304 research outputs found
Distribution and rate of spread of scentless chamomile on the Black and Gray soils in Saskatchewan
Non-Peer ReviewedIn 1987 a questionnaire survey was conducted to determine the distribution of the noxious weed scentless chamomile on the Black and Gray soils of Saskatchewan. As well information was obtained on the year of first sighting, habitats affected, farmers' perception of the problem, the percentage of their land affected, and methods used to control or manage the weed. A total of 29,666 questionnaires were distributed, of which 2120 (7.1 %) usable responses were returned. Of these, 35.6 % indicated that scentless chamomile occurred on land they farmed or on adjacent roadsides. In the group which reported occurrence the most common habitat, reported by 69.5 %, was the roadside. Annual crops were reported as scentless chamomile habitats by 30.0 % and wet areas of fields, which can sometimes be cropped, by 39.0 %. The most common methods reported for control of the weed were tillage, hand-weeding and herbicide use. Of the 214 farmers who indicated herbicide use, 26.2 % used herbicides containing bromoxynil, 16.4 % used herbicides containing dicamba and 15.4 % used glyphosate. Spread of the weed has increased rapidly in the last 20 years. Of the responses to year of first sighting 19.0 % were between 1968 and 1977, and 69.0 % reported first sighting the weed within the last decade
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Test plan for immobilization of salt-containing surrogate mixed wastes using polyester resins
Past operations at many Department of Energy (DOE) sites have resulted in the generation of several waste streams with high salt content. These wastes contain listed and characteristic hazardous constituents and are radioactive. The salts contained in the wastes are primarily chloride, sulfate, nitrate, metal oxides, and hydroxides. DOE has placed these types of wastes under the purview of the Mixed Waste Focus Area (MWFA). The MWFA has been tasked with developing and facilitating the implementation of technologies to treat these wastes in support of customer needs and requirements. The MWFA has developed a Technology Development Requirements Document (TDRD), which specifies performance requirements for technology owners and developers to use as a framework in developing effective waste treatment solutions. This project will demonstrate the use of polyester resins in encapsulating and solidifying DOE`s mixed wastes containing salts, as an alternative to conventional and other emerging immobilization technologies
Giant Alcohol: A Worthy Opponent for the Children of the Band of Hope
From its foundation in 1847, the temperance organisation the Band of Hope addressed its young members as consumers, victims, and agents. In the first two roles they encountered the effects of drink of necessity, but in the third role they were encouraged to seek it out, attempting to influence individuals and wider society against 'Giant Alcohol'.
With an estimated membership of half the school-age population by the early twentieth century, well over three million, the Band of Hope also acted more directly to influence policy, and encouraged young people to consider issues of policy and politics. With its wide range of activities and material to educate, entertain and empower millions of children, and its radical view of the place of the child, the Band of Hope not only mobilised its child members to lobby for legal change, including prohibition, but took an active part in pointing out the cost of alcohol to society, particularly during the 14-18 war. The organisation began to decline post 1918, and this paper focuses on the address made to children by the Band of Hope in the late nineteenth and early twentieth centuries, at a time when its innovative view of children as able to understand and influence policy decisions reflected developments in the construction of childhood. This article draws on the archive of the British National Temperance League, over 50,000 items located in the Livesey Collection, University of Central Lancashire
Effects on Safety of Pavement- Truck Tire Interaction
DTFH61-85-C-00148A new truck tire tester was built to measure tire forces in braking and cornering under various speed, vertical load, and slip angle conditions and on different pavement surfaces. Six of the most common truck and bus tires were tested. In general, rib tires performed better than lug tires and radial tires performed better than bias-ply tires. Overall, the radial rib tire performed best, both in braking and in cornering, among the six test tires. All of the independent test variables - pavement type, vehicle speed, axle load, and slip angle - have a significant effect on tire traction. The experimental data were processed to derive 48 regression models relating peak and sliding coefficients of braking and cornering friction and critical longitudinal slip to the independent variables. A computer simulation study using the T3DRS, Phase 4 program was also conducted to investigate the effects of suspension type, tire type, roadway alignment, pavement roughness, and surface wetness on truck braking distance. The simulation results showed that trucks may require considerably larger stopping distances than passenger cars
Cosmological parameters from SDSS and WMAP
We measure cosmological parameters using the three-dimensional power spectrum
P(k) from over 200,000 galaxies in the Sloan Digital Sky Survey (SDSS) in
combination with WMAP and other data. Our results are consistent with a
``vanilla'' flat adiabatic Lambda-CDM model without tilt (n=1), running tilt,
tensor modes or massive neutrinos. Adding SDSS information more than halves the
WMAP-only error bars on some parameters, tightening 1 sigma constraints on the
Hubble parameter from h~0.74+0.18-0.07 to h~0.70+0.04-0.03, on the matter
density from Omega_m~0.25+/-0.10 to Omega_m~0.30+/-0.04 (1 sigma) and on
neutrino masses from <11 eV to <0.6 eV (95%). SDSS helps even more when
dropping prior assumptions about curvature, neutrinos, tensor modes and the
equation of state. Our results are in substantial agreement with the joint
analysis of WMAP and the 2dF Galaxy Redshift Survey, which is an impressive
consistency check with independent redshift survey data and analysis
techniques. In this paper, we place particular emphasis on clarifying the
physical origin of the constraints, i.e., what we do and do not know when using
different data sets and prior assumptions. For instance, dropping the
assumption that space is perfectly flat, the WMAP-only constraint on the
measured age of the Universe tightens from t0~16.3+2.3-1.8 Gyr to
t0~14.1+1.0-0.9 Gyr by adding SDSS and SN Ia data. Including tensors, running
tilt, neutrino mass and equation of state in the list of free parameters, many
constraints are still quite weak, but future cosmological measurements from
SDSS and other sources should allow these to be substantially tightened.Comment: Minor revisions to match accepted PRD version. SDSS data and ppt
figures available at http://www.hep.upenn.edu/~max/sdsspars.htm
Zodiacal Exoplanets in Time (ZEIT). VII. A Temperate Candidate Super-Earth in the Hyades Cluster
Transiting exoplanets in young open clusters present opportunities to study how exoplanets evolve over their lifetimes. Recently, significant progress detecting transiting planets in young open clusters has been made with the K2 mission, but so far all of these transiting cluster planets orbit close to their host stars, so planet evolution can only be studied in a high-irradiation regime. Here, we report the discovery of a long-period planet candidate, called HD 283869 b, orbiting a member of the Hyades cluster. Using data from the K2 mission, we detected a single transit of a super-Earth-sized (1.96 0.12 R â) planet candidate orbiting the K-dwarf HD 283869 with a period longer than 72 days. As we only detected a single-transit event, we cannot validate HD 283869 b with high confidence, but our analysis of the K2 images, archival data, and follow-up observations suggests that the source of the event is indeed a transiting planet. We estimated the candidate's orbital parameters and find that if real, it has a period P â 100 days and receives approximately Earth-like incident flux, giving the candidate a 71% chance of falling within the circumstellar habitable zone. If confirmed, HD 283869 b would have the longest orbital period, lowest incident flux, and brightest host star of any known transiting planet in an open cluster, making it uniquely important to future studies of how stellar irradiation affects planetary evolution
When Do Stalled Stars Resume Spinning Down? Advancing Gyrochronology with Ruprecht 147
Recent measurements of rotation periods () in the benchmark open clusters Praesepe (670 Myr), NGC 6811 (1 Gyr), and NGC 752 (1.4 Gyr) demonstrate that, after converging onto a tight sequence of slowly rotating stars in mass-period space, stars temporarily stop spinning down. These data also show that the duration of this epoch of stalled spin-down increases toward lower masses. To determine when stalled stars resume spinning down, we use data from the K2 mission and the Palomar Transient Factory to measure for 58 dwarf members of the 2.7 Gyr old cluster Ruprecht 147, 39 of which satisfy our criteria designed to remove short-period or near-equal-mass binaries. Combined with the Kepler data for the approximately coeval cluster NGC 6819 (30 stars with M â > 0.85, our new measurements more than double the number of â2.5 Gyr benchmark rotators and extend this sample down to â0.55. The slowly rotating sequence for this joint sample appears relatively flat (22 ± 2 days) compared to sequences for younger clusters. This sequence also intersects the Kepler intermediate-period gap, demonstrating that this gap was not created by a lull in star formation. We calculate the time at which stars resume spinning down and find that 0.55 stars remain stalled for at least 1.3 Gyr. To accurately age-date low-mass stars in the field, gyrochronology formulae must be modified to account for this stalling timescale. Empirically tuning a core-envelope coupling model with open cluster data can account for most of the apparent stalling effect. However, alternative explanations, e.g., a temporary reduction in the magnetic braking torque, cannot yet be ruled out
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