The Scaled-Charge Additive Force Field for Amino Acid Based Ionic Liquids

Abstract. Ionic liquids (ILs) constitute an emerging field of research. New ILs are continuously introduced involving more and more organic and inorganic ions. Amino acid based ILs (AAILs) represent a specific interest due to their evolutional connection to proteins. We report a new non- polarizable force field (FF) for the eight AAILs comprising 1-ethyl-3-methylimidazolium cation and amino acid anions. The anions were obtained via deprotonation of carboxyl group. Specific cation-anion non-covalent interactions have been taken into account by computing electrostatic potential for ion pairs, in contrast to isolated ions. The van der Waals interactions have been transferred from the CHARMM36 FF with minor modifications. Therefore, compatibility between our parameters and CHARMM36 parameters is preserved. Our FF can be easily implemented using a variety of popular molecular dynamics programs. It will find broad applications in computational investigation of ILs

Exploding Nitromethane in silico, in real time

Nitromethane (NM) is widely applied in chemical technology as a solvent for extraction, cleaning and chemical synthesis. NM was considered safe for a long time, until a railroad tanker car exploded in 1958. We investigate detonation kinetics and reaction mechanisms in a variety of systems consisting of NM, molecular oxygen and water vapor. State-of-the-art reactive molecular dynamics allows us to simulate reactions in time-domain, as they occur in real life. High polarity of the NM molecule is shown to play an important role, driving the first exothermic step of the reaction. Presence of oxygen is important for faster oxidation, whereas its optimal concentration is in agreement with the proposed reaction mechanism. Addition of water (50 mol%) inhibits detonation; however, water does not prevent detonation entirely. The reported results provide important insights for improving applications of NM and preserving safety of industrial processes.Comment: arXiv admin note: text overlap with arXiv:1408.372

Policing in the United States: Balancing Crime Fighting and Legal Rights

Policing in any nation is an inextricable and essential aspect of the existing government. The government of the United States is an elected democracy. It is a tripartite system including legislative, executive, and judicial branches. Essentially, the legislature creates the laws, the executive is charged with enforcing laws, and the judiciary interprets the laws. At the federal level these branches are the president, Congress, and federal courts (the highest court being the United States Supreme Court). Because the founding fathers of the U.S. (the authors and supporters of the Constitution of the United States) feared tyranny, no branch of government has unlimited power. That is, the branches of government check and balance one another. As James Madison writes in The Federalist Papers (No. 48), “An elective despotism was not the government we fought for; but one which should not only be founded on free principles, but in which the powers of government should be so divided and balanced among several bodies of magistracy as that no one could transcend their legal limits without being effectually checked and restrained by the others.” Americans, taken as a whole, cherish these limits and the freedoms that come with them

Molecular interactions between fullerene C-60 and ionic liquids

Structural and energetic aspects of solvation of fullerene C-60 in ionic liquids at room temperature were analyzed by using atomistic molecular dynamics simulations. Ethylammonium Nitrate (EAN) and 1-Butyl-3-Methylimidazolium Tetrafluoroborate (BMIMBF4) ionic liquids were conveniently chosen for presenting different polarities. Analysis of the spatial distribution of the ionic liquid revealed different patterns for the solvation of C-60. Energetics indicated that the presence of C-60 weakened the ionic interactions in solution compared to those in pure liquids. Our free energy calculations showed that there is an energy cost of 235 kJ mol(-1) for transferring fullerene C-60 from BMIMBF4 to EAN. (C) 2013 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210270 Santo Andre, SP, BrazilUniversidade Federal de São Paulo, Inst Ciencia & Tecnol, BR-12231280 Sao Jose Dos Campos, SP, BrazilUniversidade Federal de São Paulo, Inst Ciencia & Tecnol, BR-12231280 Sao Jose Dos Campos, SP, BrazilWeb of Scienc

Initial design and evaluation of automatic restructurable flight control system concepts

Results of efforts to develop automatic control design procedures for restructurable aircraft control systems is presented. The restructurable aircraft control problem involves designing a fault tolerance control system which can accommodate a wide variety of unanticipated aircraft failure. Under NASA sponsorship, many of the technologies which make such a system possible were developed and tested. Future work will focus on developing a methodology for integrating these technologies and demonstration of a complete system

Attitude Determination and Control Systems

The importance of accurately pointing spacecraft to our daily lives is pervasive, yet somehow escapes the notice of most people. In this section, we will summarize the processes and technologies used in designing and operating spacecraft pointing (i.e. attitude) systems