1,986 research outputs found

    spl(2,1) dynamical supersymmetry and suppression of ferromagnetism in flat band double-exchange models

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    The low energy spectrum of the ferromagnetic Kondo lattice model on a N-site complete graph extended with on-site repulsion is obtained from the underlying spl(2,1) algebra properties in the strong coupling limit. The ferromagnetic ground state is realized for 1 and N+1 electrons only. We identify the large density of states to be responsible for the suppression of the ferromagnetic state and argue that a similar situation is encountered in the Kagome, pyrochlore, and other lattices with flat bands in their one-particle density of states.Comment: 7 pages, 1 figur

    CuisineNet: Food Attributes Classification using Multi-scale Convolution Network

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    Diversity of food and its attributes represents the culinary habits of peoples from different countries. Thus, this paper addresses the problem of identifying food culture of people around the world and its flavor by classifying two main food attributes, cuisine and flavor. A deep learning model based on multi-scale convotuional networks is proposed for extracting more accurate features from input images. The aggregation of multi-scale convolution layers with different kernel size is also used for weighting the features results from different scales. In addition, a joint loss function based on Negative Log Likelihood (NLL) is used to fit the model probability to multi labeled classes for multi-modal classification task. Furthermore, this work provides a new dataset for food attributes, so-called Yummly48K, extracted from the popular food website, Yummly. Our model is assessed on the constructed Yummly48K dataset. The experimental results show that our proposed method yields 65% and 62% average F1 score on validation and test set which outperforming the state-of-the-art models.Comment: 8 pages, Submitted in CCIA 201

    Temperature dependence of the resistivity in the double-exchange model

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    The resistivity around the ferromagnetic transition temperature in the double exchange model is studied by the Schwinger boson approach. The spatial spin correlation responsible for scattering of conduction electrons are taken into account by adopting the memory function formalism. Although the correlation shows a peak lower than the transition temperature, the resistivity in the ferromagnetic state monotonically increases with increasing temperature due to a variation of the electronic state of the conduction electron. In the paramagnetic state, the resistivity is dominated by the short range correlation of scattering and is almost independent of the temperature. It is attributed to a cancellation between the nearest-neighbor spin correlation, the fermion bandwidth, and the fermion kinetic energy. This result implies the importance of the temperature dependence of the electronic states of the conduction electron as well as the localized spin states in both ferromagnetic and paramagnetic phases.Comment: RevTex, 4 pages, 4 PostScript figures, To appear in Phys. Rev.

    Effect of Fly Ash on the Durability Properties of High Strength Concrete

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    Utilization of fly ash as a supplementary cementitious material adds sustainability to concrete by reducing the CO2 emission of cement production. The positive effects of fly ash as a partial replacement of cement on the durability of concrete are recognized through numerous researches; however, the extent of improvement depends on the properties of fly ash. In this study, durability properties of high strength concrete utilizing high volume Class F fly ash sourced from Western Australia have been investigated. Concrete mixtures with fly ash as 30% and 40% of total binder wereused to cast the test specimens. The compressive strength, drying shrinkage, sorptivity and rapid chloride permeability of the fly ash and control concrete specimens were determined. The 28-day compressive strength of the concrete mixtures varied from 65 to 85 MPa. The fly ash concrete samples showed less drying shrinkage than the control concrete samples when designed for the same 28-day compressive strength of the control concrete. Inclusion of fly ash reduced sorptivity and chloride ion permeation significantly at 28 days and reduced further at 6 months. In general, incorporation of fly ash as partial replacement of cement improved the durability properties of concrete

    Acute Pancreatitis Secondary to a Perivaterian Duodenal Diverticular Abscess

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    A 46-year-old previously fit lady was admitted with acute pancreatitis. She had no history of gallstones. She was not on any medications and consumed minimal amounts of alcohol. On subsequent investigations as to the causative factor, she was found at ultrasound to have an air-fluid filled cystic structure posterior to the head of pancreas which was compressing the common bile duct. Further magnetic resonance imaging and computer tomography scans showed that this cystic lesion was located around the ampulla of Vater. A diagnosis of a perivaterian abscess was made. At endoscopy, a large contained abscess was seen which was successfully drained. She made a full and uneventful recovery

    Actividad antibacteriana y antioxidante de los extractos de Piper cubeba (Piperaceae)

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    Piper cubeba L. (Piperaceae), commonly known as ‘cubeb’, is native to Indonesia, and also found in many other countriesof the South-East Asia, and in some African countries. This plant has been used as a popular food additive, andin folklore medicine to treat various ailments, particularly bacterial infections. The n-hexane, dichloromethane (DCM)and methanol (MeOH) extracts of the dried berries (fruit) of this plant were assessed for their antioxidant (free radicalscavenging) and antibacterial activities using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and the micro titre basedantimicrobial assay incorporating resazurin as an indicator of cell growth, respectively. While all extracts showed antioxidantactivity in the qualitative assay, the most prominent antioxidant activity was observed with the MeOH extract inthe quantitative assay with a RC50 value of 2.71 x 10-1 mg/mL. The antioxidant potency of the DCM extract was about3 fold less (RC50 = 6.50 x 10-1 mg/mL) than that of the MeOH extract. None of the extracts showed any antibacterialproperty against Bacillus subtilis, Escherichia coli, and ampicillin resistant Escherichia coli. While both the n-hexaneand the DCM extracts inhibited the growth of Bacillus cereus, Pseudomonas aeruginosa and Staphylococcus aureus, theMeOH extract was active only against B. cereus and P. aeruginosa. The most potent antibacterial activity was displayedby the n-hexane extract against B. cereus with an MIC value of 1.56 mg/mL. All antibacterial activities of the extractswere found to be bacteriostatic rather than bactericidal.Piper cubeba L. (Piperaceae), conocida comúnmente como ‘cubeb’, es autóctona de Indonesia y también se encuentraen muchos otros países del sureste de Asia, así como en algunos países africanos.Esta planta se ha utilizado como un popular aditivo alimentario y, en la medicina tradicional, para tratar diversasdolencias, especialmente infecciones bacterianas. Para evaluar la actividad antioxidante (barrido de radicales libres)y la actividad antibacteriana de los extractos de n-hexano, diclorometano (DCM) y metanol (MeOH) de las bayassecas (fruto) de esta planta, se llevó a cabo un ensayo 2,2-difenil-1-picrilhidracil (DPPH) y un ensayo antimicrobianobasado en microtitulación que incorporaba resazurina como indicador del crecimiento celular, respectivamente. Aunquetodos los extractos mostraron actividad antioxidante en el ensayo cualitativo, la actividad antioxidante más destacadase observó con el extracto de MeOH en el ensayo cuantitativo con un valor de RC50 de 2,71 x 10-1 mg/mL.La potencia antioxidante del extracto de DCM fue aproximadamente 3 veces menor (RC50 = 6,50 x 10-1 mg/mL)que la del extracto de MeOH.Ninguno de los extractos mostró propiedades antibacterianas frente a Bacillus subtilis, Escherichia coli y Escherichiacoli resistente a la ampicilina. Aunque ambos extractos, el n-hexano y el DCM, inhibieron el crecimiento de Bacilluscereus, Pseudomonas aeruginosa y Staphylococcus aureus, el extracto de MeOH sólo mostró actividad frente a B.cereus y P. aeruginosa. El extracto de n-hexano fue el que mostró mayor potencia antibacteriana frente a B. cereus,con un valor de concentración inhibitoria mínima (CIM) de 1,56 mg/mL. Se observó que todas las actividades antibacterianasde los extractos resultaron más bacteriostáticas que bactericidas

    Comparative Study of Monosex Tilapia (Oreochromis niloticus) Production under Different Stocking Density in Ponds

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    A field experiment was conducted to study the effect of stocking density on the growth and production of monosex male tilapia (Oreochromis niloticus L.) conducted in six ponds commencing from 7th July to 4th November, 2012. Feeding frequency were two times in a day. The mean initial weight of fry in all the treatments were 5.7±0.04 g and after completion of the experiment the mean final weight of tilapia was 321.62±1.11 g for T1, 300.12±0.87 g for T2 and 256.25±2.38 g for T3. The mean weight gain of 315.92±1.11, 294.42±0.87  and 250.552.38g and mean percent weight gain of 5542.40, 5165.20 and 4395.61% and mean FCR was 1.41±0.00, 1.46±0.01 and 1.59±0.00and mean SGRof 3.36, 3.30 and 3.17% and the survival rate was 97.67, 94.25 and 93.40% were recorded in T1, T2 and T3, respectively. The highest weight gain, percent weight gain, SGR and survival rate were found in T1 and lowest were found in T3. The production was observed to be 47.12±0.52, 56.57±0.80 and 59.84±1.10 kg/dec/4 months in T1, T2 and T3, respectively. The significant (P?0.01) highest fish production and FCR was obtained 59.84 kg/dec/4 months and 1.59 respectively in T3 under stocking density was 250 fish/decimal and production, FCR was found to be decreased significantly with the decrease in stocking density. The lowest fish production 47.12 kg/dec/4 months were observed in T1. Although higher production was obtained in T3 but individually growth performance of monosex tilapia was higher in T1. Keywords: Monosex tilapia, growth performance, stocking density, tilapia production

    In-medium two-nucleon properties in high electric fields

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    The quantum mechanical two - particle problem is considered in hot dense nuclear matter under the influence of a strong electric field such as the field of the residual nucleus in heavy - ion reactions. A generalized Galitskii-Bethe-Salpeter equation is derived and solved which includes retardation and field effects. Compared with the in-medium properties in the zero-field case, bound states are turned into resonances and the scattering phase shifts are modified. Four effects are observed due to the applied field: (i) A suppression of the Pauli-blocking below nuclear matter densities, (ii) the onset of pairing occurs already at higher temperatures due to the field, (iii) a field dependent finite lifetime of deuterons and (iv) the imaginary part of the quasiparticle self-energy changes its sign for special values of density and temperatures indicating a phase instability. The latter effect may influence the fragmentation processes. The lifetime of deuterons in a strong Coulomb field is given explicitly.Comment: ps file + 7 figures (eps
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