branch is achieved. Based on the observed current, a super-twisting sliding mode controller (STSMC) is designed to suppress the circulating current flowing through branches. To realize fast output of the branch current and circulating current suppression for the branches, a new STSMC with a linear term and parameter adaptive structure is designed, speeding up the convergence rate of the whole control system. The linear term and designed parameter adaptive structure based on the sliding mode system status ensure fast convergence speed and excellent control performance of the system. Simulation and experiments show that the designed control method can achieve fast output current control for each branch and that the tracking performance of the total output current is good. While reducing the inductance of the current sharing reactor, the circulating current for the branches is effectively suppressed compared with traditional control methods. The proposed method has great significance in cost savings and performance improvement in engineering practice applications.

PVA Coated Glass Substrates for Acetone Detection

Technology advancement in photonics has progressively tailor human need in healthcare industries. Inventing a new medical device or application for the mental and health sectors have make disease diagnosis easier. Without prevention, the number of sufferers may rise quickly. Studies have identified a way to diagnose diabetes illness by measuring a person's acetone level. The existing blood test have inferiority in term of invasive and dangerous if not handled properly. In this report, acetone concentration has been detected using a simple, low-cost Polyvinyl Alcohol (PVA) coated glass substrate platform as a potential diagnosis tool for diabetes patient. Based on the experiment results, the proposed sensor exhibits exceptional sensing performances for acetone detection in term of sensitivity, linearity, repeatability, stability and hysteresis

Can fish species co-occurrence patterns be predicted by their trait dissimilarities?

Trait-based analyses have been successful in determining and predicting species association outcomes in diverse communities. Most studies have limited the scope of this approach to the biotic responses of a small number of species or geographical regions. We focused on determining whether three biologically relevant traits (body size, temperature preference and trophic level) influence the patterns of co-occurrence between multiple species. We used fish species presence/absence from 9204 lakes in Ontario, Canada, to obtain effect sizes of 2001 species-pair co-occurrence values, using a null model approach. Euclidean distances between each species-pair were calculated for each of the three traits selected. Multiple regression models and randomization tests were used to determine the direction and significance of the relationship of each trait with the observed co-occurrence values. The results show that species temperature preference was significantly related to co-occurrence patterns, indicating the effect of environmental filtering. Trophic level was significantly related to co-occurrence values for both linear and quadratic terms, suggesting that segregation between species is driven by large differences in this trait (predation effects). Unexpectedly, body size was not significantly related to the observed co-occurrence patterns. We provide a new approach to test relationships between species assemblages and trait conditions.

Multiple scattering theory for modeling sonic booms in atmospheric turbulence.

Sonic booms are often modeled using Burgers equations accounting for dominant propagation effects. Scattering effects of turbulence, however, have not been incorporated into such equations, although these effects are ubiquitous in measured sonic booms. This paper formulates the mean scattering effects, including backscattering, using multiple scattering theory and ensemble averaging. It obtains an acousto-turbulence interaction energy representing the interaction of an acoustic wavefield with a turbulence field. The interaction energy gives rise to a scattering wavenumber, a complex-valued correction to the free-space wavenumber. The scattering wavenumber leads to a dispersion and attenuation of the mean waveform due to backscattering, and can be obtained from a derived exact solution. An existing Burgers equation is extended to include the scattering effects of turbulence as an additional linear term. Numerical simulations of an N-wave and a low boom show that the mean scattering effects lead to shock thickening in the mean waveforms as well as reduce the peak amplitudes and total energy contents. The energy reduction is less severe in the low boom than in the N-wave and is dependent on the variance, correlation length, and thickness of the turbulence field.