Three terminal capacitance technique for magnetostriction and thermal expansion measurements

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

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

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

A Carboxy-terminal Inter-Helix Linker As the Site of Phosphatidylinositol 4,5-Bisphosphate Action on Kv7 (M-type) K+ Channels

The regulation of M-type (KCNQ [Kv7]) K+ channels by phosphatidylinositol 4,5-bisphosphate (PIP2) has perhaps the best correspondence to physiological signaling, but the site of action and structural motif of PIP2 on these channels have not been established. Using single-channel recordings of chimeras of Kv7.3 and 7.4 channels with highly differential PIP2 sensitivities, we localized a carboxy-terminal inter-helix linker as the primary site of PIP2 action. Point mutants within this linker in Kv7.2 and Kv7.3 identified a conserved cluster of basic residues that interact with the lipid using electrostatic and hydrogen bonds. Homology modeling of this putative PIP2-binding linker in Kv7.2 and Kv7.3 using the solved structure of Kir2.1 and Kir3.1 channels as templates predicts a structure of Kv7.2 and 7.3 very similar to the Kir channels, and to the seven-β-sheet barrel motif common to other PIP2-binding domains. Phosphoinositide-docking simulations predict affinities and interaction energies in accord with the experimental data, and furthermore indicate that the precise identity of residues in the interacting pocket alter channel–PIP2 interactions not only by altering electrostatic energies, but also by allosterically shifting the structure of the lipid-binding surface. The results are likely to shed light on the general structural mechanisms of phosphoinositide regulation of ion channels

On the Tail of the Overlap Probability Distribution in the Sherrington--Kirkpatrick Model

We investigate the large deviation behavior of the overlap probability density in the Sherrington--Kirkpatrick model from several analytical perspectives. First we analyze the spin glass phase using the coupled replica scheme. Here generically $\frac1N \log P_N(q)$ $\approx$ $- {\cal A}$ $((|q|-q_{EA})^3$, and we compute the first correction to the expansion of \A in powers of $T_c-T$. We study also the $q=1$ case, where $P(q)$ is know exactly. Finally we study the paramagnetic phase, where exact results valid for all $q$'s are obtained. The overall agreement between the various points of view is very satisfactory. Data from large scale numerical simulations show that the predicted behavior can be detected already on moderate lattice sizes.Comment: 18 pages including ps figure

Discrete breathers in dc biased Josephson-junction arrays

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

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

Equilibrium properties of a Josephson junction ladder with screening effects

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 $\omega$, 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 $\omega$. 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 $\omega=0$ 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

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

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