Field studies were conducted at the Pontotoc Ridge–Flatwoods Branch Experiment Station in Pontotoc, MS, in 2016 and 2017 to determine sweetpotato crop response to saflufenacil and rimsulfuron/thifensulfuron-methyl. Saflufenacil treatments consisted of a factorial of two rates (25 or 50 g ai ha–1) by three application timings [0, 3, or 6 wk before transplanting (WBP)]. Rimsulfuron/thifensulfuron-methyl treatments consisted of a factorial of two rates (18/18 or 35/35 g ai ha–1) by two application timings (3 or 6 WBP). A nontreated check was included for comparison. Saflufenacil resulted in as much as 20% stunting injury in 2016, but ≤4% crop injury in 2017. Compared to the nontreated check, saflufenacil did not reduce yield of any sweetpotato grade regardless of application rate or timing. Findings from this trial indicate that saflufenacil applied in pre-transplanting burndown and field preparation procedures did not have a negative impact on the subsequent sweetpotato crop and that the current plant-back interval (4 to 5 mo) may be excessive. Applications of rimsulfuron/thifensulfuron-methyl at 35/35 g ha–1 made 3 WBP resulted in significant crop injury but did not reduce yield of any sweetpotato grade. Findings from this trial suggest that rimsulfuron/thifensulfuron-methyl applications up to 35/35 g ha–1 applied at least 6 WBP and 18/18 g ha–1 applied at least 3 WBP had little impact on sweetpotato crop growth and may be a safe preplant burndown option.

We present a new solution for the steady boundary-layer flow over the rotating sphere that also accounts for the eruption of the boundary layer at the equator and other higher-order viscous effects. Non-parallel corrections to the local type I and type II convective instability modes of this flow are also computed as a function of spin rate. Our instability results are associated with the previously observed spiral vortices and remarkable agreement between our predictions of the number of vortices and experimental observations is found. Vortices travelling at 70 %–80 % of the local surface speed are found to be the most amplified for sufficient spin rates, also consistent with prior experimental observations.

In this study, a new centrifugal instability mode, which dominates within the boundary-layer flow over a slender rotating cone in still fluid, is used for the first time to model the problem within an enforced oncoming axial flow. The resulting problem necessitates an updated similarity solution to represent the basic flow more accurately than previous studies in the literature. The new mean flow field is subsequently perturbed, leading to disturbance equations that are solved via numerical and short-wavelength asymptotic approaches, yielding favourable comparisons with existing experiments. Essentially, the boundary-layer flow undergoes competition between the streamwise flow component, due to the oncoming flow, and the rotational flow component, due to effect of the spinning cone surface, which can be described mathematically in terms of a control parameter, namely the ratio of streamwise to axial flow. For a slender cone rotating in a sufficiently strong axial flow, the instability mode breaks down into Görtler-type counter-rotating spiral vortices, governed by an underlying centrifugal mechanism, which is consistent with experimental and theoretical studies for a slender rotating cone in otherwise still fluid.

We present the results of two 2.3 μm near-infrared (NIR) radial velocity (RV) surveys to detect exoplanets around 36 nearby and young M dwarfs. We use the CSHELL spectrograph (R ~ 46,000) at the NASA InfraRed Telescope Facility (IRTF), combined with an isotopic methane absorption gas cell for common optical path relative wavelength calibration. We have developed a sophisticated RV forward modeling code that accounts for fringing and other instrumental artifacts present in the spectra. With a spectral grasp of only 5 nm, we are able to reach long-term radial velocity dispersions of ~20–30 m s−1 on our survey targets.

Existing experimental and theoretical studies are discussed which lead to the clear hypothesis of a hitherto unidentified convective instability mode that dominates within the boundary-layer flow over slender rotating cones. The mode manifests as Görtler-type counter-rotating spiral vortices, indicative of a centrifugal mechanism. Although a formulation consistent with the classic rotating-disk problem has been successful in predicting the stability characteristics over broad cones, it is unable to identify such a centrifugal mode as the half-angle is reduced. An alternative formulation is developed and the governing equations solved using both short-wavelength asymptotic and numerical approaches to independently identify the centrifugal mode.

massMobile is a client-server system for large audience participation in live performances using mobile devices. It allows for rapid development, deployment and iterative experimentation in participatory design, while minimising technical and logistical overhead. It was designed to flexibly adapt to a variety of participatory performance needs and to a variety of performance venues. It allows for real-time bi-directional communication between performers and audiences utilising existing 3G, 4G or WiFi networks. Audience members access massMobile through a smartphone-optimised web application utilising common web standards. An offsite server passes data between the audience and the performer(s) and stores the data for later analysis. In this paper, we discuss the goals, design and implementation of the framework, and we describe several projects realised with massMobile.