What is Circular: Definition and 1000 Discussions

A circular economy (also referred to as "circularity") is an economic system aimed at eliminating waste and the continual use of resources. Circular systems employ reuse, sharing, repair, refurbishment, remanufacturing and recycling to create a closed-loop system, minimising the use of resource inputs and the creation of waste, pollution and carbon emissions. The circular economy aims to keep products, equipment and infrastructure in use for longer, thus improving the productivity of these resources. Waste materials and energy should become input for other processes through waste valorization: either as a component or recovered resource for another industrial process or as regenerative resources for nature (e.g., compost). This regenerative approach is in contrast to the traditional linear economy, which has a "take, make, dispose" model of production.In recent years, concepts based on (re-)cycling resources are increasingly gaining importance. The most prominent among these concepts might be the circular economy, with its comprehensive support by China and the European Union. There is also a broad range of similar concepts or schools of thought, including cradle-to-cradle laws of ecology, looped and performance economy, regenerative design, industrial ecology, biomimicry, and the blue economy. These concepts seem intuitively to be more sustainable than the current linear economic system. The reduction of resource inputs into and waste and emission leakage out of the system reduces resource depletion and environmental pollution. However, these simple assumptions are not sufficient to deal with the involved systemic complexity and disregards potential trade-offs. For example, the social dimension of sustainability seems to be only marginally addressed in many publications on the Circular Economy, and some cases require different or additional strategies, such as purchasing new, more energy-efficient equipment.

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  1. U

    Relativity and Circular Magnetic Field

    According to relativity, If magnetic field is just an electric field viewed from a different frame of reference, why is the magnetic field around the wire is circular?
  2. Shinwasha

    Circular loop with uniform magnetic field

    Homework Statement A current carrying wire is bent into a circular loop with radius R and lies in the XY plane. A uniform magnetic field in the +z direction exists through out the plane of the loop. What is the magnetic force exerted on the loop? Homework Equations Fb = I lb sin (theta) The...
  3. C

    MHB How Does Angular Velocity Affect a Block on a Rotating Wedge?

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  4. samjohnny

    Mastering Perturbations in Near Circular Orbits: A Comprehensive Guide

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  5. H

    A thin circular ring of radius R has charge Q/2

    Homework Statement A thin circular ring of radius R has charge Q/2 uniformly distributed on the top half, and -Q/2 on the bottom half. a) What is the value of the electric potential at a point a distance x along the axis through the center of the circle? b) What can you say about the electric...
  6. F

    PDF of multimodal circular data

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  7. S

    How to calculate natural frequency of a circular plate

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  8. P

    Perturbed circular orbit under central force motion?

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  9. A

    Uniform Circular Motion Background theory?

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  10. A

    Circular Motion. Roller-coaster mass of car and max speed

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  11. Q

    Direction cosine matrix of rolling disk on circular ring

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  12. Adam Harris

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  13. P

    Acceleration in circular motion -- conceptual doubt

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  14. fhc6791

    Dipole moment of small circular antenna - only magnetic?

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  15. E

    Circular motion: find velocity with angle, mass, and radius

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  16. J

    Circular Motion: Tension in String w/ Bob Weight

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  17. J

    Circular Motion and centripetal acceleration

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  18. B

    For a circular motion period to length and mass question.

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  19. T

    Angle of total acceleration of an object in circular motion

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  20. P

    Average velocity in uniform circular motion

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  21. RJLiberator

    Simple circular motion conceptual question

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  22. D

    Statics Question -- Bar and roller resting on a circular surface

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  23. P

    What is causing the normal force in circular motion?

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  24. C

    Dot product in uniform circular motion question -- Finding angle?

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  25. A

    Physics investigation guidance: Vibration of circular plate

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  26. Heather

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  27. R

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  28. U

    General Relativity - Circular Orbit around Earth

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  29. H

    Circular motion and work done by non conservative forces

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  30. terryds

    Conservation of Energy in circular motion

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  31. Quadrat

    Circular motion, tension and angular speed

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  32. D

    Gravitational field owing to a uniform circular plate

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  33. D

    Work in Uniform Circular Motion

    Uniform circular motion requires a force perpendicular to the velocity. Therefore, the work done by such a force is zero because the dot product of the force and the path is zero. So there is no energy gain beyond the kinetic energy arising from its constant speed. But if I have a mass (rocket...
  34. M

    Air flow over a circular cylinder

    Hi, Could you explain the reason why the velocity varies in the wake region behind the cylinder in "flow over a circular cylinder"? the velocity variation is, minimum at a point parallel to the centre point of the cylinder and increases to free stream velocity as the vertical distance increases...
  35. cseil

    Calculating magnetic force on circular coil carrying current

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  36. P

    Circular Motion Problem: Finding Tension in a Vertical Circle [11.8 N]

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  37. D

    Circular interference from the equation of a hyperbola

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  38. B

    Fluid Mechanics: velocity u for circular pipe

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  39. B

    Circular Motion: Find Speed at Point A

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  40. S

    Why Can't Conservation of Energy Be Used to Solve the Loop Problem in Physics?

    Homework Statement Bob starts at rest from the top of a frictionless ramp. At the bottom of the ramp, he enters a frictionless circular loop. The total mass of the child and the cart he sits in his m. What must the height of the ramp be in order for the cart to successfully traverse the loop...
  41. Coffee_

    Force on a shrinking circular loop in a constant B field

    1. A conducting loop is shrinking in a constant ##\vec{B}##-field that is perpendicular to the loop-axis. The radius of the loop is given by ##r(t)=r_{0}e^{-at}##. The resistance in the loop is ##R(t)=2 \pi \rho r(t)##. What force is needed to keep the loop shrinking like this?2. Faraday's law...
  42. A

    Is the Circular Orbit in a Multi-Electron Atom Stable?

    Homework Statement In a classical model of a multi-electron atom, electrons are assumed to move in a modified electrostatic potential $V(r)$, given by; $$V(r)=\dfrac{-k}{r}e^{-r/a}$$ Show that the effective potential is ; $$V_e(r)=\dfrac{J^2}{2mr^2}+\dfrac{-k}{r}e^{-r/a}$$ Then show that...
  43. F

    How Can You Alter the Speed of an Object in Circular Motion?

    Homework Statement When you are spinning an object in a circular path, you are applying centripetal force towards the center of the circle while the velocity vector is perpendicular to it. Therefore the Force component affecting the velocity is FCos(90) = 0. Keeping this in mind, how can you...
  44. J

    Angular momentum in Uniform circular flow

    My book says that for uniform rotational flow, the velocity at any point is proportional to r (v = wr.) In vortex flow, the velocity at any point is proportional to 1/r (angular momentum is conserved.) However, in uniform rotational flow, isn't angular momentum also conserved so the same logic...
  45. B

    Circular motion problem -- A ball rolling down an incline

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  46. H

    Circular motion in planets and satellites

    Homework Statement A spaceship in outerspace has a donut shaped with a 500 m outer radius. The inhabitants stand with their heads towards the center and their feet on an outside rim. Over what time interval with the spaceship have to complete one rotation on its axis to make a bathroom scale...
  47. P

    Double integral in Rectangular coordinates for anything circular

    This is the equation for the cone A \sqrt{x^2 + y^2} The double integral \iint A \sqrt{x^2 + y^2} \space dy \space dx \space \space \space\text {From x= -1 to 1 and y=} -\sqrt{1-x^2} \space to \space \sqrt{1-x^2} \text{ is very difficult to evaluate. I've tried polar coordinate substitution...
  48. Nathanael

    Do tidal forces slowly make orbits more circular?

    I don't understand, how can tidal forces make the orbits more circular? Perhaps it has something to do with the fact that in elliptical orbits (unlike in circular orbits) the velocity is not always perpendicular to the acceleration? Or maybe it does not have to do with the tidal forces from the...
  49. J

    Circular Linear guide solutions

    I am working on a system that uses circular motion of 65° of a circle with 8,5cm radius. Thing is, What first comes to mind are Linear guides with a curved/circular track and I've found some examples such as; http://ind-techno.com.ua/en/cat/20/556/78030/...
  50. R

    What is the Maximum Radius for a Bucket of Water in Circular Motion?

    Homework Statement A 3.75 kg bucket pile of water is swung in a vertical circle. If the speed of the bucket at the top of the loop is 6.20 m/s, then the radius of the largest circle through which this pail could move without the water leaving the bottom of the pail would be what? m = 3.75 kg...
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