Order Of Magnitude Difference Research Articles

Multi-attribute decision-making analysis based on the bipolar N-soft PROMETHEE method

The multi-attribute decision-making (MADM) methods can deeply mine hidden information in data and make a more reliable decision with actual needs and human cognition. For this reason, this paper proposes the bipolar N-soft PROMETHEE (preference ranking organization method for enrichment of evaluation) method. The method fully embodies the advantages of the PROMETHEE method, which can limit the unconditional compensation between attribute values and effectively reflect the priority between attribute values. Further, by introducing an attribute threshold to filter research objects, the proposed method not only dramatically reduces the amount of computation but also considers the impact of the size of the attribute value itself on decision-making. Secondly, the paper proposes the concepts of attribute praise, attribute popularity, total praise, and total popularity for the first time, fully mining information from bipolar N-soft sets, which can effectively handle situations where attribute values have different orders of magnitude. In addition, this paper presents the decision-making process of the new method, closely integrating theoretical models with real life. Finally, this paper analyses and compares the proposed method with the existing ones, further verifying the effectiveness and flexibility of the proposed method.

Acute Toxicity of the Lampricide 4-Nitro-3-(trifluoromethyl)phenol to the Mussel (Obovaria subrotunda), Its Host (Percina maculata), and a Surrogate Mussel Species (Obovaria olivaria).

The risk of lampricide applications (such as 4-nitro-3-[trifluoromethyl]phenol [TFM]) to nontarget fauna continues to be a concern within the Great Lakes Fishery Commission Sea Lamprey Control Program, especially among imperiled aquatic species-such as native freshwater mussels. The Grand River (Ohio, USA) is routinely treated for larval sea lampreys (Petromyzon marinus), and this river contains populations of the federally threatened mussel Obovaria subrotunda. Given this spatial overlap, information on the sensitivity of O. subrotunda to TFM is needed. Our objectives were to assess the toxicity of TFM to (1) adult Obovaria olivaria (a surrogate for O. subrotunda), (2) glochidial larvae of O. olivaria and O. subrotunda, (3) juveniles of O. olivaria and O. subrotunda, and (4) adult Percina maculata (host for O. subrotunda glochidia). In acute toxicity tests, TFM was not toxic to glochidia and adult mussels at exposure concentrations that exceed typical treatment rates. Although significant dose-response relationships were observed in hosts and juveniles, survival was ≥95% (Percina maculata), ≥93% (O. olivaria), and ≥74% (O. subrotunda) at typical treatment rates. However, the steep slope of these dose-response relationships indicates that an approximately 20% difference in the treatment level can result in nearly an order of magnitude difference in survival. Collectively, these data indicate that routine sea lamprey control operations are unlikely to acutely affect these species or their host. However, given that many mussel species are long-lived (30-100 years), the risks posed by lampricide treatments in the Great Lakes would be further informed by research on the potential long-term effects of lampricides on imperiled species. Environ Toxicol Chem 2024;43:1423-1430. Published 2024. This article is a U.S. Government work and is in the public domain in the USA.

High-contrast coercive field engineering for periodic poling of RbKTiOPO4 with Ba2+/K+ ion-exchange

We investigate a new method of coercive field engineering for periodic poling of RbKTiOPO4 (RKTP). By ion exchanging RKTP in a molten salt containing 7 mol% Ba(NO3)2 and 93 mol% KNO3 we achieve more than an order of magnitude difference in polarization switching time between the exchanged and non-exchanged regions. This method is used to fabricate periodic gratings of 2.92 µm in 1 mm thick bulk RKTP for second harmonic generation at 779 nm with a normalized conversion efficiency of 2%/Wcm. We show that the poled domain structures are stable at 300 °C, and that there is no bulk refractive index modification associated with the periodic ion exchange.

Effects of ammonia on the cellular, physiological, biochemical and genetic traits of Indian major carp (Labeo rohita) fry in artisanal Bangladeshi aquaculture

AbstractThe major carp Rohu (Labeo rohita) is a prime freshwater aquaculture species across the Indian subcontinent that faces various production‐related issues associated with water quality parameters. The present study examined the effects of three different doses of NH3 (T1 = 1 mg/L, T2 = 2 mg/L and T3 = 3 mg/L) on cellular (gill ultrastructure), physiological (growth and oxygen consumption rate), biochemical (blood cell counts, blood cortisol and glucose levels) and genetic (expression of five genes involved in growth, immunity and metabolism) traits of Rohu. The experimental ammonia dose significantly affected the tested biological parameters (p < 0.05), causing moderate‐to‐severe gill tissue damage. In general, compared with those in the control group, 16%–25% slower growth, 12%–30% lower survival and 15%–56% higher O2 consumption were observed for the treatment groups. Blood glucose and cortisol levels increased with increasing ammonia levels, but blood cell counts decreased. The five selected candidate genes showed a differential expression pattern in response to the ammonia dose, with higher expression in the control group and lower expression in the treatment groups. The results indicate that different concentrations of ammonia impose stress on different orders of magnitude in the experimental fishes. Therefore, it can be inferred that the presence of ammonia in aquatic/farming environments can adversely affect production performance; the severity of damage during production depends on the concentration of ammonia. Therefore, maintaining no or minimum ammonia levels in farming environments is urgently needed for sustainable aquaculture production of Rohu.

Generation of photoionized plasmas in the laboratory of relevance to accretion-powered x-ray sources using keV line radiation

We describe laboratory experiments to generate x-ray photoionized plasmas of relevance to accretion-powered x-ray sources such as neutron star binaries and quasars, with significant improvements over previous work. A key quantity is referenced, namely the photoionization parameter, defined as ξ=4πF/ne where F is the x-ray flux and ne the electron density. This is normally meaningful in an astrophysical steady-state context, but is also commonly used in the literature as a figure of merit for laboratory experiments that are, of necessity, time-dependent. We demonstrate emission-weighted values of ξ>50 erg-cm s−1 using laser-plasma x-ray sources, with higher results at the centre of the plasma which are in the regime of interest for several astrophysical scenarios. Comparisons of laboratory experiments with astrophysical codes are always limited, principally by the many orders of magnitude differences in time and spatial scales, but also other plasma parameters. However useful checks on performance can often be made for a limited range of parameters. For example, we show that our use of a keV line source, rather than the quasi-blackbody radiation fields normally employed in such experiments, has allowed the generation of the ratio of inner-shell to outer-shell photoionization expected from a blackbody source with ∼keV spectral temperature. We compare calculations from our in-house plasma modelling code with those from Cloudy and find moderately good agreement for the time evolution of both electron temperature and average ionisation. However, a comparison of code predictions for a K-β argon X-ray spectrum with experimental data reveals that our Cloudy simulation overestimates the intensities of more highly ionised argon species. This is not totally surprising as the Cloudy model was generated for a single set of plasma conditions, while the experimental data are spatially integrated.

Realization of exciton-polariton optical chirality based on strong coupling between intrinsic chiral quasibound states in the continuum and monolayer WS2.

Hybrid quasiparticles produced by the strong interaction between nanostructures and excitons will exhibit optical chirality when one of the coupled components is chiral. Due to the tunability of hybrid states, the coupled system has potential applications in chiral devices and chiral sensing. However, reported chiral materials including chiral molecules and three-dimensional chiral structures in the coupled system limit the application due to the weak chiroptical responses and difficult fabrication, respectively. In this paper, we design chiral quasibound states in the continuum (q-BIC) metasurface by introducing planar symmetry-breaking and z-axis perturbation into an array structure whose unit cell is a C4 rotational symmetric disk. By tuning the polarization state of the eigenmode, a significant chiroptical response is obtained in our q-BIC metasurface. Furthermore, mode splitting is observed not only in the reflection spectrum but also in the circular dichroism (CD) spectrum in the chiral q-BIC and monolayer WS2 strong coupling system, which indicates the realization of the exciton-polariton optical chirality. More importantly, one order of magnitude difference in the reflection to left and right circularly polarized light is achieved resulting in significant CD signals. Our work provides a new strategy to realize the exciton polaritons with significant chiroptical responses, which exhibits promising applications in on-chip chiral devices.

Biochemical and biomechanical characterization of an autologous protein-based fibrin sealant for regenerative medicine

Accidental events or surgical procedures usually lead to tissue injury. Fibrin sealants have proven to optimize the healing process but have some drawbacks due to their allogeneic nature. Autologous fibrin sealants present several advantages. The aim of this study is to evaluate the performance of a new autologous fibrin sealant based on Endoret®PRGF® technology (E-sealant). One of the most widely used commercial fibrin sealants (Tisseel®) was included as comparative Control. E-sealant´s hematological and biological properties were characterized. The coagulation kinetics and the microstructure were compared. Their rheological profile and biomechanical behavior were also recorded. Finally, the swelling/shrinkage capacity and the enzymatic degradation of adhesives were determined. E-sealant presented a moderate platelet concentration and physiological levels of fibrinogen and thrombin. It clotted 30 s after activation. The microstructure of E-sealant showed a homogeneous fibrillar scaffold with numerous and scattered platelet aggregates. In contrast, Control presented absence of blood cells and amorphous protein deposits. Although in different order of magnitude, both adhesives had similar rheological profiles and viscoelasticity. Control showed a higher hardness but both adhesives presented a pseudoplastic hydrogel nature with a shear thinning behavior. Regarding their adhesiveness, E-sealant presented a higher tensile strength before cohesive failure but their elastic stretching capacity and maximum elongation was similar. While E-sealant presented a significant shrinkage process, Control showed a slight swelling over time. In addition, E-sealant presented a high enzymatic resorption rate, while Control showed to withstand the biodegradation process in a significant way. E-sealant presents optimal biochemical and biomechanical properties suitable for its use as a fibrin sealant with regenerative purposes.Graphical

Thomson scattering measurements in the krypton plume of a lanthanum hexaboride hollow cathode in a large vacuum test facility

Laser Thomson scattering is a minimally intrusive diagnostic technique for determining electron temperature, density, and bulk velocity in plasma systems. Advances in technology have made possible the application of Thomson scattering to electric propulsion-relevant plasma systems, with reported electron number-density detection limits as low as 1×1016 m−3, and electron temperatures from one-to-tens eV. However, the implementation of laser Thomson scattering in large vacuum testing facilities, wherein electric propulsion devices are tested, remains a challenge. This work presents the implementation of a laser Thomson scattering system in a large vacuum test facility at the Georgia Tech High Power Electric Propulsion Laboratory. The diagnostic was optimized for maximum light-collection efficiency and ease of re-alignment while the facility is at vacuum. The high light-collection efficiency allowed reduced accumulation times to achieve the target detection limit of 1×1017 m−3. The diagnostic is used to measure axial electron property profiles in the near-field plume of a lanthanum hexaboride hollow cathode operating at 25 A on krypton at a background pressure of 1.3×10−6 Torr—Kr. The diagnostic is quantitatively compared to similar systems in the literature. The resulting axial points, collected from 2 to 8 mm downstream of the cathode keeper orifice, are qualitatively and quantitatively compared with simulations and experimental measurements made with electrostatic probes and laser-induced fluorescence. The main quantitative difference between measured values and results is the one to two order of magnitude difference in the peak electron density, being attributed to the relative size and location of the external anode with respect to the cathode keeper.

Creep behavior of dry and saturated medium-grain sandstone and its relationship with conventional mechanical properties

With the large scale mining of coal and the increase of abandoned goafs under weakly cemented aquifer strata in Western China, it is urgent to study the time dependent mechanical properties of water sensitive aquifer strata. In this paper, creep behavior of dry and saturated medium-grain sandstone, which represent two limit states affected by water, were studied and compared. The results showed that water greatly weakens the compressive strength of medium-grained sandstone, but the difference in axial strain between dry and saturated rock samples decreases with the increase of confining pressure. The creep compression volume of rocks decreases with the increase of deviatoric stress, and only under low confining pressure does the creep volume of rocks exhibit expansion. There is an order of magnitude difference in creep strain between medium grained sandstone and other common rocks. The instantaneous elastic modulus has a negative exponential relationship with deviating stress. The creep rate has a positive exponential relationship with deviating stress. Based on Burges model with exponential damage variables, the law of the influence of confining pressure on creep model parameters has been discussed. The linear relationship between elastic modulus of medium-grained sandstone and parameters of Burgers model with damage was found. The research results are conducive to the convenient prediction of creep behavior of medium grained sandstone engineering and the long-term stability control of the surrounding rock.

Efficient numerical methods for semilinear one dimensional parabolic singularly perturbed convection-diffusion systems

In this work we deal with the numerical solution of one dimensional semilinear parabolic singularly perturbed systems of convection-diffusion type. We assume that the coupling in the convection terms is weak and also that the coupling reaction terms are nonlinear. In the case of considering different small diffusion parameters at each equation with different orders of magnitude, the exact solution usually shows overlapping boundary layers on the outflow of the spatial domain. To approximate it, we construct a numerical scheme which combines the upwind finite difference scheme, defined on a piecewise uniform Shishkin mesh, to discretize in space and a linearized version of the fractional implicit Euler method together with an appropriate splitting by components to discretize in time. Then, the fully discrete method is uniformly convergent with respect to both diffusion parameters, having first order in time and almost first order in space. The choice of this time integrator provokes that only tridiagonal linear systems must be solved at each time step; in this way, the computational cost of the algorithm is considerably lower than this one associated to classical implicit methods. The numerical results obtained for different test problems corroborate in practice the good performance of the numerical algorithm.

The Constitutional Isomerism of One-Component Ionizable Amphiphilic Janus Dendrimers Orchestrates the Total and Targeted Activities of mRNA Delivery.

Constitutional isomerism has been previously demonstrated by one of our laboratories to represent a powerful design strategy for the elaboration of complex functional self-organizations. Here we report the design, synthesis, and characterization of 14 positional, skeletal, and functional constitutional isomeric one-component, multifunctional, sequence-defined, amphiphilic ionizable Janus dendrimers (IAJDs). Their coassembly by simple injection with luciferase mRNA (Luc-mRNA) to form dendrimersome nanoparticles (DNPs) was studied. Subsequently, the resulting DNPs were employed to investigate, with screening experiments, the delivery of Luc-mRNA in vivo. Constitutional isomerism was shown to produce changes of up to two orders of magnitude of the total-body luciferase activity and targeted luciferase activity to the spleen and liver, of up to three orders of magnitude difference in targeted luciferase activity to the lungs and up to six orders of magnitude to lymph nodes. These results indicate that constitutional isomerism may represent not only a simple but also an important synthetic strategy that most probably may impact the activity of all components of synthetic vectors used in RNA-based nanomedicine, including in mRNA vaccines and therapeutics.

Calculations of Arctic Ice‐Ocean Interface Photosynthetically Active Radiation (PAR) Transmittance Values

AbstractSea ice algae play an important role in the Arctic Ocean ecosystem, driving primary production in the spring and sequestering carbon to the deep ocean. Up to 45% of Arctic Ocean primary production occurs in ice‐covered areas; photosynthetically active radiation (PAR) is fundamental to driving this production. Sea ice, and particularly snow, strongly scatter and reflect light, reducing the amount of PAR transmitted to the ice‐ocean interface. The effect that varying thicknesses of sea ice (0.2–3.5 m) and snow (0.01–1 m) have on the value of PAR transmittance at the ice‐ocean interface are considered for a Winter, Spring, and Summer scenario. When characteristic Arctic Ocean conditions (2 m sea ice and ∼0.2 m snowpack) are modeled, there is roughly a two‐fold difference in PAR transmittance at the ice‐ocean interface between the Winter (0.003) and Spring (0.007) scenarios and an order of magnitude difference with the Summer scenario (0.04). The modeled values correlate within one standard deviation of measured values and show good agreement with extended pan‐Arctic Ocean field campaign measurements. The results also indicate that simple exponential decay methods may lead to inaccurate results, and radiative‐transfer modeling is required to accurately predict PAR transmittance at the ice‐ocean interface. Therefore, this study offers a novel mathematical technique to predict the value of PAR transmittance at the ice‐ocean interface. Coupled with year‐round near‐real‐time sea ice and snow thickness remote sensing data, this technique may improve understanding of primary production and carbon budgets in the changing Arctic Ocean.

Theoretical study of influence of laser pulse chirp on terahertz emission characteristics of gas induced by two-color laser field

With the development of terahertz (THz) wave research, the demand for controllable THz sources is increasing. How to obtain the regulated THz waves has been one of the research hotspots and key problem in the field of THz science. There have been researches in which the resulting THz wave is modulated by changing the wavelength, relative phase, energy, or chirp of the laser produced by a two-color laser. In this work, we establish a three-dimensional theoretical model of THz wave generation and subsequent propagation induced by two-color laser. And we investigate the influence of chirp modulation of different laser on THz wave by chirp modulation of the fundamental wave (FW) and the second harmonic wave (SHW) of two-color laser, including THz wave amplitude, THz wave center frequency and spectrum width, and analyze the physical mechanism of related phenomena. At the same time, the effects of different orders of magnitudes of laser chirp parameters (femtosecond and picosecond) and initial phase of laser pulse on THz wave parameters are also studied. The results are shown below. 1) In the two-color laser, the chirp of FW mainly affects the shape of THz wave when the initial phase is unchanged. The chirp modulation of SHW can cause the amplitude of THz wave to change significantly, and affect the center frequency and spectrum width of THz waves. 2) In the case of laser pulse width of femtosecond order, 40 fs is taken as an example. When the chirp parameter is of femtosecond magnitude, the chirp parameter has a great influence on the THz wave generation efficiency of two-color laser filament. At the picosecond magnitude, the chirp parameter has a weak effect on the THz wave energy and mainly affects the phase of the THz wave. 3) The initial phase of the two-color laser can aid in chirp modulation of THz wave to optimize the energy generated. 4) The initial phase of two-color laser can assist in the process of chirped laser modulation of terahertz waves to optimize the energy generated. Our research shows that the chirp modulation, as a controllable parameter, has multiple regulation effect on the properties of radiated THz waves. The related research results provide a new idea and basis for studying the generation and regulation of THz waves.

Collisional excitation of propargylimine by helium: new ab initio 3D-potential energy surfaces and scattering calculations.

We present quantum coupled-state calculations for the rotational excitation of interstellar propargylimine due to collisions with helium. The calculations are based on new high-accurate three-dimensional potential energy surfaces (3D-PESs) adapted for rigid-rotor scattering computations. The two PESs (Z/E-PGIM-He) were determined using the explicitly correlated coupled-cluster approach with single, double and perturbative triple excitation [CCSCD(T)-F12] and the standard aug-cc-pVTZ basis set. These PESs present many minima with a global minimum of -47.61 cm-1 for Z-PGIM-He and -54.16 cm-1 for E-PGIM-He. While the PESs for both complexes are qualitatively similar, that of E-PGIM-He is more anisotropic. The state-to-state collisional cross-section calculations are performed for all rotational levels J ≤ 12 with energies below Erot = 30 cm-1 and for total energies up to 500 cm-1. The corresponding collisional rate coefficients are derived for kinetic temperatures up to 120 K. A propensity rule is seen, for rotational excitation cross sections and de-excitation rate coefficients, that favors even ΔJ transitions but with different orders of magnitude. We expect that the retrieved results will contribute to improving atmospheric and astrophysics models.

Many-objective optimization of operation strategy for district cooling system based on the per-unit value form

The operational strategy of the district cooling system (DCS) with an ice storage system must be carefully optimized for many objectives to achieve optimal operation. However, owing to the fact that the variables of DCS are in different orders of magnitude and there is a vast gap between the variables, it is not easy to perform arithmetic. In this paper, the DCS model based on the per-unit value form is formulated to develop a many-objectives operational strategy that is solved by the linear weighting method. And a multiple-attribute decision-making method is taken to get the optimal operating strategy. The simulation results are discussed for an existing cooling system with 619-node and 614-branch to illustrate that the model based on the per-unit value form can obtain satisfactory optimization results and a significant reduction in time consumption.

Impact of the Brink-Axel hypothesis on unique first-forbidden β-transitions for r-process nuclei* *J.-U. Nabi is supported by the Higher Education Commission Pakistan through Project (0-15394/NRPU/R&D/HEC/2021)

Key nuclear inputs for the astrophysical r-process simulations are the weak interaction rates. Consequently, the accuracy of these inputs directly affects the reliability of nucleosynthesis modeling. The majority of the stellar rates, used in simulation studies are calculated by invoking the Brink-Axel (BA) hypothesis. The BA hypothesis assumes that the strength functions of all parent excited states are the same as for the ground state, only shifted in energies. However, the BA hypothesis has to be tested against microscopically calculated state-by-state rates. In this project, we study the impact of the BA hypothesis on calculated stellar -decay and electron capture rates. Our investigation include both unique first forbidden (U1F) and allowed transitions for 106 neutron-rich trans-iron nuclei ([27, 77] ≤ [Z, A] ≤ [82, 208]). The calculations were performed using the deformed proton-neutron quasiparticle random-phase approximation (pn-QRPA) model with a simple plus quadrupole separable and schematic interaction. Waiting-point and several key r-process nuclei lie within the considered mass region of the nuclear chart. We computed electron capture and -decay rates using two different prescriptions for strength functions. One was based on invoking the BA hypothesis and the other was the state-by-state calculation of strength functions, under stellar density and temperature conditions ([10, 1] ≤ [ ( ), T( )] ≤ [1011, 30]). Our results show that the BA hypothesis invoked U1F rates are overestimated by 4–5 orders of magnitude as compared to microscopic rates. For capture rates, more than two orders of magnitude differences were noted when applying the BA hypothesis. It was concluded that the BA hypothesis is not a reliable approximation, especially for -decay forbidden transitions.

Development and Validation of a Segregated Conjugate Heat Transfer Procedure on a sCO2 Dry Gas Seal Test Bench

Abstract Carbondioxide at supercritical state shows particularly favorable thermodynamic properties for closed-loop Brayton and Rankine cycles. High density, close to a liquid, and low viscosity, close to a gas, drive to achieve higher energy conversion efficiency with smaller size turbines and components. Since minimizing the sCO2 leakage flows drives to a further increasing of overall efficiency, dry gas seals (DGS) are considered as a key enabling technology for achieving this purpose and for achieving a carbon footprint in line with the increasingly stringent targets. DGSs are gas-lubricated, mechanical, noncontacting, end-face seals, consisting of a mating (rotating) ring and a primary (stationary) ring. The operating equilibrium clearance of the seal is determined by the balance of opening dynamic forces, mainly depending on angular velocity and grooves shape, and closing forces caused by pressure gradients and spring force. Due to high rotational speeds, typical small size sealing gaps (order of magnitude of Micron), high fluid pressure and density, the heat generated by friction through the seal has a large impact on the temperature distribution, therefore a thermal design is needed to stay below the seal allowable temperature; this requirement has been even amplified in the last years with the DGS application to hot turbomachinery. Nowadays, numerical conjugate heat transfer (CHT) analysis is a good industrial practice to quantify the thermal distribution in turbomachinery components. On the other hand, due to different order of magnitude of secondary flows cavity sizes and DGS seal gaps, simulating the whole fluid domain with three-dimensional (3D) computational fluid dynamic (CFD) calculation could drive to prohibitive computational costs. In this regard, this paper presents a fast numerical iterative procedure based on a commercial one-dimensional flow network modeler (altair flow simulator), with real gas effects included, coupled with a commercial finite element solver (ansys mechanical). Additional 3D CFD simulations are carried out to enhance the predictability of the fluid solver in specific critical areas. The proposed procedure is applied and validated in a DGS specific test bench designed, owned and operated by Flowserve. The validation dataset has been generated operating the DGS in the test bench at 15 different conditions in terms of angular velocity and housing temperature with sCO2 as working fluid aligned with those expected on the unit. Test rig consists of a rotor and housing where the turbomachine operating condition (pressure, speed, temperature and sealing fluid) are mirrored to verify the seal performance. The rig is equipped with test seal and a plug seal mounted in a back-to-back configuration. Data set used for this comparison is composed by thermocouples on the statoric rings, retainers and housing of each seal, operating at five different angular speeds and three minimum levels of housing temperature (100 °C, 210 °C, and 250 °C). These temperatures are designed to mirror turbomachinery conditions around the seal, and, if friction heat is not enough to guarantee them, a series of 18x1 kW heating elements circumferentially distributed in the test bench housing, are activated. The nominal operating condition has been considered as the starting point of the model predictions and, there, several sensitivity analyses have been carried out to align the model to test bench measurements; then, the selected configuration has been frozen and used to assess the model performance on other operating conditions. The numerical results have shown a good agreement with experimental data at each operating condition in terms of punctual temperatures previously described and with extremely low computational times.

Design of nonlinear control method for pressure of pintle solid rocket motor

A pressure control method that incorporates parameter adaptation has been devised for the pressure control system of pintle solid rocket motors, which exhibit notable nonlinearities and uncertainties in parameters. Firstly, the mathematical relationship between pressure and pintle displacement is derived using the zero-dimensional interior ballistic model., and the state space equation is deduced by incorporating the dynamics of motor inertia load. Secondly, by capitalizing on the robustness of robust control, the parameter identification capabilities of adaptive control, and the rigor of Lyapunov stability theory, the proposed approach enables precise control of the pintle position while effectively addressing uncertainties, thereby enhancing the overall performance and stability of the system. Finally, the aforementioned theoretical framework has been validated through rigorous numerical simulations. The findings demonstrate a notable enhancement in the pressure response speed of the adaptive robust controller, with improvements of 10.01 % and 13.16 %, 0.03 % and 1.54 %, 0.06 % and 22.39 % in different orders of magnitude of free volume as compared to the robust controller and PID controller, respectively. Moreover, it is evident that the adaptive robust controller relies on the accuracy of the model. The applied controller demonstrates notable advantages in terms of stability, robustness, and accuracy, thereby substantially enhancing the overall performance of the pressure control system.

Equal-order finite element method for the Stokes equations with variable viscosity

In this brief note, we extend the initial investigation proposed in John et al. (2016) to study the Stokes equations with variable viscosity considering a stabilized finite element scheme based on equal order polynomials for approximating the velocity and the pressure. We establish optimal a priori error estimates for this new stabilized scheme, which are further confirmed by numerical tests. Moreover, these tests show a weak viscosity dependence in the error bounds for different orders of magnitude between νmax and νmin.

Applying recurrent neural networks to predict the work function of metal adatom adsorption on graphene

The barrier height has a large impact on the performance of transistors, lasers, and solar cells. To tune such a barrier height, a bidirectional long short-term memory network (LSTM) model is proposed to predict the work function of adsorbed metal atoms on graphene. The largest relative errors predicted by the proposed model compared to those obtained from first-principles calculations are less than 10 %. However, more than one order of magnitude difference in field-emission currents can be caused by such errors according to calculations. It implies that the proposed model can be used to quickly screen surface structures with its work function being around a target work function before performing first-principles calculations. Thus, it can save a lot of computing costs and time costs. The selected adsorbed metal atoms at different sites on graphene can be implemented to improve the performance of graphene-based devices by using the proposed method.PACS numbers85.30.De, 85.30.Tv, 73.40.Kp.