On the bursting of a balloon

Abstract

The tear behaviour during the bursting of natural rubber balloons under 100%, 300% and 400% biaxial strain has been investigated in detail by means of high speed cinematography. The tear velocity was observed to be approximately three times the finite elastic wave velocity during unloading (the retraction velocity), in each case. A theoretical analysis is provided for the case of uniform biaxial strain, relevant to the present work, leading to formulae for the retraction and elastic wave velocities. Observed retraction velocities were consistent with theoretical predictions based on the static stress-strain curve in biaxial tension. It is suggested that tear velocity is determined by the elastic properties of the rubber in a localised region of high strains just around the tip.

A new paradigm for the molecular basis of rubber elasticity

“…The rapid retraction of a stretched rubber sample as one end is abruptly released, is commonly referred to as 'snapback' and quantitative measurements of the speed of both the free end and intermediate points along the sample have been reported [51][52][53][54][55][56][57][58]. There are several surprising results from these experiments.…”

12.4: Surface Exciton Properties of MgO in ZnO‐MgO Core‐Shell Quantum‐Dots

“…MgO is thought to be an ideal candidate shell material for ZnO passivation based on its electronic properties, while the stability and performance of ZnO nanocrystals has been improved by the MgO shell. [10][11][12] The bottom of conduction-band of MgO crystals, is located near the vacuum energy level [18][19][20][21]. Based on the electronic band structures of ZnO [ 29 ] and MgO presented in figure 6, the potential steps of 3.8 eV for band offset of electrons and 0.6 eV for band offset of holes at the interface could confine the charge carriers are in the ZnO core, resulting in an improved luminescent efficiency at the ZnO bandgap energy.…”

“…The large value of the exciton binding energy of MgO (80 meV) [16] and small radius (1.5 nm) [17] is advantageous for exciton transport. The bottom of the conduction-band of MgO crystals is located around the vacuum energy (depending on the reference, the electron affinity is stated as either positive or negative [18][19][20][21]). This is supposed to balance the injection of electrons and holes by impeding electron injection [9].…”

The energy flux number and three types of planetary dynamo

“…An equally important effect is likely to be the unavoidable presence of substantial latitudinal temperature gradients. Fourth, convection of this type is likely to have substantial helicity, not only locally but in the horizontal average over many cylinders (STEENBECK et al 1966;CHIL-DRESS 1977;STEVENSON 1983). It is important to realize that this convection will still involve a turbulent cascade to small eddies, even though the large scale flow may be highly organized and very different from the non-rotating case.…”