Influence of Tribological Parameters on the Railway Wheel Derailment

At present, Nadal’s formula is used for prediction of derailment that contains a limited number of parameters. Besides, insufficient study of laws of variation of the noted parameters and ignorance of the influence of other parameters on the derailment complicate solution of the problem. The sliding distance and the relative sliding velocity are the most sensitive factors contributing to the destruction of the third body. Moreover, increased friction coefficient between the steering surfaces of the wheel and rail promotes climbing of a wheel on the rail and derailment. Dependences of the main parameters, influencing the destruction of the third body, the sliding distance and the relative sliding velocity on the rail track curvature, and difference of diameters of wheels of the wheelset and the non-roundness of one of the wheels of the wheelset are shown in the work. The methods for estimation of the third body destruction degree and consideration in Nadal’s formula of the additional criterion of impossibility of the wheel rolling on the contact point of the wheel and rail steering surfaces, containing a value of this contact point advancing, which in turn depends on the angle of attack, are proposed

A New Concept of the Mechanism of Variation of Tribological Properties of the Machine Elements Interacting Surfaces

The methods of estimation and prediction of tribological properties of the contact zone of interacting elements of machines are characterized by the low informativeness and accuracy that complicates provision of the proper tribological properties and hinders reliable and effective operation of machines. For obtaining more wide information about factors influencing tribological properties of the interacting surfaces, the experimental researches on the high speed (up to 70-m/s) and serial twin-disk machines were carried out. Our researches have shown that with different properties and degrees of destruction of the third body, the coefficient of friction can change up to 10 times or more, the wear rate up to 102-104 times, etc. This was the basis for a new concept of the mechanism of variation of tribological properties of interacting surfaces. The researches have shown a dependence of tribological properties of the contact zone on the properties and destruction degree of the third body that was assumed as a basis of new concept of the mechanism of variation of tribological properties of these surfaces. The monitoring of the third body destruction onset and development was carried out in the laboratory conditions and a criterion of the third body destruction was developed. The reasons of the negative, neutral and positive friction and mild, severe and catastrophic wear are shown

INFORMING THE PUBLIC ABOUT ONGOING CRIMINAL CASES NFORMING THE PUBLIC ABOUT ONGOING CRIMINAL CASES AND PROCEDURAL GUARANTEES OF THE ACCUSED

Public hearing of criminal cases is an important element of the state-legal criminal process. The public has a legitimate interest in being informed about ongoing criminal cases and in assessing the extent to which criminal justice is administered in accordance with their expectations. The openness of administration of criminal justice precisely serves the requirement of public awareness. Due to the fact that a large part of criminal cases may not even reach the stage of discussion on the merits in court, and it is terminated at the stage of investigation, therefore the public is interested not only in hearing criminal cases in the courtroom and their results, but also in the administration of criminal cases at the stage of investigation. Accordingly, both the media and investigative and criminal prosecution bodies ensure provision of information to the public on current criminal cases and the satisfaction of the latter's legitimate interest in providing information. Incorrect and unbalanced public information about criminal cases may pose significant challenges and threats to the fairness of criminal proceedings, the rights of the accused and the interests of justice. In particular, the presumption of innocence and the right to privacy of the accused are at risk. Accordingly, the criminal law enforcement bodies and the media should be aware of the existing threats and pay special attention to the implementation of the correct information policy when informing the public about the criminal case and the accused persons. This article discusses the role and influence of the media in the criminal justice process, reviews the risks that may threaten the procedural guarantees of the accused, the interests of justice, and develops separate recommendations in the direction of a balanced information policy