From Magma Ocean turbulent convection to lithosphere formation and mantle convection: insights from laboratory experiments

<p>A clear understanding of the transition from a liquid magma ocean (MO) to a convective solid mantle is still lacking. Part of the problem is that there is still no clear view of all the physical phenomena at play during this crucial stage. As the MO cools down, the formation of a solid and therefore very viscous lithosphere at its surface has often been considered to trigger a new pattern of motion where convection occurs below the lithosphere which remains stagnant. However, when the liquid thermal boundary layer at the top of the MO cools down, it first becomes a mushy lithosphere through which melt and exsolved gas bubbles can still percolate to the surface. Using laboratory experiments of thermal convection in colloidal suspensions, we study the formation of this mushy lithosphere and its different regimes of deformation and coupling to mantle convection. We observe that deformation of the lithosphere can include « heat pipe » formation at high heat, melt and volatile flux. On the other hand, rapid thermal contraction of the lithosphere can cause buckling, leading to subduction. Transition from MO to solid-state convection could involve both processes in succession , or in competition, depending on the temperature and volatiles conditions. </p>

Determination of basic parameters and their boundary conditions of modern passive infrared motion detectors

The principle of work of modern passive infrared motion detectors of the known world manufacturers is considered; their peculiarities and fields of use are indicated. Both the typical structural and schematic diagrams are given. The basic parameters of modern passive infrared motion detectors and their boundary conditions have been determined based on the principle of operation of the detector and the synthetic processing of information from primary sources. The boundary conditions for the number of rays of the near middle and far zones of the pattern of motion detectors are given. Limit conditions for supply voltage, operating temperatures, and consumption currents in different operating modes are also given.

The Modern Image, II

Over the course of the modern period, a kinesthetic shift occurred in the arts from a tensional to a more elastic pattern of motion. The argument of this chapter is that meter, action art, and molecular art are also defined predominately by a distinctly elastic pattern of motion and a differential aesthetics. This chapter concludes the book’s historical analysis of the moving image and provides a material and historical foundation for interpreting the hybrid kinetic structure of contemporary arts in the next part of the book. Art history is not dead. It all returns and resurfaces in the present, forming hybrid combinations. Although their name and appearance might have changed, the same regimes are still at work today.

The Ancient Image, II

This chapter continues the thesis presented in Chapter 7, in demonstrating that a kinesthetic shift occurs in the arts from a centripetal to a more centrifugal pattern of motion over the course of the ancient period. In Chapter 7, we looked closely at this centrifugal pattern in the formal arts of written verse, tragedy, and metallurgy. In this chapter, we demonstrate the dominance of the same kinetic pattern in the arts of architecture, music, and medicine. The argument of this chapter is that each of these major fields is defined predominately by a distinctly centrifugal pattern of motion and a formal aesthetics. The argument is that the origin of form is not eternal or immaterial but rather in the kinetic structure of matter itself.

The Ancient Image, I

This chapter and the next argue that a kinesthetic shift occurred in the arts from a centripetal to a more centrifugal pattern of motion during the ancient period. This claim is supported by looking closely at the kinetic patterns produced by six major aesthetic fields that define the ancient image, the first three of which are discussed in this chapter: written verse, tragedy, and metallurgy (the city, the chordophone, and pharmakon are discussed in the next chapter). The argument here is that each of these major fields is defined predominately by a distinctly centrifugal pattern of motion and a formal aesthetics. Although all ancient arts relied on modeling, no one art was modeled on another. Rather, just like the prehistoric arts, the ancient arts entered into a kinesthetic resonance pattern or regime of motion. In the ancient period, this was broadly, although not exclusively, a centrifugal regime of motion.

The Prehistoric Image

This chapter argues that the kinesthetic shift occurs increasingly from less ordered and gathered images to more and larger gatherings of images on new and larger fields of sensation. This is done by looking closely at the kinetic patterns produced by six major aesthetic fields that define the prehistoric image: the body, the hearth, the cave, the vessel, the wind instrument, and the house. The argument of this chapter is that each of these major fields is defined predominately by a distinctly centripetal pattern of motion and a functional aesthetics. The prehistoric field gathers the flows of matter and images toward a central or hollowed-out region and begins to distribute them across the body, the hearth, the cave, the house, and so on. All this attests to the predominantly centripetal and functional nature of prehistoric aesthetic fields.

The Medieval Image, II

This chapter continues the thesis of Chapter 10 in demonstrating that a kinesthetic shift occurred in the arts from a centrifugal to a more tensional pattern of motion over the course of the Middle Ages. This chapter demonstrates that same thesis in the arts of perspective, keyboard music, and epistolography. The argument is that each of these major fields is defined predominately by a distinctly tensional pattern of motion and a relational aesthetics. All the newly dominant arts of the Middle Ages are defined by the kinesthetic pattern of relational or linked tensional motions holding images together and apart. The brilliant insight of the Middle Ages is that aesthetic form is nothing other than the polygonal intersection of a network of material kinetic relations.

Elastic Motion

This chapter begins Part IV by offering a purely kinomenological theory of the elastic motions that define the appearance of being as time. Time, like space, eternity, and force, is an ontological description structured according a specific regime of motion. Part IV argues that the concept of time is a fundamentally kinetic concept. With some exceptions, almost all modern ontologies of the eighteenth through twentieth centuries, in one way or another, accept the reality and foundational nature of time. The thesis of this chapter is that temporal being is defined by a material and kinetic elasticity of motion. This elastic pattern of motion is defined by seriality, subjectivity, and elastic subjectivity.

Bogie-monitoring technology: Extending the detection of derailments to cover applications with slab tracks

Detection of derailments based on the irregular pattern of motion of an axle, bogie, or even an entire vehicle is becoming increasingly important due to extensive track use and higher frequency of freight and passenger operations. The current technology detects the irregular oscillation of wheels, and is therefore limited to tracks with sleepers and ballast. During a derailment, the wheels begin to oscillate violently and the detection device is triggered. However, this system faces a challenge due to the increasing use of slab tracks that have no or only a minimal number of sleepers. Knorr-Bremse, in a joint project with the Technical University of Berlin, is currently testing a new electronic derailment detector for these types of tracks. The new, model-based validation process will focus on a detection algorithm that can be used for all vehicle types.