Restriction Operators Research Articles

Development and application of lateral flow strip with three test lines for detection of deoxynivalenol in wheat.

Lateral flow strip was widely used and their qualitative and quantitative performance was in continuous improvement. However, the traditional strip was in a single-test-line format, which restricted operators to making a semi-quantitative judgment around a desired threshold concentration. Herein, a single strip with three test lines (TTLS) was developed for the semi-quantitative and quantitative determination of deoxynivalenol (DON). Four visual detection thresholds were obtained under optimized conditions and 35 wheat samples with DON content from 45µg/kg to 2841µg/kg were used to verify the method. The detection results were compared with that of the traditional strip and UPLC-MS/MS. In a three-test-line format, TTLS could reveal at least 200, 500, 1000, and 2000µg/kg DON existed in different samples by the naked eye. The agreement analysis and statistical results indicated the new TTLS can be used as a useful tool for quantitative detection of DON with wide dynamic range.

V2O5 supported on NbTiOx: A novel NH3-SCR catalyst with high performance induced by V-Nb-Ti interaction

The traditional vanadia-based catalysts frequently employed for selective catalytic reduction of NOx with NH3 (NH3-SCR) have been criticized for their restricted operating temperature window and subpar low-temperature activity. In the present work, a series of NbTiOx solid solutions were used as supports to prepare V/NbxTi1-x (1.0 wt% V2O5) catalysts. The novel 1V/Nb0.15Ti0.85 catalyst presented superior catalytic performance and excellent resistance to SO2 in the SCR reaction, reaching above 95% NOx conversion in a wide temperature range from 270 to 485 °C. In comparison to pure TiO2, Nb-Ti-O solid solution support exhibited different pore structures and pore sizes, contributing to much larger specific surface area. Meanwhile, the surface Nb-OH and Nb = O bonds could serve as new acid sites to facilitate more NH3 adsorption. More importantly, there was a strong redox-acid interaction (V-Nb-Ti) for 1V/Nb0.15Ti0.85 catalyst, which induced the formation of highly redox-active V sites and promoted the activation of adsorbed ammonia, facilitating the NH3-SCR reaction. Unlike 1V/Ti, NOx species adsorbed on 1V/Nb0.15Ti0.85 participated in NH3-SCR reaction below 250 °C, further promoting the low-temperature activity. This study provides a novel vanadium-based catalyst with a low vanadium loading and high SCR activity for practical NOx abatement.

Effect of Laparoscopic Sleeve Gastrectomy on Serum Adipokine Levels.

Bariatric procedures are considered to be the most effective treatment options for obesity. One of them is laparoscopic sleeve gastrectomy (LSG), which is nowadays very popular and widely used. LSG leads to weight loss and metabolic improvement and also changes adipokine levels, although it is just a restrictive operation. We describe changes in pro-inflammatory (leptin, resistin, visfatin and chemerin) and anti-inflammatory adipokines (adiponectin, omentin), with adiponectin and leptin being most studied. Their levels are markedly changed after LSG and this may partially explain the weight loss seen after LSG. Adipokines are closely connected to insulin resistance and chronic inflammation both being positively influenced after LSG. Leptin regulates amount of body fat, appetite, thermogenesis and metabolic rate and its levels are positively correlated with both weight and BMI changes after operation. Resistin influences insulin sensitivity, modulates body cholesterol trafficking and its changes after operation correlate with BMI, waist circumference, fat mass, LDL cholesterol and C-reactive protein. Chemerin, an important component of immune system, decreases after bariatric surgery and its levels correlate with BMI, triglyceride levels, and blood glucose. On the other hand, pro-inflammatory adipokine adiponectin, which influences fatty acid oxidation, browning of fat tissue and energy metabolism, is declining after LSG. This decline explains improvement of glucose status after bariatric surgery in patients with diabetes and is correlated with BMI loss, waist circumference and LDL cholesterol level. Effect of LSG goes beyond calory restriction and the changes of adipokines have a great impact on health status of the bariatric patients.

Factorization in Fourier restriction theory and near extremizers

AbstractIn Fourier restriction theory, abstract so‐called Maurey–Nikishin–Pisier factorization has often been used as a convenient off‐the‐shelf means to prove certain factorizations of the Fourier restriction operator. We give an alternative approach to such factorizations in Fourier restriction theory. Based on an induction‐on‐scales argument, our comparably simple method applies to any compact quadratic surface, in particular compact parts of the paraboloid and the hyperbolic paraboloid. This is achieved by constructing near extremizers with big “mass,” which itself might be of interest.

Sugeno-Like Operators in Preference and Uncertain Environments

Sugeno-like operators are binary operations based generalization of Sugeno integral and are still defined on real valued fuzzy measures. This work discusses the aggregation methods in the situation where both inputs and fuzzy measures are attached with numerical uncertainties. That is, when an input vector and a fuzzy measure are given, each of the entries of the vector and the measure value on each subset can be attached with numerical uncertainty degrees. To fulfill this meaningful aim of performing Sugeno-like aggregation with numerical uncertainties, it needs two parts of work. We firstly formally define basic uncertain vector and basic uncertain fuzzy measure. Then we discuss the methods to construct or adjust basic uncertain vector and basic uncertain fuzzy measure in two situations, the general fuzzy measure situation and the probability measure only situation, respectively. With uncertain input and uncertain fuzzy measure, we then accordingly propose the corresponding restricted Sugeno-like operator, for which some different logic restrictions are analyzed. All the proposals also have full consistency for they can immediately degenerates into Sugeno-like operator when the attached uncertainties disappear.

Full-temperature all-solid-state dendrite-free Zn-ion electrochromic energy storage devices for intelligent applications

Zn-ion electrochromic energy storage devices (ZEESDs) incorporate electrochromism and energy storage into one platform that can visually indicate the working status through a real-time color change, attracting considerable attention in energy-saving buildings and intelligent electronics. However, typical ZEESDs generally consist of Zn metal electrodes and normal liquid electrolytes, resulting in the dendrite issues and restricted operating temperatures as well as inferior cycle stability. Herein, an all-solid-state dendrite-free ZEESD was constructed based on polyaniline (PANI) positive electrode, monoclinic WO3 (m-WO3) negative electrode and Zn2+-based gel electrolyte. Benefiting from the complementary synergistic effect of electrodes and electrolytes, the resultant ZEESD avoids heavy Zn metals, addresses the dendrite formation problem, and exhibits remarkable electrochromic and electrochemical performances. The prototype ZEESD possesses high energy/power density (97 Wh kg−1/976.2 W kg−1 and 28.6 μWh cm−2/0.27 mW cm−2), large optical modulation (∼52.4%@630 nm), high coloration efficiency (96.8 cm2 C−1 at 630 nm), along with outstanding cycling stability (∼94.4% capacity retention even after 6000 cycles). Impressively, the quasi-solid-state electrolyte maintained outstanding electrochemical activity enabling the ZEESD to cycle efficiently even under hash temperatures, presenting enormous potential for intelligent electronics in all-climate (−30 °C to 60 °C) conditions. This work provides a novel strategy to construct next-generation dendrite-free Zn-ion electrochromic energy storage devices for innovative consumer electronics even in harsh environments.

A three-dimensional solver for simulating detonation on curvilinear adaptive meshes

A generic solver in a parallel Cartesian adaptive mesh refinement framework is extended to simulate detonations on three-dimensional structured curvilinear meshes. A second-order accurate finite volume method is used with grid-aligned Riemann solvers for thermally perfect gas mixtures. Detailed, multi-step chemical kinetic mechanisms are employed and numerically incorporated with a splitting approach. The adaptive mesh refinement technique is applied to a mapped mesh using modified prolongation and restriction operators. The flux along the coarse-fine interface is considered in a correction procedure to ensure the conservation of the solver. The numerical accuracy, conservation and robustness of the simulations are verified and validated with suitable benchmark tests. The new solver is then used to simulate detonation problems in non-Cartesian geometries. A simulation is conducted of the three-dimensional detonation propagation in a 90-degree pipe bend. A detonation in a round tube is also simulated in a Galilean frame of reference. Both a rectangular mode and a spinning mode are observed in the simulations. In addition, the fundamental problem of detonation wave/boundary layer interaction is studied. The results show that the new solver can simulate high-speed reactive flows efficiently by the combined use of a curvilinear mapping with mesh adaptation.

A Wave Equation-Based Hybridizable Discontinuous Galerkin–Robin Transmission Condition Algorithm for Electromagnetic Problems Analyzing

In this work, a wave-equation-based discontinuous Galerkin (DG) method hybridized with the Robin transmission condition (DG-RTC) is developed to solve the frequency-domain electromagnetic (EM) problems. The proposed DG method directly discretizes the vector electric field wave equation in each subdomain, and subsequently, a term named numerical flux is introduced at the subdomain interfaces to connect the solutions between neighboring subdomains. However, the numerical flux depends not only on the electric field <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathbf {E}$ </tex-math></inline-formula> but also on the magnetic field <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathbf {H}$ </tex-math></inline-formula> residing over the interface. Thereby, another equation is essential for solving <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathbf {E}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathbf {H}$ </tex-math></inline-formula> simultaneously. Realizing that <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathbf {H}$ </tex-math></inline-formula> only situates at the interface of adjacent subdomains, it is thus desired that the auxiliary equation also merely involves <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathbf {H}$ </tex-math></inline-formula> at the interfaces. To reach this aim, at the subdomain interfaces, a Robin transmission condition (RTC) based on the tangential continuity of EM fields across the interface is introduced as the second equation. With this proposed DG-RTC algorithm, only <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathbf {E}$ </tex-math></inline-formula> is a volume variable, while <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathbf {H}$ </tex-math></inline-formula> is a two-dimensional (2-D) one, and the degrees of freedom (DoFs) are thus greatly reduced compared with the traditional DG method. On the other hand, in the frequency domain, the established subdomain matrix equations are implicitly coupled with each other, resulting in a global matrix system. Directly solving it is not yet cheap. To alleviate the computational cost, a finite-element tearing and interconnecting (FETI)-like approach resorts. With the block-diagonal preconditioner and a restriction operator, the global matrix is decomposed into a surface matrix equation and several local matrix equations pertinent to each subdomain. In this way, a direct solver can be applied to solve these small matrix equations efficiently. To validate the proposed DG method in solving various EM problems, several representative examples are presented.

A Modulation Scheme Based on Virtual Voltage Levels for Capacitor Voltage Balancing of the Four-Level Diode Clamped Converter

This paper proposes a modulation scheme based on the concept of virtual voltage levels for regulating the DC-link capacitor voltages of a four-level diode clamped converter under restricted operating conditions. The proposed virtual-level space vector modulation (VL-SVM) scheme sets the average neutral point currents to zero, which results in no net change in dc-link capacitor voltages and thereby voltage balancing. In addition, a closed-loop algorithm is developed to compensate for any voltage drift due to unideal practical conditions. Consequently, the modulation of the reference voltages results in the desired output voltages while regulating the DC-link capacitor voltages at various operating points. In the proposed modulation scheme, switching frequencies are not significantly increased, and they are lower than those in the classic virtual-vector SVM method. The simulation results demonstrate the effectiveness of the proposed modulation scheme and highlight its main benefits and features. The simulation results are verified through a laboratory-type experimental setup.

Education and Promotion of Online Transaction Services for Traditional Market Traders in Sleman: An Alternative to Alleviate the Impact of COVID-19 "Layanan Online Pasar Ing Sleman (LOPIS)"

Spreading in Special Region of Yogyakarta (DIY) since March 2020, the Covid-19 pandemic has slowed down economic activities. Activities in traditional markets decreased due to restricted operating time and people movement. Traders should use online transactions to reach potential consumers. Expanding market segments is also necessary to target the younger generation who regularly use online transactions. Unluckily, traders were not well-trained in online transactions. This activity was aimed to encourage well-implemented online transaction services by traditional market traders in Sleman Regency. Four measures were taken: 1) identifying conditions of traders, 2) formulating online transaction models for traders and potential consumers, 3) online transaction training, and 4) Disseminating/promoting online transaction services. A survey was done in 22 of 37 markets to identify market conditions. Collected data were analysed using the interactive model. Formulated online transaction model includes offer, order, payment and delivery of products. Traders in 25 markets received the training. Service marketing activities include publications on social media, data presentation of markets and traders on Google Maps page, and webinar. All activities were conducted under the tagline "LOPIS (Layanan Online Pasar Ing Sleman)", which means Online Services by Traditional Markets in Sleman Regency. Monitoring is planned for three months after the training is conducted. However, this monitoring could not be carried out due to a significant increase in Covid-19 cases, hence the limitation of this community service activity.

Covid-19 Lockdown in Ecuador: Are there Gender Differences in Unemployment?

To fight Covid-19, governments have imposed restrictions on personal mobility and social interactions which may have negative consequences in the labor market. These consequences may be different across demographic groups particularly for female workers. We examine whether the policy that restricted operations in some economic sectors affected formal employment for Ecuadorian female workers differently. We use a difference-in-differences-in-differences model to compare female employees working in restricted economic sectors with other workers, before and after the lockdown policy. The results show that the number of unemployment spells rose by approximately 15 per cent for women working in the restricted economic activities. We also document a decrease in the probability of being employed, which is particularly strong for the youngest women (15–24 years-old), oldest women (45–65 years-old), and less educated female workers. We conclude that the lockdown policy imposed in Ecuador is a plausible explanation for women’s job loss in the formal sector.

About Currency Restrictions in 2022, Introduced in Respect of Individuals

The focus of this article is the currency restrictions imposed by the Russian Federation on resident individuals in response to the deployment by foreign states and their unions of a policy of sanctions pressure on the national banking system. First, the authors identify regulatory windows and types of country sanctions: freezing of reserves and assets of the Bank of Russia, a ban for the Bank of Russia on access to the capital market and a ban on the sale, supply, transfer or export of cash euros and US dollars to Russia. Further, the domestic legal order is analyzed in terms of the introduction and operation of currency restrictions that apply to resident individuals. It is revealed that the main restrictions consisted in the forced conversion of part of foreign currency deposits, prohibitions on crediting currency to foreign accounts and providing loans to non-residents, setting thresholds for crossborder transfer of non-cash and cash funds; prohibition of electronic money transfers with the help of foreign payment service providers and transactions with persons of foreign states committing unfriendly acts or included in the sanctions list by the Government of the Russian Federation. The legality of the establishment of these currency restrictions and the practice of their application are investigated. Based on the results of the analysis, ways to improve domestic legislation are proposed.

Existence of extremizers for Fourier restriction to the moment curve

We show that the restriction and extension operators associated to the moment curve possess extremizers and that L p L^p -normalized extremizing sequences of these operators are precompact modulo symmetries.

A simplified new multigrid algorithm of lattice Boltzmann method for steady states

In the present paper, a new strategy of multigrid method is introduced to accelerate the convergence speed of numerical simulations via lattice Boltzmann method. Based on the popular V-cycle multigrid algorithm, a simplified multigrid algorithm is presented and validated through the simulations of the classic lid-driven cavity flow for steady states. The novelty of the present algorithm resides in the construction of the information transferring process, in which, for a full cycle, the numerical simulation starts on the coarse mesh, transferring to medium mesh and then streams to the fine mesh through a prolongation operator. Afterwards, instead of using a restriction operator, the fluid information jumps back directly from the fine mesh to the coarse mesh via an assignment operator. The accuracy and efficiency of the simplified new algorithm are validated by comparing the results obtained when employing the classic V-cycle multigrid algorithm and the traditional lattice Boltzmann method with uniform Cartesian grid.

A Generic Framework for Multiscale Simulation of High and Low Enthalpy Fractured Geothermal Reservoirs under Varying Thermodynamic Conditions

We develop a multiscale simulation strategy, namely, algebraic dynamic multilevel (ADM) method, for simulation of fluid flow and heat transfer in fractured geothermal reservoirs under varying thermodynamic conditions. Fractures with varying conductivities are modeled using the projection-based embedded discrete fracture model (pEDFM) in an explicit manner. The developed ADM method allows the fine-scale system to be mapped to a discrete domain with an adaptive grid resolution via the use of the restriction and prolongation operators. The developed framework is used (a) to investigate the impacts of formulations with different primary variables on the simulation results, and (b) to assess the performance of ADM in a high-enthalpy reservoir by comparing the simulation results against those obtained from fine-scale grids. Results show that the two formulations produce similar results in the case of single-phase flow, which indicates that the molar formulation is a favorable option that can be applied to varying thermodynamic conditions. Moreover, the ADM can provide accurate solutions with only a fraction of fine-scale grids, e.g., for the studied case, the maximum error is by average 1.3 with only 42% of active cells, thereby improving the computational efficiency. This is promising for applying the developed method to field-scale geothermal systems.

A NEW SOFT SET OPERATION: COMPLEMENTARY SOFT BINARY PIECEWISE GAMMA(𝜸) OPERATION

Soft set theory, introduced by Molodtsov, is as an efficacious mathematical tool to deal with uncertainty and it has been applied to many fields both as theoretical and application aspect. Since its inception, different kinds of soft set operations are defined and used in various types. In this paper, we define a new kind of soft set operation called, complementary soft binary piecewise gamma operation and we investigate its basic algebraic properties. Moreover by examing the distribution rules, it is aimed to contribute to the soft set literature by obtaining the relationships between this new soft set operation and other types of soft set operations such as extended soft set operations, complementary extended soft set operations, soft binary piecewise operations, complementary soft binary piecewise operations and restricted soft set operations. This paper can be regarded as a theoritical study of soft set theory.

Revisional surgeries after failed restrictive bariatric operations: a meta-analysis

Revisional surgeries after failed restrictive bariatric operations: a meta-analysis

ANALYSIS ON AN AUTOMOBILE BASED HYBRID ELECTRIC VEHICLE SYSTEM BASED ON VARIOUS INTERNAL COMBUSTION ENGINE

Increased environmental impact from the fast consumption of fossil fuel has provided a significant drive for the creation of more fuel-efficient automobiles. Having matured from their embryonic stage, hybrid electric vehicles (HEVs) are showing signs of being a viable solution to the critical existential threat to Earth. Higher efficiency vehicles (HEVs) not only help drivers save money on gas by getting greater mileage and producing fewer harmful emissions, but they also cushion drivers and passengers from the financial blow of steadily increasing gas costs. The electrification of powertrains is a tried-and-true response to environmentalists' worries about dependence on nonrenewable fuels and greenhouse gas emissions. Hybrid electric vehicles, which bridge the gap between conventional internal combustion engine vehicles and pure electric vehicles, are gaining market share and garnering a lot of attention from researchers in both the private and public sectors. An integral part of hybrid powertrains, the internal combustion engine affects vehicle performance significantly. There has been a lot of work done in recent years on engine technologies tailored to hybrid electric vehicles. It is crucial to study the engine's dynamic features through testing that mimic the vehicle's road running mode. The electric eddy current machine of an automotive engine test stand mimics the loading conditions of being driven on the road. Recommendations from a technological perspective all the way up to a powertrain perspective are presented in response to challenges and issues related to system complexity, restricted operating conditions, controls, cost, safety, etc. To inspire further study in this area, several potential avenues for future research are given.

A Novel Operation Optimization Method Based on Mechanism Analytics for the Quality of Molten Steel in the BOF Steelmaking Process

This paper investigates a dynamic analytics and operation optimization method for the basic oxygen furnace (BOF) steelmaking process, which is a multi-stage process. First, based on reaction kinetics, fluid dynamics and conservation of mass, that a novel discrete-time nonlinear system with process disturbance, time delay and the constrained operation input is established characterizes the dynamics of the quality (the carbon content and the temperature) of molten steel in the BOF steelmaking process. It is difficult and complicated to realize analytics and operation optimization for the BOF steelmaking process by using the established nonlinear system directly, so a surrogate-model-based discrete-time switched system with time delay and actuator saturation is given to describe the multi-stage BOF steelmaking process. Then, sufficient conditions are derived under which the stability is guaranteed and the tracking performance is achieved. The parameters of analytics-based operation optimization algorithm can be obtained by solving linear matrix inequality problems (LMIPs). Finally, the effectiveness of the proposed method is verified by a BOF steelmaking numerical experiment example. Note to Practitioners—This paper deals with the problem of dynamic analytics and operation optimization arising from the BOF steelmaking process. Based on the real-time estimation of the carbon content and the temperature of molten steel, the plan for the operation of oxygen lance and the addition of auxiliary materials is given to produce the qualified molten steel. This paper establishes a system model based on the mechanism, and the model parameters are derived from papers verified by a large amount of data to ensure the correctness of the model. In addition, actuator saturation is applied to describe the phenomenon of restricted operation variables. Through a surrogate model approximation and theoretical analysis, the parameters of dynamic analytics and operation optimization algorithm can be obtained by solving LMIPs, which is a convex optimization problem that is easy to solve. The numerical experiment results show that the proposed method can give operators some desired references.

Regular approximation of singular third-order differential operators

In this paper, regular approximation of third-order differential operators with two singular endpoints is investigated. Firstly the induced restriction operator is constructed and proved to be a self-adjoint operator in the Hilbert space. Moreover the convergence of operators and spectrum is obtained by strong resolvent convergence. In particular, norm resolvent convergence is given when the two endpoints are both limit circle.