Effect of Railcar Wheel Tire Profiles on the Contact Stress Level in Subway Rails

Strength of Materials - The statistical analysis performed on the defectiveness of rails in the Kiev subway railway shows that the main cause of the occurrence of most defects is the contact...     

Inelastic Interaction of an Electron with a C60 Cluster

The method of intersecting beams of C₆₀ fullerene clusters and of electrons is used to investigate the production of C ₆₀ ⁺ and C ₆₀ ^– ions and the radiation in the wavelength range from 300 to 800 nm for the electron energy E _e ranging from zero to 100 eV. The absolute values of the ionization and electron-attachment cross sections [⁺(E _e ) and ^–(E _e ), respectively] are determined. A maximum of ⁺(E _e ) of 0.53 nm²is observed at E _e = 52 eV. For a C₆₀ cluster excited by electron impact, delayed (150 s) ionization initiated by collision with the surface and ionization due to thermionic emission (its characteristic time at E _e = 60 eV is 6 s) is observed. It is found that, for E _e < 0.4 eV, the formation of C ₆₀ ^– is defined by the polarization capture of an s-electron (^– E _e ^–1 ), and a formula is suggested for determining ^–(E _e ). In the region of E _e from 1 to 6 eV, the cross section ^–(E _e ) shows only slight variations about ^–(E _e ) = 0.36 ± 0.03 nm². For E _e > 7.5 eV, C ₆₀ ^– ions proved to be unstable to electron autodetachment. In the region of intersection of C₆₀ and electron beams, radiation of a quasicontinuous spectrum described by a modified Planck formula for the thermal emission of spherical particles of diameter d is recorded. For E _e > 47 eV, the brightness temperature proved to be 3150 ± 50 K. It is found that this radiation is emitted predominantly by hot C ₆₀ ^+* ions produced as a result of thermionic emission from C ₆₀ ^* . The rate of radiation loss of energy by a C ₆₀ ^+* ion and the cross section for the formation of radiating C ₆₀ ^+* ions are found to be, respectively, 5.5 × 10⁵ eV/s at T = 3150 K and 2 × 10^–2 nm² at E _e = 60 eV.     

Differential criteria and classification of traumatisms at home

Communal traumatism represents a heterogeneous phenomenon in whose structure latent, outpatient, hospital, invalidating, and lethal communal traumatism should be distinguished. The said types of traumatism differ by the incidence, share, mean age of the victims, predominating type of injuries, share of multiple injuries, time of application for primary health care, share of ambulance calls, percent share of invalidity, type and duration of invalidity, and outcome of injury. The severity of communal traumatism gradually increases from the first to the last named type and depends on the type of injury and development of complications.     

Development of Manufacturing Technology for a Continuously-Cast Wheel Billet with a Controlled Aluminum Content

Metallurgist - The quality of railway wheels significantly affects the economy and security of railway transportation. In order to improve the properties of railway wheels steel is used currently...