3,810 research outputs found
Thermal modulation of skin friction at the finger pad
No full textPreliminary human studies show that reduced skin temperature minimises the risk of mechanically induced skin damage. However, the mechanisms by which cooling enhances skin tolerance to pressure and shear remain poorly understood. We hypothesized that skin cooling below thermo-neutral conditions will decrease kinetic friction at the skin-material interface. To test our hypothesis, we measured the friction coefficient of a thermally pre-conditioned index finger pad sliding at a normal load (5N) across a plate maintained at three different temperatures (38, 24, and 16 °C) in 8 healthy young adults (29±5y). To quantify the temperature distribution of the skin tissue, we used 3D surface scanning and Optical Coherence Tomography to develop an anatomically representative thermal model of the finger. Our group-level data indicated that the sliding finger with thermally affected tissues (up to 8 mm depth) experienced significantly lower frictional forces (p<0.01) at plate temperatures of 16 °C (i.e. 32% decrease) and 24 °C (i.e. 13% decrease) than at 38 °C, respectively. This phenomenon occurred consistently across participants (i.e. N = 6/8, 75%) and without large changes in skin hydration during sliding. Our complementary experimental and theoretical results provide new insights into thermal modulation of skin friction that can be employed for developing thermal technologies to maintain skin integrity under mechanical loading and shearing
New experimental results in proton radioactivity
No full textA review of experimental data obtained recently on proton-radioactive nuclei is presented. The highlights include the observation of fine structure in proton emission, for the decays of {sup 131}Eu, {sup 145}Tm and {sup 145}Tm, and the studies of the excited states in proton-emitting nuclei. The observation limits are extended to few nanobarns cross sections ({sup 140}Ho, {sup 164}In and {sup 130}Eu) and few microsecond half-lives (e.g. {sup 145}Tm). Measured decay properties for thirty nine proton-emitting ground and isomeric states contributed to the understanding of nuclear masses and evolution of single-particle states at and beyond the proton drip-line. Experimental results have stimulated new theoretical approaches to proton emission and the structure of unbound narrow resonance states
Shell structure beyond the proton drip line studied via proton emission from deformed 141Ho
No full textFine structure in proton emission from the 7/2−[523] ground state and from the 1/2+[411] isomer in deformed
nucleus 141Ho was studied by means of fusion-evaporation reactions and digital signal processing.
Proton transitions to the first excited 2+ state in 140Dy, with the branching ratio of Igs
p (2+) = 0.9 ± 0.2%
and Imp
(2+) = 1.7 ± 0.5%, were observed. The data are analyzed within the non-adiabatic weak coupling
model assuming a large quadrupole deformation of the daughter nucleus 140Dy as predicted by
the self-consistent theory. Implications of this result on coexistence effects around N = 74 are discussed.
Significant modifications of the proton shell structure when going from the valley of beta stability to the
proton drip line are discussed in terms of self-consistent theory involving the two-body tensor interaction
Need for monitoring and maintaining sustainable marine ecosystem services
No full textAbstract
Increases in human population and their resource use have drastically intensified pressures on marine ecosystem services. The oceans have partly managed to buffer these multiple pressures, but every single area of the oceans is now affected to some degree by human activities. Chemical properties, biogeochemical cycles and food-webs have been altered with consequences for all marine living organisms. Knowledge on these pressures and associated responses mainly originate from analyses of a few long-term monitoring time series as well as spatially scattered data from various sources. Although the interpretation of these data can be improved by models, there is still a fundamental lack of information and knowledge if scientists are to predict more accurately the effects of human activities. Scientists provide expert advices to society about marine system governance, but such advices should rest on a solid base of observations. Nevertheless, many monitoring programs around the world are currently facing financial reduction. Marine ecosystem services are already overexploited in some areas and sustainable use of these services can only be devised on a solid scientific basis, which requires more observations than presently available
Thermal modulation of skin friction at the finger pad
No full textPreliminary human studies show that reduced skin temperature minimises the risk of mechanically induced skin damage. However, the mechanisms by which cooling enhances skin tolerance to pressure and shear remain poorly understood. We hypothesized that skin cooling below thermo-neutral conditions will decrease kinetic friction at the skin-material interface. To test our hypothesis, we measured the friction coefficient of a thermally pre-conditioned index finger pad sliding at a normal load (5N) across a plate maintained at three different temperatures (38, 24, and 16 °C) in 8 healthy young adults (29±5y). To quantify the temperature distribution of the skin tissue, we used 3D surface scanning and Optical Coherence Tomography to develop an anatomically representative thermal model of the finger. Our group-level data indicated that the sliding finger with thermally affected tissues (up to 8 mm depth) experienced significantly lower frictional forces (p<0.01) at plate temperatures of 16 °C (i.e. 32% decrease) and 24 °C (i.e. 13% decrease) than at 38 °C, respectively. This phenomenon occurred consistently across participants (i.e. N = 6/8, 75%) and without large changes in skin hydration during sliding. Our complementary experimental and theoretical results provide new insights into thermal modulation of skin friction that can be employed for developing thermal technologies to maintain skin integrity under mechanical loading and shearing
Measurement of the double-differential inclusive jet cross section in proton-proton collisions at s = 5.02 TeV
No full textAbstract The inclusive jet cross section is measured as a function of jet transverse momentum p T and rapidity y. The measurement is performed using proton-proton collision data at s = 5.02 TeV, recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 27.4 pb −1. The jets are reconstructed with the anti-k T algorithm using a distance parameter of R = 0.4, within the rapidity interval |y| < 2, and across the kinematic range 0.06 < p T < 1 TeV. The jet cross section is unfolded from detector to particle level using the determined jet response and resolution. The results are compared to predictions of perturbative quantum chromodynamics, calculated at both next-to-leading order and next-to-next-to-leading order. The predictions are corrected for nonperturbative effects, and presented for a variety of parton distribution functions and choices of the renormalization/factorization scales and the strong coupling α S
Final State in Two-Photon Collisions and Implications for Glueballs
No full textThe \mbox{K}^0_{\rm S}\mbox{K}^0_{\rm S} final state in two-photon collisions is studied with the L3 detector at LEP. The mass spectrum is dominated by the formation of the (1525) tensor meson in the helicity-two state with a two-photon width times the branching ratio into of . A clear signal for the formation of the f(1710) is observed and it is found to be dominated by the spin-two helicity-two state. No resonance is observed in the mass region around and an upper limit of at 95\% C.L. is derived for the two-photon width times the branching ratio into \mbox{K}^0_{\rm S}\mbox{K}^0_{\rm S} for the glueball candidate .The K 0 S K 0 S final state in two-photon collisions is studied with the L3 detector at LEP. The mass spectrum is dominated by the formation of the f ′ 2 (1525) tensor meson in the helicity-two state with a two-photon width times the branching ratio into K K ̄ of 76±6±11 eV. A clear signal for the formation of the f J (1710) is observed and it is found to be dominated by the spin-two helicity-two state. No resonance is observed in the mass region around 2.2 GeV and an upper limit of 1.4 eV at 95% C.L. is derived for the two-photon width times the branching ratio into K 0 S K 0 S for the glueball candidate ξ (2230).The K0s K0s final state in two-photon collisions is studied with the L3 detector at LEP. The mass spectrum is dominated by the formation of the f_2'(1525) tensor meson in the helicity-two state with a two-photon width times the branching ratio into K Kbar of 76 +- 6 +- 11 eV. A clear signal for the formation of the f_J(1710) is observed and it is found to be dominated by the spin-two helicity-two state. No resonance is observed in the mass region around 2.2 GeV and an upper limit of 1.4 eV at 95% C.L. is derived for the two-photon width times the branching ratio into K0s K0s for the glueball candidate xi(2230)
α decay of 109I and its implications for the proton decay of 105Sb and the astro-physical rapid proton-capture process
No full textAn α-decay branch of (1.4±0.4)×10-4 has been discovered in the decay of 109I, which predominantly decays via proton emission. The measured Qα value of 3918±21 keV allows the indirect determination of the Q value for proton emission from 105Sb of 356±22 keV, which is approximately of 130 keV more bound than previously reported. This result is relevant for the astrophysical rapid proton-capture process, which would terminate in the 105Sn(p,γ)106Sb(p,γ)107Te(α decay)103Sn cycle at the densities expected in explosive hydrogen burning scenarios, unless unusually strong pairing effects result in a 103Sn(p,γ)104Sb(p,γ)105Te(α decay)101Sn) cycle
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