Investigation of a 2-Colour Undulator FEL Using Puffin

Initial studies of a 2-colour FEL amplifier using one monoenergetic electron beam are presented. The interaction is modelled using the unaveraged, broadband FEL code Puffin. A series of undulator modules are tuned to generate two resonant frequencies along the FEL interaction and a self-consistent 2-colour FEL interaction at widely spaced non-harmonic wavelengths at 1nm and 2.4nm is demonstrated.Comment: Submitted to The 35th International Free-Electron Laser Conference, Manhattan, New York (2013

MEASURING THE IMPACTS OF PRIME-AGE ADULT DEATH ON RURAL HOUSEHOLDS IN KENYA

Using a two-year panel of 1,422 Kenyan households surveyed in 1997 and 2000, we measure how working-age adult mortality affects rural households= size and composition, crop production, asset levels, and off-farm income. First, the paper uses adult mortality rates from available data on an HIV-negative sample to predict the proportion of deaths observed between 1997 and 2000 due to AIDS. Next, using a difference-in-differences estimation, we measure changes in outcomes between households afflicted by adult mortality vs. those not afflicted over the three-year survey period. The effects of adult mortality are highly sensitive to the gender and position of the deceased family member in the household. Households suffering the death of the head-of-household or spouse incurred a greater-than-one person loss in household size. The death of a male head-of-household between 16 and 59 years is associated with a 68% reduction in the net value of the household=s crop production. Female head-of-household or spouse mortality causes a greater decline in cereal area cultivated, while cash crops such as coffee, tea, and sugar are most adversely affected in households incurring the death of a male head-of-household. Off-farm income is also significantly affected by the death of the male head-of-household, but not in the case of other adult members. The death of other working-age family members is partially offset by an inflow of other individuals into the family and has less dramatic effects on the households= agricultural production, assets, and off-farm income. The effects of adult mortality are also sensitive to the household=s initial asset levels. Lastly, there is little indication that households are able to recover quickly from the effects of working-age head-of-household adult mortality; the effects on crop and non-farm incomes do not decay at least over the three-year survey interval.Consumer/Household Economics,

Doug Murray’s The ‘Nam: A Literary examination of the Traumatic Effects of War Told through Visual Literature

This thesis examines Marvel’s The ‘Nam comic series, written by Doug Murray, through the analytical lens of trauma studies. The paper looks at the early run of the comic series, and shows how the author of the comic book exposes the readers to the traumas of being a US Army infantry man serving in Vietnam. The third chapter explores how the draft and the young age of the soldiers played a role in their experience of trauma and how they reacted to it, while the fourth chapter explains how the traumas of war affected the soldiers during their time in war. The fifth chapter examines the use of the comic book as a medium and shows how the comic book was used to amerce the reader into the experiences of trauma that the young soldiers of the comic stories had to live through. Finally, the paper concludes with how comic books, specifically comics like The ‘Nam, can be used in education and as a tool to start a conversation about what it means to be a veteran of war

Living History and War Reenactment Stories From Weekend Warriors

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Surfing or still drowning? Student nurses’ Internet skills

A study into student nurses’ ability to use the Internet was published in Nurse Education Today in 2004. This paper repeats the research with a cohort of students starting their pre-registration programme in a UK university in 2007. In 2004 students were reported as having poor Internet skills, and as not being frequent users of the Internet. In this study students were found to have significantly better ability to carry out basic tasks and significantly higher levels of Internet use. Their ability to apply these skills to more complex information literacy tasks however had not increased, with more than half of all students saying they found far too much irrelevant information when searching for specific information on the Internet. The earlier study found that skills and age were not related, which appears to still be the case. The need for these skills is increasing as education, lifelong learning, and patient information are all increasingly drawing on the developing Internet. Nurse education however is not integrating the skill and knowledge base essential to support this into pre-registration programmes, and the evidence suggests that this will not happen without active management

An extended model of the quantum free-electron laser

Previous models of the quantum regime of operation of the Free Electron Laser (QFEL) have performed an averaging and the application of periodic boundary conditions to the coupled Maxwell - Schrodinger equations over short, resonant wavelength intervals of the interaction. Here, an extended, one-dimensional model of the QFEL interaction is presented in the absence of any such averaging or application of periodic boundary conditions, the absence of the latter allowing electron diffusion processes to be modeled throughout the pulse. The model is used to investigate how both the steady-state (CW) and pulsed regimes of QFEL operation are affected. In the steady-state regime it is found that the electrons are confined to evolve as a 2-level system, similar to the previous QFEL models. In the pulsed regime Coherent Spontaneous Emission (CSE) due to the shape of the electron pulse current distribution is shown to be present in the QFEL regime for the first time. However, unlike the classical case, CSE in the QFEL is damped by the effects of quantum diffusion of the electron wavefunction. Electron recoil from the QFEL interaction can also cause a diffusive drift between the recoiled and non-recoiled parts of the electron pulse wavefunction, effectively removing the recoiled part from the primary electron-radiation interaction.Comment: Submitted to Optics Expres

Vibrational frequencies and tuning of the African mbira

The acoustic spectrum of the mbira, a musical instrument from Africa that produces sound by the vibration of cantilevered metal rods, has been measured. It is found that the most prominent overtones present in the spectrum have frequencies that are approximately 5 and 14 times the lowest frequency. A finite-element model of the vibration of the key that takes into account the acoustic radiation efficiency of the various normal modes reveals that the far-field power spectrum is dominated by modes involving predominately transverse motion of the key. Modes involving longitudinal motion do not radiate efficiently, and therefore contribute little to the sound produced. The high frequencies of the dominant overtones relative to the fundamental make it unlikely that the tunings of the mbira that are used by expert musicians are determined by matching the fundamental frequencies of the upper keys with the overtones of the lower keys

Decreasing the Polymerization Potential Improves the Selectivity of PPD-Coated Disc Biosensors for Glutamate

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The selectivity of glutamate microdisc biosensors coated with poly(o-phenylenediamine) (PPD) as the interference-rejecting layer against ascorbic acid was observed to be very low. Enhancement in the selectivity was noticed when the electropolymerization potential for the polymerization of the o-phenylenediamine monomer was decreased from 0.65 V to 0.40 V vs. Ag/AgCl. The selectivity coefficient increased from −34.93±3.75% (n = 5) to 53.05 ± 4.33% (n = 3). Decreasing the polymerization potential decreases the rate of formation of the polymer and improves the compactness of the polymer layer formed, thereby increasing the selectivity of the electrodes