1,716 research outputs found
^{63}Cu, ^{35}Cl, and ^{1}H NMR in the S=1/2 Kagom\'e Lattice ZnCu_{3}(OH)_{6}Cl_{2}
ZnCu(OH)Cl () is a promising new candidate for an
ideal Kagom\'e Heisenberg antiferromagnet, because there is no magnetic phase
transition down to 50 mK. We investigated its local magnetic and lattice
environments with NMR techniques. We demonstrate that the intrinsic local spin
susceptibility {\it decreases} toward T=0, but that slow freezing of the
lattice near 50 K, presumably associated with OH bonds, contributes to a
large increase of local spin susceptibility and its distribution. Spin dynamics
near T=0 obey a power-law behavior in high magnetic fields.Comment: Phys. Rev. Lett. (in press
Development of an Equilibrium-based Model of Gasification of Biomass by Aspen Plus
Abstract Agricultural and forestry residues are usually processed as wastes; otherwise, they can be recovered to produce electrical and thermal energy through processes of thermochemical conversion, such us torrefaction, pyrolysis and gasification. Currently, the gasification of residual biomass for producing neutral CO 2 fuel for energy production is in development stage. In this context, this study proposes anequilibrium-based model, developed by the commercial software Aspen Plus, of a co-current gasifier fueled with agriculture residual, which allows estimating the chemical composition and theheating value of the syngas produced. The prediction of such model includes the main gaseous species, the yields of char and tar and describes the gasification process through the mass and energy balances, the water-gas shift (WGS) and the methanation reaction. The model validation was carried out through the comparison with experimental data, concerning two biomass with different moisture content and different gasification conditions, for sixteen cases compared. Overall, the comparison between the results of the simulations and the experimental data have shown a good agreement
Dynamic Scaling in the Susceptibility of the Spin-1\2 Kagome Lattice Antiferromagnet Herbertsmithite
The spin-1/2 kagome lattice antiferromagnet herbertsmithite,
ZnCu(OH)Cl, is a candidate material for a quantum spin liquid
ground state. We show that the magnetic response of this material displays an
unusual scaling relation in both the bulk ac susceptibility and the low energy
dynamic susceptibility as measured by inelastic neutron scattering. The
quantity with can be expressed as a
universal function of or . This scaling is discussed in
relation to similar behavior seen in systems influenced by disorder or by the
proximity to a quantum critical point.Comment: 5 pages, 3 figures v2: updated to match published version
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Urban traffic management and Intelligent Transport Systems: A European perspective
The objective of this paper is to establish the state-of-the-art of urban traffic management in Europe, with a particular focus on Intelligent Transport Systems (ITS), using data collected from 34 cities directly with the help of a purpose-developed questionnaire. Several areas of traffic management are covered, such as: general statistics of the transport systems, organisational structures, monitoring and forecasting, provision of traffic information and urban traffic control. Special focus is also given to demand management, traffic control centres, public transport and parking. Broadly summarising the results, it can be said that a wide range of traffic management technologies and policies are used in Europe. It is encouraging to see that strategic plans and traffic control centres are generally present in the participating cities, as well as facilities for public transport, ITS technologies and real-time public transport information. In addition, most cities have cycling infrastructure, pedestrian zones and alternative mobility schemes, as well as good policies for weaker population categories, such as the elderly, the jobless and the disabled. While the study has some limitations with respect to the reliability of the data provided by the cities, mainly originating from different definitions or from the absence of data all together, it can be considered a fairly good overview of the state-of-the art of urban traffic management in Europe
Evaluation of different methods to estimate the transfer of immunity in donkey foals fed with colostrum of good IgG quality: A preliminary study
The aims of the present study were to evaluate the correlation between IgG Serum Radial Immunodiffusion (SRID), Electrophoresis Gamma Globulins (EGG), Electrophoresis Total Protein (ETP) and the serum total protein (TP) analyzed by refractometry and by a dry chemistry analyzer (Biuret) and to estimate serum IgG concentrations using serum TP. A total of 36 samples collected at four different times (birth, 6, 12, 24 hours after birth) from nine Amiata donkey foals were evaluated with SRID, EGG, ETP, serum TP Biuret and refractometry. SRID IgG concentration increased significantly over time until T12. Serum TP analyzed with refractometry, electrophoresis and Biuret showed a statistically significant difference between T0 and T6 vs T12 and T24. A good or strong correlation was found between different tests performed. Equations to quantify serum IgG were created and can be used for estimating the donkey foals’ serum IgG in the first day of life. Serum TP refractometry showed a high correlation with SRID IgG (0.91) which may be a particularly useful and economic instrument to estimate the transfer of immunity in donkey foals during the first day of life
Radiographic parameters of the digit in a cohort population of amiata donkeys
Background: The most common musculoskeletal conditions reported in donkeys are related to the foot. Radiographic examinations are clinically important in the diagnosis of foot abnormalities and are commonly used. However, few studies have been conducted to establish the normal radiographic appearance of a donkey’s foot. Aim: To determine the radiographic features of the front digit in healthy Amiata donkeys. Methods: Radiographic examinations were performed on 56 forefeet of 28 Amiata donkeys. Three radiographic views of each front foot were taken: lateromedial, dorsopalmar and dorso-65°proximal/palmarodistal oblique. Seventeen angular and linear radiographic parameters and the crena solearis were evaluated in all forefeet, and 18 morphometric parameters were evaluated in 16 out of 56 forefeet. Statistical analysis was carried out on all the measures assessed. Results: The radiographic appearance of the forefoot was ascertained, and data were reported as median ± standard error, minimum and maximum values. No statistical differences were obtained between the right and left forefeet. Conclusion: The normal baseline parameters of the forefeet of Amiata donkeys were recorded and described and compared with other donkey breeds and horses. The findings highlighted that the donkey breed affects the radiographic parameters of the digit
English Words in Time
English Words in Time brings together a fairly wide range of current work on English lexis. The different chapters draw on considerations and perspectives from various areas in English linguistics: historical lexicology and lexicography, translation studies, sociolinguistics, English as a global language and Internet English
Improved fertilization and implantation rates after non-touch zona pellucida microdrilling of mouse oocytes with a 1.48 μm diode laser beam
The safety of microdrilling the zona pellucida of moose oocytes with a 1.48 μm diode laser has been investigated by determining the ability of mouse oocytes to fertilize in vitro and develop in vivo. Mice born after transfer of control and zona pelludda-microdrilled embryos into foster mothers were submitted to anatomical and immunohisto-chemical investigations, and their aptitude to breed was assessed in two subsequent generations. Decolonization of the oocytes with hyaluronidase induced a reduction of the fertilization and implantation rates, which was attributed to a zona hardening phenomenon. After laser zona pellucida microdrilling, these rates were restored to those obtained with embryos derived from untreated oocyte-cumulus complexes. Pups derived from zona pellucida microdrilled embryos were comparable with those obtained from control embryos, confirming the lack of deleterious effects of the laser treatment In conclusion, the 1.48 μm diode laser allows safe microdrilling of the zona pellucida of mouse oocytes after decoronization with hyaluronidase. Based on the health of the F2 generation and the lack of neuroanatom-ical and neurochemical differences, we concluded that this technology may be investigated in the human, particularly when the zona pellucida represents the main impediment for fertilization or embryo hatchin
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