647 research outputs found

    Hamilton - Jacobi treatment of front-form Schwinger model

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    The Hamilton-Jacobi formalism was applied to quantize the front-form Schwinger model. The importance of the surface term is discussed in detail. The BRST-anti-BRST symmetry was analyzed within Hamilton-Jacobi formalism.Comment: 11 pages, to be published in Int. Journ. Mod. Phys.

    First Order Actions: a New View

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    We analyse systems described by first order actions using the Hamilton-Jacobi (HJ) formalism for singular systems. In this study we verify that generalized brackets appear in a natural way in HJ approach, showing us the existence of a symplectic structure in the phase spaces of this formalism

    Effects of coagulating enzyme types (commercial calf rennet, Aspergillus niger var. awamori as recombinant chymosin and rhizomucor miehei as microbial rennet) on the chemical and sensory characteristics of white pickled cheese

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    The possibilities of using recombinant chymosin as an alternative coagulant to commercial calf rennet in the production of white pickled cheese was investigated. For this purpose, white pickled cheese produced by using commercial calf rennet, recombinant chymosin (Aspergillus niger var. awamori) and microbial rennet (Rhizomucor miehei) were compared in terms of their chemical and organoleptic properties. The cheese samples were stored in brine containing 12% salt at 4±1°C for 60 days. In the study, which was carried out in duplicate, pH, titratable acidity, dry matter, fat, fat-in-dry matter, protein, salt, nitrogeneous compounds (water sobuble nitrogen (WSN), ripening index (RI), non-protein nitrogen (NPN), electrophoretic and organoleptic properties of the cheese samples were determined at 1, 15, 30 and 60 days of storage. According to the results, the effects of enzyme type on the titratable acidity, dry matter, salt, nitrogeneous compounds and all sensory properties, except for the odour was significant (p<0.05). At the end of storage, the titratable acidity, salt, WSN, RI, NPN values and sensory scores of the cheeses increased, while the pH, fat, total nitrogen (TN), protein, b- and as1-casein contents of cheeses decreased compared to initial values.Keywords: White pickled cheese, calf rennet, recombinant chymosin, microbial rennet.African Journal of Biotechnology Vol. 12(37), pp. 5588-559

    Opportunities in utilization of agricultural residues in bio-composite production: Corn stalk (Zea mays indurata Sturt) and oak wood (Quercus Robur L.) fiber in medium density fiberboard

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    In this paper, corn stalk as an agricultural residue was mixed with oak wood fiber to produce medium density fiberboards (MDF). Urea formaldehyde resin was used as binder. Hygroscopic and mechanical properties were evaluated according to the commercial standards in MDF production. Partial substitution of wood fiber with corn stalks fiber negatively affected all board properties. However, the mechanical properties fulfill the minimum requirements of the relevant standards such as TS-EN 310, 1999 and TS-EN 319, 1999. In some cases, they exceeded the standards, even with partial blending of corn stalk fibers.Key words: Corn stalks, Quercus robur, medium density fiberboard, physical and mechanical properties

    A Novel Method for Epileptic Seizure Detection Using Coupled Hidden Markov Models

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    We propose a novel Coupled Hidden Markov Model to detect epileptic seizures in multichannel electroencephalography (EEG) data. Our model defines a network of seizure propagation paths to capture both the temporal and spatial evolution of epileptic activity. To address the intractability introduced by the coupled interactions, we derive a variational inference procedure to efficiently infer the seizure evolution from spectral patterns in the EEG data. We validate our model on EEG aquired under clinical conditions in the Epilepsy Monitoring Unit of the Johns Hopkins Hospital. Using 5-fold cross validation, we demonstrate that our model outperforms three baseline approaches which rely on a classical detection framework. Our model also demonstrates the potential to localize seizure onset zones in focal epilepsy.Comment: To appear in MICCAI 2018 Proceeding

    Multi Hamilton-Jacobi quantization of O(3) nonlinear sigma model

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    The O(3) non-linear sigma model is investigated using multi Hamilton-Jacobi formalism. The integrability conditions are investigated and the results are in agreement with those obtained by Dirac's method. By choosing an adequate extension of phase space we describe the transformed system by a set of three Hamilton-Jacobi equations and calculate the corresponding action.Comment: 10 pages, LaTeX, to be published in Mod. Phys. Lett.

    Performance and health of dairy calves fed limited amounts of acidified milk replacer

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    To compare growth performance of Brown Swiss calves fed acidified milk replacer (AMR) at 8% of birth weight, 20 newborn calves were reared under a new calf-feeding programme. Body weights, total weight gains and gains in body measurements, feed intake and feed efficiency values determined at different stages of growth of AMR-fed calves were comparable to those of calves fed sweet milk replacer (SMR). Faecal consistency scores and percent days with diarrhoea of calves offered AMR from four to 35 days of age were respectively 0.4 and 19.1% lower than those fed SMR. Most of the behavioural parameters studied were not unfavourably influenced by acidification of the replacer. In conclusion, growth, feed intake and feed efficiency characteristics of Brown Swiss calves fed AMR or SMR were not different from each other. However, incidence of diarrhoea of the young calves was decreased and health status of the calves was improved with the feeding of acidified milk. South African Journal of Animal Science Vol. 36(3) 2006: 149-15

    Apical extrusion of debris using reciprocating files and rotary instrumentation systems

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    Background: To compare the preparation time and amount of apically extruded debris after the  preparation of root canals in extracted human teeth using the reciprocating files and rotary nickel.titanium systems.Procedure: Sixty extracted human mandibular premolars were used. The root canals were instrumented using reciprocating (WaveOne, Reciproc, SafeSider) or rotary motion (Typhoon, ProTaper Universal,  Mtwo), and the debris produced was collected in glass vials. The remaining debris was assessed using a microbalance and statistically analyzed using the one.way ANOVA and Duncan multiple range tests at a significance level of P < 0.05. The time required to prepare the canals with different instruments was also recorded.Results: The Reciproc group produced significantly less debris when compared to the Typhoon group (P < 0.05), and instrumentation with the single.file systems was significantly faster than in the multi.file systems (P < 0.05). The WaveOne group extruded significantly more debris per unit of time than the other groups, with the exception of the Typhoon group (P < 0.05).Conclusion: According to our study, all systems caused apical debris extrusion. However, the Reciproc group was associated with less debris extrusion when compared to the other groups.Key words: Apical extrusion, endodontics, single file system
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