247 research outputs found

    Social considerations for the cultivation of industrial crops on marginal agricultural land as feedstock for bioeconomy

    Get PDF
    Marginal agricultural land (MAL) has received much attention in research and policy formation as a potential resource for cultivating biomass for energy and biobased products. However, it is still unclear whether biomass from MAL meets the requirements of social sustainability. This study develops a conceptual linkage between value-chain analysis and social life-cycle analysis (S-LCA), and assesses both positive impacts (handprints) and negative impacts (footprints). A participatory approach including interviews and surveys was used to understand views and perceptions of the relevant stakeholders. A systemic strategy was applied to analyze value-chain activities, understand challenges, and identify competitive advantages and disadvantages. For S-LCA, the variety of impacts and indicators was met through a literature review and a consistent scoring system. The cultivation of perennial crops on MAL tends to cause skepticism among stakeholders, who are concerned about long-term commitment and biodiversity risks. Annual crops, on the other hand, are perceived by all stakeholder categories as very promising opportunities across all impact categories and indicators. They can facilitate income diversification and offer smart sustainable cropping options through crop rotation, agroforestry, etc. Most of the technological pathways examined are highly innovative, have a low technological readiness level, and are still at the early market development stage. As such they are ranked by stakeholders as medium opportunities for short-term implementation. In contrast, pyrolysis to industrial heat, ethanol from switchgrass, insulation material from hemp, and biogas/biomethane from sorghum are considered opportunities with good chances of being implemented in the short term. © 2022 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons, Ltd

    Three terminal capacitance technique for magnetostriction and thermal expansion measurements

    Full text link
    An instrument has been constructed to measure a large range of magnetostriction and thermal expansion between room temperature and 4 K in a superconductive split-coil magnet, that allows investigation in magnetic fields up to 12 T. The very small bulk samples (up to 1 mm in size) as well as big ones (up to 13 mm) of the irregular form can be measured. The possibility of magnetostriction investigation in thin films is shown. A general account is given of both electrical and the mechanical aspects of the design of capacitance cell and their associated electronic circuitry. A simple lever device is proposed to increase the sensitivity twice. The resulting obtained sensitivity can be 0.5 Angstrom. The performance of the technique is illustrated by some preliminary measurements of the magnetostriction of superconducting MgB2, thermal expansion of (La0.8Ba0.2)0.93MnO3 single crystal and magnetoelastic behavior of the Ni/Si(111) and La0.7Sr0.3CoO3/SAT0.7CAT0.1LA0.2(001) cantilevers.Comment: 6 pages, 6 figures, journal pape

    Renormalization Group Study of the soliton mass on the (lambda Phi^4)_{1+1} lattice model

    Full text link
    We compute, on the (λΦ4)1+1(\lambda \Phi^4)_{1+1} model on the lattice, the soliton mass by means of two very different numerical methods. First, we make use of a ``creation operator'' formalism, measuring the decay of a certain correlation function. On the other hand we measure the shift of the vacuum energy between the symmetric and the antiperiodic systems. The obtained results are fully compatible. We compute the continuum limit of the mass from the perturbative Renormalization Group equations. Special attention is paid to ensure that we are working on the scaling region, where physical quantities remain unchanged along any Renormalization Group Trajectory. We compare the continuum value of the soliton mass with its perturbative value up to one loop calculation. Both quantities show a quite satisfactory agreement. The first is slightly bigger than the perturbative one; this may be due to the contributions of higher order corrections.Comment: 19 pages, preprint DFTUZ/93/0

    Effect of increasing dietary aminoacid concentration in late gestation on body condition and reproductive performance of hyperprolific sows

    Get PDF
    A total of 62 highly prolific Danbred sows was used to evaluate the implications of increasing dietary amino acid (AA) concentration during late gestation (from day 77 to 107 of pregnancy) on body condition and reproductive performances. Sows were assigned to one of the two treatments (n = 31, with similar number of sows in the second-, third-and fourth-cycle); control diet (containing 6 g of standardized ileal digestible lysine-SID Lys-)/kg) and high AA level (containing 10 g SID Lys/kg and following the ideal protein concept for the remaining essential AA). On day 108 of pregnancy, animals were moved to the farrowing-lactating facilities where they spent until weaning receiving a common standard lactation diet. After farrowing, litters were standardized to 13 piglets each. At 107 d of gestation, backfat depth was thicker in sows fed high AA concentration than in those fed control diet (p 0.05). Additionally, at farrowing, the litter size (p = 0.043) and weight (p = 0.017) were higher in sows fed high AA level. It can be concluded that the increase in the AA content in the feed during the last month of gestation could improve the body condition of the sows and their performance results

    Absence of stable collinear configurations in Ni(001)ultrathin films: canted domain structure as ground state

    Full text link
    Brillouin light scattering (BLS) measurements were performed for (17-120) Angstrom thick Cu/Ni/Cu/Si(001) films. A monotonic dependence of the frequency of the uniform mode on an in-plane magnetic field H was observed both on increasing and on decreasing H in the range (2-14) kOe, suggesting the absence of a metastable collinear perpendicular ground state. Further investigation by magneto-optical vector magnetometry (MOKE-VM) in an unconventional canted-field geometry provided evidence for a domain structure where the magnetization is canted with respect to the perpendicular to the film. Spin wave calculations confirm the absence of stable collinear configurations.Comment: 6 pages, 3 figures (text, appendix and 1 figure added

    Equilibrium properties of a Josephson junction ladder with screening effects

    Full text link
    In this paper we calculate the ground state phase diagram of a Josephson Junction ladder when screening field effects are taken into account. We study the ground state configuration as a function of the external field, the penetration depth and the anisotropy of the ladder, using different approximations to the calculation of the induced fields. A series of tongues, characterized by the vortex density ω\omega, is obtained. The vortex density of the ground state, as a function of the external field, is a Devil's staircase, with a plateau for every rational value of ω\omega. The width of each of these steps depends strongly on the approximation made when calculating the inductance effect: if the self-inductance matrix is considered, the ω=0\omega=0 phase tends to occupy all the diagram as the penetration depth decreases. If, instead, the whole inductance matrix is considered, the width of any step tends to a non-zero value in the limit of very low penetration depth. We have also analyzed the stability of some simple metastable phases: screening fields are shown to enlarge their stability range.Comment: 16 pp, RevTex. Figures available upon request at [email protected] To be published in Physical Review B (01-Dec-96

    Discrete breathers in dc biased Josephson-junction arrays

    Full text link
    We propose a method to excite and detect a rotor localized mode (rotobreather) in a Josephson-junction array biased by dc currents. In our numerical studies of the dynamics we have used experimentally realizable parameters and included self-inductances. We have uncovered two families of rotobreathers. Both types are stable under thermal fluctuations and exist for a broad range of array parameters and sizes including arrays as small as a single plaquette. We suggest a single Josephson-junction plaquette as an ideal system to experimentally investigate these solutions.Comment: 5 pages, 5 figure, to appear June 1, 1999 in PR

    A Numerical Study of Ultrametricity in Finite Dimensional Spin Glasses

    Full text link
    We use a constrained Monte Carlo technique to analyze ultrametric features of a 4 dimensional Edwards-Anderson spin glass with quenched couplings J=\pm 1. We find that in the large volume limit an ultrametric structure emerges quite clearly in the overlap of typical equilibrium configurations.Comment: 8 one column pages, latex, 4 figures with epsfig.st

    About the Functional Form of the Parisi Overlap Distribution for the Three-Dimensional Edwards-Anderson Ising Spin Glass

    Full text link
    Recently, it has been conjectured that the statistics of extremes is of relevance for a large class of correlated system. For certain probability densities this predicts the characteristic large xx fall-off behavior f(x)exp(aex)f(x)\sim\exp (-a e^x), a>0a>0. Using a multicanonical Monte Carlo technique, we have calculated the Parisi overlap distribution P(q)P(q) for the three-dimensional Edward-Anderson Ising spin glass at and below the critical temperature, even where P(q)P(q) is exponentially small. We find that a probability distribution related to extreme order statistics gives an excellent description of P(q)P(q) over about 80 orders of magnitude.Comment: 4 pages RevTex, 3 figure

    Static chaos and scaling behaviour in the spin-glass phase

    Full text link
    We discuss the problem of static chaos in spin glasses. In the case of magnetic field perturbations, we propose a scaling theory for the spin-glass phase. Using the mean-field approach we argue that some pure states are suppressed by the magnetic field and their free energy cost is determined by the finite-temperature fixed point exponents. In this framework, numerical results suggest that mean-field chaos exponents are probably exact in finite dimensions. If we use the droplet approach, numerical results suggest that the zero-temperature fixed point exponent θ\theta is very close to d32\frac{d-3}{2}. In both approaches d=3d=3 is the lower critical dimension in agreement with recent numerical simulations.Comment: 28 pages + 6 figures, LateX, figures uuencoded at the end of fil
    corecore