Long-term Periodicities in the Flux from Low Mass X-ray Binaries

Using data from the All Sky Monitor (ASM) on the Rossi X-ray Timing Explorer (RXTE) we have searched for long term periodicities in the X-ray flux of GX 1+4, Sco X-2 (GX 349+2), and GX 339-4. For GX 1+4 we also used data from BATSE and Galactic Centre scans performed by RXTE. We find no evidence for X-ray modulations at the suggested ~304 d orbital period of GX 1+4. However, we find tentative evidence for a periodicity at 420 d to 460 d. An upper limit of 15% peak-to-peak is set on any sinusoidal modulation in the 1.5 - 3.0 keV flux of Sco X-2 for periods in the 30 to 100 d range. For GX 339-4 we confirm the Low State modulation and report the detection of significant low-frequency modulations in both the High State and Very High State. We fail to detect this modulation in the Off State. We show that if the reported orbital period of GX 339-4 lies in the range 0.5 - 1.7 d, then it is not present in the RXTE ASM light curve.Comment: 7 pages, 8 figures. Accepted for publication in Advanced in Space Research, 16th of March 200

Creative accounting three score years ago; Office management as a profession

Professor Garner brought the following human interest item to the attention of this editor. Emphasis (italics) was supplied throughout by Dr. Garner. From: Alpha Kappa Psi Diary, June, 1924 OFFICE MANAGEMENT AS A PROFESSION By A. W. T. Ogilvie, Gamma Chapter. There is also a note acknowledging Dr. Garner\u27s contribution to the Endowment Fund

Human trafficking in Scotland: the legislative response.

Human trafficking in Scotland has entered the realms of political rhetoric, governmental consciousness and academic debate. Following a summit on human trafficking in October 2012 in Edinburgh Justice Minister Kenny MacAskill said 'We want to send out the message that Scotland is closed for business to traffickers'. The Scottish Government notes on its website that 'Trafficking in human beings is an abhorrent evil practice which has no place in a civilised society'. The non-departmental Equalities and Human Rights Commission (EHRC) has published a thorough report on the subject, in November 2011, following its Inquiry into Human Trafficking in Scotland (EHRC Report 2011). The Report describes in considerable detail human trafficking in Scotland and set out ten findings with accompanying recommendations. A Follow-on Report was recently published, in March 2013. In it the progress made on the recommendations in the period since publication is adjudged. Academically, a body of work focusing on human trafficking in Scotland is beginning to emerge. Through this research a clearer picture of the insidious and complex nature of human trafficking is being demonstrated. There is no doubt that a serious problem exists and that governmental bodies and commentators have started to campaign and research in the area. A specific question arising, from a legal perspective, concerns the nature and adequacy of the legislative response

Edge selective gas detection using Langmuir films of graphene platelets

Recent advances in large-scale production of graphene have led to the availability of solution processable platelets at the commercial scale. Langmuir-Schaefer (L-S) deposition is a scalable process for forming a percolating film of graphene platelets which can be used for electronic gas sensing. Here, we demonstrate the use of this deposition method to produce functional gas sensors, using a chemiresistor structure from commercially-available graphene dispersions. The sensitivity of the devices and repeatability of the electrical response upon gas exposure has been characterized. Raman spectroscopy and Kelvin probe force microscopy (KPFM) show doping of the basal plane using ammonia (n-dopant) and acetone (p-dopant). The resistive signal is increased upon exposure to both gases showing that sensing originates from the change in contact resistance between nanosheets. We demonstrate that Arrhenius fitting of the desorption response potentially allows measurements of the desorption process activation energies for gas molecules adsorbed onto the graphene nanosheets

Graduate College Climate Survey

The purpose of this survey is to assess the diverse climate of graduate students’ experiences at ISU. The retention and persistence of graduate students at ISU continues to be an ongoing topic of conversation within the graduate college and academic departments. Graduate students play an integral role in research and scholarship on campus and it is critical that the department and lab climate foster a positive environment for all graduate students at ISU. In an unhealthy climate, students are less likely to adjust academically and are less likely to develop a sense of belonging on the campus. Assessing campus climate and then taking action to create and sustain a healthy climate are essential steps to creating an environment that supports the fundamental mission of the university —teaching, research, and service. Addressing climate benefits all campus community members, not just historically underrepresented students, faculty and staff. Our aims are to provide an outlet for graduate students to share their experiences within departments, bring awareness of climate issue, and equip faculty, staff and students with the skills and tools need to address current and future problems

[Letter] Size selection of liquid-exfoliated 2D nanosheets

Here we present a size selection model for liquid-exfoliated two-dimensional nanosheets. The ability to consistently select exfoliated nanosheets with desired properties is important for development of applications in all areas. The model presented facilitates determination of centrifugation parameters for production of dispersions with controlled size and thickness for different materials, solvents and exfoliation processes. Importantly, after accounting for the influence of viscosity on exfoliation, comparisons of different solvents are shown to be well described by the surface tension and Hansen parameter matching. This suggests that previous analyses may have overestimated the relative performance of more viscous solvents. This understanding can be extended to develop a model based on the force balance of nanosheets falling under viscous drag during centrifugation. By considering the microscopic aspect ratio relationships, this model can be both calibrated for size selection of nanosheets and compare the exfoliation processes themselves

Selective mechanical transfer deposition of Langmuir graphene films for high-performance silver nanowire hybrid electrodes

In this work we present silver nanowire hybrid electrodes, prepared through the addition of small quantities of pristine graphene by mechanical transfer deposition from surface-assembled Langmuir films. This technique is a fast, efficient, and facile method for modifying the opto-electronic performance of AgNW films. We demonstrate that it is possible to use this technique to perform two-step device production by selective patterning of the stamp used, leading to controlled variation in the local sheet resistance across a device. This is particularly attractive for producing extremely low-cost sensors on arbitrarily large scales. Our aim is to address some of the concerns surrounding the use of AgNW films as replacements for indium tin oxide (ITO); namely the use of scarce materials and poor stability of AgNWs against flexural and environmental degradation

Developing and evaluating complex interventions: the new Medical Research Council guidance

<p><i>Evaluating complex interventions is complicated. The Medical Research Council's evaluation framework (2000) brought welcome clarity to the task. Now the council has updated its guidance</i></p> <p>Complex interventions are widely used in the health service, in public health practice, and in areas of social policy that have important health consequences, such as education, transport, and housing. They present various problems for evaluators, in addition to the practical and methodological difficulties that any successful evaluation must overcome. In 2000, the Medical Research Council (MRC) published a framework<sup>1</sup> to help researchers and research funders to recognise and adopt appropriate methods. The framework has been highly influential, and the accompanying BMJ paper is widely cited.<sup>2</sup> However, much valuable experience has since accumulated of both conventional and more innovative methods. This has now been incorporated in comprehensively revised and updated guidance recently released by the MRC (<a href="www.mrc.ac.uk/complexinterventionsguidance">www.mrc.ac.uk/complexinterventionsguidance</a>). In this article we summarise the issues that prompted the revision and the key messages of the new guidance. </p&gt

Bioarchaeological and Climatological Evidence for the Fate of Norse Farmers in Medieval Greenland

Greenland, far north land of the Atlantic, has often been beyond the limit of European farming settlement. One of its Norse settlements, colonized just before AD 1000, is — astonishingly — not even at the southern tip, but a way up the west coast, the \u27Western Settlement\u27. Environmental studies show why its occupation came to an end within five centuries, leaving Greenland once more a place of Arctic-adapted hunters