1,233 research outputs found

    Quantifying Electrophoretic Deposition of Nanocrystal Superlattices Using Quartz Crystal Microbalance

    Get PDF
    Please click Additional Files below to see the full abstract

    SAFE Acoustics: an open-source, real-time eco-acoustic monitoring network in the tropical rainforests of Borneo

    Get PDF
    1. Automated monitoring approaches offer an avenue to unlocking largeā€scale insight into how ecosystems respond to human pressures. However, since data collection and data analyses are often treated independently, there are currently no openā€source examples of endā€toā€end, realā€time ecological monitoring networks. 2. Here, we present the complete implementation of an autonomous acoustic monitoring network deployed in the tropical rainforests of Borneo. Realā€time audio is uploaded remotely from the field, indexed by a central database, and delivered via an API to a publicā€facing website. 3. We provide the openā€source code and design of our monitoring devices, the central web2py database, and the ReactJS website. Furthermore, we demonstrate an extension of this infrastructure to deliver realā€time analyses of the ecoā€acoustic data. 4. By detailing a fully functional, open source, and extensively tested design, our work will accelerate the rate at which fully autonomous monitoring networks mature from technological curiosities, and towards genuinely impactful tools in ecology

    Application of Hamamatsu MPPC to T2K Neutrino Detectors

    Full text link
    A special type of Hamamatsu MPPC, with a sensitive area of 1.3x1.3mm^2 containing 667 pixels with 50x50um^2 each, has been developed for the near neutrino detector in the T2K long baseline neutrino experiment. About 60 000 MPPCs will be used in total to read out the plastic scintillator detectors with wavelength shifting fibers. We report on the basic performance of MPPCs produced for T2K.Comment: Contribution to the proceedings of NDIP 2008, Aix-les-Bains, France, June 15-20, 200

    Performance of Multi-Pixel Photon Counters for the T2K near detectors

    Full text link
    We have developed a Multi-Pixel Photon Counter (MPPC) for the neutrino detectors of T2K experiment. About 64,000 MPPCs have been produced and tested in about a year. In order to characterize a large number of MPPCs, we have developed a system that simultaneously measures 64 MPPCs with various bias voltage and temperature. The performance of MPPCs are found to satisfy the requirement of T2K experiment. In this paper, we present the performance of 17,686 MPPCs measured at Kyoto University.Comment: 15 pages, 14 figure

    Anisotropic States of Two-Dimensional Electron Systems in High Landau Levels: Effect of an In-Plane Magnetic Field

    Get PDF
    We report the observation of an acute sensitivity of the anisotropic longitudinal resistivity of two-dimensional electron systems in half-filled high Landau levels to the magnitude and orientation of an in-plane magnetic field. In the third and higher Landau levels, at filling fractions nu=9/2, 11/2, etc., the in-plane field can lead to a striking interchange of the "hard" and "easy" transport directions. In the second Landau level the normally isotropic resistivity and the weak nu=5/2 quantized Hall state are destroyed by a large in-plane field and the transport becomes highly anisotropic.Comment: 5 pages, 4 figures, minor errors correcte

    Presencia de diferentes virus del pimiento ( Capsicum annuum L.) en especies de malezas asociadas al cultivo

    Get PDF
    In a two growth-cycle survey, 30 annual and 13 perennial weed species were determined in different sweet pepper ( Capsicum annuum L.) growing areas of the Limari and Elqui valleys of Coquimbo Region of Chile (29\ub0 to 30\ub0 S lat). The samples were randomly taken in and outside tomato fields, with and without crops present, in winter and spring. A total of 676 weed plants were collected, with a total of 379 samples being analyzed. DAS-ELISA was used to test the presence of Cucumber mosaic virus (CMV), Tomato spotted wilt virus (TSWV), Alfalfa mosaic virus (AMV), Potato virus Y (PVY) and Impatients necrotic spot virus (INSV). A 17% (64) of all collected samples were positive to at least one virus, of which 7.4% (28) came from symptomatic weeds and 9.4% (36) were from symptomless hosts. Jimsonweed (Datura spp.) was positive to CMV and PVY; apple-of-Peru ( Nicandra physalodes ) to AMV, CMV and PVY; black nightshade ( Solanum nigrum ) to CMV and PVY; sowthistle (Sonchus spp.) to AMV and TSWV; small-flower galinsoga ( Galinsoga parviflora ) to AMV, CMV, TSWV and INSV; common lambsquarters (Chenopodium spp.) to AMV, CMV, TSWV, PVY and INSV, among the principle species. Using a relative potential infection index (IPIR), weeds having highest values were small-flower galinsoga (74.7), apple-of-Peru (11.2), black nightshade (6.3) and lambsquarters (6.0). Species such as sowthistle, jimsonweed, bristly mallow ( Modiola caroliniana ), chickweed ( Stellaria media ) and pigweed (Amaranthus spp.) had indexes lower than 1.0. Small-flower galinsoga and apple-of-Peru had more than one virus, and these multiple virus infections were prevalent over single infections. It is imperative to control host weeds within cultivated areas and surroundings to reduce the incidence and dispersal of the viruses in sweet pepper plants.En prospecciones de malezas realizadas durante dos temporadas agr\uedcolas, 30 especies anuales y 13 perennes fueron determinadas en cultivos de pimientos ( Capsicum annuum L.) de los Valles de Elqui y Limar\ued, Regi\uf3n de Coquimbo (29\ub0 a 30\ub0 lat. Sur). Los muestreos fueron aleatorios dentro y fuera de los potreros, con y sin cultivo presente, en invierno y primavera. Se recolectaron 676 plantas de malezas, analiz\ue1ndose un total de 379 muestras. Utilizando la prueba DAS-ELISA se determin\uf3 Virus del mosaico del pepino (CMV), Virus del bronceado del tomate (TSWV), Virus del mosaico de la alfalfa (AMV), Virus Y de la papa (PVY) y Virus INSV (Impatients necrotic spot virus). Un 17% (64) de las muestras fueron positivas al menos a un virus, de las cuales 7,4% (28) provinieron de plantas con s\uedntomas y 9,4% (36) fueron hospederos asintom\ue1ticos. Chamico (Datura spp.) hosped\uf3 a CMV y PVY; nicandra (Nicandra physalodes) a AMV, CMV y PVY; tomatillo ( Solanum nigrum ) a CMV y PVY; \uf1ilhue (Sonchus spp.) a AMV y TSWV; pacoyuyo ( Galinsoga parviflora ) a AMV, CMV, TSWV y INSV; quing\ufcilla (Chenopodium spp.) a AMV, CMV, TSWV, PVY e INSV, entre las principales. Usando un \uedndice potencial de infecci\uf3n relativa (IPIR), los mayores valores se obtuvieron con pacoyuyo (74,7), nicandra (11,2), tomatillo (6,3) y quing\ufcilla (6,0). Especies como \uf1ilhue, chamico, pila-pila ( Modiola caroliniana ), quilloi-quilloi ( Stellaria media ) y bledo (Amaranthus spp.), tuvieron \uedndices inferiores a 1,0. Nicandra y pacoyuyo portaron m\ue1s de un virus y estas infecciones m\ufaltiples prevalecieron sobre las simples. Controlar malezas portadoras tanto dentro como en las inmediaciones de los potreros, resulta imperioso para poder minimizar la incidencia y dispersi\uf3n de las enfermedades virales en pimientos

    Orientation of the Stripe Formed by the Two-Dimensional Electrons in Higher Landau Levels

    Full text link
    Effect of periodic potential on the stripe phase realized in the higher Landau levels is investigated by the Hartree-Fock approximation. The period of the potential is chosen to be two to six times of the fundamental period of the stripe phase. It is found that the stripe aligns perpendicularly to the external potential in contrast to a naive expectation and hydrodynamic theory. Charge modulation towards the Wigner crystallization along the stripe is essential for the present unexpected new result.Comment: 5 pages, RevTex, two figures included in the tex

    Changes in electric-field noise due to thermal transformation of a surface ion trap

    Full text link
    We aim to illuminate how the microscopic properties of a metal surface map to its electric-field noise characteristics. In our system, prolonged heat treatments of a metal film can induce a rise in the magnitude of the electric-field noise generated by the surface of that film. We refer to this heat-induced rise in noise magnitude as a thermal transformation. The underlying physics of this thermal transformation process is explored through a series of heating, milling, and electron treatments performed on a single surface ion trap. Between these treatments, 40^{40}Ca+^+ ions trapped 70 Ī¼\mum above the surface of the metal are used as detectors to monitor the electric-field noise at frequencies close to 1 MHz. An Auger spectrometer is used to track changes in the composition of the contaminated metal surface. With these tools we investigate contaminant deposition, chemical reactions, and atomic restructuring as possible drivers of thermal transformations. The data suggest that the observed thermal transformations can be explained by atomic restructuring at the trap surface. We hypothesize that a rise in local atomic order increases surface electric-field noise in this system

    Density Induced Interchange of Anisotropy Axes at Half-Filled High Landau Levels

    Full text link
    We observe density induced 90āˆ˜^{\circ} rotations of the anisotropy axes in transport measurements at half-filled high Landau levels in the two dimensional electron system, where stripe states are proposed (Ī½\nu=9/2, 11/2, etc). Using a field effect transistor, we find the transition density to be 2.9Ɨ10112.9\times10^{11}cmāˆ’2^{-2} at Ī½\nu=9/2. Hysteresis is observed in the vicinity of the transition. We construct a phase boundary in the filling factor-magnetic field plane in the regime 4.4<Ī½<4.64.4<\nu<4.6. An in-plane magnetic field applied along either anisotropy axis always stabilizes the low density orientation of the stripes.Comment: 1 revtex file, 3 eps figure

    Tolerancia del Tomate (Lycopersicon EsculentumMill.) a Aplicaciones Post Trasplante del Herbicida Halosulfuron-metil

    Get PDF
    During the 1998/99 season at La Platina Research Regional Center of the National Agricultural Research Institute (INIA) (33\ub034' S lat, 70\ub038' W long, altitude 625 m.o.s.l.), on a loamy-clay soil, field trials were conducted to determine crop tolerance of tomatoes (Lycopersicon esculentum Mill.) of the industrial cultivars H-993, P-76, APT-127, APT-410, and fresh consumption cultivars Cal Ace, and XPH-12221, to post transplant applications of halosulfuron-methyl (Sempra\uae 75 WG) at the recommended rate 75 g ha-1 and at an overdose of 150 and 300 g ha-1. At all of the doses halosulfuron-methyl did not produce any significant adverse effects on the foliage. The greatest levels of foliar discoloration were observed on cv. P-76 at 300 g ha-1 seven days after treatment (DDA). This phytotoxicity was temporary, restricted to 7-15 DDA, disappearing almost completely at 21 DDA. There was no reduction in plant height and width to 30 DDA, except the width of cv. P-76 treated at 300 g ha-1. Single plant and total tomato yield of the varieties Cal Ace, XPH-12221, H-993, APT-127 y APT-410 were not affected by any herbicide applications of halosulfuron-methyl. No dose produced adverse effects on the polar and equatorial fruit diameter. The industrial hybrid P-76 had a significant reduction in total fruit yield and number of fruit per plant at 150 and 300 g ha-1, but not at 75 g ha-1. Tomato plants were tolerant to early post transplant applications at the normal recommended rate of halosulfuron-methyl.Durante la temporada 1998/99 en el Centro Regional de Investigaci\uf3n La Platina del Instituto de Investigaciones Agropecuarias (INIA) (33\ub034' lat. Sur, 70\ub038' long. Oeste, 625 m.s.n.m.), en un suelo franco-arcilloso, se realizaron ensayos para determinar la tolerancia de tomate (Lycopersicon esculentum Mill.) de los cultivares industriales H-993, P-76, APT-127, APT-410 y cultivares de consumo fresco Cal Ace y XPH-12221 a aplicaciones de post trasplante de halosulfur\uf3n-metil (Sempra 75 WG) en la dosis recomendada 75 g ha-1 y en sobredosis de 150 y 300 g ha-1. En todas las dosis halosulfur\uf3n-metil no produjo s\uedntomas adversos importantes sobre el follaje. Los mayores niveles de decoloraci\uf3n foliar se observaron en la sobredosis 300 g ha-1 en el cv. P-76 siete d\uedas despu\ue9s de la aplicaci\uf3n (DDA). Esta fitotoxicidad fue temporal, restringida a 7-15 DDA, desapareciendo casi completamente 21 DDA. No hubo reducciones en alto y ancho de las plantas 30 DDA, a excepci\uf3n del ancho del cv. P-76 a 300 g ha-1. 0El rendimiento individual y total de frutos en los cvs. Cal Ace, XPH-12221, H-993, APT-127 y APT-410 no fueron afectados por las aplicaciones de halosulfur\uf3n-metil. Ninguna dosis produjo efectos adversos en el di\ue1metro ecuatorial y polar de los frutos. El h\uedbrido industrial P-76 tuvo una baja significativa en rendimiento y n\ufamero de frutos planta-1 a 150 y 300 g ha-1, pero no con la dosis de 75 g ha-1. Las plantas de tomate fueron tolerantes a aplicaciones tempranas de post trasplante en la dosis m\ue1xima recomendada de halosulfur\uf3n-metil
    • ā€¦
    corecore