We thought it might encourage participation.” Using lottery incentives to improve LibQUAL+(TM) response rates among students

Libraries deploying the LibQUAL+™ survey can offer a lottery incentive and many do in the hope of increasing response rates. Other libraries may be prohibited from offering one because of Institutional Review Board restrictions, as is the case at [institution name]. We wanted to discover why libraries offer lottery incentives and what kinds and if they believe these incentives have a positive impact on their response rates. The responding libraries hold a general belief that lottery incentives are effective but base this on feeling rather than research. We examine what the literature says about lottery incentives and student populations

Generation of 1180 Å period gratings with a Xe ion laser

Holographic lithography with the 2315 Å line of a xenon ion laser is used to produce gratings in polymethylmethacrylate. An 1180 Å period grating is made and examined with a scanning electron microscope (SEM). This grating period is appropriate for use as a first-order grating with a GaAs distributed feedback laser

The relationship between the surface pressure spectrum and transverse velocity spectrum in a Rapid-distortion theory model of trailing edge noise

Accurate jet-surface interaction noise prediction remains an important aspect of the aircraft design process. This is particularly true for the next generation aircraft configurations, one of which could see the exhaust system tightly integrated to the airframe. Use of Rapid- distortion theory of turbulence (RDT) to determine the radiated sound represents one such approach to model the sound generation/propagation process. Recent work on the application of RDT to the canonical problem of a jet flow interacting with a flat plate trailing edge gave accurate predictions across the frequency and acoustic Mach number range. In this paper we ascertain whether an RDT based model that uses the unsteady surface pressure spectrum as the source term can also be utilized to determine accurate edge noise predictions. Surface pressure based models have been widely used in the Amiet formulation of trailing edge noise. The upstream boundary condition in the RDT formulation enters via a streamwise convected quantity, ω ̃c(τ − y1/U(yT ), yT ), that is an arbitrary function of its arguments. But since the pressure fluctuation possesses an upstream asymptote that decays algebraically faster than curl of the out-of-plane vorticity fluctuation in the local hydrodynamic relation given by Eq. 3.9 in Goldstein, Leib & Afsar (J. Fluid Mech., vol. 824, pp. 477-512, 2017), this latter relation cannot be used to determine the surface pressure near the trailing edge. In this paper we show to obtain this relation using an inversion of Fourier transforms similar to that used in our earlier paper Goldstein, Afsar & Leib (J. Fluid Mech., vol. 736, pp. 532-569, 2013). The relation we obtain shows how the surface pressure spectrum can therefore be related to the velocity fluctuation correlation function

Tourists' perceptions of the free-roaming dog population in Samoa

A study was undertaken to establish how visiting tourists to Samoa perceived free-roaming dogs (Canis familiaris) and their management, additionally some factors that influence their perceptions were assessed. Questionnaires were administered to 281 tourists across Samoa over 5 weeks. Free-roaming dogs were seen by 98.2% (n = 269/274) of respondents, with 64.9% (n = 137/211) reporting that their presence had a negative effect on overall holiday experience. Respondents staying in the Apia (capital city) area were more likely to consider dogs a problem (p < 0.0001), and there was a significant association between whether the respondent owned a dog and if they thought dogs were a nuisance in Samoa (p < 0.003). Forty-four percent (20/89) of non-dog owners agreed that dogs were a nuisance compared to 22% (80/182) of dog owners. The majority felt that dogs required better control and management in Samoa (81%, n = 222) and that there were too many “stray” dogs (67.9%, n = 188). More respondents were negatively affected by the dogs’ presence (64.9%, 137/211), and felt that the dogs made their holiday worse, than respondents that felt the dogs’ presence improved their holiday experience (35.1%, 74/211). Most respondents stated that the dogs had a low impact (one to three; 68%, 187/275) on their stay in Samoa, whilst 24% (65/275) and 8% (23/275) stated they had a medium or high impact, respectively, on their stay. Respondents showed strong support for humane population management. Free-roaming dogs present a complex problem for Samoa and for its tourism industry in particular. The findings of this study further support the need for more discussion and action about the provision of veterinary services and population management for dogs in Samoa. It also provides information complementing an earlier study of the attitudes of local Samoans

Conservation laws of semidiscrete canonical Hamiltonian equations

There are many evolution partial differential equations which can be cast into Hamiltonian form. Conservation laws of these equations are related to one-parameter Hamiltonian symmetries admitted by the PDEs. The same result holds for semidiscrete Hamiltonian equations. In this paper we consider semidiscrete canonical Hamiltonian equations. Using symmetries, we find conservation laws for the semidiscretized nonlinear wave equation and Schrodinger equation.Comment: 19 pages, 2 table

Experimental Investigation of a One-Sided Ejector Nozzle

A fundamental exploratory experiment is conducted assessing the performance of a one-sided ejector with the eventual goal of noise reduction for jet engines. The hardware is comprised of an 8:1 rectangular nozzle together with an ejector box whose lower surface is flush with the lower lip of the nozzle. Secondary flow is allowed through a gap between the upper lip of the nozzle and a flap that constitutes the upper surface of the ejector. Wall static pressures and Pitot probe surveys are conducted to evaluate the performance of the ejector with variation of geometric parameters. It is found that addition of vortex generating tabs at the upper lip of the nozzle significantly increases secondary flow entrainment. The entrainment is further enhanced by a divergence of the ejector upper surface. Limited noise measurements are done. The baseline ejector (without tabs) often encounters flow resonance with accompanying tones. The tabs have the additional benefit of eliminating those tones in all cases. However, for the tabbed case, addition of the ejector produces insignificant further noise reduction. This is due to the fact that the flow remains unmixed on the lower half of the ejector. The focus of ongoing and future efforts is to achieve sufficient mixing of the flow so that the exhaust velocities are uniformly low, while keeping the ejector hardware short and lightweight

Precise Repair of mPing Excision Sites is Facilitated by Target Site Duplication Derived Microhomology

A key difference between the Tourist and Stowaway families of miniature inverted repeat transposable elements (MITEs) is the manner in which their excision alters the genome. Upon excision, Stowaway-like MITEs and the associated Mariner elements usually leave behind a small duplication and short sequences from the end of the element. These small insertions or deletions known as “footprints” can potentially disrupt coding or regulatory sequences. In contrast, Tourist-like MITEs and the associated PIF/Pong/Harbinger elements generally excise precisely, returning the genome to its original state. The purpose of this study was to determine the mechanisms underlying these excision differences, including the role of the host DNA repair mechanisms