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Science education at the junior high school level requires an approach that maximally develops students' science process skills (SPS). One way to achieve this is by utilizing interactive learning media, such as virtual laboratories, combined with an inquiry-based learning model. This study aims to determine the effect of implementing an inquiry-based virtual laboratory on improving students' SPS. The method used in this study is pre-experimental with a one-group pretest-posttest design. The subjects in this study were 32 students from class VIII D at SMP Negeri 4 Yogyakarta. Data collection was carried out by administering a pretest before treatment and a posttest after treatment. The data obtained were analyzed using paired t-test and N-Gain test. The paired t-test results showed a significance value (2-tailed) = (0.00) < 0.05, indicating the effect of the treatment on students' SPS. The N-Gain result was 0.73 in the high category, so it can be concluded that applying virtual laboratory media with the inquiry-based learning model in the inclined plane topic can enhance students' SPS in science subjects.

Musicians who play wind instruments have been rehabilitated with complete dentures and often feel discomfort while playing their instruments. The difficulty arises during treatment planning owing to the intense physiological demands imposed on the oral and perioral structures, notably the facial muscles when a wind musician blows. Embouchure dentures are designed for their carrier purpose, primarily to suit the functional needs of the orofacial muscles, ensuring that there is no dislodgment of the dentures during the blowing of wind instruments. An embouchure denture for a 50-year-old male patient is developed in this case report with a system of inclined planes in the posterior tooth region and a pair of magnets to repel the retentive trait. A properly constructed embouchure denture can help the musician continue their career, along with functional rehabilitation. This case report aims to describe the process of fabricating a specially engineered prosthesis for a completely edentulous wind instrument player, “the embouchure denture, magnet assisted.”

This scientific paper presents original research and the authors personal views on the technical-economic and practical acceptance of pulley and inclined plane applications in transport engineering. Engineering specialists appreciate that the active type experiment carried out by practical determinations leads to concrete, important results in the field addressed. In order to demonstrate theoretically and practically what the specialists say, we have made a small-scale laboratory model in which we have experimented with situations similar to those encountered in real life. In this way, we have presented the front end of pulley systems used for lifting or towing damaged or damaged vehicles (motor vehicles) on trailer trailers, which are common in transport engineering. In this way, those interested can learn how these applications can be used in the laboratory but also in real life, the advantages and concrete results obtained when applied. Other experiments and applications of the laboratory mock-up are specified in the paper, in which the results, their usefulness, real-life applicability, how certain measuring instruments are used, the units of measurement and their conversions, as well as how to calculate the voltages occurring in lifting/pulling cables with pulleys are presented. The scale model can be successfully used in the laboratories of art and craft schools, high schools or colleges. In this way pupils or students can acquire practical knowledge in car knowledge or road vehicle dynamics laboratories. At the end of the work, conclusions in the field covered and further research directions are presented.

Musicians who play wind instruments have been rehabilitated with complete dentures and often feel discomfort while playing their instruments. The difficulty arises during treatment planning owing to the intense physiological demands imposed on the oral and perioral structures, notably the facial muscles when a wind musician blows. Embouchure dentures are designed for their carrier purpose, primarily to suit the functional needs of the orofacial muscles, ensuring that there is no dislodgment of the dentures during the blowing of wind instruments. An embouchure denture for a 50-year-old male patient is developed in this case report with a system of inclined planes in the posterior tooth region and a pair of magnets to repel the retentive trait. A properly constructed embouchure denture can help the musician continue their career, along with functional rehabilitation. This case report aims to describe the process of fabricating a specially engineered prosthesis for a completely edentulous wind instrument player, "the embouchure denture, magnet assisted." [ABSTRACT FROM AUTHOR]

This study examines the impact of the transfer of mass and heat characteristics on the magnetohydrodynamic natural convection travel over a slanted surface in an impermeable, electrically conductive fluid. The equations that govern can be transformed into standard differential equations through the use of nondimensional quantities, which can subsequently be solved through the ordinary perturbation method. Equations for temperature, concentration, and velocity were produced by using this method. Furthermore, MATLAB-generated graphics were used to analyse and illustrate the effects of several parameters on acceleration, concentration and temperature, including the Schmidt number, thermal Grashof, singular Grashof number and angle of inclination. [ABSTRACT FROM AUTHOR]

This scientific paper presents original research and the authors personal views on the technical-economic and practical acceptance of pulley and inclined plane applications in transport engineering. Engineering specialists appreciate that the active type experiment carried out by practical determinations leads to concrete, important results in the field addressed. In order to demonstrate theoretically and practically what the specialists say, we have made a small-scale laboratory model in which we have experimented with situations similar to those encountered in real life. In this way, we have presented the front end of pulley systems used for lifting or towing damaged or damaged vehicles (motor vehicles) on trailer trailers, which are common in transport engineering. In this way, those interested can learn how these applications can be used in the laboratory but also in real life, the advantages and concrete results obtained when applied. Other experiments and applications of the laboratory mock-up are specified in the paper, in which the results, their usefulness, real-life applicability, how certain measuring instruments are used, the units of measurement and their conversions, as well as how to calculate the voltages occurring in lifting/pulling cables with pulleys are presented. The scale model can be successfully used in the laboratories of art and craft schools, high schools or colleges. In this way pupils or students can acquire practical knowledge in car knowledge or road vehicle dynamics laboratories. At the end of the work, conclusions in the field covered and further research directions are presented. [ABSTRACT FROM AUTHOR]

A transportation system requires an asymmetry to achieve objects' motion on an oscillating surface. Transportation methods based on vibrational techniques usually employ different types of asymmetries, such as temporal (time) asymmetry, kinematic asymmetry, wave asymmetry or power asymmetry. However, transporting an object on an inclined angle requires a relatively high net frictional force over each period of vibrational cycles due to the gravitational potential energy exerted on the object. This paper investigates the transportation of an object upward on an inclined plane that harmonically oscillates in its longitudinal direction. The novelty of this research is attributed to the upward motion of the object on the inclined plane, which is achieved by creating an additional asymmetry of the system through dry friction dynamic manipulations. For this reason, periodic dynamic dry friction manipulations have been employed to create the asymmetry of frictional conditions, resulting in a net frictional force that outweighs the gravitational force. A mathematical model has been developed using the Lagrange method, which describes the moving object's motion. Moreover, the theoretical findings and results confirmed that the object's velocity and direction can be controlled by dynamic dry friction manipulations. To demonstrate the technical feasibility of the proposed method, an experimental investigation was carried out where the results demonstrated that the control parameters significantly influence the characteristics of the directional motion of the moving object. This transportation method is beneficial for various modern industries engaged in transportation and manipulation tasks with objects spanning a broad range of sizes, including those operating at small scales for applications in lab-on-a-chip technology, micro-assembly lines, micro-feeder systems and other delicate component manipulation systems. The presented research advances the classical theories of vibrational transportation on inclined surfaces. [ABSTRACT FROM AUTHOR]

A transportation system requires an asymmetry to achieve objects’ motion on an oscillating surface. Transportation methods based on vibrational techniques usually employ different types of asymmetries, such as temporal (time) asymmetry, kinematic asymmetry, wave asymmetry or power asymmetry. However, transporting an object on an inclined angle requires a relatively high net frictional force over each period of vibrational cycles due to the gravitational potential energy exerted on the object. This paper investigates the transportation of an object upward on an inclined plane that harmonically oscillates in its longitudinal direction. The novelty of this research is attributed to the upward motion of the object on the inclined plane, which is achieved by creating an additional asymmetry of the system through dry friction dynamic manipulations. For this reason, periodic dynamic dry friction manipulations have been employed to create the asymmetry of frictional conditions, resulting in a net frictional force that outweighs the gravitational force. A mathematical model has been developed using the Lagrange method, which describes the moving object’s motion. Moreover, the theoretical findings and results confirmed that the object’s velocity and direction can be controlled by dynamic dry friction manipulations. To demonstrate the technical feasibility of the proposed method, an experimental investigation was carried out where the results demonstrated that the control parameters significantly influence the characteristics of the directional motion of the moving object. This transportation method is beneficial for various modern industries engaged in transportation and manipulation tasks with objects spanning a broad range of sizes, including those operating at small scales for applications in lab-on-a-chip technology, micro-assembly lines, micro-feeder systems and other delicate component manipulation systems. The presented research advances the classical theories of vibrational transportation on inclined surfaces.

We study the effects of odd viscosity on the stability of a thin Newtonian liquid film flowing down a nonuniformly heated plane under a slip boundary condition. The effect of odd viscosity arises in classical fluids when the time-reversal symmetry breaks down. Due to the odd viscosity, the odd part of the Cauchy stress tensor consists of symmetric and antisymmetric parts and shows several striking effects. We apply the Navier slip boundary condition for the slippery inclined plane at the solid-liquid interface. For our problem, we first derive an evolution equation whose solution describes the film thickness. The equation contains parameters considering the effect of inertia, thermocapillarity, slip length, and odd viscosity. We then perform the linear stability analysis and find that odd viscosity can significantly suppress the combined destabilizing effects of the thermocapillarity and slip length. Next, we analyze the dynamics using the weakly nonlinear approach, which provides details of different subregions of the instability zone. We observe that as the influence of the odd viscosity increases, the supercritical stable and explosive zones shrink while the unconditional stable and subcritical unstable zones expand. We also perform numerical investigation and observe that linear analysis, weakly nonlinear theory, and numerical results are consistent. [ABSTRACT FROM AUTHOR]

In the present analysis, we discussed the influence of heat and mass transfer on the hydro-magnetic peristaltic flow of a Casson fluid in a rotating inclined system through an asymmetric channel. The model governing equations are obtained, simplified by applying long wavelength and assumptions of low Reynolds number, and then addressed analytically. DSolve command of Mathematica software was used to solve these equations. The numerical results regarding the impacts of embedded parameters on axial velocity, secondary velocity, stream function, temperature, concentration, and streamline patterns are graphed and explained. It has been discovered that velocity slip reduces the size of the trapped bolus while the permeability parameter increases it. The velocity and temperature profiles decrease as the Casson fluid parameter and magnetic field strength increase. In the fields of biomedical engineering and crude oil refinement, the current problem is quite significant. The trapping phenomenon for different parameters is presented. The visual discussion of numerical results for various values of relevant physical parameters. The current work, which focuses on electromagnetic peristaltic pumps, offers several applications in biomedical engineering.

Multi-phase flows, encountered in nature or in industry, exhibit non-trivial rheological properties, which we attempt to better understand thanks to model materials and appropriate rheometers. Unsaturated wet granular flows down a rough inclined plane turn out to be steady and uniform for a wide range of parameters, despite the cohesion and the grain aggregates. The cohesive Mohr–Coulomb yield criterion extended to inertial granular flows, with a cohesion stress dependent on the liquid content and an internal friction coefficient dependent on the inertial number, allows for predictions in good agreement with our experimental measurements, when one introduces a grain aggregate size, which defines the appropriate length and relaxation time scales in the inertial number. We found that the grain aggregate size depends not monotonically on the liquid content and does not scale with the cohesion length induced by the cohesion stress, due to the non-trivial distribution of the liquid within the granular material. [ABSTRACT FROM AUTHOR]

In the present analysis, we discussed the influence of heat and mass transfer on the hydro-magnetic peristaltic flow of a Casson fluid in a rotating inclined system through an asymmetric channel. The model governing equations are obtained, simplified by applying long wavelength and assumptions of low Reynolds number, and then addressed analytically. DSolve command of Mathematica software was used to solve these equations. The numerical results regarding the impacts of embedded parameters on axial velocity, secondary velocity, stream function, temperature, concentration, and streamline patterns are graphed and explained. It has been discovered that velocity slip reduces the size of the trapped bolus while the permeability parameter increases it. The velocity and temperature profiles decrease as the Casson fluid parameter and magnetic field strength increase. In the fields of biomedical engineering and crude oil refinement, the current problem is quite significant. The trapping phenomenon for different parameters is presented. The visual discussion of numerical results for various values of relevant physical parameters. The current work, which focuses on electromagnetic peristaltic pumps, offers several applications in biomedical engineering. [ABSTRACT FROM AUTHOR]

A simple two-body model of a limbless crawler moving on an inclined rough plane is considered. The bodies are regarded as point masses. The system is controlled by the force of interaction of the bodies. Coulomb's friction force acts between the underlying plane and each of the bodies. The controllability of the crawler is investigated. It is proved that if no constraints are imposed on the control force, then the system can be driven from any initial state of rest on the plane into an arbitrarily small neighborhood of any prescribed terminal state of rest, provided that at the initial time instant the bodies do not lie on the common line of maximum slope. A control strategy that alternates infinitely slow (quasistatic) and infinitely fast motions is defined. It is important that the plane is inclined; on the horizontal plane, the two-body crawler is uncontrollable. [ABSTRACT FROM AUTHOR]

An analysis is presented for the stability of a viscous liquid film flowing down an inclined plane with respect to three-dimensional disturbances under the action of gravity and surface tension. Using momentum-integral method, the nonlinear free surface evolution equation is derived by introducing the self-similar semiparabolic velocity profiles along the flow (x - and y -axis) directions. A normal mode technique and the method of multiple scales are used to obtain the theoretical (linear and nonlinear stability) results of this flow problem, which conceive the physical parameters: Reynolds number R e , Weber number W e , angle of inclination of the plane θ and the angle of propagation of the interfacial disturbances ϕ. The temporal growth rate ω i + and second Landau constant J 2 , based on which various (explosive, supercritical, unconditional, subcritical) stability zones of this flow problem are categorized, contain the shape factors B and β owing to the non-zero steady basic flow along the y -axis direction. A novel result which emerges from the linear stability analysis is that for any given value of R e , W e and θ , any stability that arises in two-dimensional disturbances (ϕ = 0) must also be present in three-dimensional disturbances. For ϕ = 0, there exists a second explosive unstable zone (instead of unconditional stable zone) after a certain value of R e (or θ) due to the involvement of B and β in the expression of J 2. This explosive unstable zone vanishes after a certain value of ϕ depending upon the values of R e , W e and θ , which confirms the stabilizing influence of ϕ on the thin film flow dynamics irrespective of the values of R e , W e and θ. • Steady basic solution. • Three-dimensional waves. • Linear stability. • Weakly nonlinear tability. [ABSTRACT FROM AUTHOR]

In physics, several problems are solved by considering the extended object as being a particle with all the mass concentrated in the center of mass and neglected dimensions, however for rotating and rolling objects this approximation will result in a serious disagreement between theory and experimentation. In this work we present an experimental assembly of a sliding body on an inclined plane, which can measure its position as a function of time and thus predict its velocity and acceleration. In addition to basic kinematics, the moment of inertia of rotating bodies will be considered. We will use bodies with different shapes and moments of inertia, experimentally identifying their contribution along the displacement. We propose the construction and use of an experimental apparatus using Arduino, collecting a large number of points, in which it is possible to analyze the temporal displacement of the center of mass of the object along the inclined plane with different angles, cylindrical and spherical objects, identifying the discrepancy when disregarding the moment of inertia of the rotating bodies. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Polonorum: Architectura is the property of Wydawnictwo SGGW and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents aspects of how an exoskeleton assists disabled people to walk on an inclined plane. This study is carried out with the help of the dynamic modelling software for mobile mechanical systems, ADAMS. Variation laws of kinematic parameters of interest, such as rotation angles in knee and hip kinematic couplings, and connecting forces in kinematic couplings are presented. The next stage in the development of this research is the realization of the experimental prototype using 3D printing technology. For this purpose, in the last part of the work we performed a structural optimization using ANSYS software for a kinematic element of the exoskeleton structure. The results obtained allow us to validate the virtual model and give us the certainty of the functionality of the robotic system for assisting human subjects when walking on an inclined plane. [ABSTRACT FROM AUTHOR]

[Display omitted] The shape of the "freezing tip" formed by the crystallization of water droplets demonstrated remarkable universality - no dependence on the cooling rate and physico-chemical properties of the substrate has been observed. At the same time, the spatial orientation of the freezing cone may be varied. We hypothesized that the orientation of the freezing tip is determined by the direction of heat flux at the base of the sessile droplet. This direction is expected to be changed when the substrate with a low thermal diffusivity is not cooled uniformly. We studied the freezing of water droplets placed on the inclined surface of wedges made from a variety of materials (polymers: Polymethylmethacrylate, Polytetrafluoroethylene, Polyurethane and metal: Titanium), which were cooled from below. The shape of the frozen droplets was controlled in situ. The computational model was suggested for the transient temperature field in the polymer wedge to determine a time variation of the local heat flux under the droplets. A comparison of numerical results and the measurements enabled us to confirm the aforementioned hypothesis relating the orientation of the freezing tips to the direction of the heat flux. It was established that the orientation of the freezing cone axis depends on the location of the frozen droplet on the inclined surface of the wedge. Calculations of the transient temperature field of the wedge confirmed our hypothesis about the physical reason of the various spatial orientations of the freezing cones. [ABSTRACT FROM AUTHOR]

This work presents an alternative method of teaching undergraduate introductory physics laboratory. Students are presented with an experimental scenario "Rolling object on an inclined plane" and guided to develop their own laboratory activities in a studio-style setting. The overall goal of this alternative approach is to shift part of the learning responsibility to students. Through guided self-developed activities, students establish the connections between different physics concepts. Such a shift makes students active participants in the classroom, allows them to explore ideas independently, and discover through doing the exploring. Furthermore, the pedagogy is aimed at (i) motivating and actively engaging students in the learning process, (ii) helping students learn how to think independently, (iii) developing scientific ideas, and (iv) taking ownership of the learning process. Assessment of data from a 3-year pilot study showed improvement in students' technical writing skills (30%), creative lab and research skills (6%), as well as critical thinking and quantitative skills (6%). In addition, students who participated in the study scored higher (6%) than their control group counterparts on the final exam. Other benefits are improvement in understanding of the research process and laboratory technical skills. [ABSTRACT FROM AUTHOR]

Analogous to the Amonton–Coulomb relation, which states the linear dependency between the dynamic sliding friction and the normal reaction, the rolling friction moment is commonly accepted as proportional to the normal reaction in a concentrated point contact. This hypothesis persists since it gives simple dynamic models and also due to difficulties met in experimental estimations of the rolling friction torques. Recent theoretical studies proved that this dependency is nonlinear even for elastic materials. A special rotor is designed, with an adjustable position for the center of mass but with constant mass and constant axial inertia moment. The pure rolling motion of the rotor on an inclined controlled small slope is studied. The angular acceleration of motion is theoretically deduced, assuming that the rolling friction torque is proportional to the normal force raised at a certain power. The deduced theoretical dynamic model evidences the influence of the eccentricity of the rotor upon the acceleration. For the particular case of linear dependency—the exponent of the power equal to one, the law of motion is independent of the configuration of the rotor. Experimental tests were made using the rotor constructed according to the theoretical model. For two positions of the center of mass, the experimental law of motion on the inclined plane is established by a non-contact method and the two different laws obtained to validate the nonlinear dependence rolling friction torque-normal force. The paper validates in an experimental manner the considered nonlinear assumption. The experimental tests concerning the microtopography of the contacting surfaces reveal that the hypothesis required by Hertzian theory, namely smooth contacting surfaces, is not satisfied. Thus, the distribution of pressure on the contact area does not obey the Hertzian semi-ellipsoidal distribution and further experimental tests are required for quantitative findings on the rolling friction torque-normal force relationship. [ABSTRACT FROM AUTHOR]

Featured Application: An insight into the possible influence of the nonuniform normal stress distribution in the inclined plane test, by comparing the results with an unconventional direct shear device, working with increasing shear load rather than controlled displacement. The evaluation of geosynthetic interface friction is a key parameter for the stability of coupled geosynthetics, as in landfill capping liner. At the present time, few types of tests are suitable for measuring the interface friction at low normal stress: one of these is the inclined plane, usually carried out under a vertical stress of 5 kPa. This type of test is not without critical aspects, mainly due to the nonuniform normal stress state induced by the inclination of the plane, but, on the other hand, the most widespread direct shear test generally cannot be performed at such low values of normal stress. After a short discussion on the pros and cons of these two types of test, the paper presents a comparison of the interface friction angles obtained, for three interfaces, by means of an inclined plane and an unconventional direct shear apparatus, under the same low normal stress. The peculiarity of this latter device is of ensuring a gradual increase of the mobilized strength, in a way similar to what occurs during the inclined plane test. The good correspondence of the results of the two types of tests confirmed the validity of both the test approaches. [ABSTRACT FROM AUTHOR]

This paper investigates the effects of thermal radiation and variable viscosity flow down along an inclined plane with boundary conditions at free surface. The major problem includes internal heat generation, increase or decrease in temperature, and other thermophysical properties. The thermophysical properties include Grashof number, Nusselt number, Viscosity and Solar radiation parameter. The problems created have not been examined. Thus, this work examined the effect of temperature and velocity profiles on the various values of coefficient of viscosity, also the effects of solar radiation parameter on the major property of the fluid flow down along an inclined plane. The partial differential equations for the problem are continuity, momentum and energy equations. These are nonlinear dimensionless equations governing the fluid flow down the inclined plane using integration method. The equations for the fluid flow, temperature and velocity of the problem are reduced to their final forms using perturbation method. Analytical expressions are employed to obtain the value of the velocity and temperature profiles in terms of parameters under the considerations in the flow field. The parameters are the major factors influencing the properties of the fluid flow down along an inclined plane. Hence, the viscosity of the fluid increases as the velocity of the fluid decreases while increase in the solar radiation parameter increases velocity of the fluid. Also the quantities of radiant energy absorbed by the fluid flow bring changes in the temperature of the fluid. Increase in Nusselt decreases the velocity of the fluid. Grashof number increases while the temperature of the fluid decreases. In conclusion, viscosity of the fluid decreases with an increase in temperature due to cohesion and molecular momentum exchange between fluid layer and the parameters are found to have a significant effect over the velocity and temperature profiles of the fluid flow down an inclined plane at free surface. It will also useful for the 13 industries in the production of the various fluids (liquid or gas) such as vegetable oil, palm oil and steam generation along an inclined plane and so on.

In an increasingly data-oriented science, the use of automatic computational methods is progressively indispensable. In this context, it becomes important to expose undergraduate physics students to artificial intelligence and machine learning methodologies. In this work we propose a way to use such methods in physics, solving the didactic problem of rolling on an inclined plane. We introduce the main concepts of machine learning techiniques and measure the travel time of different objects (rim, disk and sphere) for an initial height and tilt angle. Based on these data, we used classification models capable of predicting the object that was dropped with an accuracy of 83%, and regression models which were able to predict the average speed of the object that was rolled with mean absolute error of 1.4 cms-1. We also show that this didactic model is instructive because it allows a direct comparison with physical models and serves as a discussion of the meaning of teaching physics to the computer. [ABSTRACT FROM AUTHOR]

Rolling with the slipping of an infinite elastic cylinder with a horizontal axis in the gravity field on a flat surface made of the same material is considered. The angle between the nondeformed boundary of the surface and the horizon is nonzero. Based on solution of the corresponding contact problem in Carter's quasi-static formulation, the reaction of the flat surface in dynamic equations is determined. It is shown that if the tangent of the inclination angle does not exceed the product of the friction coefficient and the coefficient that depends on the elastic properties of the material and the mass distribution, motion with constant relative slip δ and a constant acceleration of the center of mass is possible; there is a region in the contact area where the materials stick together. This motion is found to be asymptotically stable with respect to δ. The dependence of the cylinder-axis acceleration on the mechanical properties of the material and the friction coefficient is examined. The results obtained are compared with those of the classical problem of rigid-disk motion along an inclined straight line. [ABSTRACT FROM AUTHOR]

The paper is concerned with the dynamics of advancing liquid blobs of fluid on curved and flat solid surfaces, such as cycloids and inclined planes. We investigate the kinematics of such blobs on hydrophobic surfaces with emphasis on the shape of the interface as the fluid advances. A theoretical model is proposed that captures the shape of the interface at early times. Also, the trajectory of the fluid, as it detaches from the cycloid, is investigated and compared with theoretical predictions. We find a good qualitative agreement between predictions and experimental data. As an extension of the present findings, we also investigate the shape and the dynamics of advancing drops on cycloids, placed in a viscous outer immiscible liquid. We find both similarities, in terms of kinematics, and specific differences in the shape of the advancing drop.

Analysis of intrinsic irreversibility and heat transfer in a buoyancy-driven changeable viscosity liquid along an incline heated wall with convective cooling taking into consideration the heated isothermal and isoflux wall is investigated. By Newton’s law of cooling, we assumed the free surface exchange heat with environment and fluid viscosity is exponentially dependent on temperature. Appropriate governing model equations for momentum and energy balance with volumetric entropy generation expression are obtained and then transformed using dimensionless variables to form set of nonlinear boundary valued problem. Using shooting method with Runge-Kutta-Fehlberg integration scheme, the model is numerically tackled. Pertinent results for the fluid velocity, temperature, skin friction, Nusselt number, entropy generation rate and Bejan number are obtained and discussed.

The dynamics and stability of thin liquid films have fascinated scientists over many decades. Thin film flows occur over a wide range of length scales and are central to numerous areas of engineering, geophysics and biophysics. These include nanofluidics and microfluidics, lava flows, coating flows, tear-film rupture, dynamics of continental ice sheets and surfactant replacement therapy. Study of falling film instability has its wide applications in the practical field of industry and engineering. Practical applications in industrial processing motivate the recent research to investigate the factors which may affect the formation of waves on the surface of the coating layers and/or to determine the ways to overcome or to minimize the unwanted factors within the desired limit of tolerance. The dynamics of a liquid film flowing down a plane under the action of gravity is a problem which appears in many technological and natural systems, namely large scale geophysical environments such as lava flows or spillways, daily life scenarios such as water flowing down a window pane or a slippery road on a rainy day, chemical engineering processes such as evaporators, heat exchanges and falling film reactors or surface coating. The aim of this paper is to throw light on the studies conducted on hydrodynamical stability.

Twin block appliance is mostly for correction of class II malocclusion part with mandibular skeletal retrusion. This appliance uses the force of occlusion of teeth, the most natural functional mechanism to initiate bone remodelling process for functional correction of malocclusion. [ABSTRACT FROM AUTHOR]

The major focus of this research is to discuss the precise results of the unstable, indirect and natural free convection flow of radiating fluid with heat and the analysis of its collective transmission along with an inclined plane. The subsequent liquid is optically thick, sticky and is unable to be compressed and further it is prone to electrical conducting. Analytical solutions are developed by applying the method of Laplace transform for the governing differential equations. The obtained results are discussed minutely for some special cases and further the effects of the related parameters are considered in detail. Rosseland radiational flux model is employed in order to model the impacts of the thermal radiation. For this purpose, graphical and numerical results are derived for the appropriate parameters in flow regime and these parameters exert significant impact on the obtained results. [ABSTRACT FROM AUTHOR]

The paper focuses on the evaluation of the shear strength in conditions of low normal stress of various geosynthetic-geosynthetic interfaces, which are typical of landfill cover systems, by means of the inclined plane test, with the aim of studying the friction mobilisation in relation to various kinematic behaviours. The results of three different methods to evaluate the angle of friction were analysed, together with the sensitivity of the interfaces in relation to the wear effect and the influence of the state of hydration. The results showed very different responses of the interfaces to the shear stress, which involved three main types of sliding mechanisms, referred to as sudden, gradual and uneven sliding. Another outcome observed was that the shear strength of geosynthetic-geosynthetic interfaces cannot always be properly characterised following the procedure proposed by the European standard for soil-geosynthetic interfaces (EN ISO 12957–2), since the actual mobilised kinematic behaviour should be taken into consideration. In this regard, the paper provides some hints on the choice of the more representative parameter of friction for each type of sliding. A particular focus was given to the case of gradual sliding interfaces, for which the static friction is difficult to detect due to the very slow movements; for practical purposes, the design friction of these interfaces should be evaluated by using an adequate safety factor with respect to the friction evaluated at 1 mm of displacement. • The paper offers a comparison of the results of three different methods to evaluate the angle of interface friction at low normal stress by means of the inclined plane test for various interfaces, considering alsowearing and hydration state. • The research highlights the response of the interfaces to the shear stress may be very different, involving various sliding mechanisms. • These kinematics cannot be revealed by the common direct shear test, in which the speed is imposed by the apparatus. From this point of view, the inclined plane device allows increasing stress state rather than imposed strain rate. • The results show that the shear strength of geosynthetic-geosynthetic interfaces cannot be correctly characterised if the real sliding kinematics is not taken into consideration. • The paper provides some hints on the choice of the more representative parameter of friction, for design purposes, according to the various interface behaviours. [ABSTRACT FROM AUTHOR]

Differential equations of material particle movement on an inclined rough plane, which performs oscillatory motion in such a way that its every point describes a circle in the same plane, have been deduced. Peculiarities of relative particle movement on a plane depending on the angle of its inclination to the horizon have been investigated. The equations have been solved using numerical methods. Relative velocities have been found and particle motion trajectories have been constructed. Kinematic characteristics of relative particle movement depending on the angle of plane inclination, angular velocity, the coefficient of particle friction on a plane and the radius of circular motion of plane points have been determined.

Copyright of Annals of Warsaw University of Life Sciences - SGGW, Forestry & Wood Technology is the property of Wydawnictwo SGGW and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigates how the shear rate can affect the geomembrane – protective geotextile friction angle. Four types of geomembranes (GMB) were considered (EPDM, HPDE, PP, and PVC) and a single nonwoven needle-punched geotextile (GTX nw) was used to make the interfaces with the geomembrane. Three shear devices were used: a large-scale inclined plane (IP), a shear box (SB), and a small-scale shear device (ssSD). The ssSD allows two shear modes to be compared: one mode involves incrementally increasing the shear stress, and the other involves imposing a constant tangential velocity at the interface. Only the PP GMB- GTX nw was tested with the SB and the ssSD. Inclined plane standardised tests show that for the three interfaces that undergoes gradual sliding (EPDM, PP and PVC GMB- GTX nw), it is shown that a step-by-step experimental procedure gives significantly lower interface friction angle than that given by the procedure from the current international standard, which is explained by the increase of interface shear stress with sliding speed. These observations are confirmed by shear box tests. One major practical result is that, following the nature of geosynthetics, the shear rate applied in large-scale shear box tests should be adapted to assess a safety value of a geosynthetic - geosynthetic interface friction angle. [ABSTRACT FROM AUTHOR]

The aim of this article is to study the natural convection boundary-layer flow over a semi-infinite heated plate with arbitrary inclination. Existing solutions of similar models can be recovered as the limiting cases of horizontal and vertical plates from our generalized problem. Moreover, porous effects and the influence of transverse magnetic field; fixed to the fluid or the plate are accounted. The dimensionless velocity, in conjunction with the corresponding skin friction, have been presented as the sum of mechanical, thermal and concentration components. Furthermore, the contribution of the system parameters to the fluid motion in question has been depicted graphically. The novelty of the present study is to analyze the effect of angle of inclination of the plate and the case when the magnetic field is fixed relative to the fluid or to the plate on the fluid motion. [ABSTRACT FROM AUTHOR]

The evaluation of geosynthetic interface friction is a key parameter for the stability of coupled geosynthetics, as in landfill capping liner. At the present time, few types of tests are suitable for measuring the interface friction at low normal stress: one of these is the inclined plane, usually carried out under a vertical stress of 5 kPa. This type of test is not without critical aspects, mainly due to the nonuniform normal stress state induced by the inclination of the plane, but, on the other hand, the most widespread direct shear test generally cannot be performed at such low values of normal stress. After a short discussion on the pros and cons of these two types of test, the paper presents a comparison of the interface friction angles obtained, for three interfaces, by means of an inclined plane and an unconventional direct shear apparatus, under the same low normal stress. The peculiarity of this latter device is of ensuring a gradual increase of the mobilized strength, in a way similar to what occurs during the inclined plane test. The good correspondence of the results of the two types of tests confirmed the validity of both the test approaches.

This paper investigates the effects of thermal radiation and variable viscosity flow down along an inclined plane with boundary conditions at free surface. The major problem includes internal heat generation, increase or decrease in temperature, and other thermo physical properties. The thermo physical properties include Grashf number, Nusselt number, Viscosity and Solar radiation parameter. The problems created have not been examined. Thus, this work examined the effect of temperature and velocity profiles on the various values of coefficient of viscosity, also the effects of solar radiation parameter on the major property of the fluid flow down along an inclined plane. The partial differential equations for the problem are continuity, momentum and energy equations. These are non- linear dimensionless equations governing the fluid flow down the inclined plane using integration method. The equations for the fluid flow, temperature and velocity of the problem are reduced to their final forms using perturbation method. Analytical expressions are employed to obtain the value of the velocity and temperature profiles in terms of parameters under the considerations in the flow field. The parameters are the major factors influencing the properties of the fluid flow down along an inclined plane. Hence, the viscosity of the fluid increases as the velocity of the fluid decreases while increase in the solar radiation parameter increases velocity of the fluid. Also the quantities of radiant energy absorbed by the fluid flow bring changes in the temperature of the fluid. Increase in Nusselt decreases the velocity of the fluid. Grashof number increases while the temperature of the fluid also decreases. In conclusion, viscosity of the fluid decreases with an increase in temperature due to cohesion and molecular momentum exchange between fluid layer and the parameters are found to have a significant effect over the velocity and temperature profiles of the fluid flow down an inclined plane at free surface. It will also useful for the industries in the production of the various fluids (liquid or gas) such as vegetable oil, palm oil and steam generation along an inclined plane and so on.

The flow of fractional Jeffrey fluid due to time-dependent motion of plate has been investigated. An inclined plate is considered, and thermal effects with mass diffusivity in flow are also taken into account. The set of governing equations is operated by integral transform namely Laplace transform technique. Caputo–Fabrizio time-fractional derivative is considered in energy and diffusion equations. Moreover, exact analytical solutions are achieved. In the limiting cases, the general solutions for accelerating and oscillating motion of Jeffrey fluid are obtained. Effects of involved physical parameters, fractional parameter α , inclination of plate θ , Prandtl number Pr and Schmidt number Sc on the flow, are graphically detected. [ABSTRACT FROM AUTHOR]

The paper is concerned with the dynamics of advancing liquid blobs of fluid on curved and flat solid surfaces, such as cycloids and inclined planes. We investigate the kinematics of such blobs on hydrophobic surfaces with emphasis on the shape of the interface as the fluid advances. A theoretical model is proposed that captures the shape of the interface at early times. Also, the trajectory of the fluid, as it detaches from the cycloid, is investigated and compared with theoretical predictions. We find a good qualitative agreement between predictions and experimental data. As an extension of the present findings, we also investigate the shape and the dynamics of advancing drops on cycloids, placed in a viscous outer immiscible liquid. We find both similarities, in terms of kinematics, and specific differences in the shape of the advancing drop. [ABSTRACT FROM AUTHOR]

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This article analyzes the 'Hay inclined plane' designed by the English engineer and entrepreneur William Reynolds and put into operation in 1792 to facilitate the transport of vessels between channels at different levels using an inclined plane. To this end, a study of computer-aided engineering (CAE) was carried out using the parametric software Autodesk Inventor Professional, consisting of a static analysis using the finite-element method (FEM) of the 3D model of the invention under real operating conditions. The results obtained after subjecting the mechanism to the two most unfavorable situations (blockage situation of the inertia flywheel and emergency braking situation) indicate that, with the exception of the braking bar, the rest of the assembly is perfectly designed and dimensioned. In particular, for the blockage situation, the point with the greatest stress is at the junction between the inertia flywheel and the axle to which it is attached, the maximum value of von Mises stress being at that point (186.9 MPa) lower than the elastic limit of the cast iron. Also, at this point the deformation is very low (0.13% of its length), as well as the maximum displacement that takes place in the inertia flywheel itself (22.98 mm), and the lowest safety factor has a value of 3.51 (located on the wooden shaft support), which indicates that the mechanism is clearly oversized. On the other hand, the emergency braking situation, which is technically impossible with a manual operation, indicates that the braking bar supports a maximum von Mises stress of 1025 MPa, above the elastic limit of the material, so it would break. However, other than that element, the rest of the elements have lower stresses, with a maximum value of 390.7 MPa, and with safety factors higher than 1.7, which indicates that the mechanism was well dimensioned. [ABSTRACT FROM AUTHOR]

Fillet end milling is widely used in mould, aerospace, shipping manufacture and other fields. As one of the important parameter in milling machining, milling force is related to machining efficiency and quality, as well as tool wear, but it is difficult to predict. Aiming at fillet end milling under a pre-determined inclination angle, considering cutter run-out, this paper presents a cutting force coefficients identification model related to chip thickness and axial position angle, and then achieve milling force prediction. A parametric relationship among feed direction, cutter axis and to-be-machined surface are established, and then, the analytic expression of previous swept surface, to-be-machined surface and cutter envelope surface is derived. Boundary curves of cutter workpiece engagement (CWE) are established based on spatial surface intersection analytically. The criterion of the cutter edge element involved in cutting is proposed. Judging element along the cutter edge one by one, whereafter the algorithm of in-cut-cutting edge (ICCE) is proposed. Combining mechanical force model with chip thickness considering feed direction and cutter run-out, a milling force prediction model is established. Based on the method of undetermined coefficients, combining average instantaneous measured force, coefficients corresponding to axial position angle and chip thickness are solved. Further instantaneous peak measured force is used to obtain cutter run-out parameters. Simulation and experiments show that CWE agrees well with that of experiment and ICCE is consistent well with that of simulation. Milling force experiments of different machining parameters show the milling force coefficients and run-out parameters can be applied to fillet end milling under pre-determined inclination angle well. [ABSTRACT FROM AUTHOR]

Key points: It is known that interception of targets accelerated by gravity involves internal models coupled with visual signals.Non‐visual signals related to head and body orientation relative to gravity may also contribute, although their role is poorly understood.In a novel experiment, we asked pitched observers to hit a virtual target approaching with an acceleration that was either coherent or incoherent with their pitch‐tilt.Initially, the timing errors were large and independent of the coherence between target acceleration and observer's pitch. With practice, however, the timing errors became substantially smaller in the coherent conditions.The results show that information about head and body orientation can contribute to modelling the effects of gravity on a moving target. Orientation cues from vestibular and somatosensory signals might be integrated with visual signals in the vestibular cortex, where the internal model of gravity is assumed to be encoded. Interception of moving targets relies on visual signals and internal models. Less is known about the additional contribution of non‐visual cues about head and body orientation relative to gravity. We took advantage of Galileo's law of motion along an incline to demonstrate the effects of vestibular and somatosensory cues about head and body orientation on interception timing. Participants were asked to hit a ball rolling in a gutter towards the eyes, resulting in image expansion. The scene was presented in a head‐mounted display, without any visual information about gravity direction. In separate blocks of trials participants were pitched backwards by 20° or 60°, whereas ball acceleration was randomized across trials so as to be compatible with rolling down a slope of 20° or 60°. Initially, the timing errors were large, independently of the coherence between ball acceleration and pitch angle, consistent with responses based exclusively on visual information because visual stimuli were identical at both tilts. At the end of the experiment, however, the timing errors were systematically smaller in the coherent conditions than the incoherent ones. Moreover, the responses were significantly (P = 0.007) earlier when participants were pitched by 60° than when they were pitched by 20°. Therefore, practice with the task led to incorporation of information about head and body orientation relative to gravity for response timing. Instead, posture did not affect response timing in a control experiment in which participants hit a static target in synchrony with the last of a predictable series of stationary audiovisual stimuli. Key points: It is known that interception of targets accelerated by gravity involves internal models coupled with visual signals.Non‐visual signals related to head and body orientation relative to gravity may also contribute, although their role is poorly understood.In a novel experiment, we asked pitched observers to hit a virtual target approaching with an acceleration that was either coherent or incoherent with their pitch‐tilt.Initially, the timing errors were large and independent of the coherence between target acceleration and observer's pitch. With practice, however, the timing errors became substantially smaller in the coherent conditions.The results show that information about head and body orientation can contribute to modelling the effects of gravity on a moving target. Orientation cues from vestibular and somatosensory signals might be integrated with visual signals in the vestibular cortex, where the internal model of gravity is assumed to be encoded. [ABSTRACT FROM AUTHOR]

Abstract The influence of transverse mechanical vibrations on dense flows of granular material down inclines with a rough bed is analyzed using 3D DEM simulations and compared with experimental results. The vibrations make appear two distinct behaviors: a gravity-driven regime and a vibration-driven regime. In the gravity-driven regime, our results are consistent with previous studies from the literature. The vibrations induce particles velocity fluctuations in the vibration-driven regime, which generate a granular temperature profile along the depth of the packing related to the velocity profile. The velocity profile is consistent with a creeping flow which makes appear a critical length scale related to a nonlocal rheology. Our results suggest that this length scale emerges from the characteristic damping length of transverse vibration waves which propagate in the bulk of the granular material. These results could be of interest for the optimization of powders conveying. Graphical ABSTRACT Unlabelled Image Highlights • Vibrations allow the transport of granular materials to be tuned. • Vibrations allow possible flows below the angle of avalanche. • Vibrations induce a nonlocal rheology related to a characteristic length. • This characteristic length depends on the acceleration of the vibrations. [ABSTRACT FROM AUTHOR]

Abstract The stability of shear-thinning fluid down an inclined plane is investigated theoretically with application to process engineering (coating process) and natural hazards as well (debris flow impact). The power-law model is used to describe the fluid rheological behavior. A linear stability analysis is brought out for building a generalized Orr-Sommerfeld model with appropriate definition of non-dimensional numbers in order to overcome the inconsistency of the existing shallow-water models. The solution to the secular equation showed that at zeroth order, there is no instability with respect to the long wave perturbations considered. Waves propagate without dispersion, at the same dimensional speed for any wavenumber. Moreover, the interface and the stream function are in phase, while the components of the perturbation velocities are respectively in phase and in quadrature of phase. Finally, the perturbation celerity decreases for increasing power law index, with a value of 2 as minimum for the Newtonian fluid. At first order, the effect of the different forces acting on the flow has been pointed out. It was particularly shown that pressure and surface tension have a stabilizing effect, while inertia and rheofluidification have a destabilizing effect. Moreover, the relative variation of critical Reynolds number increases with increasing reduced wavenumber for all values of slope tested while it decreases with increasing power-law index for all values of reduced wavenumber tested. Highlights • A generalized Orr-Sommerfeld equation was built and solved by a perturbation method. • Order zero: waves propagate without dispersion at the same speed for any wavenumber. • Perturbation celerity decreases for increasing power law index, with 2 as minimum. • Order one: the celerity correction only affects its growth rate but not its value. • Effects of all forces acting on flow stability have been respectively characterized. [ABSTRACT FROM AUTHOR]