2,214 research outputs found
Identification of Thermal Degradation Process of Starch in Production of Environmentally Friendly Flocculants
Chemical modification of starch can be used to produce environmentally degradable
flocculants. This is carried out at elevated temperature, which in turn causes thermal
degradation, influencing the quality of the product. Starting from experimental results
and the probabilistic nature of the process stochastic model was established to identify
the rate and the mechanism of degradation under various conditions. It was concluded
that applying moderate temperature around 143 Celsius ensures sufficient production rate
without excessive thermal degradation
Investigation of the relation between the colorant content and the colour characteristics of the edible oil based extracts of the paprika grist
During our work we performed the color measurements of the oily extracts from the Hungarian paprika grist. We defined a color index from the C'lELab color coordinates, by means of which the rank in the redness sequence of the oily colorant extract can be evaluated. Wc established that there was a tight linear relation between the colorant content of the grist expressed in ASTA value and the color index of the oily extract. In case of the oily extracts the coloi index calculated from the data of the color measurement is adaptable to evaluate the coloring capability and via this ii is appropriate for the color classification of the paprika grist
Power map permutations and symmetric differences in finite groups
Let be a finite group. For all , such that , the
function sending to defines a permutation of the
elements of . Motivated by a recent generalization of Zolotarev's proof of
classic quadratic reciprocity, due to Duke and Hopkins, we study the signature
of the permutation . By introducing the group of conjugacy equivariant
maps and the symmetric difference method on groups, we exhibit an integer
such that for all in a large
class of groups, containing all finite nilpotent and odd order groups.Comment: Electronic version of an article to be published as, Journal of
Algebra and its Applications, 2011, DOI No: 10.1142/S0219498811005051,
\c{opyright} copyright World Scientific Publishing Company,
http://www.worldscinet.com/jaa/jaa.shtm
A new xinjiangchelyid turtle from the Middle Jurassic of Xinjiang, China and the evolution of the basipterygoid process in Mesozoic turtles
Background: Most turtles from the Middle and Late Jurassic of Asia are referred to the newly defined clade Xinjiangchelyidae, a group of mostly shell-based, generalized, small to mid-sized aquatic froms that are widely considered to represent the stem lineage of Cryptodira. Xinjiangchelyids provide us with great insights into the plesiomorphic anatomy of crown-cryptodires, the most diverse group of living turtles, and they are particularly relevant for understanding the origin and early divergence of the primary clades of extant turtles. Results: Exceptionally complete new xinjiangchelyid material from the ?Qigu Formation of the Turpan Basin (Xinjiang Autonomous Province, China) provides new insights into the anatomy of this group and is assigned to Xinjiangchelys wusu n. sp. A phylogenetic analysis places Xinjiangchelys wusu n. sp. in a monophyletic polytomy with other xinjiangchelyids, including Xinjiangchelys junggarensis, X. radiplicatoides, X. levensis and X. latiens. However, the analysis supports the unorthodox, though tentative placement of xinjiangchelyids and sinemydids outside of crown-group Testudines. A particularly interesting new observation is that the skull of this xinjiangchelyid retains such primitive features as a reduced interpterygoid vacuity and basipterygoid processes. Conclusions: The homology of basipterygoid processes is confidently demonstrated based on a comprehensive review of the basicranial anatomy of Mesozoic turtles and a new nomenclatural system is introduced for the carotid canal system of turtles. The loss of the basipterygoid process and the bony enclosure of the carotid circulation system occurred a number of times independently during turtle evolution suggesting that the reinforcement of the basicranial region was essential for developing a rigid skull, thus paralleling the evolution of other amniote groups with massive skulls. © 2013 Rabi et al.; licensee BioMed Central Ltd
Multiscale Analysis of Spreading in a Large Communication Network
In temporal networks, both the topology of the underlying network and the
timings of interaction events can be crucial in determining how some dynamic
process mediated by the network unfolds. We have explored the limiting case of
the speed of spreading in the SI model, set up such that an event between an
infectious and susceptible individual always transmits the infection. The speed
of this process sets an upper bound for the speed of any dynamic process that
is mediated through the interaction events of the network. With the help of
temporal networks derived from large scale time-stamped data on mobile phone
calls, we extend earlier results that point out the slowing-down effects of
burstiness and temporal inhomogeneities. In such networks, links are not
permanently active, but dynamic processes are mediated by recurrent events
taking place on the links at specific points in time. We perform a multi-scale
analysis and pinpoint the importance of the timings of event sequences on
individual links, their correlations with neighboring sequences, and the
temporal pathways taken by the network-scale spreading process. This is
achieved by studying empirically and analytically different characteristic
relay times of links, relevant to the respective scales, and a set of temporal
reference models that allow for removing selected time-domain correlations one
by one
Circadian pattern and burstiness in mobile phone communication
The temporal communication patterns of human individuals are known to be
inhomogeneous or bursty, which is reflected as the heavy tail behavior in the
inter-event time distribution. As the cause of such bursty behavior two main
mechanisms have been suggested: a) Inhomogeneities due to the circadian and
weekly activity patterns and b) inhomogeneities rooted in human task execution
behavior. Here we investigate the roles of these mechanisms by developing and
then applying systematic de-seasoning methods to remove the circadian and
weekly patterns from the time-series of mobile phone communication events of
individuals. We find that the heavy tails in the inter-event time distributions
remain robustly with respect to this procedure, which clearly indicates that
the human task execution based mechanism is a possible cause for the remaining
burstiness in temporal mobile phone communication patterns.Comment: 17 pages, 12 figure
Defect flows in minimal models
In this paper we study a simple example of a two-parameter space of
renormalisation group flows of defects in Virasoro minimal models. We use a
combination of exact results, perturbation theory and the truncated conformal
space approach to search for fixed points and investigate their nature. For the
Ising model, we confirm the recent results of Fendley et al. In the case of
central charge close to one, we find six fixed points, five of which we can
identify in terms of known defects and one of which we conjecture is a new
non-trivial conformal defect. We also include several new results on exact
properties of perturbed defects and on the renormalisation group in the
truncated conformal space approach.Comment: 35 pages, 21 figures. 1 reference adde
Approaching the self-dual point of the sinh-Gordon model
One of the most striking but mysterious properties of the sinh-Gordon model (ShG) is the b -> 1/b self-duality of its S-matrix, of which there is no trace in its Lagrangian formulation. Here b is the coupling appearing in the model's eponymous hyperbolic cosine present in its Lagrangian, cosh(b phi). In this paper we develop truncated spectrum methods (TSMs) for studying the sinh-Gordon model at a finite volume as we vary the coupling constant. We obtain the expected results for b MUCH LESS-THAN 1 and intermediate values of b, but as the self-dual point b = 1 is approached, the basic application of the TSM to the ShG breaks down. We find that the TSM gives results with a strong cutoff E-c dependence, which disappears according only to a very slow power law in E-c. Standard renormalization group strategies - whether they be numerical or analytic - also fail to improve upon matters here. We thus explore three strategies to address the basic limitations of the TSM in the vicinity of b = 1. In the first, we focus on the small-volume spectrum. We attempt to understand how much of the physics of the ShG is encoded in the zero mode part of its Hamiltonian, in essence how 'quantum mechanical' vs 'quantum field theoretic' the problem is. In the second, we identify the divergencies present in perturbation theory and perform their resummation using a supra-Borel approximate. In the third approach, we use the exact form factors of the model to treat the ShG at one value of b as a perturbation of a ShG at a different coupling. In the light of this work, we argue that the strong coupling phase b > 1 of the Lagrangian formulation of model may be different from what is naively inferred from its S-matrix. In particular, we present an argument that the theory is massless for b > 1
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