9,522 research outputs found
Syzygies and the Rees algebra
No full textAbstractLet a,b,c be linearly independent homogeneous polynomials in the standard Z-graded ring R≔k[s,t] with the same degree d and no common divisors. This defines a morphism P1→P2. The Rees algebra Rees(I)=R⊕I⊕I2⊕⋯ of the ideal I=〈a,b,c〉 is the graded R-algebra which can be described as the image of an R-algebra homomorphism h: R[x,y,z]→Rees(I). This paper discusses one result concerning the structure of the kernel of the map h and its relation to the problem of finding the implicit equation of the image of the map given by a, b, c. In particular, we prove a conjecture of Hong, Simis and Vasconcelos. We also relate our results to the theory of adjoint curves and prove a special case of a conjecture of Cox
Cartes de Visite -- Virginia -- Richmond (II), Item 109
No full textCaption on back: Mrs. Neville R. Blakemore
Summary data for tracer gas dispersion tests for landfill methane emission monitoring at a UK landfill
No full textThis dataset supports the publications:
1) Rees-White, T. C., Mønster, J., Beaven R. P., Scheutz, C. (2018) Measuring methane emissions from a UK landfill sing the tracer dispersion method and the influence of operational and environmental factors https://doi.org/10.1016/j.wasman.2018.03.023
2) Matacchiera F, Manes C, Beaven RP, Rees-White TC, Boano F, Mønster J and Scheutz C (2018). AERMOD as a Gaussian dispersion model for planning tracer gas dispersion tests for landfill methane emission quantification https://doi.org/10.1016/j.wasman.2018.02.007
Contents
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This dataset contains the data discussed within the papers listed above and in certain Figures from the Rees-White paper.
The figures are as follows:
Fig. 3. Atmospheric pressure and wind speed during the period of August 5th to August 14th, 2014. Start and end times of each TDM experiment are given as vertical lines
Fig. 4. Incoming solar radiation and air temperature during the period of August 3th to August 14th, 2014. Start and end times of each TDM experiment are given as vertical lines
Fig. 6 (a to f). Methane emission data for each transect in a TDM with average overall emission and the 95% confidence interval. The name of the monitoring route used for a given transect is also shown
Fig. 7. Measured methane emissions vs. average wind speed for the six TDM trials. Linear regression is given (R2 = -0.82).
Fig. 8. Individual transect data from TDM2 shown against estimated wind speed, interpolated between measurement points. Data are colour coded to reflect the monitoring route used. a) shows data between 18:07 and 20:09, and b) 20:59 to 22:14.
Fig. 9. a) Average methane emission data from each monitoring route shown against measuring distance, b) Average methane emission rate from each monitoring route for a given TDM measured at different monitoring distances.
Geographic location of this data collection: University of Southampton, U.K.
Dataset available under a CC BY 4.0 licence
Publisher: University of Southampton, U.K.
Date: April 2018</span
A note on the Rees algebra of a bipartite graph
No full textAbstractLet R=K[x1,…,xn] be a polynomial ring over a field K and let I be an ideal of R generated by a set xα1,…,xαq of square-free monomials of degree two such that the graph G defined by those monomials is bipartite. We study the Rees algebra R(I) of I, by studying both the Rees cone R+A′ generated by the set A′={e1,…,en,(α1,1),…,(αq,1)} and the matrix C whose columns are the vectors in A′. It is shown that C is totally unimodular. We determine the irreducible representation of the Rees cone in terms of the minimal vertex covers of G. Then we compute the a-invariant of R(I)
Oral History Interview with James R. O'Donnel, December 8, 2001
No full textThe National Museum of the Pacific War presents an oral interview with James R. O'Donnel. He was born in Donora, Pennsylvania and joined the Aviation Cadet training program in December 1942. Upon graduation from Bombardier School in late 1943 he was sent to Clovis, New Mexico as a B-29 crewmember. Upon completion of training in November 1944 his crew flew a B-29 to Saipan as part of the 499th Bomber Group of the 20th Air Force. He recalls their first mission over Japan on Thanksgiving Day 1944 and 29 subsequent raids ending in June 1945. He describes one mission over Japan at high altitude on March 17, 1945 gathering weather data for future bombing runs, when his aircraft was shot up by the Japanese and had to make an emergency landing on Iwo Jima, even while mop up operations were occurring on the island. He describes meeting General Holland M. Smith while awaiting a flight off the island. He recalls that he had been transferred back to the States when the war ended
Green index and finiteness conditions for semigroups
No full textLet S be a semigroup and let T be a subsemigroup of S. Then T acts on S by left and by right multiplication. If the complement S \ T has finitely many strong orbits by both these actions we say that T has finite Green index in S. This notion of finite index encompasses subgroups of finite index in groups, and also subsemigroups of finite Rees index (complement). Therefore, the question of S and T inheriting various finiteness conditions from each other arises. In this paper we consider and resolve this question for the following finiteness conditions: finiteness, residual finiteness, local finiteness, periodicity, having finitely many right ideals, and having finitely many idempotents. (c) 2008 Elsevier Inc. All rights reserved.Peer reviewe
Online preconcentration ICP-MS analysis of rare earth elements in seawater
No full textThe rare earth elements (REEs) with their systematically varying properties are powerful tracers of continental inputs, particle scavenging intensity and the oxidation state of seawater. However, their generally low (∼pmol/kg) concentrations in seawater and fractionation potential during chemical treatment makes them difficult to measure. Here we report a technique using an automated preconcentration system, which efficiently separates seawater matrix elements and elutes the preconcentrated sample directly into the spray chamber of an ICP-MS instrument. The commercially available “seaFAST” system (Elemental Scientific Inc.) makes use of a resin with ethylenediaminetriacetic acid and iminodiacetic acid functional groups to preconcentrate REEs and other metals while anions and alkali and alkaline earth cations are washed out. Repeated measurements of seawater from 2000 m water depth in the Southern Ocean allows the external precision (2σ) of the technique to be estimated at <23% for all REEs and <15% for most. Comparison of Nd concentrations with isotope dilution measurements for 69 samples demonstrates that the two techniques generally agree within 15%. Accuracy was found to be good for all REEs by using a five point standard addition analysis of one sample and comparing measurements of mine water reference materials diluted with a NaCl matrix with recommended values in the literature. This makes the online preconcentration ICP-MS technique advantageous for the minimal sample preparation required and the relatively small sample volume consumed (7 mL) thus enabling large data sets for the REEs in seawater to be rapidly acquired
The history of Pembrokeshire,
No full text"The author had projected a history that would have dealt with the county to the close of the nineteenth century. His outline included three chapters ... Georgian Pembrokeshire, The landing of the French, and Modern days, which he did not live to write." The incomplete manuscript was pub. after his death under the general superintendence of T. C. Rees. cf. Foreword (by J. and M. Phillips)Mode of access: Internet
Protocol for the United Kingdom Rotator Cuff Study (UKUFF) : a randomised controlled trial of open and arthroscopic rotator cuff repair
No full textThis project was funded by the NIHR Health Technology Assessment programme (project number 05/47/02). J. L. Rees has received a grant from Oxford University which is related to this paper. J. Dawson reports that Oxford University has received a grant from HTA which is related to this paper, as well as a study grant.Peer reviewe
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