1,668 research outputs found

    Circular 35

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    Revised April 1991 by Grant E.M. Matheke, Patricia J. Wagner, and Patricia S. Holloway; Reprinted by Cooperative Extension Service, University of Alaska Fairbanks, and U.S.D.A. Cooperating. Publication 300C-00235A technique for growing high-yielding, everbearing strawberries with clear polyethylene (plastic) mulch and row covers has been developed at the Agricultural and Forestry Experiment Station at Fairbanks. This technique eliminates the long delay from planting to fruiting that occurs with other culture systems and it has created an interest in commercial production and an increased home-garden effort in Alaska. The production system involves planting nursery plants each season as early as possible through clear polyethylene mulch, using row covers for the early part o f the season. Using this technique, harvest begins about July 15 and extends until freeze-up, com pared to a production season from about July 10 to July 28 for hardy types o f strawberries such as Toklat or Pioneer. This system produces clean fruit, easy to pick and relatively free from fruit rot. The harvest season can be extended in the fall by again using the row covers for frost protection

    Circular 114

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    Trials were begun in 1989 at the Georgeson Botanical Garden (64°51’N, 147° 52’W, elevation 475 feet; 136 meters) to evaluate the hardiness and ornamental potential of trees, shrubs, and herbaceous perennial ornamentals. Woody ornamentals are tested for 10 years, and herbaceous perennials for five years. This report is the first summary of perennials that have survived the trial period with a winter hardiness rating between zero and 2.5. Each plant in the trial is evaluated annually for winter injury and rated on a scale of zero through four. A zero rating denotes no visible injury, and four is death. A score of 2.5 and lower indicates the plant grew well in the Garden. It may have shown symptoms of winter injury but recovered in subsequent seasons. The species and cultivars listed in Table 1 are recommended for further trial throughout Interior Alaska. Plants are grown on a south-facing slope in Fairbanks silt loam soil. The plots have been cultivated since about 1910. All plants receive full sun except those located in the shade house. Plants receive supplemental irrigation, mostly hand weeding, and an annual application of 500 lb per acre (560.5 kg/ha) 10-20-20S fertilizer. Lilies receive 1500 lb (1,681.5 kg/ha) per acre of the same fertilizer. No plant receives winter protection such as mulches, wind barriers or snow fences. Weather data are compiled annually from U.S. Weather Service station (elevation 475 feet; 136 meters) located approximately 350 feet (105 meters) west of the Garden. A summary of pertinent weather statistics is shown in Table 2

    Circular 102

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    In 1989, a systematic evaluation of woody and herbaceous perennial landscape plants was begun at the University of Alaska Fairbanks Georgeson Botanical Garden (64°51’N, 147°52’W). These evaluations were expanded to include annual flowers in 1992 and ferns in 1993. The purpose of this research is to identify hardy perennials capable of surviving in subarctic environments; to evaluate the ornamental potential of perennials and annuals; and to fulfill a growing demand for information on landscape plant materials by homeowners, commercial growers, and landscapers.Introduction -- Explanation of Plant Evaluation Tables -- Table 1. Weather records for the test years -- Table 2. All plant materials evaluated in 1994: Herbaceous perennials; Ferns; Ornamental grasses; Woody perennials -- Table 4. Plantings from 1994 that have not yet been evaluated for winter survival: Herbaceous perennials; Ferns; Woody perennials -- Table 5. Annual flowers evaluated in 1994 -- Appendix 1. Commercial Sources and Organizations -- Map of GB

    Quality systems in Dutch health care institutions

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    The implementation of quality systems in Dutch health care was supervised by a national committee during 1990-1995. To monitor the progress of implementation a large survey was conducted in the beginning of 1995. The survey enclosed all subsectors in health care. A postal questionnaire-derived from the European Quality Award-was sent to 1594 health care institutions; the response was 74%. The results showed that in 13% of the institutions a coherent quality system had been implemented. These institutions reported, among other effects, an increase in staff effort and job satisfaction despite the increased workload; 59% of the institutions had implemented parts of a quality system. It appeared that management pay more attention to human resource management compared to documentation of the quality system. The medical staff pay relatively more attention to protocol development than to quality-assurance procedures. Patients were hardly involved in these quality activities. The research has shown that it is possible to monitor the progress of implementation of quality systems on a national level in all subsectors of health care. The results play an important role in the discussions and policy on quality assurance in health care. (aut.ref.

    Circular 98

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    In 1989, a systematic evaluation of woody and herbaceous perennial landscape plants was begun at the University of Alaska Fairbanks Georgeson Botanical Garden (64051’N, 147°52’W). These evaluations were expanded to include annual flowers in 1992 and ferns in 1993. The purpose of this research is to identify hardy perennials capable of surviving in subarctic environments; to evaluate the ornamental potential of perennials and annuals; and to fulfill a growing demand for information on landscape plant materials by homeowners, commercial growers, and landscapers.Introduction -- Explanation of Plan Evaluation Tables -- Table 1. Weather records for the test years -- Table 2. All plant materials evaluated in 1992: Herbaceous perennials; Ornamental grasses; Woody perennials -- Table 3. All plants that have been evaluated but did not survive the minimum number of test years: Hebaceous perennials; Ornamental grasses; Woody perennials -- Table 4. Plantings from 1993 that have not yet been evaluated for winter survival: Herbaceous perennials; Ferns; Ornamental grasses; Woody perennials -- Table 5. Annual flowers evaluated in 1993 -- Appendix 1. Commercial Sources and Organizations -- Map of GB

    Higgs Signal for h to aa at Hadron Colliders

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    We assess the prospect of observing a neutral Higgs boson at hadron colliders in its decay to two spin-zero states, a, for a Higgs mass of 90-130 GeV, when produced in association with a W or Z boson. Such a decay is allowed in extensions of the MSSM with CP-violating interactions and in the NMSSM, and can dominate Higgs boson final states, thereby evading the LEP constraints on standard Higgs boson production. The light spin-zero state decays primarily via a to bb and tau+tau-, so this signal channel retains features distinct from the main backgrounds. Our study shows that at the Tevatron, there may be potential to observe a few events in the bb tau+tau- or bbbb channels with relatively small background, although this observation would be statistically limited. At the LHC, the background problem is more severe, but with cross sections and integrated luminosities orders of magnitude larger than at the Tevatron, the observation of a Higgs boson in this decay mode would be possible. The channel h to aa to bbbb would provide a large statistical significance, with a signal-to-background ratio on the order of 1:2. In these searches, the main challenge would be to retain the adequate tagging efficiency of b's and tau's in the low p_T region.Comment: Version to be published in JHEP. 20 pages, 5 figure

    Wireless sensor networks for in-situ image validation for water and nutrient management

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    Water and Nitrogen (N) are critical inputs for crop production. Remote sensing data collected from multiple scales, including ground-based, aerial, and satellite, can be used for the formulation of an efficient and cost effective algorithm for the detection of N and water stress. Formulation and validation of such techniques require continuous acquisition of ground based spectral data over the canopy enabling field measurements to coincide exactly with aerial and satellite observations. In this context, a wireless sensor in situ network was developed and this paper describes the results of the first phase of the experiment along with the details of sensor development and instrumentation set up. The sensor network was established based on different spatial sampling strategies and each sensor collected spectral data in seven narrow wavebands (470, 550, 670, 700, 720, 750, 790 nm) critical for monitoring crop growth. Spectral measurements recorded at required intervals (up to 30 seconds) were relayed through a multi-hop wireless network to a base computer at the field site. These data were then accessed by the remote sensing centre computing system through broad band internet. Comparison of the data from the WSN and an industry standard ground based hyperspectral radiometer indicated that there were no significant differences in the spectral measurements for all the wavebands except for 790nm. Combining sensor and wireless technologies provides a robust means of aerial and satellite data calibration and an enhanced understanding of issues of variations in the scale for the effective water and nutrient management in wheat.<br /

    Infinite-Order Percolation and Giant Fluctuations in a Protein Interaction Network

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    We investigate a model protein interaction network whose links represent interactions between individual proteins. This network evolves by the functional duplication of proteins, supplemented by random link addition to account for mutations. When link addition is dominant, an infinite-order percolation transition arises as a function of the addition rate. In the opposite limit of high duplication rate, the network exhibits giant structural fluctuations in different realizations. For biologically-relevant growth rates, the node degree distribution has an algebraic tail with a peculiar rate dependence for the associated exponent.Comment: 4 pages, 2 figures, 2 column revtex format, to be submitted to PRL 1; reference added and minor rewording of the first paragraph; Title change and major reorganization (but no result changes) in response to referee comments; to be published in PR

    bsb \to s Transitions in Family-dependent U(1)U(1)^\prime Models

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    We analyze flavor-changing-neutral-current (FCNC) effects in the bsb\to s transitions that are induced by family non-universal U(1)U(1)' gauge symmetries. After systematically developing the necessary formalism, we present a correlated analysis for the ΔB=1,2\Delta B =1, 2 processes. We adopt a model-independent approach in which we only require family-universal charges for the first and second generations and small fermion mixing angles. We analyze the constraints on the resulting parameter space from BsBˉsB_s - \bar B_s mixing and the time-dependent CP asymmetries of the penguin-dominated Bd(π,ϕ,η,ρ,ω,f0)KSB_d \to (\pi, \phi, \eta', \rho, \omega, f_0)K_S decays. Our results indicate that the currently observed discrepancies in some of these modes with respect to the Standard Model predictions can be consistently accommodated within this general class of models.Comment: 36 pages, 11 figure

    Optimization of the electrochemical impedance spectroscopy measurement parameters for PEM fuel cell spectrum determination

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    Currently, electrochemical Impedance Spectroscopy (EIS) is a widely used tool for the study of electrochemical systems, in general; and fuel cells, in particular. A great effort is typically invested in the analysis of the obtained spectra; whereas, little time is usually spent optimizing the measurement parameters used to obtain these spectra. In general, the default settings provided by the control software used to perform the measurements, or the parameters used in similar systems available in literature, are selected to carry out the measurements. The goal of this work is to determine the optimal measurement parameters for obtaining impedance spectra of a commercial PEM fuel cell. In order to achieve this, a 2^5 factorial design was considered. Five factors were considered, the five impedance spectroscopy measurement parameters: maximum integration time; minimum number of integration cycles; number of stabilization cycles; maximum stabilization time; and minimum cycle fraction. For each factor combination envisaged in the experimental design, the cell spectrum was obtained in given operation conditions, for which the reference spectrum of the system was known, since it had been determined in previous works. The experimentally obtained spectra were fitted to the reference electric equivalent circuit. The mean square error between the experimental data fitting and the reference spectrum fitting was determined in each case, and was used as the dependant variable for the experimental design analysis. An analysis of the variance was performed in order to determine which measurement parameters have a significant effect on the dependant variable; and a model relating the dependant variable and the measurement parameters was built. This model was used in order to obtain the optimal value of each one of the measurement parameters that minimized the mean square error of the fit obtained from the experimental data with respect to the reference fit.The authors are very grateful to the Generalitat Valenciana for its economic support in form of Vali+d grant (Ref: ACIF-2013-268).Giner Sanz, JJ.; Ortega Navarro, EM.; Pérez-Herranz, V. (2015). Optimization of the electrochemical impedance spectroscopy measurement parameters for PEM fuel cell spectrum determination. Electrochimica Acta. 174:1290-1298. https://doi.org/10.1016/j.electacta.2015.06.106S1290129817
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