Momentum Principle Research Articles

The Mini Blast Furnace Process: An Efficient Reactor for Green Pig Iron Production Using Charcoal and Hydrogen-Rich Gas: A Study of Cases

The mini blast furnace process is an efficient route to produce pig iron based on the burden with granulated charcoal. New, improved technologies have recently been introduced in the mini blast furnace process, such as pulverized charcoal and gas injections, new burden materials, and peripheral devices that improve the overall process efficiency. In this paper, we revise the new injection possibilities and discuss new aspects for further developments. The analysis is carried out with a comprehensive multiphase multicomponent mathematical model using mass, momentum, and energy conservation principles coupled with the rate equations for chemical reactions, multiphase momentum, and heat exchanges. We analyze new technological possibilities for the enhancement of this process as follows: (i) a base case of pulverized charcoal injection with industrial data comparison; (ii) a set of scenarios with raceway injections, combining pulverized charcoal with hydrogen-rich fuel gas, replacing granular charcoal in the burden; (iii) a set of scenarios with hydrogen-rich gas injection at the shaft level, replacing reducing gas in the granular zone of the reactor; and the possible combination of both methodologies. The simulated scenarios showed that a considerable decrease in granular charcoal consumption in the burden materials could be replaced by combining a pulverized charcoal injection of 150 kg/tHM and increasing rich gas injections and oxygen enrichment values, decreasing the specific blast injection and granular charcoal. The productivity of the mini blast furnace process was increased for all scenarios compared with the reference case. We review the aspects of these operational conditions and present an outlook for improvements on the process efficiency.

A novel linear elastic constitutive model for continuum-kinematics-inspired peridynamics

Javili et al. recently reported a continuum-kinematics-inspired peridynamic model, in which theoretical aspects regarding the balance of linear and angular momentum and other conservation principles are considered. However, the analytical formulation of the model constants and the microelastic potential energy functions and numerical implementation were not defined. In this paper, a novel linear elastic constitutive model is proposed for the continuum-kinematics-inspired peridynamics by introducing specific expressions for various interaction potentials. The one-neighbor interaction potential equivalent to conventional bond-based interaction potential is utilized to account for the constitutive relationship within line elements between two material points. In contrast, the two- and three-neighbor interaction potentials are employed to consider the areal and volumetric effects under general mechanical loads. Three relevant material parameters are introduced and derived from energy equivalence to a classical linear elastic continuum mechanics model. Equipped with the three types of interaction potentials, the novel continuum-kinematics-inspired peridynamics is extended from classical bond-based peridynamics, wherein the two interaction force vectors within a bond are unequal and not parallel to the bond direction, can be regarded as an alternative version of non-ordinary state-based peridynamics. The proposed model is numerically demonstrated to be effective in absolutely eliminating the restriction of the fixed Poisson’s ratio in classical bond-based peridynamics, notably improving the effectiveness of the other enriched bond-based peridynamics in reproducing the elastic deformation of solids subjected to heterogeneous deformation fields and completely removing the numerical oscillations in non-ordinary state-based peridynamics.

Impact of charged polarizable core on mobility of a soft particle embedded in a hydrogel medium

Electrophoresis of a soft particle with a charged polarizable core is analyzed theoretically. The soft particle is embedded in an uncharged hydrogel medium. The hydrodynamics in both the gel medium and the soft layer encapsulating the hard core are governed by the Darcy-Brinkman model. We have considered the numerical model based on the conservation principle of mass, momentum, and ion flux, leading to a coupled set of partial differential equations. A simplified approach under the weak field and low charge density consideration is also proposed. The subtle nonlinear effects arising due to the polarization and relaxation of the double layer and the convective transport of counterions induced by the immobile charge of soft layer are elucidated. These nonlinear effects have negligible impact when the bulk ionic concentration becomes high. The simplified model under the weak field consideration is independent of the core dielectric permittivity. However, the numerical model shows a strong dependence on core permittivity when the applied electric field is moderate. We have also addressed the ion partitioning effect when the dielectric permittivity of the soft layer is different from the gel medium. This creates a counterion saturation in the soft layer, and hence an augmentation in the electrophoresis.

Hydrodynamic effects on the overall adsorption rate of phenol on activated carbon cloth through the advection-diffusion model application

In this work, a mathematical formulation based on fundamental principles of momentum and mass transport with a kinetic adsorption model at the liquid-solid interface is proposed. This formulation was numerically solved and used for the interpretation of adsorption rate data of phenol onto an activated carbon cloth in a stirred tank adsorber under different agitation rates. The mathematical model solution was compared with the obtained by mathematical models that neglect the local velocity and concentration profiles in the solution; external mass transfer model (EMTM) and the first-order kinetic model (FOM). The results showed that under all studied stirring speeds (30−200rpm) the proposed model was able to capture the dynamics of the concentration decay curves, while EMTM and FOM models were only able to interpret the data at high stirring speeds, indicating that velocity profiles play an important role during phenol adsorption. Particular “wake zones” were identified behind the mobile adsorbent, which importantly promotes the transport of solute toward the activated carbon cloth. As a result, it was found that convective transport is much more important than diffusive transport in the solution.

A Survey of Orbital Angular Momentum in Wireless Communication

Electromagnetic vortices are introduced into wireless communication to improve spectral efficiency and anti-interference capability. In this paper, the basic principle and characteristics of Orbital Angular Momentum (OAM) and electromagnetic eddy are introduced firstly. The principle of generating Orbital Angular Momentum from supersurface is given, and the methods and research status of generating orbital angular momentum based on supersurface are summarized. The transmission performance, receiving and detecting method, multiplexing and demultiplexing performance of orbital angular momentum are summarized. Finally, the key problems to be solved in the future application of wireless communication orbital angular momentum are discussed.

Pumping flow model for couple stress fluids with a propagative membrane contraction

A pumping flow model induced by propagative and non-propagative wall contraction is presented to examine the pumping and flow characteristics. A couple stress fluid model is considered to see the effect of couple stress parameter. An inelastic single membrane is used in upper wall of the channel with rhythmic contraction to produce unidirectional flow which can be applied in many physiological transports. Governing equations are derived using basic conservation principles of mass and momentum. Furthermore scaling analysis is made to introduce the lubrication theory (typical length scale δ=(H/λ)≪1 and low Reynolds number approximation). The influence of the couple stress parameter, propagative shape membrane, and the time variation on axial velocity, volumetric flow rate, local shear stress, pressure gradient, and streamline distribution are evaluated with aid of in-house code in Matlab. The significant stagnation line in the flow streamline with the membrane parameter is computed where the pressure gradient is zero. This study is relevant in the simulation of fluid dynamics of duodenum and intestine and other physiological systems. Novel smart biomimetic pumping devices are relatively easy to engineer using this pumping mechanism.

A Novel Boat Shock Vibration Control using Momentum Exchange Principle with Pre-Straining Spring Mechanism

This research proposes a new method for boat impact vibration attenuation using the exchange of momentum principle with a pre-straining spring mechanism. The boat dynamic is modeled using a hinged-supported beam structure. The wave excitation on the boat hull is expressed using one degree of freedom spring-mass system. The simulation study is performed to evaluate the impact damper performance in reducing the boat shock response. Two kinds of momentum exchange impact damper i.e., without and with pre-straining spring mechanism, are evaluated. The simulation results show that the impact damper with pre-straining spring mechanism (PSMEID) is better than the passive momentum exchange impact damper (PMEID) in reducing the boat shock vibration response

A Framework for Modeling Flood Depth Using a Hybrid of Hydraulics and Machine Learning

Solving river engineering problems typically requires river flow characterization, including the prediction of flow depth, flow velocity, and flood extent. Hydraulic models use governing equations of the flow in motion (conservation of mass and momentum principles) to predict the flow characteristics. However, solving such equations can be substantially expensive, depending upon their spatial extension. Moreover, modeling two- or three-dimensional river flows with high-resolution topographic data for large-scale regions (national or continental scale) is next to impossible. Such simulations are required for comprehensive river modeling, where a system of connected rivers is to be simulated simultaneously. Machine Learning (ML) approaches have shown promise for different water resources problems, and they have demonstrated an ability to learn from current data to predict new scenarios, which can enhance the understanding of the systems. The aim of this paper is to present an efficient flood simulation framework that can be applied to large-scale simulations. The framework outlines a novel, quick, efficient and versatile model to identify flooded areas and the flood depth, using a hybrid of hydraulic model and ML measures. To accomplish that, a two-dimensional hydraulic model (iRIC), calibrated by measured water surface elevation data, was used to train two ML models to predict river depth over the domain for an arbitrary discharge. The first ML model included a random forest (RF) classification model, which was used to identify wet or dry nodes over the domain. The second was a multilayer perceptron (MLP) model that was developed and trained by the iRIC simulation results, in order to estimate river depth in wet nodes. For the test data the overall accuracy of 98.5 percent was achieved for the RF classification. The regression coefficient for the MLP model for depth was 0.88. The framework outlined in this paper can be used to couple hydraulics and ML models to reduce the computation time, resources and expenses of large-scale, real-time simulations, specifically for two- or three-dimensional hydraulic modeling, where traditional hydraulic models are infeasible or prohibitively expensive.

Value and Momentum in Anomalies

We document value and momentum across thirteen well-known stock market anomalies. We find anomalies that have performed well in the past month continue to outperform those that have performed poorly by about 60bp per month. These results hold for both relative momentum and absolute momentum across the anomalies. Similarly, we investigate future abnormal returns when anomalies exhibit a value or growth orientation with respect to historical levels. We find anomalies that exhibit a value orientation outperform anomalies that exhibit a growth orientation going forward by about 30bp per month. Furthermore, we find favorable anomalies based on combined momentum and value principles outperform unfavorable anomalies by about 90 bp per month. Our findings further corroborate the hypothesis that mispricing is an important source of anomaly profits.

Dynamics of a sliding‐rocking block considering impact with an adjacent wall

SummaryA freestanding rigid block subjected to base excitation can exhibit complicated motion described by five response modes: rest, pure rocking, pure sliding, combined sliding‐rocking, and free flight. Previous studies on the dynamics of a rocking block have assumed that the block does not interact with neighboring objects. However, there are many applications in which the block may start or come in contact with an adjacent boundary during its motion, for example, a bookcase or cabinet colliding with a partition wall in an earthquake. This paper investigates the dynamics of a sliding‐rocking block considering impact with an adjacent wall. A model is developed in which the base and wall are assumed rigid, and impact is treated using the classical impulse and momentum principle. The model is verified by comparing its predictions in numerical simulations against those of an existing general‐purpose rigid‐body model in which impact is treated using a viscoelastic impact model. The developed model is used to investigate the effects of different parameters on the stability of a block subjected to analytical pulse excitations. It is found that wall placement (left or right) has a dominant effect on the shape of the overturning acceleration spectra for pulse excitations. In general, decreasing the gap distance, base friction coefficient, and wall coefficient of restitution enhance the stability of the block. Similar observations are made when evaluating the overturning probability of a block using earthquake floor motions.

Blast-off simulation sebagai alternatif media pembelajaran siswa dalam mempelajari mekanika gerak roket berbasis matlab

Blast-off or rocket launcher is a physics phenomena about mechanical of motion specially momentum principal. Unlike other flying objects like blimps and airplanes, blass-off uses the principle of changing momentum as a driving force to able fly in the air. The definition of force is a rate of changing momentum, the definition is illustrated by first-order differential equation which can be solved analytically or numerically. Unfortunately, during class learning, the equation is only used to solve collision problems instead of being used to explain blast-off phenomena which is very interesting to learn mostly. Moreover, if the explanation in the class uses visual media such as Graphic User Interface (GUI). Blast-off simulation is designed from the solving of the first differential numerically, and then the algorithm is compiled using Matlab aplication with an output in the form of a GUI so students become more interested in learning momentum and learning effectiveness will be incrised.

Improved Desalination Pipeline System Utilizing the Temperature Difference under Sub-Atmospheric Pressure

Based on the principles of mass conservation, momentum, and energy, an improved version of the Desalination pipeline called Improved Desalination Pipeline System (IDPS) has been studied in the present paper. The main features of IDPS are the high transfer rate and the high raw water production rate. IDPS works with the help of thermal gradient generated due to the temperature difference between the seaside/destination. Heat injection has also been used to increase the efficiency of IDPS. In the condensation part, the heat pipe concept is adopted to facilitate the vapor-liquid process. The main portion of heat injected to the IDPS is recovered by generating electrical power using water flow due to available water head. To show the efficiency of IDPS, a case study is performed from Bandar Abbas (seaside) to Mount GNU (the destination) located30 km away with 2347 m height. The results show that IDPS does not necessarily require large diameter pipes for greater efficiencies. The energy consumption for distillation and transferring1 m3 of water is about 6.6 Kwh. In addition to the distilled transferred water, a significant amount of water is distilled on the site, which is about 25% of the transferred water.

Mathematical Modeling for Flood Mitigation: Effect of Bifurcation Angles in River Flowrates

This paper investigates the river flowrate at two branches of bifurcated river. The mathematical model from the literature is formulated based on momentum principle and mass continuity to cope with river flowrate at different bifurcation angles. The hydraulic variables, geometric properties of trapezoidal cross-sectional river and other physical characteristics of bifurcated river are provided, which may be assumed to be given beforehand for practical applications. An example of river bifurcation problem is given by UTM Centre for Industrial and Applied Mathematics (UTM-CIAM), Universiti Teknologi Malaysia. Maple software is used to implement the proposed model equation and generate the results. The amount of bifurcated river flowrate with different bifurcation angles is determined, resulting in a reasonable discussion. It is shown that for specific bifurcation angles, the river flowrates after the bifurcated junction are less than the critical flowrate. Finally, the results of applied problem indicate that the right-angled river bifurcation would be preferable to mitigate flood.

Peristalsis of carbon nanotubes with radiative heat flux

The purpose of this analysis is to highlight the CNTs characteristics in peristaltic flows through non-uniform channels. Viscosity is considered temperature in this analysis. Peristaltic walls comprise the momentum and thermal slip effects. Radiative heat flux is also taken into account to study the thermal radiation aspects. Physical properties for CNTS (i.e. single and multiple wall) are used which was suggested by Iijima. Flow equations are modeled in view of mass, momentum and energy conservation principles. Moreover, such equations are simplified through lubrication assumptions. Solution for flow quantities is carried out in the form of exact solution. Numerical integration technique is used for pressure rise per wavelength plotting. Bar charts are made for effective heat transfer rate analysis.

Transverse photon spin of bulk electromagnetic waves in bianisotropic media

Photons possess spin degree of freedom, which plays an important role in various applications such as optical communications, information processing and sensing. In isotropic media, photon spin is aligned with the propagation direction of light, obeying the principle of spin momentum locking. Interestingly, surface waves decaying away from an interface have a photon spin transverse to its propagation, opening exciting opportunities for the observation of spin-dependent excitation in confined systems. Here, we propose and realize transverse photon spin (T-spin) in a bulk medium, without relying on the presence of any interfaces. We show the mapping of the T-spin of surface modes to that of the bulk modes by introducing bianisotropy into the medium. We further discover that the interface between two bianisotropic media of opposite orientations supports edge-dependent propagating modes with tunable cutoff frequencies. Our results provide a new platform for manipulating the spin–orbit interaction of electromagnetic waves. A method to map the known tranverse photon spin of electromagnetic surface waves over to bulk modes is enabled thanks to bianisotropy.

Optimizing basket transplanting parameters using the mechanical properties of tomato plug seedlings

The collision between tomato plug seedlings and the planting device during basket transplanter function causes the seedlings’ root lump to lose some mass. To resolve this problem, we establish a contact mechanics model using Hertzian contact theoretical and Newtonian methods, enabling us to formally derive the maximum deformation of the root lump. The equation of motion describing the collision between the tomato plug seedling and planting device is constructed using the principles of impulse and momentum. Then, we identify the optimization function of contact angle θ—which consists of the maximum deformation of the root lump, the angular velocity of the tomato plug seedling, and the absolute velocity of the root lump—via multi-objective methods. When the angular velocity of the planting device is 1.05 rad/s or 1.15 rad/s, the optimal contact angle is 67°. Further, we examine the velocity of the tomato plug seedling after collision. A small plant height reduces the root lump’s mass loss; we found that 12-cm-tall tomato plug seedlings lose less root lump mass than taller seedlings. Finally, for angular velocities of 1.05 rad/s and 1.15 rad/s, we carry out of tomato plug seedling crush tests with the optimized parameters, achieving minimum root lump mass losses of 8.76% and 7.43%, respectively.

Quantum vacuum torque on a bi-anisotropic absorbing magneto-dielectric cylindrical shell co-axis with a perfectly conductor cylindrical shell

A fully canonical quantization of electromagnetic field in the presence of a bi-anisotropic absorbing magneto-dielectric cylindrical shell is provided. The mode expansions of the dynamical quantum fields, contained in the theory, is achieved and the ladder operators of the system are introduced. Using the Frobenius’s series technique, the Maxwell’s equations in the presence of the bi-anisotropic absorbing magneto-dielectric cylindrical shell are solved and the space–time dependence of the quantized electromagnetic field is obtained. Applying the conservation principle of the angular momentum, the net quantum vacuum torque exerted on the bi-anisotropic absorbing magneto-dielectric cylindrical shell is calculated. The net quantum vacuum torque exerted on the cylindrical shell is calculated in the vacuum state and the thermal state of the system. The quantum vacuum torque on the cylindrical shell identically vanishes when the bi-anisotropic absorbing magneto-dielectric cylindrical shell is converted to an isotropic one.

Machine learning in cardiovascular flows modeling: Predicting arterial blood pressure from non-invasive 4D flow MRI data using physics-informed neural networks

Advances in computational science offer a principled pipeline for predictive modeling of cardiovascular flows and aspire to provide a valuable tool for monitoring, diagnostics and surgical planning. Such models can be nowadays deployed on large patient-specific topologies of systemic arterial networks and return detailed predictions on flow patterns, wall shear stresses, and pulse wave propagation. However, their success heavily relies on tedious pre-processing and calibration procedures that typically induce a significant computational cost, thus hampering their clinical applicability. In this work we put forth a machine learning framework that enables the seamless synthesis of non-invasive in-vivo measurement techniques and computational flow dynamics models derived from first physical principles. We illustrate this new paradigm by showing how one-dimensional models of pulsatile flow can be used to constrain the output of deep neural networks such that their predictions satisfy the conservation of mass and momentum principles. Once trained on noisy and scattered clinical data of flow and wall displacement, these networks can return physically consistent predictions for velocity, pressure and wall displacement pulse wave propagation, all without the need to employ conventional simulators. A simple post-processing of these outputs can also provide a relatively cheap and effective way for estimating Windkessel model parameters that are required for the calibration of traditional computational models. The effectiveness of the proposed techniques is demonstrated through a series of prototype benchmarks, as well as a realistic clinical case involving in-vivo measurements near the aorta/carotid bifurcation of a healthy human subject.

Non-ideal behavior of a treadmill depends on gait phase, speed, and weight

Noticeable differences exist between treadmill and overground walking; kinematics, kinetics, and muscle activation patterns differ between the two. Many previous studies have attributed the differences to changes in visual information, air resistance, and psychological effects such as fear. In this study, we demonstrate that no treadmill serves as an inertial frame of reference. Considering the linear momentum principle, the finite sampling rate of the controller, and the limited power of the treadmill motor, we predict that 1) the error of the treadmill speed periodically varies depending on the locomotion phase and 2) this non-ideal behavior becomes more evident as the locomotion speed or the weight of the walker increases. Experimental observation confirmed our predictions by quantifying the variation of the actual treadmill belt speed and the ground reaction force in the anterior–posterior direction for different locomotion speeds and subject weights. These results emphasize a need for design criteria like the minimum sampling rate and the minimum motor power that treadmill locomotion studies should consider.

Variational Calculus Approach to Optimal Interception Task of a Ballistic Missile in 1D and 2D Cases

The paper presents the application of variational calculus to achieve the optimal design of the open-loop control law in the process of anti-ballistic missile interception task. It presents the analytical results in the form of appropriate Euler–Lagrange equations for three different performance indices, with a simple model of the rocket and the missile, based on the conservation of momentum principle. It also presents the software program enabling rapid simulation of the interception process with selected parameters, parametric analysis, as well as easy potential modification by other researchers, as it is written in open code as m-function of Matlab.