1,010 research outputs found

    Future Supply of Nature-Made Petroleum and Gas

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    This book deals with the availability and extractability of nature made petroleum and gas deposits. It is the result of a joint IIASA/UNITAR conference held in July 1976, and contains 57 chapters arranged in 9 sections: world perspectives on conventional petroleum, petroleum resource classification, conventional oil and gas deposits, enhanced oil recovery, gas in tight formations, gas in geopressurized reservoirs, other unconventional deposits, and technology transfer. The book discusses broad aspects of present and future supplies of nature made oil and gas, and brings out the increasing necessity of international cooperation in the field of energy resources. Through international cooperation and the development and use of advanced technology, natural energy resources may be sufficient to allow a more gradual transition to non-fossil fuels than was previously thought possible

    Linear stability analysis of resonant periodic motions in the restricted three-body problem

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    The equations of the restricted three-body problem describe the motion of a massless particle under the influence of two primaries of masses 1−μ1-\mu and μ\mu, 0≤μ≤1/20\leq \mu \leq 1/2, that circle each other with period equal to 2π2\pi. When μ=0\mu=0, the problem admits orbits for the massless particle that are ellipses of eccentricity ee with the primary of mass 1 located at one of the focii. If the period is a rational multiple of 2π2\pi, denoted 2πp/q2\pi p/q, some of these orbits perturb to periodic motions for μ>0\mu > 0. For typical values of ee and p/qp/q, two resonant periodic motions are obtained for μ>0\mu > 0. We show that the characteristic multipliers of both these motions are given by expressions of the form 1±C(e,p,q)μ+O(μ)1\pm\sqrt{C(e,p,q)\mu}+O(\mu) in the limit μ→0\mu\to 0. The coefficient C(e,p,q)C(e,p,q) is analytic in ee at e=0e=0 and C(e,p,q)=O(e^{\abs{p-q}}). The coefficients in front of e^{\abs{p-q}}, obtained when C(e,p,q)C(e,p,q) is expanded in powers of ee for the two resonant periodic motions, sum to zero. Typically, if one of the two resonant periodic motions is of elliptic type the other is of hyperbolic type. We give similar results for retrograde periodic motions and discuss periodic motions that nearly collide with the primary of mass 1−μ1-\mu

    Provision of NHS generalist and specialist services to care homes in England: review of surveys

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    Background: The number of beds in care homes (with and without nurses) in the United Kingdom is three times greater than the number of beds in National Health Service (NHS) hospitals. Care homes are predominantly owned by a range of commercial, not-for-profit or charitable providers and their residents have high levels of disability, frailty and co-morbidity. NHS support for care home residents is very variable, and it is unclear what models of clinical support work and are cost-effective. Objectives: To critically evaluate how the NHS works with care homes.MethodsA review of surveys of NHS services provided to care homes that had been completed since 2008. It included published national surveys, local surveys commissioned by Primary Care organisations, studies from charities and academic centres, grey literature identified across the nine government regions, and information from care home, primary care and other research networks. Data extraction captured forms of NHS service provision for care homes in England in terms of frequency, location, focus and purpose. Results: Five surveys focused primarily on general practitioner services, and 10 on specialist services to care home. Working relationships between the NHS and care homes lack structure and purpose and have generally evolved locally. There are wide variations in provision of both generalist and specialist healthcare services to care homes. Larger care home chains may take a systematic approach to both organising access to NHS generalist and specialist services, and to supplementing gaps with in-house provision. Access to dental care for care home residents appears to be particularly deficient. Conclusions:Historical differences in innovation and provision of NHS services, the complexities of collaborating across different sectors (private and public, health and social care, general and mental health), and variable levels of organisation of care homes, all lead to persistent and embedded inequity in the distribution of NHS resources to this population. Clinical commissioners seeking to improve the quality of care of care home residents need to consider how best to provide fair access to health care for older people living in a care home, and to establish a specification for service delivery to this vulnerable population

    Accessing transversity with interference fragmentation functions

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    We discuss in detail the option to access the transversity distribution function h1(x)h_1(x) by utilizing the analyzing power of interference fragmentation functions in two-pion production inside the same current jet. The transverse polarization of the fragmenting quark is related to the transverse component of the relative momentum of the hadron pair via a new azimuthal angle. As a specific example, we spell out thoroughly the way to extract h1(x)h_1(x) from a measured single spin asymmetry in two-pion inclusive lepton-nucleon scattering. To estimate the sizes of observable effects we employ a spectator model for the fragmentation functions. The resulting asymmetry of our example is discussed as arising in different scenarios for the transversity.Comment: 17 pages, 15 figures in .eps format included, typesetted in RevTeX and epsfig.sty, submitted to Phys. Rev.

    Heterogeneity of genetic parameters for calving difficulty in Holstein heifers in Ireland

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    Calving difficulty is a trait that greatly affects animal welfare, herd profitability, and the amount of labor required by cattle farmers. It is influenced by direct and maternal genetic components. Selection and breeding strategies can optimize the accuracy of genetic evaluations and correctly emphasize calving difficulty in multiple-trait indices provided there are accurate estimates of genetic parameters. In Ireland, large differences exist in the age at which heifers first give birth to calves. The objective of this study was to estimate genetic parameters for calving difficulty in first-parity Holsteins and to determine whether these differed with age of the heifer at calving. Transformed calving difficulty records for 18,798 Holstein heifers, which calved between January 2002 and May 2006, were analyzed using univariate, multitrait, and random regression linear sire-maternal grandsire models. The model that 1) fitted a second-order random regression of dam age at first parity for the direct component, 2) treated the maternal component as a single trait regardless of dam age, and 3) fitted a single residual variance component was optimal. Heritabilities for direct (0.13) and maternal (0.04) calving difficulty were significantly different from zero. These 2 components were moderately negatively correlated (¿0.47). Estimates of direct genetic variance and heritability were heterogeneous along the dam age trajectory, decreasing initially with dam age before subsequently increasing. Heritability estimates ranged between 0.11 and 0.37 and were higher for records with younger and older dams at parturition. Genetic correlations between the direct components of calving difficulty decreased from unity to 0.5 with increasing distance between dam ages at parturition. The results of this study indicated that heterogeneity of direct genetic variance existed for calving difficulty, depending on dam age at first parturition

    The Optimal Study: Describing the Key Components of Optimal Health Care Delivery to UK Care Home Residents: A Research Protocol

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    Long-term institutional care in the United Kingdom is provided by care homes. Residents have prevalent cognitive impairment and disability, have multiple diagnoses, and are subject to polypharmacy. Prevailing models of health care provision (ad hoc, reactive, and coordinated by general practitioners) result in unacceptable variability of care. A number of innovative responses to improve health care for care homes have been commissioned. The organization of health and social care in the United Kingdom is such that it is unlikely that a single solution to the problem of providing quality health care for care homes will be identified that can be used nationwide. Realist evaluation is a methodology that uses both qualitative and quantitative data to establish an in-depth understanding of what works, for whom, and in what settings. In this article we describe a protocol for using realist evaluation to understand the context, mechanisms, and outcomes that shape effective health care delivery to care home residents in the United Kingdom. By describing this novel approach, we hope to inform international discourse about research methodologies in long-term care settings internationally

    Predictions of total and total reaction cross sections for nucleon-nucleus scattering up to 300 MeV

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    Total reaction cross sections are predicted for nucleons scattering from various nuclei. Projectile energies to 300 MeV are considered. So also are mass variations of those cross sections at selected energies. All predictions have been obtained from coordinate space optical potentials formed by full folding effective two-nucleon (NN) interactions with one body density matrix elements (OBDME) of the nuclear ground states. Good comparisons with data result when effective NN interactions defined by medium modification of free NN t matrices are used. Coupled with analyses of differential cross sections, these results are sensitive to details of the model ground states used to describe nuclei

    BMO spaces associated with semigroups of operators

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    We study BMO spaces associated with semigroup of operators and apply the results to boundedness of Fourier multipliers. We prove a universal interpolation theorem for BMO spaces and prove the boundedness of a class of Fourier multipliers on noncommutative Lp spaces for all 1 < p < \infty, with optimal constants in p.Comment: Math An

    High-resolution study of 0+ and 2+ excitations in 168Er with the (p,t) reaction

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    Excited states in the deformed nucleus 168Er have been studied with high-energy resolution, in the (p, t ) reaction, with the Munich Q3D spectrograph. A number of 25 excited 0+ states (four tentative) and 63 2+ states have been assigned up to 4.0 MeV excitation energy. This unusually rich characterization of the 0+ and 2+ states in a deformed nucleus, close to a complete level scheme, offers a unique opportunity to check, in detail, models of nuclear structure that incorporate many excitation modes. A comparison of the experimental data is made with two such models: the quasiparticle-phonon model (QPM), and the projected shell model (PSM). The PSM wave functions appear to contain fewer correlations than those of the QPM and than required by the data
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