The electrification of water drops on freezing or f4elting at terminal velocity in air

Measurements on the electrification on freezing of individual water drops of diameter between 3 and 5 mm supported by an air stream have shown that the freezing behaviour of the drops is temperature-dependent. Above -10 C the freezing progressed uniformly throughout the drop from a single point. Below -10 C the outer surface of the drop froze rapidly with the exception of a small area at the top of the drop. Freezing then progressed uniformly from the base of the drop upwards. Mo shattering or electrification of the drops was observed during their freezing. These results are contrasted with those of previous workers who observed the freezing of drops suspended on fibres. Measurements of the electrification of ice spheres supported by an air stream have indicated that the sign of the charge acquired by the spheres due to riming is temperature-dependent. When the sphere is rimed by droplets at temperatures above -10 C it acquires a negative charge, and v/hen the riming droplets are at temperatures below -10 C the ice sphere acquires a positive charge. An explanation is proposed for this effect in terms of the observed freezing behaviour of individual water drops. It I suggested that this effect could lead to thunderstorm electrification of the observed polarity. Measurements on the electrification of melting ice spheres supported by an air stream indicated that the sign of the charge acquired by the spheres is dependent on whether or not water is flung off the charge was negative. This may explain the discrepancies between the laboratory and field measurements of MacCready and Proudfit

The electrification of water drops on freezing or belting at terminal velocity in air

Measurements on the electrification on freezing of individual water drops of diameter between 3 and 5 mm supported by an air stream have shown that the freezing behaviour of the drops is temperature-dependent. Above -10 c the freezing progressed uniformly throughout the drop from a single point. Below -10 c the outer surface of the drop froze rapidly with the exception of a small area at the top of the drop. Freezing then progressed uniformly from the base of the drop upwards. No shattering or electrification of the drops were observed during their freezing. These results are contracted with those of previous workers who observed the freezing of drops suspended on fibres. Measurements of the electrification of ice spheres supported by an air stream have indicated that the sign of the charge acquired by the spheres due to riming is temperature dependent. When the sphere is rimed by droplets at temperatures above -10 c it acquires a negative charge, and when the riming droplets are at temperatures below -10 c the ice sphere acquires a positive charge. An explanation is proposed for this effect in terms of the observed freezing behaviour of individual water drops. It is suggested that this effect could lead to thunderstorm electrification of the observed polarity. Measurements on the electrification of melting ice spheres supported by an air stream indicated that the sign of the charge acquired by the spheres is dependent on whether or not water is flung off from the sphere during melting. If no. water was flung off the charge was positive, while if water was flung off the charge was negative. This may explain the discrepancies between the laboratory and field measurements of MacCready and Proudfit

Geometric Langevin equations on submanifolds and applications to the stochastic melt-spinning process of nonwovens and biology

In this article we develop geometric versions of the classical Langevin equation on regular submanifolds in euclidean space in an easy, natural way and combine them with a bunch of applications. The equations are formulated as Stratonovich stochastic differential equations on manifolds. The first version of the geometric Langevin equation has already been detected before by Leli\`evre, Rousset and Stoltz with a different derivation. We propose an additional extension of the models, the geometric Langevin equations with velocity of constant absolute value. The latters are seemingly new and provide a galaxy of new, beautiful and powerful mathematical models. Up to the authors best knowledge there are not many mathematical papers available dealing with geometric Langevin processes. We connect the first version of the geometric Langevin equation via proving that its generator coincides with the generalized Langevin operator proposed by Soloveitchik, Jorgensen and Kolokoltsov. All our studies are strongly motivated by industrial applications in modeling the fiber lay-down dynamics in the production process of nonwovens. We light up the geometry occuring in these models and show up the connection with the spherical velocity version of the geometric Langevin process. Moreover, as a main point, we construct new smooth industrial relevant three-dimensional fiber lay-down models involving the spherical Langevin process. Finally, relations to a class of self-propelled interacting particle systems with roosting force are presented and further applications of the geometric Langevin equations are given

Sequential Decision Making with Untrustworthy Service Providers

In this paper, we deal with the sequential decision making problem of agents operating in computational economies, where there is uncertainty regarding the trustworthiness of service providers populating the environment. Specifically, we propose a generic Bayesian trust model, and formulate the optimal Bayesian solution to the exploration-exploitation problem facing the agents when repeatedly interacting with others in such environments. We then present a computationally tractable Bayesian reinforcement learning algorithm to approximate that solution by taking into account the expected value of perfect information of an agent's actions. Our algorithm is shown to dramatically outperform all previous finalists of the international Agent Reputation and Trust (ART) competition, including the winner from both years the competition has been run

Computer mapping of LANDSAT data for environmental applications

The author has identified the following significant results. Land cover overlays and maps produced from LANDSAT are providing information on existing land use and resources throughout the 208 study area. The overlays are being used to delineate drainage areas of a predominant land cover type. Information on cover type is also being combined with other pertinent data to develop estimates of sediment and nutrients flows from the drainage area. The LANDSAT inventory of present land cover together with population projects is providing a basis for developing maps of anticipated land use patterns required to evaluate impact on water quality which may result from these patterns. Overlays of forest types were useful for defining wildlife habitat and vegetational resources in the region. LANDSAT data and computer assisted interpretation was found to be a rapid cost effective procedure for inventorying land cover on a regional basis. The entire 208 inventory which include acquisition of ground truth, LANDSAT tapes, computer processing, and production of overlays and coded tapes was completed within a period of 2 months at a cost of about 0.6 cents per acre, a significant improvement in time and cost over conventional photointerpretation and mapping techniques

Kinematics of Current Region Fragmentation in Semi-Inclusive Deeply Inelastic Scattering

Different kinematical regimes of semi-inclusive deeply inelastic scattering (SIDIS) processes correspond to different underlying partonic pictures, and it is important to understand the transition between them. This is particularly the case when there is sensitivity to intrinsic transverse momentum, in which case kinematical details can become especially important. We address the question of how to identify the current fragmentation region --- the kinematical regime where a factorization picture with fragmentation functions is appropriate. We distinguish this from soft and target fragmentation regimes. Our criteria are based on the kinematic regions used in derivations of factorization theorems. We argue that, when hard scales are of order a few GeVs, there is likely significant overlap between different rapidity regions that are normally understood to be distinct. We thus comment on the need to take this into account with more unified descriptions of SIDIS, which should span all rapidities for the produced hadron. Finally, we propose general criteria for estimating the proximity to the current region at large Q.Comment: 9 Pages, 5 figures; minor clarifications and corrections, version appearing in Physics Letters

Automatic classification of eutrophication of inland lakes from spacecraft data

The author has identified the following significant results. Spacecraft data and computer techniques can be used to rapidly map and store onto digital tapes watershed land use information. Software is now available by which this land use information can be rapidly and economically extracted from the tapes and related to coliform counts and other lake contaminants (e.g. phosphorus). These tools are basic elements for determining those land use factors and sources of nutrients that accelerate eutrophication in lakes and reservoirs

A dispersive wave pattern on Jupiter's fastest retrograde jet at 20∘20^\circS

A compact wave pattern has been identified on Jupiter's fastest retrograding jet at 20S (the SEBs) on the southern edge of the South Equatorial Belt. The wave has been identified in both reflected sunlight from amateur observations between 2010 and 2015, thermal infrared imaging from the Very Large Telescope and near infrared imaging from the Infrared Telescope Facility. The wave pattern is present when the SEB is relatively quiescent and lacking large-scale disturbances, and is particularly notable when the belt has undergone a fade (whitening). It is generally not present when the SEB exhibits its usual large-scale convective activity ('rifts'). Tracking of the wave pattern and associated white ovals on its southern edge over several epochs have permitted a measure of the dispersion relationship, showing a strong correlation between the phase speed (-43.2 to -21.2 m/s) and the longitudinal wavelength, which varied from 4.4-10.0 deg. longitude over the course of the observations. Infrared imaging sensing low pressures in the upper troposphere suggest that the wave is confined to near the cloud tops. The wave is moving westward at a phase speed slower (i.e., less negative) than the peak retrograde wind speed (-62 m/s), and is therefore moving east with respect to the SEBs jet peak. Unlike the retrograde NEBn jet near 17N, which is a location of strong vertical wind shear that sometimes hosts Rossby wave activity, the SEBs jet remains retrograde throughout the upper troposphere, suggesting the SEBs pattern cannot be interpreted as a classical Rossby wave. Cassini-derived windspeeds and temperatures reveal that the vorticity gradient is dominated by the baroclinic term and becomes negative (changes sign) in a region near the cloud-top level (400-700 mbar) associated with the SEBs, suggesting a baroclinic origin for this meandering wave pattern. [Abr]Comment: 19 pages, 11 figures, article accepted for publication in Icaru

Vertical Market Strategy: The Case of an Executive Education Startup in a Medium-Sized Business School

This paper provides an account of a vertical market go-to-market strategy that has been used by an executive education startup in the College of Business at the University of Colorado, Colorado Springs. The executive education startup is titled the “Office of Professional & Executive Development” and has been in operation for approximately 18 months. The office was launched explicitly using a vertical market strategy. That is, public training programs were designed for vertical markets only, enabling instructors to design programs with deep, industry-specific examples, cases, and lessons