Coulomb

expressed by: However, the above equation fails to give accurate prediction in high normal stress conditions. Several studies applied modified Coulomb friction law [e.g., [42], [40], [63],[41]] in which critical friction stress depends on pressure normal to the tool-chip interface, coefficient of friction, and threshold value for the conventional Coulomb friction stress. In this model the contact point is in the sticking…

How was Avogadro’s number determined? What are the evidence of international co-operation and evidences used to support the value of Avogadro’s hypothesis (numer)? What is a hypothesis? It is a proposed explanation for a phenomenon, which can be described as ‘provisional'. However, a hypothesis cannot be identified as a prediction; it is a priority for it to allow people to make predictions of experiments that can be tested. If the results from this experiment are coherent with the prediction…

In this work, we assume two different potentials for the initial and final heavy quarkonia and the intermediary hybrid states. The most popular potential form for the study of heavy quarkonia is the Cornell potential [11] V(r)= -κ/r + b r (2.13) Usually many authors prefer α_s (r) instead of κ. The relation between them is κ=(4α_s (r))/3 and α_s (r) can treated as constant for bb ̅ and cc ̅…

Ella True 11/16/14 Schneck 3 Honors Chemistry Energy Persuasive Essay Before reading this paper, one should understand what electricity is and how it works. One should also understand that electricity is a type of energy. Electricity is simply the flow of electric charge. This may sound fairly straight forward, but there is a lot more to this simple statement. One might wonder: Where exactly is this charge coming from? What is obtaining this charge? How is the charge flowing and to where? How…

Critical assessment of the article: Quantitative analysis by Auger Electron Spectroscopy 1 Introduction When the outer electron fills the vacancy left by an ionized electron in the inner shell, the released energy can be passed to another outer electron that causes further emitting of an electron with characteristic energy, this is the basic principle of the Auger electron spectroscopy (AES) [1]. Nowadays, AES is almost an indispensable tool in nanoscience research for its high surface…

Because of the static configuration is a stable one, in the absence of streaming, the density of the upper fluid be lighter than the density of the lower one. The basic unperturbed flows have uniform velocities and . The two fluids are dielectrics and having the uniform dielectric constants and . The two fluids are influenced by an oblique electric field at the interface between the two media, according to: (2.1) where…

Niels Henrick David Bohr was born in Copenhagen, Denmark on 1885. In 1911 he received his Ph.D. from Copenhagen University. Later on he moved to England to study under J.J. Thomson in Cambridge and under Ernest Rutherford in Manchester. In 1913 he published his model of the atom, which was based on Rutherford’s planetary model. After his publication of his model he received worldwide fame. Unfortunately, Bohr’s model worked only for hydrogen atoms. Which made the final atomic model yet to be…

Clear! The physics behind the electrical life savers, defibrillators “Defibrillation has become an integral part of the emergency response routine. In fact, the American Heart Association considers defibrillation a basic life support skill for paramedics and rescue workers.” (DIRECT QUOTE) The human heart is arguably the most vital organ of the human body, as its coordinated and controlled two-part pumping is necessary to supply blood to the entire body. This supply rate is regulated by the…

Development of the atomic theory throughout history Abstract This paper will explain many concepts of the atomic theory. It will also include very important information that involves 15 scientists and their contributions to the atomic theory. There are many different models that scientists constructed, that they believed atoms looked like. There are only 5 atomic models that have ever been accepted. Our perspective on the atom has changed throughout the years…

Rotor and touchdown bearing models Fig. 1 features the case study of the high-speed rotor. The photo was taken after manufacturing of the electric motor part, when the rotor was carried to the laboratory for an experimental modal analysis. During normal operation, the rotor is supported by AMBs. In the dropdown event, the rotor is in contact with touchdown bearings at both ends of the rotor. Fig. 1. Rotor under investigation. In this work, the finite element model of the rotor employs…