An atomistic study on the stretching of nanowires

In this work we present an atomic-scale investigation of elastic and plastic deformation, and force variations in metal nanowires that are pulled from their ends. The atomic simulations are performed by using a molecular dynamics method with an empirical two-body potential; the effect of the initial size, shape, temperature and rate of stretching on the necking and fracture are investigated. We find that the necking occurs mainly due to the formation of a new layer with a smaller cross-section after every structural yield, and concurrently the tensile force falls abruptly. The relationship between the atomic structure and the conductance of the wire is analysed by constructing a realistic potential for the neck in terms of a linear combination of atomic pseudopotentials and by calculating the conductance using the transfer matrix method. Our results show that the variation of the conductance is strongly correlated with the sudden structural changes in the neck, and reflects the quantization of electronic states in the neck, but not the quantization of the conductance

A novel index in healthy infants and children — subarachnoid space: ventricle ratio

Background: The subarachnoid space (SAS) and ventricular width (VW) in normalinfants and children were studied with ultrasonography to provide the objectivemeasurement and define a normal range for these measurements. The additional aim was to determine the stable ratio as a SAS/VW.Materials and methods: A total of 100 healthy subjects, including 48 males and52 females, were studied. The cases were divided into 3 age groups: 0–6 months(n = 65), 7–12 months (n = 24) and > 13 months (n = 11). Transfontanel ultrasonography was performed in all the cases. SAS, VW and the SAS/VW ratios were calculated. The study was approved by the ethical committee. All parents wereinformed about the sonographic examination and their approvals were taken.Results: SAS was calculated as 3.1 (0.5–6) mm and VW was calculated as 3.6(1.3–5) mm. SAS/VW ratio was 0.9 ± 0.3. There was no statistically significant difference among SAS, VW and SAS/VW ratios in 3–97 percentile group (p > 0.05).Conclusions: Ultrasonography can be used as a practicable and reproducible modalityin the measurement of SAS and VW in healthy children. It is a non-invasivemethod and allows for serial follow-up. SAS/VW ratio can be used as an index inhealthy children

A General Approach for the Exact Solution of the Schrodinger Equation

The Schr\"{o}dinger equation is solved exactly for some well known potentials. Solutions are obtained reducing the Schr\"{o}dinger equation into a second order differential equation by using an appropriate coordinate transformation. The Nikiforov-Uvarov method is used in the calculations to get energy eigenvalues and the corresponding wave functions.Comment: 20 page

Dealing with tyranny: Fulke Greville’s Mustapha in the context of his other writings and of his view on Anglo-Ottoman relations [Fulke greville’in mustapha’sını yazarın diğer politik yazıları ve İngiliz-osmanlı İlişkileri Üzerine görüşleri işığında yeniden okumak]

Mustapha, the tragedy by Fulke Greville depicting the execution of the eldest son of Suleyman the Magnificent, has received increasing attention in recent research on representations of the Eastern “other.” Unlike earlier works treating Mustapha as an anti-absolutist work with an only incidental Ottoman context, recent studies have underlined Greville’s seemingly balanced depiction of the Ottomans, showing both good and bad Ottoman characters. Accepting and elaborating on the actual importance of the Ottoman context in Mustapha, the present article challenges these recent studies. First, it compares Mustapha to the literary and narrative sources available to Greville and concludes that Greville does not produce a more nuanced rhetoric such as has been argued to exist in other early modern English plays. Second, taking Greville’s two other narrative works into account, it argues that his representation of the Ottoman Empire in Mustapha is closely connected to his overall evaluation of it as a political theorist. © 2015, ISAM, Turkish Religious Foundation Centre for Islamic Studies. All rights reserved

Investigation of Metal and Non-Metal Doped Dimer and Trimer C-60 Fullerene Chains as Prospective Spin Cluster Qubits

We have calculated the optimized geometries, electronic structures and spin distributions of metal and non-metal elements Li, Na, N and P doped C60 fullerene dimers and trimers with different spin multiplicities using hybrid density functional theory (DFT) at the B3LYP/6-31G level of theory. Natural population analysis and Mulliken population analysis show that non-metal elements (N, P) inside the C60 fullerene dimers and trimers are well isolated and preserve their electronic structures while charge transfer processes occur between metal elements (Li, Na) and C60 structures. Energy calculations showed that both doped and undoped linear C60 structures are energetically lower than triangular C60 structures. Calculated spin density distributions make non-metal doped C60 structures advantageous over metal doped C60 cases as spin cluster qubits

Energetics of carbon nanotubes

We have investigated the energetics of carbon nanotubes. Calculations have been performed by using the empirical many-body potential energy function developed by Tersoff for carbon

Carbon Nanobuggy is Ready for a Test Drive!

A nanostructure made of carbon atoms, resembling a real world buggy car has been designed respecting the sp2 bonding of the carbons as present in graphene and derived systems. The components of the carbon nanobuggy (nanotubes, nanotori, nanojunctions and nanogears) had been observed and tested for their stability in previous works, endorsing the stability and the plausibility of the nanobuggy itself. The resulting nanobuggy is optimized using MM+ force field

Some criteria for solvability and nilpotency of finite groups by strongly monolithic characters

http://dx.doi.org/10.1017/S000497271200033

A comparative study of empirical potential energy functions: Applications to clusters

We have made a comparative study for the empirical potential energy functions proposed and parametrized for coinacal metals, namely Cu, Ag, and Au. We have considered four different potential energy functions, and applied them to investigate the structural properties and energetics of clusters of the elements considered

Investigating students' mental models about the quantization of light, energy, and angular momentum

This paper is the first part of a multiphase study examining students' mental models about the quantization of physical observables - light, energy, and angular momentum. Thirty-one second-year physics and physics education college students who were taking a modern physics course participated in the study. The qualitative analysis of data revealed six variations in students' mental models about the quantization of physical observables: scientific model, primitive scientific model, shredding model, alternating model, integrative model, and evolution model. These models were determined to be context dependent. In addition, some students are in a mixed-model state where they use multiple mental models in explaining a phenomenon and use these models inconsistently. © Published by the American Physical Society