Stochastic Nonlinear Free Vibration Analysis of Piezolaminated Composite Conical Shell Panel Subjected to Thermoelectromechanical Loading With Random Material Properties

This paper presents the effect of randomness in material properties on piezolaminated composite geometrically nonlinear conical shell panel subjected to thermoelectromechanical loading acting simultaneously or individually. Material properties such as modulus ratio, Poisson's ratio, and thermal expansion coefficients are modeled as independent random variables. The temperature field considered is assumed to be a uniform distribution over the shell panel surface and through the shell thickness and the electric field is assumed to be the transverse component E z only. It is assumed that the mechanical properties do not depend on temperature and electric fields. The basic formulation is based on higher order shear deformation theory (HSDT) with von-Karman nonlinearity. A C 0 nonlinear finite element model based on direct iterative approach in conjunction with mean centered first order perturbation technique (FOPT) used by the present author for plate is now extended for conical shell panel to solve a random nonlinear generalized eigenvalue problem. Parametric studies are carried out to examine the effect of amplitude ratios, stacking sequences, cone angles, circumferential length to thickness ratios, piezoelectric layers, applied voltages, change in temperature, types of thermoelectromechanical loadings, and support boundary conditions on the dimensionless mean and coefficient of variance (COV) of laminated conical shell panels. The present outlined approach has been validated with those available results in literature and independent Monte Carlo simulation (MCS)

Pseudorapidity densities of charged particles with transverse momentum thresholds in pp collisions at √ s = 5.02 and 13 TeV

The pseudorapidity density of charged particles with minimum transverse momentum (pT) thresholds of 0.15, 0.5, 1, and 2 GeV/c is measured in pp collisions at the center of mass energies of √s=5.02 and 13 TeV with the ALICE detector. The study is carried out for inelastic collisions with at least one primary charged particle having a pseudorapidity (η) within 0.8pT larger than the corresponding threshold. In addition, measurements without pT-thresholds are performed for inelastic and nonsingle-diffractive events as well as for inelastic events with at least one charged particle having |η|2GeV/c), highlighting the importance of such measurements for tuning event generators. The new measurements agree within uncertainties with results from the ATLAS and CMS experiments obtained at √s=13TeV.

Pancreatic surgery outcomes: multicentre prospective snapshot study in 67 countries

Background: Pancreatic surgery remains associated with high morbidity rates. Although postoperative mortality appears to have improved with specialization, the outcomes reported in the literature reflect the activity of highly specialized centres. The aim of this study was to evaluate the outcomes following pancreatic surgery worldwide.Methods: This was an international, prospective, multicentre, cross-sectional snapshot study of consecutive patients undergoing pancreatic operations worldwide in a 3-month interval in 2021. The primary outcome was postoperative mortality within 90 days of surgery. Multivariable logistic regression was used to explore relationships with Human Development Index (HDI) and other parameters.Results: A total of 4223 patients from 67 countries were analysed. A complication of any severity was detected in 68.7 percent of patients (2901 of 4223). Major complication rates (Clavien-Dindo grade at least IIIa) were 24, 18, and 27 percent, and mortality rates were 10, 5, and 5 per cent in low-to-middle-, high-, and very high-HDI countries respectively. The 90-day postoperative mortality rate was 5.4 per cent (229 of 4223) overall, but was significantly higher in the low-to-middle-HDI group (adjusted OR 2.88, 95 per cent c.i. 1.80 to 4.48). The overall failure-to-rescue rate was 21 percent; however, it was 41 per cent in low-to-middle-compared with 19 per cent in very high-HDI countries.Conclusion: Excess mortality in low-to-middle-HDI countries could be attributable to failure to rescue of patients from severe complications. The authors call for a collaborative response from international and regional associations of pancreatic surgeons to address management related to death from postoperative complications to tackle the global disparities in the outcomes of pancreatic surgery (NCT04652271; ISRCTN95140761)