USCID 14th technical conference

Presented at Contemporary challenges for irrigation and drainage: proceedings from the USCID 14th technical conference on irrigation, drainage and flood control held on June 3-6, 1998 in Phoenix, Arizona.Includes bibliographical references.Water properties, such as the viscosity and surface tension, can be affected by temperature and surfactants to increase infiltration rates into soils. Specifically, they will change the hydraulic conductivity of the soil. A simple soap solution and the new material PAM (inexpensive polymer chemical) were evaluated as surfactants. Laboratory experiments and field tests on a site in Davis, California were done to quantify the effects of changing the water properties. Additional effects, like the improved soil structure during infiltration and less soil particles in tailwater (reduced erosion due to runoff) were observed and are described in this paper. The conclusions of this study are translated into suggestions for improved on-farm water use in furrows, sprinklers, and drip irrigation

In the Absence of Animacy: Superordinate Category Structure Affects Subordinate Label Verification (vol 8, e83282, 2013)

Theoretical accounts as well as behavioral studies reporting animacy effects offer inconsistent and sometimes contradictory results. A possible explanation for these inconsistencies may be inadvertent biases in the stimuli selected for test - with category-specific effects driven by characteristics of test stimuli other than animacy per se. In this study, we pit animacy against feature structure (intra-item variability), in a picture-word matching task. For unimpaired adults, regardless of whether objects were from animate (mammals; insects) or inanimate (clothes; musical instruments) superordinate categories, participants were faster to match basic level labels with objects from categories with low intra-item variability (mammals; clothes) than from categories with high intra-item variability (insects; instruments). Thus, pitting animacy against variability allowed us to clarify that observable differences in processing speed between animals and instruments are systematically driven by the intra-item variability of the superordinate categories, and not by animacy itself

Chemical and physical heterogeneity within native gold: implications for the design of gold particle studies

Studies of populations of gold particles are becoming increasingly common; however, interpretation of compositional data may not be straightforward. Natural gold is rarely homogenous. Alloy heterogeneity is present as microfabrics formed either during primary mineralization or by modification of pre-existing alloys by chemical and physical drivers during subsequent residence in either hypogene or surficial environments. In electron-probe-microanalysis (EPMA)-based studies, the combination of Cu, Hg, and Pd values and mineral inclusion suites may be diagnostic for source style of mineralization, but Ag alone is rarely sufficient. Gold characterization studies by laser-ablation-ICP mass spectrometry linked to both quadrupole and Time-of-Flight (ToF-MS) systems show that only Ag, Cu, and Hg form homogenous alloys with Au sufficiently often to act as generic discriminants. Where present, other elements are commonly distributed highly heterogeneously at the micron or submicron scale, either as mineral inclusions or in highly localized, but low concentrations. Drawing upon our own data derived from individual inspection and analyses of approximately 40,000 gold particles from 526 placer and in situ localities worldwide, we show that adequate characterization of gold from a specific locality normally requires study of a minimum of 150 particles via a two-stage approach comprising spatial characterization of compositional heterogeneity, plus crystallographic orientation mapping, that informs subsequent targeted acquisition of quantitative compositional data by EPMA and/or laser-ablation ICP-MS methods. Such data provide the platform to review current understanding of the genesis of gold particle characteristics, elevating future compositional studies from empirical descriptions to process-focused interpretations

Boundary friction characterisation of a used cylinder liner subject to fired engine conditions and surface deposition

In cylinder friction contributes as a primary source of parasitic dissipations in IC engines. For future engines to become more efficient, with enhanced fuel economy and increased power output, accurate prediction of new designs is required over the full lifetime of an engine. The work carried out presents use of a local pressure coefficient of boundary shear strength of asperities value, taking into account the localised effects of surface texture, coating and surface deposition. XPS spectra analysis was also carried out to identify the surface depositions as a result of combustion, not previously taken into account during piston ring pack simulation. Friction was shown by simulation to drop by up to 30% between the compression and combustion stroke as a result of using a carriable coefficient of boundary shear strength of asperities. It was found that piston varnish on the liner corresponded to higher values of the pressure coefficient of boundary shear strength of asperities, therefore showing the importance of using real system components run under representative operating conditions or numerical analyses

Search for CP violation in D+→K−K+π+D^{+} \to K^{-}K^{+}\pi^{+} decays

A model-independent search for direct CP violation in the Cabibbo suppressed decay $D^+ \to K^- K^+\pi^+$ in a sample of approximately 370,000 decays is carried out. The data were collected by the LHCb experiment in 2010 and correspond to an integrated luminosity of 35 pb$^{-1}$. The normalized Dalitz plot distributions for $D^+$ and $D^-$ are compared using four different binning schemes that are sensitive to different manifestations of CP violation. No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.