Water distribution rules and water distribution performance: a case study in the Tambraparani Irrigation System

Irrigation management / Irrigation systems / Performance / Irrigation operation / Irrigation scheduling / Water distribution / Water allocation / Water delivery / Water users' associations / Legislation / Large-scale systems / Bananas / Case studies / India / Tamil Nadu / Tambraparani Irrigation System

Modification of silicon carbide fibers for use in SiC/Ti composites

The degradation of silicon carbide fibers during exposure to conditions typical of composite fabrication was investigated. The tensile strength of pristine fibers and fibers sputtered with thin metal coatings were determined before and after treatment at 870 C for one hour in vacuum. Each fiber strength distribution was related by an analytical procedure to a projected composite ultimate tensile strength (PC UTS). The results indicate that a thin aluminum diffusion barrier can yield a 150 percent increase in PC UTS over the baseline SiC/Ti system

Cumulus cloud venting of mixed layer ozone

Observations are presented which substantiate the hypothesis that significant vertical exchange of ozone and aerosols occurs between the mixed layer and the free troposphere during cumulus cloud convective activity. The experiments utilized the airborne Ultra-Violet Differential Absorption Lidar (UV-DIAL) system. This system provides simultaneous range resolved ozone concentration and aerosol backscatter profiles with high spatial resolution. Evening transects were obtained in the downwind area where the air mass had been advected. Space-height analyses for the evening flight show the cloud debris as patterns of ozone typically in excess of the ambient free tropospheric background. This ozone excess was approximately the value of the concentration difference between the mixed layer and free troposphere determined from independent vertical soundings made by another aircraft in the afternoon

Introduction to Vacuum Technology

Vacuum systems are critical to many industries. They are vital to establishing required process pressures, establishing a clean process environment, and removing reaction by-products from the process chamber. This text, a revision and expansion of David Hata’s Introduction to Vacuum Technology published in 2008, addresses basic topics in vacuum technology for individuals tasked with maintaining vacuum systems and instructors teaching technician-level courses. The topics are carefully curated to the needs of technicians in a production environment and the types of vacuum systems used, and the accompanying laboratory manual and instructor’s guide support the delivery of lecture-laboratory courses. This book approaches vacuum systems from a pressure regime viewpoint, covering basic vacuum science, followed by the rough vacuum regime, including gas load, pumping mechanisms, pressure measurement, vacuum system construction, and basic troubleshooting concepts. The study of high vacuum systems follows and the same topics are revisited, and finally the topics of leak detection and residual gas analysis are discussed. Access all versions of this text and ancillaries at milneopentextbooks.org. Reader’s feedback via this survey would greatly help the authors to maintain and improve this book which was developed under National Science Foundation grant #2000454.https://knightscholar.geneseo.edu/oer-ost/1033/thumbnail.jp

The SWELLS survey. IV. Precision measurements of the stellar and dark matter distributions in a spiral lens galaxy

We construct a fully self-consistent mass model for the lens galaxy J2141 at z=0.14, and use it to improve on previous studies by modelling its gravitational lensing effect, gas rotation curve and stellar kinematics simultaneously. We adopt a very flexible axisymmetric mass model constituted by a generalized NFW dark matter halo and a stellar mass distribution obtained by deprojecting the MGE fit to the high-resolution K'-band LGSAO imaging data of the galaxy, with the (spatially constant) M/L ratio as a free parameter. We model the stellar kinematics by solving the anisotropic Jeans equations. We find that the inner logarithmic slope of the dark halo is weakly constrained (gamma = 0.82^{+0.65}_{-0.54}), and consistent with an unmodified NFW profile. We infer the galaxy to have (i) a dark matter fraction within 2.2 disk radii of 0.28^{+0.15}_{-0.10}, independent of the galaxy stellar population, implying a maximal disk for J2141; (ii) an apparently uncontracted dark matter halo, with concentration c_{-2} = 7.7_{-2.5}^{+4.2} and virial velocity v_{vir} = 242_{-39}^{+44} km/s, consistent with LCDM predictions; (iii) a slightly oblate halo (q_h = 0.75^{+0.27}_{-0.16}), consistent with predictions from baryon-affected models. Comparing the stellar mass inferred from the combined analysis (log_{10} Mstar/Msun = 11.12_{-0.09}^{+0.05}) with that inferred from SPS modelling of the galaxies colours, and accounting for a cold gas fraction of 20+/-10%, we determine a preference for a Chabrier IMF over Salpeter IMF by a Bayes factor of 5.7 (substantial evidence). We infer a value beta_{z} = 1 - sigma^2_{z}/sigma^2_{R} = 0.43_{-0.11}^{+0.08} for the orbital anisotropy parameter in the meridional plane, in agreement with most studies of local disk galaxies, and ruling out at 99% CL that the dynamics of this system can be described by a two-integral distribution function. [Abridged]Comment: Accepted for publication in MNRAS. 17 pages, 9 figure

Red nuggets grow inside-out: evidence from gravitational lensing

We present a new sample of strong gravitational lens systems where both the foreground lenses and background sources are early-type galaxies. Using imaging from HST/ACS and Keck/NIRC2, we model the surface brightness distributions and show that the sources form a distinct population of massive, compact galaxies at redshifts $0.4 \lesssim z \lesssim 0.7$, lying systematically below the size-mass relation of the global elliptical galaxy population at those redshifts. These may therefore represent relics of high-redshift red nuggets or their partly-evolved descendants. We exploit the magnifying effect of lensing to investigate the structural properties, stellar masses and stellar populations of these objects with a view to understanding their evolution. We model these objects parametrically and find that they generally require two S\'ersic components to properly describe their light profiles, with one more spheroidal component alongside a more envelope-like component, which is slightly more extended though still compact. This is consistent with the hypothesis of the inside-out growth of these objects via minor mergers. We also find that the sources can be characterised by red-to-blue colour gradients as a function of radius which are stronger at low redshift -- indicative of ongoing accretion -- but that their environments generally appear consistent with that of the general elliptical galaxy population, contrary to recent suggestions that these objects are predominantly associated with clusters.Comment: 21 pages; accepted for publication in MNRA

Virtual light-by-light scattering and the g factor of a bound electron

The contribution of the light-by-light diagram to the g factor of electron and muon bound in Coulomb field is obtained. For electron in a ground state, our results are in good agreement with the results of other authors obtained numerically for large Z. For relatively small Z our results have essentially higher accuracy as compared to the previous ones. For muonic atoms, the contribution is obtained for the first time with the high accuracy in whole region of Z.Comment: 10 pages, 3 figures, RevTe

Screening Sunflower for Tolerance to Sunflower Midge Using the Synthetic Auxin 2,4-Dichlorophenoxyacetic Acid

The sunflower midge, Contarinia schulzi Gagné, causes economic damage by inducing abnormal growth in infested heads (capitula) of sunflower, Helianthus annuus L. The primary objective of this study was to determine whether sunflower midge damage could be simulated and whether that simulated damage could be used to select midge-tolerant sunflower germplasm. An additional objective was to develop a quantitative alternative to the scoring systems used to visually estimate damage. Sunflower plants were treated by injecting buds with the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D), which resulted in a distortion of the head morphology that was similar in appearance to the damage caused by the sunflower midge. The extent of distortion depended not only on the dose of 2,4-D but also on the size and growth stage of the head when injected. Among sunflower hybrids tested, resistance to the sunflower midge was significantly, negatively correlated with 2,4-D damage. Therefore, injection of sunflower heads with 2,4-D appears to be an effective method of screening sunflower germplasm for tolerance to the sunflower midge. Two distortion indices, based on measurements of head shape, were compared with the visual damage system. Although the visual rating system is faster, distortion index 2 gave similar results and is preferred when it is necessary to avoid individual differences in scoring techniques

Screening Sunflower for Tolerance to Sunflower Midge Using the Synthetic Auxin 2,4-Dichlorophenoxyacetic Acid

The sunflower midge, Contarinia schulzi Gagné, causes economic damage by inducing abnormal growth in infested heads (capitula) of sunflower, Helianthus annuus L. The primary objective of this study was to determine whether sunflower midge damage could be simulated and whether that simulated damage could be used to select midge-tolerant sunflower germplasm. An additional objective was to develop a quantitative alternative to the scoring systems used to visually estimate damage. Sunflower plants were treated by injecting buds with the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D), which resulted in a distortion of the head morphology that was similar in appearance to the damage caused by the sunflower midge. The extent of distortion depended not only on the dose of 2,4-D but also on the size and growth stage of the head when injected. Among sunflower hybrids tested, resistance to the sunflower midge was significantly, negatively correlated with 2,4-D damage. Therefore, injection of sunflower heads with 2,4-D appears to be an effective method of screening sunflower germplasm for tolerance to the sunflower midge. Two distortion indices, based on measurements of head shape, were compared with the visual damage system. Although the visual rating system is faster, distortion index 2 gave similar results and is preferred when it is necessary to avoid individual differences in scoring techniques