601 research outputs found

    Karakterisasi Material Kemasan Pulp Cetak tanpa Perekat dari Pulp Batang Jagung

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    Molded pulp is an alternative packaging which has renewable and biodegradable properties. The use of molded pulp as packaging material still constrained due to the specific data that describes the characteristics of molded pulp has not widely publicized yet. This study was conducted to identify the characteristics of molded pulp as an alternative packaging material. Cornstalk was selected as raw materials which has abundant availabilty. Molded pulp packaging was manufactured by thermoformed methods. The thermoset nature of lignin in cornstalks would give possibilties in manufacture of molded pulp without using adhesive. The results showed the mechanical characteristics of binderless molded pulp from cornstalk pulp which have tensile index from 17.78 to 35.78 Nm/g, tear index from 9,25 to 26,09 mN.m2/g, and burst index from 0.901 to 1.5 kPa.m2/g. The effects of dependent variables on the mechanical properties of molded pulp were studied by statistical modelling using a polynomial second order. The empirical models were deduced to satisfactorily fit experimental data with the values of independent variables and allow to quantifiying the effects of each variables. The most influential factor on tensile and burst index of molded pulp was temperature of processing. Whereas, the processing pressure has greater influence on tear index of molded pulp

    Semantic aware Bayesian network model for actionable knowledge discovery in linked data

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    The majority of the conventional mining algorithms treat the mining process as an isolated data-driven procedure and overlook the semantic of the targeted data. As a result, the generated patterns are abundant and end users cannot act upon them seamlessly. Furthermore, interdisciplinary knowledge can not be obtained from domain-specific silo of data. The emergence of Linked Data (LD) as a new model for knowledge representation, which intertwines data with its semantics, has introduced new opportunities for data miners. Accordingly, this paper proposes an ontology-based Semantic-Aware Bayesian network (BN) model. In contrast to the existing mining algorithms, the proposed model does into transform the original format of the LD set. Therefore, it not only accommodates the semantic aspects in LD, but also caters to the need of connecting different data-sets from different domains. We evaluate the proposed model on a Bone Dysplasia dataset, Experimental results show promising performance

    Possible Quantum Spin Liquid States on the Triangular and Kagome Lattices

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    The frustrated spin-one-half Heisenberg model on triangualr and Kagome Lattices is mapped onto a single specis of fermion carrying statistical flux. The corresponding Chern-Simons gauge theory is analyzed at the Gaussian level and found to be massive. This provides a new motivation for the spin-liquid Kalmeyer-Laughlin wave function. Good overlap of this wave function with the numerical ground state is found for small clusters.Comment: 13 pages, revtex. IUCM-920

    Chronotype and environmental light exposure in a student population

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    In humans and most other species, changes in the intensity and duration of light provide a critical set of signals for the synchronisation of the circadian system to the astronomical day. The timing of activity within the 24 h day defines an individual’s chronotype, i.e. morning, intermediate or evening type. The aim of this study was to investigate the associations between environmental light exposure, due to geographical location, on the chronotype of university students. Over 6 000 university students from cities in the Northern Hemisphere (Oxford, Munich and Groningen) and Southern Hemisphere (Perth, Melbourne and Auckland) completed the Munich ChronoType Questionnaire. In parallel, light measures (daily irradiance, timing of sunrise and sunset) were compiled from satellite or ground stations at each of these locations. Our data shows that later mid-sleep point on free days (corrected for oversleep on weekends MFSsc) is associated with (i) residing further from the equator, (ii) a later sunset, (iii) spending more time outside and (iv) waking from sleep significantly after sunrise. However, surprisingly, MSFscdid not correlate with daily light intensity at the different geographical locations. Although these findings appear to contradict earlier studies suggesting that in the wider population increased light exposure is associated with an earlier chronotype, our findings are derived exclusively from a student population aged between 17 and 26 years. We therefore suggest that the age and occupation of our population increase the likelihood that these individuals will experience relatively little light exposure in the morning whilst encountering more light exposure later in the day, when light has a delaying effect upon the circadian system

    Spin Dynamics of the Triangular Heisenberg Antiferromagnet: A Schwinger Boson Approach

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    We have analyzed the two-dimensional antiferromagnetic Heisenberg model on the triangular lattice using a Schwinger boson mean-field theory. By expanding around a state with local 120∘120^\circ order, we obtain, in the limit of infinite spin, results for the excitation spectrum in complete agreement with linear spin wave theory (LSWT). In contrast to LSWT, however, the modes at the ordering wave vectors acquire a mass for finite spin. We discuss the origin of this effect.Comment: 15 pages REVTEX 3.0 preprint, 6 postscript figures ( uuencoded and compressed using the script uufiles ) are submitted separately

    Efficiency of Exciton and Charge Carrier Photogeneration in a Semiconducting Polymer

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    Euan Hendry, Juleon M. Schins, L. P. Candeias, L. D. A. Siebbeles, and Mischa Bonn, Physical Review Letters, Vol. 92, article 196601 (2004). "Copyright © 2004 by the American Physical Society."We determine the efficiencies for the formation of excitons and charge carriers following ultrafast photoexcitation of a semiconducting polymer (MEH-PPV). The simultaneous, quantitative determination of exciton and charge photoyields is achieved through subpicosecond studies of both the real and the imaginary components of the complex conductivity over a wide frequency range. Predominantly excitons, with near-unity quantum efficiency, are generated on excitation, while only a very small fraction (<10-2) of free charges are initially excited, consistent with rapid (∼100  fs) hot exciton dissociation. These initial charges are very short lived, decaying on subpicosecond time scales

    Clcn7F318L/+ as a new mouse model of Albers-Schönberg disease

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    Dominant negative mutations in CLCN7, which encodes a homodimeric chloride channel needed for matrix acidification by osteoclasts, cause Albers-Schönberg disease (also known as autosomal dominant osteopetrosis type 2). More than 25 different CLCN7 mutations have been identified in patients affected with Albers-Schönberg disease, but only one mutation (Clcn7G213R) has been introduced in mice to create an animal model of this disease. Here we describe a mouse with a different osteopetrosis-causing mutation (Clcn7F318L). Compared to Clcn7+/+ mice, 12-week-old Clcn7F318L/+ mice have significantly increased trabecular bone volume, consistent with Clcn7F318L acting as a dominant negative mutation. Clcn7F318L/F318L and Clcn7F318L/G213R mice die by 1 month of age and resemble Clcn7 knockout mice, which indicate that p.F318L mutant protein is non-functional and p.F318L and p.G213R mutant proteins do not complement one another. Since it has been reported that treatment with interferon gamma (IFN-G) improves bone properties in Clcn7G213R/+ mice, we treated Clcn7F318L/+ mice with IFN-G and observed a decrease in osteoclast number and mineral apposition rate, but no overall improvement in bone properties. Our results suggest that the benefits of IFN-G therapy in patients with Albers-Schönberg disease may be mutation-specific

    Quantum Ferromagnetism and Phase Transitions in Double-Layer Quantum Hall Systems

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    Double layer quantum Hall systems have interesting properties associated with interlayer correlations. At ν=1/m\nu =1/m where mm is an odd integer they exhibit spontaneous symmetry breaking equivalent to that of spin 1/21/2 easy-plane ferromagnets, with the layer degree of freedom playing the role of spin. We explore the rich variety of quantum and finite temperature phase transitions in these systems. In particular, we show that a magnetic field oriented parallel to the layers induces a highly collective commensurate-incommensurate phase transition in the magnetic order.Comment: 4 pages, REVTEX 3.0, IUCM93-013, 1 FIGURE, hardcopy available from: [email protected]
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