Modeling of velocity distributions inside and above tall crops

Reprinted from Journal of Applied Meteorology v. 7, no. 3, June 1965, pages 400-408.CER64EJP-AAQ-2.Includes bibliographical references.Velocity distributions inside and above a model crop were investigated. The model crop consisted of flexible plastic strips fastened to the floor of a low speed wind tunnel. The experimental results indicated that at some distance xo downstream from the edge of the roughness cover the velocity profiles were similar inside and also above the cover. The length xo is discussed. The experimental results for the velocity distribution inside the plant cover were compared with field data obtained from different sources. A presentation of the velocity profiles inside the canopy in nondimensional form collapsed all field and laboratory data for a given crop type on one curve. The laboratory flow above the crop cover was analyzed using a power law form and using the logarithmic velocity distribution law. On the basis of the experimental results it is recommended that a two-tower arrangement of wind velocity measuring devices be used both for the evaluation of the surface shear stress and for checking the establishment of similarity profiles in the field

Wind action on water standing in a laboratory channel

CEP6566-GMHEJP14a, CER65GMH-EJP40a.NCAR preprint-memo, PM # 135.Includes bibliographical references.The processes of wave and current development resulting from wind action on initially standing water have been investigated in a wind-water tunnel. The mean air flow over wavy water was examined along with the variation of several properties of the water motion with fetch, water depth, and wind speed. Measurements of phase speed and length of significant waves, the standard deviation of the water sur face, the average surface drift, the autocorrelation of surface displacement and the frequency spectra of the wind waves are reported. The experimental results indicate that (a) the air motion in the channel follows a three dimensional pattern characteristic of wind tunnels of rectangular cross-section; (b) the wind waves generated in the channel travel downstream at approximately the same phase speed as gravity waves of small amplitude, provided the effect of the drift current is taken into account; (c) the average drag coefficients for the action of the wind on the water surface increase with increasing wind speed, and these data are essentially the same as the results of previous investigators; (d) the autocorrelations of surface displacement and frequency spectra are consistent with the visual observations that the wind waves in the channel consist of nearly regular primary waves on which are superimposed smaller ripples; (e) energy in the high frequency range in the spectra tends to approach an equilibrium distribution rather quickly while the lower frequency components initially grow exponentially with increasing fetch but, later, tend to reach a state of equilibrium; and (f) a similarity shape for the frequency spectra developed

Micrometeorological wind tunnel facility: description and characteristics

CER63EJP-JEC9.Includes bibliographical references (pages 39).February 1963

AERODYNAMIC CHARACTERISTICS OF ATMOSPHERIC BOUNDARY LAYERS.

Prepared as an account of work by the United States Government, this report talks about the Aerodynamic Characteristics of Atmospheric Boundary Layers

Comparison between wind waves at sea and in the laboratory

Correlations between laboratory and geophysical data are presented for certain statistical properties of wind waves. The parameters chosen include: (i) relationships between wave height and the height of the highest one-third or one-tenth waves, as given by a Rayleigh probability distribution, and (ii) amplitude spectra for waves, as given by Phillips\u27 equilibrium theory. The correlation between laboratory results and geophysical data is satisfactory over a wide range of wave size

Pharmacologic IRE1/XBP1s Activation Confers Targeted ER Proteostasis Reprogramming

Activation of the IRE1/XBP1s signaling arm of the unfolded protein response (UPR) is a promising strategy to correct defects in endoplasmic reticulum (ER) proteostasis implicated in diverse diseases. However, no pharmacologic activators of this pathway identified to date are suitable for ER proteostasis remodeling through selective activation of IRE1/XBP1s signaling. Here, we use high-throughput screening to identify non-toxic compounds that induce ER proteostasis remodeling through IRE1/XBP1s activation. We employ transcriptional profiling to stringently confirm that our prioritized compounds selectively activate IRE1/XBP1s signaling without activating other cellular stress-responsive signaling pathways. Furthermore, we demonstrate that our compounds improve ER proteostasis of destabilized variants of amyloid precursor protein (APP) through an IRE1-dependent mechanism and reduce APP-associated mitochondrial toxicity in cellular models. These results establish highly selective IRE1/XBP1s activating compounds that can be widely employed to define the functional importance of IRE1/XBP1s activity for ER proteostasis regulation in the context of health and disease. [Figure not available: see fulltext.]

Geometric representations for minimalist grammars

We reformulate minimalist grammars as partial functions on term algebras for strings and trees. Using filler/role bindings and tensor product representations, we construct homomorphisms for these data structures into geometric vector spaces. We prove that the structure-building functions as well as simple processors for minimalist languages can be realized by piecewise linear operators in representation space. We also propose harmony, i.e. the distance of an intermediate processing step from the final well-formed state in representation space, as a measure of processing complexity. Finally, we illustrate our findings by means of two particular arithmetic and fractal representations.Comment: 43 pages, 4 figure

Universal neural field computation

Turing machines and G\"odel numbers are important pillars of the theory of computation. Thus, any computational architecture needs to show how it could relate to Turing machines and how stable implementations of Turing computation are possible. In this chapter, we implement universal Turing computation in a neural field environment. To this end, we employ the canonical symbologram representation of a Turing machine obtained from a G\"odel encoding of its symbolic repertoire and generalized shifts. The resulting nonlinear dynamical automaton (NDA) is a piecewise affine-linear map acting on the unit square that is partitioned into rectangular domains. Instead of looking at point dynamics in phase space, we then consider functional dynamics of probability distributions functions (p.d.f.s) over phase space. This is generally described by a Frobenius-Perron integral transformation that can be regarded as a neural field equation over the unit square as feature space of a dynamic field theory (DFT). Solving the Frobenius-Perron equation yields that uniform p.d.f.s with rectangular support are mapped onto uniform p.d.f.s with rectangular support, again. We call the resulting representation \emph{dynamic field automaton}.Comment: 21 pages; 6 figures. arXiv admin note: text overlap with arXiv:1204.546