Tunneling of Massive Dirac Fermions in Graphene through Time-periodic Potential

The energy spectrum of graphene sheet with a single barrier structure having a time periodic oscillating height and subjected to magnetic field is analyzed. The corresponding transmission is studied as function of the obtained energy and the potential parameters. Quantum interference within the oscillating barrier has an important effect on quasiparticles tunneling. In particular the time-periodic electromagnetic field generates additional sidebands at energies \epsilon + l\hbar \omega (l=0,\pm 1, \cdots) in the transmission probability originating from the photon absorption or emission within the oscillating barrier. Due to numerical difficulties in truncating the resulting coupled channel equations we limited ourselves to low quantum channels, i.e. l=0,\pm 1.Comment: 20 pages, 13 figures, references added. Version to appear in EPJ

The Influence of Engineers on Public Policy

Engineers play a vital role in society and contribute positively to economic growth in various areas, including energy, transportation, telecommunications, and others. In the United States of America, these areas are monitored by public policies that are set by policy actors—mainly lawyers, public administrators and social scientists—at legislative and regulatory levels. In these domains, engineers have a reduced voice with key decision makers on critical engineering issues, and their input is very limited. Their lack of involvement results in costly unintended consequences, affecting both the interest of the profession and the interest of the nation. Research has shown that increased input from engineers bridges disciplinary gaps, allowing clarification of technical concerns and disentanglement of system complexities in public policy issues. This dissertation explores the skills necessary for engineers to navigate effectively within organizations and society, influence policy decisions, and the different factors impacting their influence. Grounded theory method is used to analyze data collected through semi-structured interviews conducted with engineers and other engineering or engineering management professionals. The investigation will lead to the construction of a theory and topic of study referred to as socio-political engineering. Furthermore, the perception of engineers regarding this topic of study is analyzed using a Q methodology, which supports the results of the grounded theory. This knowledge provides insight into ways that socio-political engineering mayenhance engineering education and engineers’ certification through the development of capabilities to influence multidisciplinary decision making

On the Galois structure of units in totally real pp-rational number fields

The theory of factor-equivalence of integral lattices gives a far reaching relationship between the Galois module structure of units of the ring of integers of a number field and its arithmetic. For a number field $K$ that is Galois over $\mathbb{Q}$ or an imaginary quadratic field, we prove a necessary and sufficient condition on the quotients of class numbers of subfields of $K$, for the quotient $E_{K}$ of the group of units of the ring of integers of $K$ by the subgroup of roots of unity to be factor equivalent to the standard cyclic Galois module. By using strong arithmetic properties of totally real $p$-rational number fields, we prove that the non-abelian $p$-rational $p$-extensions of $\mathbb{Q}$ do not have Minkowski units, which extends a result of Burns to non-abelian number fields. We also study the relative Galois module structure of $E_{L}$ for varying Galois extensions $L/F$ of totally real $p$-rational number fields whose Galois groups are isomorphic to a fixed finite group $G$. In that case, we prove that there is a finite set $\Omega$ of $\mathbb{Z}_p[G]$-lattices such that for every $L$, $\mathbb{Z}_{p} \otimes_{\mathbb{Z}} E_{L}$ is factor equivalent to $\mathbb{Z}_{p}[G]^{n} \oplus X$ as $\mathbb{Z}_p[G]$-lattices for some $X \in \Omega$ and an integer $n \geq 0$.Comment: under revisio

Engineers\u27 Motivation to Influence Public Decision Making: A Grounded Theory Approach

In the United States of America, public policies and public decision making associated with the engineering field are set by individuals who does not possess expertise and knowledge to carry out these tasks [1]. Most of decision makers are lawyers and social scientists, not engineers [2]. The purpose of this paper is to analyze the various factors which either encourage or inhibit engineers from influencing and participating in public policy. In this study, a grounded theory approach will be followed, data will be collected using semi-structured interviews and analyzed to develop a theory of research direct toward increasing the motivation of engineers to participate in public policy