Structure and wear mechanisms of nano-structured TiAlCN/VCN multilayer coatings

Dry sliding wear of transition metal nitride coatings usually results in a dense and strongly adhered tribofilm on the worn surface. This paper presents detailed electron microscopy and Raman spectroscopy characterizations of the microstructure, a newly developed multilayer coating TiAlCN/VCN and its worn surface after pin-on-disc sliding wear against an alumina ball. The friction coefficient in a range of 0.38–0.6 was determined to be related to the environmental humidity, which resulted in a wear coefficient of the coating varying between 1017 and 1016 m3 N1 m1. TEM observation of worn surfaces showed that, when carbon was incorporated in the nitride coating, the formation of dense tribofilm was inhibited

Review of \u3cem\u3eEqbal Ahmad: Critical Outsider in a Turbulent Age\u3c/em\u3e

A review of Eqbal Ahmad: Critical Outsider in a Turbulent Age by Stuart Schaar

Transmission electron microscopy and energy dispersive X-ray spectroscopy on the worn surface of nano-structured TiAlN/VN multilayer coating

Nano-structured TiAIN/VN multilayer hard coatings grown by cathodic arc metal ion etching and unbalanced magnetron sputtering deposition have repeatedly shown low coefficients of friction and wear. In this paper, we employed the combined methods of cross-sectional ion beam milling sample preparation, conventional transmission electron microscopy, energy dispersive X-ray spectroscopy and quantitative spectrum analysis to give a comprehensive characterization of wear induced tribofilm, worn TiAIN/VN surface as well as wear debris. The major wear mechanism operating in the TiAIN/VN coating is the tribo-oxidation wear. A 20-50 nm thick tribofilm was observed on the TiAIN/VN worn surface, having inhomogeneous density, amorphous structure and multicomponent V-Al-Ti-O composition. Therefore the real sliding contact during the ball-on-disk test was a three-body sliding system including the tribofilm, in which the self-sintering and shearing deformation of the multicomponent oxide film played a significant role in determining the low friction coefficient. Owing to the low friction and high hardness, the TiAIN/VN worn surface retained good structural integrity without any crack, delamination or detectable deformation, resulting in minimized mechanical wear. (c) 2005 Elsevier B.V. All rights reserved

Quid Pro Quo: Piercing the Reporter’s Privilege for Media Who Ride Along

The reporter’s privilege, also known as the reporter’s shield law, exists to protect reporters from forced disclosure regarding confidential information and sources. Stemming from the First Amendment right to freedom of press, this privilege seeks to safeguard the free flow of information. However, reporters are frequently participating in media ride-alongs during which they are permitted to accompany police officers in their daily duties. As a result of these ride-alongs, reporters witness arrests, search warrant executions, and crime scene investigations. When subsequently subpoenaed to testify during the criminal trial related to those events, these reporters assert their privilege and refuse to testify. Often times, courts uphold their privilege. However, in doing so, it infringes upon the criminal defendant’s Sixth Amendment right to a fair trial. An exception to the reporter’s privilege should be implemented when a reporter participates in a media ride-along since testifying to their eyewitness accounts would not violate the purpose of the privilege. Mandating that the reporters testify would not disrupt the free flow of information nor would it require disclosure of confidential information. Instead, such an exception would only require reporters to testify to information witnessed as the result of the police-permitted ride-along. Moreover, the Sixth Amendment right to a fair trial trumps the First Amendment right to freedom of press in this context, further supporting the exception to the reporter’s privilege

The Only Language They Understand: Forcing Compromise in Israel and Palestine

A book review of Nathan Thrall\u27s The Only Language They Understand: Forcing Compromise in Israel and Palestine

Review of \u3cem\u3eGaza: An Inquest into Its Martyrdom\u3c/em\u3e

A review of Norman G. Finkelstein\u27s Gaza: An Inquest into Its Martyrdom, published by University of California Press

What Determines Americans’ Income: An Intersectional Multivariate Analysis of Americans’ Income

In a capitalistic society, Americans are socialized to value the earning of money more than anything. Americans are told that the best way to make this money is to go to college and further their education. Yet, millionaires such as Steve Jobs and Oprah Winfrey never bothered to earn a college degree. This begs one to question if education is the only factor in earning a sizable income. If not the only factor, is it the most important? When addressing the question of if education is the only factor, the wage gap supplies a partial answer. We know that because the wage gap exists between those with the same level of education, there are other elements to consider when looking at income earnings. Social and income inequality go hand-in-hand as contemporary research has shown gender and race can influence one’s salary as well. Although the wage gap is denied by some Americans, one cannot deny that prejudice is alive and well in the economy. This research seeks to answer the question: What contributes to an American’s income? Does education level truly affect their income or are there more prominent factors

Novel High Isolation Antennas for Simultaneous Transmit and Receive (STAR) Applications

Radio frequency (RF) spectrum congestion is a major challenge for the growing need of wireless bandwidth. Notably, in 2015, the Federal Communications Commission (FCC) auctioned just 65 MHz (a bandwidth smaller than that used for WiFi) for more than $40 billion, indicating the high value of the microwave spectrum. Current radios use one-half of their bandwidth resource for transmission, and the other half for reception. Therefore, by enabling radios to transmit and receive across their entire bandwidth allocation, spectral efficiency is doubled. Concurrently, data rates for wireless links also double. This technology leads to a new class of radios and RF frontends. Current full-duplex techniques resort to either time- or frequency-division duplexing (TDD and FDD respectively) to partition the transmit and receive functions across time and frequency, respectively, to avoid self-interference. But these approaches do not translate to spectral efficiency. Simultaneous transmit and receive (STAR) radios must isolate the transmitter from the receiver to avoid self-interference (SI). This SI prevents reception and must therefore be cancelled. Self-interference may be cancelled with one or more stages involving the antenna, RF or analog circuits, or digital filters. With this in mind, the antenna stage is the most critical to reduce the SI level and avoid circuit saturation and total system failure. This dissertation presents techniques for achieving STAR radios. The initial sections of the dissertation provide the general approach of stage to stage cancellation to achieve as much as 100 dB isolation between the receiver and transmitter. The subsequent chapters focus on different antennas to achieve strong transmit/receive isolation. As much as 35 dB isolation is shown using a new spiral antenna array with operation across a 2:1 bandwidth. Also, a new antenna feed is presented showing 42 dB isolation across a 250 MHz bandwidth. Reflections in the presence of a dynamic environment are also considered