U-Pn geochronology of deformed metagranites in central Sutherland, Scotland: evidence for widespread late Silurian metamorphism and ductile deformation of the Moine Supergroup during the Caledonian orogeny

Within the Caledonides of central Sutherland, Scotland, the Neoproterozoic metasedimentary rocks of the Moine Supergroup record NW-directed D2 ductile thrusting and nappe assembly, accompanied by widespread tight-to-isoclinal folding and amphibolite-facies metamorphism. A series of metagranite sheets which were emplaced and penetratively deformed during D2 have been dated using SHRIMP UâPb geochronology. Zircon ages of 424 8 Ma (Vagastie Bridge granite), 420 6 Ma (Klibreck granite) and 429 11 Ma (Strathnaver granite) are interpreted to date emplacement, and hence regional D2 deformation, during mid- to late Silurian time. Titanite ages of 413 3 Ma (Vagastie Bridge granite) and 416 3 Ma (Klibreck granite) are thought to date post-metamorphic cooling through a blocking temperature of c. 550â 500 8C. A mid- to late Silurian age for D2 deformation supports published models that have viewed the internal ductile thrusts of this part of the orogen as part of the same kinematically linked system of forelandpropagating thrusts as the marginal Moine Thrust Zone. The new data contrast with previous interpretations that have viewed the dominant structures and metamorphic assemblages within the Moine Supergroup as having formed during the early to mid-Ordovician Grampian arcâcontinent orogeny. The mid-to late Silurian D2 nappe stacking event in Sutherland is probably a result of the collision of Baltica with the Scottish segment of Laurentia

Deficit irrigation effects on adjunct and all-malt barley yield and quality

Semi-arid regions are reliant on supplemental irrigation to produce large-yielding and high-quality malt barley (Hordeum vulgare, L.). Current and widespread drought in the western United States is of particular concern as surface and ground water reductions are occurring that affect irrigation water availability. Implementing a seasonal deficit of water compared to evapotranspiration (ET) is a potential mechanism to reduce water usage if yield and quality can be maintained. Research was conducted at the University of Idaho Aberdeen R&E Center, Aberdeen, Idaho on the effects of deficit irrigation on yield, grain quality, and malt characteristics of barley. Five genotypes were selected to represent those used for large-scale adjunct brewing and those targeted at the all-malt craft industry. Irrigation was managed at three rates (100%, 75%, and 50%) of estimated crop evapotranspiration (ETc) using a sprinkler irrigation system. Total aboveground dry matter (TDM) was not affected by irrigation until soft dough (Feekes 11.2; F11.2). Yield was similar within a genotype with irrigation reduction from 100% ETc to 75% ETc. Averaged across genotypes, yields were 6936 kg ha-1 at 100% ETc and 6297 kg ha-1 at 75% ETc. At 75% ETc, protein was just below the adjunct target of 130 g kg-1, excluding Harrington, and no genotype stayed below 120 g kg-1, the all-malt target. Deficit irrigation is promising, particularly for adjunct brewing; however, expected changes to malting quality profiles must be understood and varietal selection, breeding advancements, and/or changes to malting criteria may be needed for successful implementation of deficit irrigation

Algebro-geometric approach in the theory of integrable hydrodynamic type systems

The algebro-geometric approach for integrability of semi-Hamiltonian hydrodynamic type systems is presented. This method is significantly simplified for so-called symmetric hydrodynamic type systems. Plenty interesting and physically motivated examples are investigated

ariable thermal crop water stress index reference temperatures for irrigated spring malt barley in a semi-arid climate

Application of canopy temperature-based crop water stress index (CWSI) for monitoring plant water stress and scheduling irrigation requires reliable estimation of well-watered (TLL) and non-transpiring (TUL) canopy temperatures under identical climatic conditions. A 3-year field study was conducted to develop and evaluate the use of data driven models to estimate TLL and TUL of irrigated spring malt barley. Five irrigation rates with four replicates each were used: full irrigation (FIT), 75, 50 and 25% of FIT and no irrigation. Three replicate continuous canopy temperatures measurements were taken in each irrigation treatment starting the first week in June ending in mid-July along with meteorological conditions. A feed forward neural network (NN) model was used to predict TLL between 13:00 and 15:00 MDT based on model inputs: solar radiation, air temperature, relative humidity, and wind speed for the same period. A physical model calibrated to the data set was used to estimate TUL. The NN model predicted TLL was well correlated with measured TLL (R2 = 0.99) with root mean square error 0.89 degrees C and mean absolute error 0.70 degrees C. There were significant differences in calculated daily average CWSI between irrigation treatments. Relative evapotranspiration, relative malt barley seed yield and percent plump kernels were negatively correlated with season average CWSI. Malt barley seed test weight was positively correlated with season average CWSI. The relationship between daily average CWSI and fraction available soil water was well described by a two-parameter exponential decay function (R2 = 0.72). These results indicate applicability of data driven models for computing CWSI of irrigated spring malt barley in a semi-arid environment and demonstrate malt barley yield response to crop water stress

Searches for solar-influenced radioactive decay anomalies using Spacecraft RTGs

Experiments showing a seasonal variation of the nuclear decay rates of a number of different nuclei, and decay anomalies apparently related to solar flares and solar rotation, have suggested that the Sun may somehow be influencing nuclear decay processes. Recently, Cooper searched for such an effect in $^{238}$Pu nuclei contained in the radioisotope thermoelectric generators (RTGs) on board the Cassini spacecraft. In this paper we modify and extend Cooper's analysis to obtain constraints on anomalous decays of $^{238}$Pu over a wider range of models, but these limits cannot be applied to other nuclei if the anomaly is composition-dependent. We also show that it may require very high sensitivity for terrestrial experiments to discriminate among some models if such a decay anomaly exists, motivating the consideration of future spacecraft experiments which would require less precision.Comment: 8 pages, 4 figures (to appear in Astroparticle Physics

Simultaneous solution of Kompaneets equation and Radiative Transfer equation in the photon energy range 1 - 125 KeV

Radiative transfer equation in plane parallel geometry and Kompaneets equation is solved simultaneously to obtain theoretical spectrum of 1-125 KeV photon energy range. Diffuse radiation field is calculated using time-independent radiative transfer equation in plane parallel geometry, which is developed using discrete space theory (DST) of radiative transfer in a homogeneous medium for different optical depths. We assumed free-free emission and absorption and emission due to electron gas to be operating in the medium. The three terms $n, n^2$ and $\displaystyle \bigg({\frac {\partial n}{\partial x_k}}\bigg)$ where $n$ is photon phase density and $\displaystyle x_k= \bigg({\frac {h \nu} {k T_e}} \bigg)$, in Kompaneets equation and those due to free-free emission are utilized to calculate the change in the photon phase density in a hot electron gas. Two types of incident radiation are considered: (1) isotropic radiation with the modified black body radiation $I^{MB}$ [1] and (2) anisotropic radiation which is angle dependent. The emergent radiation at $\tau=0$ and reflected radiation $\tau=\tau_{max}$ are calculated by using the diffuse radiation from the medium. The emergent and reflected radiation contain the free-free emission and emission from the hot electron gas. Kompaneets equation gives the changes in photon phase densities in different types of media. Although the initial spectrum is angle dependent, the Kompaneets equation gives a spectrum which is angle independent after several Compton scattering times.Comment: 31 pages, 8 figures, Accepte

A real quaternion spherical ensemble of random matrices

One can identify a tripartite classification of random matrix ensembles into geometrical universality classes corresponding to the plane, the sphere and the anti-sphere. The plane is identified with Ginibre-type (iid) matrices and the anti-sphere with truncations of unitary matrices. This paper focusses on an ensemble corresponding to the sphere: matrices of the form \bY= \bA^{-1} \bB, where \bA and \bB are independent $N\times N$ matrices with iid standard Gaussian real quaternion entries. By applying techniques similar to those used for the analogous complex and real spherical ensembles, the eigenvalue jpdf and correlation functions are calculated. This completes the exploration of spherical matrices using the traditional Dyson indices $\beta=1,2,4$. We find that the eigenvalue density (after stereographic projection onto the sphere) has a depletion of eigenvalues along a ring corresponding to the real axis, with reflective symmetry about this ring. However, in the limit of large matrix dimension, this eigenvalue density approaches that of the corresponding complex ensemble, a density which is uniform on the sphere. This result is in keeping with the spherical law (analogous to the circular law for iid matrices), which states that for matrices having the spherical structure \bY= \bA^{-1} \bB, where \bA and \bB are independent, iid matrices the (stereographically projected) eigenvalue density tends to uniformity on the sphere.Comment: 25 pages, 3 figures. Added another citation in version

Определение оптимальных параметров источника рентгеновского излучения на базе малогабаритного ускорителя электронов

Проведено моделирование спектров рентгеновского излучения, генерируемого электронами с энергией 4…10 МэВ в мишенях из различных материалов и разной толщины. Определены оптимальные параметры мишени-конвертора для использования ее в медицинских источниках монохроматического рентгеновского излучения на базе малогабаритных электронных ускорителей. Проведены оценки интенсивности излучения и сравнение источников на базе разных ускорителей

Routine activities and proactive police activity: a macro-scale analysis of police searches in London and New York City

This paper explored how city-level changes in routine activities were associated with changes in frequencies of police searches using six years of police records from the London Metropolitan Police Service and the New York City Police Department. Routine activities were operationalised through selecting events that potentially impacted on (a) the street population, (b) the frequency of crime or (c) the level of police activity. OLS regression results indicated that routine activity variables (e.g. day of the week, periods of high demand for police service) can explain a large proportion of the variance in search frequency throughout the year. A complex set of results emerged, revealing cross-national dissimilarities and the differential impact of certain activities (e.g. public holidays). Importantly, temporal frequencies in searches are not reducible to associations between searches and recorded street crime, nor changes in on-street population. Based on the routine activity approach, a theoretical police-action model is proposed