420 research outputs found
Duality Breaking of Vortex Configuration in a Hierarchical Honeycomb Network
We report measurements of Little-Parks oscillation on the hierarchical
honeycomb-superconducting network for investigating possible effects of
hierarchical structure in terms of spatial symmetry, parity and duality. We
observed an asymmetric Little-Parks oscillation about ,
although spatial symmetry was kept in the network. In comparison with a regular
honeycomb network, the asymmetric oscillation is attributed to hierarchy which
induces mixture of commensurate and incommensurate regions. The asymmetric
oscillation is found to indicate breaking of the duality of vortex
configuration.Comment: 12 pages, 6 figure
Growth of Bali Bulls Fattened with Forage Tree Legumes in Eastern Indonesia: Leucaena leucocephala in Sumbawa
The contribution of West Nusa Tenggara Province to domestic beef supply in Indonesia is relatively small, however, beef cattle are very important for the livelihoods of smallholder farmers in the region.
Bali cattle (Boss javanicus) are the predominant breed as they are adapted to harsh nutritional conditions, are highly fertile and have low calf mortality (Toelihere 2003). While genetically capable of achieving a growth rate of 0.85 kg/d (Mastika 2003), Panjaitan (2012) identified poor nutrition as a severe limitation to animal growth in traditional village systems. Improving feed quality and supply is vital to increasing growth rates and product quality. Forage tree legumes such as leucaena (Leucaena leucocephala) offer the best chance of providing high quality feed to fatten Bali bulls in village systems where leucaena is well-adapted. Indeed, the feeding of leucaena has been practiced for about two decades in Sumbawa district of West Nusa Tenggara although the practice is limited to specific villages, mostly Balinese, even though farmers nearby have similar biophysical conditions and nutritional problems. The objective of this work was to characterize the best practices employed by farmers in Sumbawa that maximize growth rates by feeding leucaena so that their detailed knowledge can be passed onto other villagers in a pilot roll-out program (Kana Hau 2013)
Growth of Bali Bulls on Rations Containing \u3cem\u3eSesbania grandiflora\u3c/em\u3e in Central Lombok, Indonesia
The demand for meat in Indonesia is currently growing by up to 8% per year, with beef cattle fattening identified as a major livestock industry (Purwantara et al. 2012). Bali cattle (Bos javanicus) account for almost 27% of total beef cattle in Indonesia; they are the predominant breed in the eastern islands and are highly favoured by smallholder farmers for their high fertility, low calf mortality and generally higher price at markets (Purwantara et al. 2012). Lombok in west Nusa Tenggara is one of the biggest suppliers of Bali cattle in Indonesia.
A major constraint to improving the overall productivity of Bali cattle is their slow growth rate, due to lack of readily available, inexpensive, high-quality protein sources. Fodder tree legumes, such as sesbania (Sesbania grandiflora), offer a fast-growing, low-cost source of protein (Evans and Rotar 1987). Farmers in Lombok have established a unique and productive integrated farming system by planting sesbania trees along the bunds of rice paddies, providing forage and timber without significantly compromising rice yield (Dahlanuddin and Shelton 2005).
As only the central part of Lombok is intensively planted with sesbania, a collaborative project funded by the Australian Centre for International Agricultural Research (ACIAR) is underway aiming to: (1) characterise the existing cattle fattening system; and (2) assess the impact of differing levels of sesbania feeding on the growth rate of Bali bulls from weaning to maturity (about 30 months old)
Chiral charge-density-waves
We discovered the chirality of charge density waves (CDW) in 1T-TiSe by
using scanning tunnelling microscopy (STM) and optical ellipsometry. We found
that the CDW intensity becomes , where (i =1, 2, 3) is the amplitude of the tunnelling current
contributed by the CDWs. There were two states, in which the three intensity
peaks of the CDW decrease \textit{clockwise} and \textit{anticlockwise} when we
index each nesting vector in order of intensity in the Fourier transformation
of the STM images. The chirality in CDW results in the three-fold symmetry
breaking. Macroscopically, two-fold symmetry was indeed observed in optical
measurement. We propose the new generalized CDW chirality H_{CDW} \equiv
{\boldmath q_1} \cdot ({\boldmath q_2}\times {\boldmath q_3}), where
{\boldmath q_i} are the nesting vectors, which is independent of the
symmetry of components. The nonzero - the triple-{\boldmath q}
vectors do not exist in an identical plane in the reciprocal space - should
induce a real-space chirality in CDW system.Comment: 12 pages, 4 figure
Electronic Properties of Topological Materials: Optical Excitations in Moebius Conjugated Polymers
Electronic structures and optical excitations in Moebius conjugated polymers
are studied theoretically. Periodic and Moebius boundary conditions are applied
to the tight binding model of poly(para-phenylene), taking exciton effects into
account. We discuss that oligomers with a few structural units are more
effective than polymers for observations of effects of discrete wave numbers
that are shifted by the change in boundary condition. Next, calculations of
optical absorption spectra are reported. Certain components of optical
absorption for an electric field perpendicular to the polymer axis mix with
absorption spectra for an electric field parallel to the polymer axis.
Therefore, the polarization dependences of an electric field of light enable us
to detect whether conjugated polymers have the Moebius boundary.Comment: 10 pages, 6 figures, to be published in J. Phys. Soc. Jpn., Vol. 74
No. 2 (February, 2005), Letter sectio
An analysis of some multiuser detectors in impulsive noise
L'object de cet article est l'étude de la détection de données à travers des canaux de communication non gaussiens, en séquence directe, spectre large et accès multiple. Ce problème apparaît dans des situations pratiques parce que la plupart des canaux physiques, dans lesquels les communications en multiple accès sont utilisées, sont connus pour être incontestablement non gaussiens. Concernant les systèmes synchrones, le détecteur multi-utilisateur optimal (au sens du maximum de vraisemblance) est obtenu et ses performances sont analysées et comparées avec plusieurs détecteurs sous optimaux
Barriers and Opportunities for the Use of Forage Tree Legumes in Smallholder Cattle Fattening Systems in Eastern Indonesia
Forage tree legumes (FTL) have existed in the Eastern Indonesian landscape since colonial traders introduced several species in the late 1800s. A specific effort was made to establish leucaena (Leucaena leucoephala) and sesbania (Sesbania grandiflora) for use as forage for cattle fattening at Amarasi in East Nusa Tenggara Province and Central Lombok in West Nusa Tenggara, in the 1970s (Yuksel et al. 1999; Dahlanuddin et al. 2005). Its spread within these provinces as potential forage to intensify cattle fattening systems, however, has been slow if not stagnant. In preparation for intensified efforts to encourage farmers in East and West Nusa Tenggara to grow and use FTLs for cattle fattening, we asked the question why successful FTL feeding practices by some communities had not spread widely to adjacent areas within the provinces. A situation analysis study was conducted in 2011-12 in East and West Nusa Tenggara Provinces aimed at identifying the barriers and opportunities for FTL use in smallholder cattle fattening systems. This paper describes the methodology of this study, its main findings and the implications for follow-up expansion of FTL innovations
Geometrically Frustrated Crystals: Elastic Theory and Dislocations
Elastic theory of ring-(or cylinder-)shaped crystals is constructed and the
generation of edge dislocations due to geometrical frustration caused by the
bending is studied. The analogy to superconducting (or superfluid) vortex state
is pointed out and the phase diagram of the ring-crystal, which depends on
radius and thickness, is discussed.Comment: 4 pages, 3 figure
Solving inverse problems of unknown contaminant source in groundwater-river integrated systems using a surrogate transport model based optimization
The paper presents a new approach to identify the unknown characteristics (release history and location) of contaminant sources in groundwater, starting from a few concentration observations at monitoring points. An inverse method that combines the forward model and an optimization algorithm is presented. To speed up the computation, the transfer function theory is applied to create a surrogate transport forward model. The performance of the developed approach is evaluated on two case studies (literature and a new one) under different scenarios and measurement error conditions. The literature case study regards a heterogeneous confined aquifer, while the proposed case study was never investigated before, it involves an aquifer-river integrated flow and transport system. In this case, the groundwater contaminant originated from a damaged tank, migrates to a river through the aquifer. The approach, starting from few concentration observations monitored at a downstream river cross-section, accurately estimates the release history at a groundwater contaminant source, even in presence of noise on observations. Moreover, the results show that the methodology is very fast, and can solve the inverse problem in much less computation time in comparison with other existing approaches
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