Memory erasure in small systems

We consider an overdamped nanoparticle in a driven double-well potential as a generic model of an erasable one-bit memory. We study in detail the statistics of the heat dissipated during an erasure process and show that full erasure may be achieved by dissipating less heat than the Landauer bound. We quantify the occurrence of such events and propose a single-particle experiment to verify our predictions. Our results show that Landauer's principle has to be generalized at the nanoscale to accommodate heat fluctuations.Comment: 4 pages, 4 figure

Quantitative tests of mixed crystal exciton theory. II. Energy denominator study of naphthalene 1B2u resonance pairs

A spectroscopic absorption study is presented of 1‐D1C10H7, 2‐D1C10H7, and 1,4‐D2C10H7 resonance pairs in C10D8, over a concentration range of 0.009% to 5% mole, at 2 °K, with a resolution of 0.5 cm−1. The resulting structure is interpreted in terms of the pairwise exciton exchange interactions, M1/2(a+b), Ma, Mb, Mc, Ma+c, and M1/2(a+b)+c. The energy denominator dependence is interpreted in terms of both exciton quasiresonance and exciton superexchange. The three parameter sets derived by Hong and Kopelman to fit earlier data on neat and isotopic mixed crystals are corroborated by this study, as they were in our previous study on monomers (I). However, it was not possible to narrow down completely the choice of parameters. A discussion is given on the feasibility of deriving a unique dispersion relation (and Green’s function) for the first naphthalene singlet exciton and on its likely precision.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70131/2/JCPSA6-66-4-1599-1.pd

Visualization of steps and surface reconstructions in Helium Ion Microscopy with atomic precision

Helium Ion Microscopy is known for its surface sensitivity and high lateral resolution. Here, we present results of a Helium Ion Microscopy based investigation of a surface confined alloy of Ag on Pt(111). Based on a change of the work function of 25\,meV across the atomically flat terraces we can distinguish Pt rich from Pt poor areas and visualize the single atomic layer high steps between the terraces. Furthermore, dechanneling contrast has been utilized to measure the periodicity of the hcp/fcc pattern formed in the 2--3 layers thick Ag/Pt alloy film. A periodicity of 6.65\,nm along the $\langle\overline{11}2\rangle$ surface direction has been measured. In terms of crystallography a hcp domain is obtained through a lateral displacement of a part of the outermost layer by $1/\sqrt{3}$ of a nearest neighbour spacing along $\langle\overline{11}2\rangle$. This periodicity is measured with atomic precision: coincidence between the Ag and the Pt lattices is observed for 23 Ag atoms on 24 Pt atoms. The findings are perfectly in line with results obtained with Low Energy Electron Microscopy and Phase Contrast Atomic Force Microscopy.Comment: 15 pages, 7 figure

From Convergence to Connectivism: Teaching Journalism 2.0

Media Convergence leads to fundamental changes in the journalistic field. This is a challenge not only for the news industry but also for teaching journalism at universities. Improved skills and competences are needed in multi-modal editorial planning and cross-channel develop-ment of news stories. This paper describes the main drivers of change in the news industry, discusses consequences for journalism and teaching, and offers an innovative didactical ap-proach, which combines an interdisciplinary perspective with the concept of connectivism and cognitive apprenticeship. The consequences of convergence that affect journalism educa-tion are inspected under three sub-topics: the changes in the curricula, the changes in the courses syllabi, and the changes in the technological infrastructures of the academic institu-tions. It is pointed out, that recognizing connections and patterns to develop novel ideas and concepts is the core skill for individuals today. The paper shows, how that approach could be realized in an international 10-day-intensive program

LIFE-SHARE Project: Developing a Digitisation Strategy Toolkit

This poster will outline the Digitisation Strategy Toolkit created as part of the LIFE-SHARE project. The toolkit is based on the lifecycle model created by the LIFE project and explores the creation, acquisition, ingest, preservation (bit-stream and content) and access requirements for a digitisation strategy. This covers the policies and infrastructure required in libraries to establish successful practices. The toolkit also provides both internal and external resources to support the service. This poster will illustrate how the toolkit works effectively to support digitisation with examples from three case studies at the Universities of Leeds, Sheffield and York

Female Labor Outcomes and Large-scale Land Investments in Tanzania

The current transformation of the agricultural sector in many African countries has been perceived to be connected to land resources and the quest to advance agriculture as a commercial enterprise. The main expectations in this agricultural transformation include increased productivity, job creation, and rural development. This paper examines to what extent this alleged transformation has delivered on its promises, particularly for rural women. We conduct comparative analyses using the Living Standards Measurement Study-Integrated Surveys on Agriculture (LSMS-ISA) dataset, complemented with a survey from two case studies of large-scale land investments (LLIs) in Kilombero district, Morogoro region, Tanzania. The finding from the study shows that the LLIs have no significant effect on agricultural wage. However, the results show that LLIs have a negative effect on the welfare of female-headed households located in communities with LLIs. Looking at the case studies, however, we find that female-headed households working in the LLIs earned slightly lower agricultural wage compared to those not working in the LLIs. This implies that the use of LLIs in Tanzania to drive agricultural transformation requires better targeting of potential beneficiaries

Dark matter concentration in the galactic center

It is shown that the matter concentration observed through stellar motion at the galactic center (Eckart & Genzel, 1997, MNRAS, 284, 576 and Genzel et al., 1996, ApJ, 472, 153) is consistent with a supermassive object of $2.5 \times 10^6$ solar masses composed of self-gravitating, degenerate heavy neutrinos, as an alternative to the black hole interpretation. According to the observational data, the lower bounds on possible neutrino masses are $m_\nu \geq 12.0$ keV$/c^2$ for $g=2$ or $m_\nu \geq 14.3$ keV$/c^2$ for $g=1$, where $g$ is the spin degeneracy factor. The advantage of this scenario is that it could naturally explain the low X-ray and gamma ray activity of Sgr A$^*$, i.e. the so called "blackness problem" of the galactic center.Comment: ApJ, 500, 591 (1998), AASTEX, aasms4.sty, v2 reference adde