Laser precipitation monitor for measurement of drop size and velocity of moving spray-plate sprinklers

Sprinkler drop size distribution and associated drop velocities have a major influence on sprinkler performance in regards to application intensity, uniformity of water application, wind drift, evaporation losses and kinetic energy transferred to the soil surface. Sprinkler drop size measurements are either labor intensive or require use of expensive equipment, both of which limit data availability. Sprinkler drop velocity data are more limited than drop size data due to measurement difficulty and associated cost of labor and instrumentation. An economical laser instrument commercially marketed for real-time rainfall measurements as a Laser Precipitation Monitor (LPM) was used to measure drop size and velocity from ten moving spray-plate type sprinklers. Measured drop size and velocity were used to determine sprinkler drop size distribution and kinetic energy applied to the soil by sprinkler discharge. Drop size distributions measured by the LPM were compared to drop size distributions measured in earlier studies using the traditional flour pellet method. Eight of the ten measured drop size distributions were not significantly different between measurement methods. However, the operating conditions when the two methods did not compare well were outside sprinkler manufacturer specifications. Based on this limited study the results from the two drop size measurement methods can be vastly different for sprinklers with relatively compact streams of water drops. Which method is more accurate for this condition remains unknown. Kinetic energy values calculated using measured drop size and velocity data were not significantly different from values determined using flour pellet drop size data and a ballistic model for estimating sprinkler drop tangential velocity. The economical laser instrument used in this study provided a relatively easy means to obtain reliable estimates of sprinkler kinetic energy per unit volume of applied water for various moving spray-plate sprinkler types and operating conditions. Estimated drop size distribution and computed kinetic energy applied by sprinkler discharge is sufficient for practical field application purposes

`In pursuit of the Nazi mind?' the deployment of psychoanalysis in the allied struggle against Germany

This paper discusses how psychoanalytic ideas were brought to bear in the Allied struggle against the Third Reich and explores some of the claims that were made about this endeavour. It shows how a variety of studies of Fascist psychopathology, centred on the concept of superego, were mobilized in military intelligence, post-war planning and policy recommendations for ‘denazification’. Freud's ideas were sometimes championed by particular army doctors and government planners; at other times they were combined with, or displaced by, competing, psychiatric and psychological forms of treatment and diverse studies of the Fascist ‘personality’. This is illustrated through a discussion of the treatment and interpretation of the deputy leader of the Nazi Party, Rudolf Hess, after his arrival in Britain in 1941

Comparison of sprinkler droplet size and velocity measurements using a laser precipitation meter and photographic method

Kinetic energy of water droplets has a substantial effect on development of a soil surface seal and infiltration rate of bare soil. Methods for measuring sprinkler droplet size and velocity needed to calculate droplet kinetic energy have been developed and tested over the past 50 years, each with advantages, disadvantages, and limitations. A laser precipitation meter and photographic method were used to measure droplet size and velocity from an impact sprinkler at three pressures and one nozzle size. Significant differences in cumulative volume drop size distributions derived from the two measurement methods were found, especially at the highest operating pressure. Significant differences in droplet velocities were found between measurement methods as well. Significant differences were attributed to differences in minimum drop sizes measured; 0.5mm for the photographic method versus 0.2 mm for the laser precipitation meter. The laser precipitation meter provided smaller cumulative volume drop size distributions compared to the photographic measurement method. The laser precipitation meter tended to provide greater drop velocities which were attributed to altitude differences at experimental sites. The difference in calculated droplet kinetic energy per unit volume based on drop and size velocity data from the laser precipitation meter and the photographic method ranged from +12.5 to -28%. The laser precipitation meter generally provided a lower estimate of sprinkler kinetic energy due to the measurement of a greater proportion of smaller drop sizes. Either method can be used to obtain drop size and velocity sprinkler drops needed to calculate sprinkler kinetic energy. The laser precipitation meter requires less skill and labor to measure drop size and velocity

Comparison of drop size and velocity measurements by a laser precipitation meter and low-speed photography for an agricultural sprinkler

Kinetic energy of water droplets has a substantial effect on development of a soil surface seal and infiltration rate of bare soil. Methods for measuring sprinkler droplet size and velocity needed to calculate droplet kinetic energy have been developed and tested over the past 50 years, each with advantages, disadvantages, and limitations. Drop size and velocity of an impact sprinkler at three operating pressures and one nozzle size were measured using a laser precipitation meter and compared with published values obtained using a photographic method. Significant differences in cumulative volume drop size distributions derived from the two measurement methods were found, especially at the highest operating pressure. Significant differences in droplet velocities were found between measurement methods as well. Significant differences were attributed to differences in minimum drop sizes measured; 0.5mm for the photographic method versus 0.2 mm for the laser precipitation meter. The laser precipitation meter provided smaller cumulative volume drop size distributions compared to the photographic measurement method. The laser precipitation meter tended to provide greater drop velocities which were attributed to altitude differences at experimental sites. The difference in calculated droplet kinetic energy per unit drop volume based on drop and size velocity data from the laser precipitation meter and the photographic method ranged from +12.5 to -28%. The laser precipitation meter generally provided a lower estimate of sprinkler kinetic energy due to the measurement of a greater proportion of smaller drop sizes. Either method can be used to obtain drop size and velocity sprinkler drops needed to calculate sprinkler kinetic energy. The laser precipitation meter requires less skill and labor to measure drop size and velocity

Collector design for measuring high intensity time variant sprinkler application rates

Peak water application rate in relation to soil water infiltration rate and soil surface storage capacity is important in the design of center pivot sprinkler irrigation systems for efficient irrigation and soil erosion control. Measurement of application rates of center pivot irrigation systems has traditionally used tipping bucket rain gauges. Calculation of application rate from tipping bucket rain gauge measurements restricts computed application rate to a discrete multiple of the rain gauge resolution and time interval. This limits the resolution of application rate measurement, especially for time intervals less than 15 minutes. A collector was designed to measure time variant high intensity sprinkler application rates under field conditions with greater resolution than a tipping bucket rain gauge. The collector funnels water into a 50 mm (2 in.) diameter tube providing a depth multiplication factor of 18.26:1. The depth of water in the tube is measured with a low pressure piezo-resistive pressure sensor connected to a differential amplifier circuit. Combination of the depth multiplication factor of the collector and differential amplifier circuit provides a collector resolution of 1.4 mm/mV. A data logger is used to record water depth in the collector tube during an irrigation event. A digital differentiating filter was designed and used to reduce the effect of random electrical noise in the sensor output on calculated application rate. The collector was tested in the laboratory and under field conditions emulating center pivot sprinkler irrigation. For a range in application rates from 15 to 200 mm/h in the laboratory, the maximum collector error was 2.1 mm/h. Collector measured application rate patterns under field conditions were well correlated to simulated application rate patterns using radial application rate profiles for the sprinklers tested. Collector measured peak application rates were not significantly different from those predicted by the Kincaid (2005) model. The collector functioned as designed in field tests and provided an effective and efficient means of measuring high intensity application rates from center pivot irrigation systems under field conditions

Unification, KK-thresholds and the top Yukawa coupling in F-theory GUTs

In a class of F-theory SU(5) GUTs the low energy chiral mass spectrum is obtained from rank one fermion mass textures with a hierarchical structure organised by U(1) symmetries embedded in the exceptional E_8 group. In these theories chiral fields reside on matter `curves' and the tree level masses are computed from integrals of overlapping wavefuctions of the particles at the triple intersection points. This calculation requires knowledge of the exact form of the wavefuctions. In this work we propose a way to obtain a reliable estimate of the various quantities which determine the strength of the Yukawa couplings. We use previous analysis of KK threshold effects to determine the (ratios of) heavy mass scales of the theory which are involved in the normalization of the wave functions. We consider similar effects from the chiral spectrum of these models and discuss possible constraints on the emerging matter content. In this approach, we find that the Yukawa couplings can be determined solely from the U(1) charges of the states in the `intersection' and the torsion which is a topological invariant quantity. We apply the results to a viable SU(5) model with minimal spectrum which satisfies all the constraints imposed by our analysis. We use renormalization group analysis to estimate the top and bottom masses and find that they are in agreement with the experimental values.Comment: 28 pages, 2 figure

An Extended Technicolor Model With QCD-like Symmetry Breaking

We present a one-doublet extended technicolor model, with all fermions in fundamental representations. The bare lagrangian has no explicit mass terms but generates masses through gauge symmetry breaking by purely QCD-like dynamics. The model generates three families of quarks and leptons and can accommodate the observed third family mass spectrum (including a large top mass and light neutrinos). In addition, we show how the model may be extended to incorporate a top color driven top mass without the need for a strong U(1) interaction. We discuss the compatiblity of the model with experimental constraints and its possible predicitive power with respect to first and second family masses.Comment: 25 pages, latex, 7 figure

Flavour Universal Dynamical Electroweak Symmetry Breaking

The top condensate see-saw mechanism of Dobrescu and Hill allows electroweak symmetry to be broken while deferring the problem of flavour to an electroweak singlet, massive sector. We provide an extended version of the singlet sector that naturally accommodates realistic masses for all the standard model fermions, which play an equal role in breaking electroweak symmetry. The models result in a relatively light composite Higgs sector with masses typically in the range of (400-700)~GeV. In more complete models the dynamics will presumably be driven by a broken gauged family or flavour symmetry group. As an example of the higher scale dynamics a fully dynamical model of the quark sector with a GIM mechanism is presented, based on an earlier top condensation model of King using broken family gauge symmetry interactions (that model was itself based on a technicolour model of Georgi). The crucial extra ingredient is a reinterpretation of the condensates that form when several gauge groups become strong close to the same scale. A related technicolour model of Randall which naturally includes the leptons too may also be adapted to this scenario. We discuss the low energy constraints on the massive gauge bosons and scalars of these models as well as their phenomenology at the TeV scale.Comment: 22 pages, 3 fig

Recognition and management of anthrax [3] (multiple letters)

To the Editor: In his timely review of anthrax, Swartz (Nov. 29 issue) 1 states that “incision or débridement of such early [cutaneous] lesions should be avoided, since this may increase the possibility of bacteremia.” We believe that this prohibition does not apply to diagnostic skin biopsies

Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays

Average charged multiplicities have been measured separately in $b$, $c$ and light quark ($u,d,s$) events from $Z^0$ decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of $b$ and light quark events, and reconstructed charmed mesons were used to select $c$ quark events. We measured the charged multiplicities: $\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.})$, $\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.})$ $\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.})$, from which we derived the differences between the total average charged multiplicities of $c$ or $b$ quark events and light quark events: $\Delta \bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.})$ and $\Delta \bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.})$. We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters