457,400 research outputs found
Multi-scale structure, pasting and digestibility of adlay (Coixlachryma-jobi L.) seed starch
peer-reviewedThe hierarchical structure, pasting and digestibility of adlay seed starch (ASS) were investigated compared with maize starch (MS) and potato starch (PS). ASS exhibited round or polyglonal morphology with apparent pores/channels on the surface. It had a lower amylose content, a looser and more heterogeneous C-type crystalline structure, a higher crystallinity, and a thinner crystalline lamellae. Accordingly, ASS showed a higher slowly digestible starch content combined with less resistant starch fractions, and a decreased pasting temperature, a weakened tendency to retrogradation and an increased pasting stability compared with those of MS and PS. The ASS structure-functionality relationship indicated that the amylose content, double helical orders, crystalline lamellar structure, and surface pinholes should be responsible for ASS specific functionalities including pasting behaviors and in vitro digestibility. ASS showed potential applications in health-promoting foods which required low rearrangement during storage and sustainable energy-providing starch fractions
Religious Pluralism and the Buridan's Ass Paradox
The paradox of ’Buridan’s ass’ involves an animal facing two equally adequate and attractive alternatives, such as would happen were a hungry ass to confront two bales of hay that are equal in all respects relevant to the ass’s hunger. Of course, the ass will eat from one rather than the other, because the alternative is to starve. But why does this eating happen? What reason is operative, and what explanation can be given as to why the ass eats from, say, the left bale rather than the right bale? Why doesn’t the ass remain caught between the options, forever indecisive and starving to death? Religious pluralists face a similar dilemma, a dilemma that I will argue is more difficult to address than the paradox just describe
An efficient ant colony system based on receding horizon control for the aircraft arrival sequencing and scheduling problem
The aircraft arrival sequencing and scheduling (ASS) problem is a salient problem in air traffic control (ATC), which proves to be nondeterministic polynomial (NP) hard. This paper formulates the ASS problem in the form of a permutation problem and proposes a new solution framework that makes the first attempt at using an ant colony system (ACS) algorithm based on the receding horizon control (RHC) to solve it. The resultant RHC-improved ACS algorithm for the ASS problem (termed the RHC-ACS-ASS algorithm) is robust, effective, and efficient, not only due to that the ACS algorithm has a strong global search ability and has been proven to be suitable for these kinds of NP-hard problems but also due to that the RHC technique can divide the problem with receding time windows to reduce the computational burden and enhance the solution's quality. The RHC-ACS-ASS algorithm is extensively tested on the cases from the literatures and the cases randomly generated. Comprehensive investigations are also made for the evaluation of the influences of ACS and RHC parameters on the performance of the algorithm. Moreover, the proposed algorithm is further enhanced by using a two-opt exchange heuristic local search. Experimental results verify that the proposed RHC-ACS-ASS algorithm generally outperforms ordinary ACS without using the RHC technique and genetic algorithms (GAs) in solving the ASS problems and offers high robustness, effectiveness, and efficienc
A continuum model accounting for the effect of the initial and evolving microstructure on the evolution of dynamic recrystallization
Laser assisted forming is a process which is increasingly being adopted by the industry. Application of heat by a laser to austenitic stainless steel (ASS) sheet provides local control over formability and strength of the material. The hot forming behavior of ASS is characterized by significant dynamic recovery and dynamic recrystallization. These two processes lead to a softening stress-strain response and have a significant impact on the microstructure of the material. Most of the research performed on hot forming of ASS focuses on dynamic recrystallization and then specifically on the behavior of the annealed state, consisting of relatively large equiaxed austenite grains. However, in industry it is common to use cold rolled ASS sheet which is a mixture of austenite and martensite. Application of a laser heat treatment to the cold rolled grades of ASS induces a socalled ‘reverse’ transformation of martensite to austenite which, depending on the exact time-temperature combinations, leads to an austenite grain size in the range of nanoto micrometer. It is known from experiments that the effect of initial grain size on dynamic recrystallization is significant, especially on the initial stages of recrystallization. Therefore any continuum model capable of describing hot forming of cold rolled ASS should include the effect of the initial grain size. In this work a physically based continuum model for dynamic recrystallization is presented which accounts for the effect of the initial and evolving grain size on the evolution of dynamic recrystallization. It is shown that the initial grain size can be accounted for by incorporating its effect on the availability of preferred nucleation sites, i.e. grain edges. The new model is compared to experimental results and it is shown that the model correctly predicts accelerated recrystallization with decrease in grain size and that there is a weak dependence of the dynamically recrystallized grain size on the initial grain size. Furthermore predicted recrystallized grain sizes are in good agreement with the experimentally measured values
Modeling the Internet
We model the Internet as a network of interconnected Autonomous Systems which
self-organize under an absolute lack of centralized control. Our aim is to
capture how the Internet evolves by reproducing the assembly that has led to
its actual structure and, to this end, we propose a growing weighted network
model driven by competition for resources and adaptation to maintain
functionality in a demand and supply ``equilibrium''. On the demand side, we
consider the environment, a pool of users which need to transfer information
and ask for service. On the supply side, ASs compete to gain users, but to be
able to provide service efficiently, they must adapt their bandwidth as a
function of their size. Hence, the Internet is not modeled as an isolated
system but the environment, in the form of a pool of users, is also a
fundamental part which must be taken into account. ASs compete for users and
big and small come up, so that not all ASs are identical. New connections
between ASs are made or old ones are reinforced according to the adaptation
needs. Thus, the evolution of the Internet can not be fully understood if just
described as a technological isolated system. A socio-economic perspective must
also be considered.Comment: Submitted to the Proceedings of the 3rd International Conference
NEXT-SigmaPh
Rational associahedra and noncrossing partitions
Each positive rational number x>0 can be written uniquely as x=a/(b-a) for
coprime positive integers 0<a<b. We will identify x with the pair (a,b). In
this paper we define for each positive rational x>0 a simplicial complex
\Ass(x)=\Ass(a,b) called the {\sf rational associahedron}. It is a pure
simplicial complex of dimension a-2, and its maximal faces are counted by the
{\sf rational Catalan number} \Cat(x)=\Cat(a,b):=\frac{(a+b-1)!}{a!\,b!}. The
cases (a,b)=(n,n+1) and (a,b)=(n,kn+1) recover the classical associahedron and
its "Fuss-Catalan" generalization studied by Athanasiadis-Tzanaki and
Fomin-Reading. We prove that \Ass(a,b) is shellable and give nice product
formulas for its h-vector (the {\sf rational Narayana numbers}) and f-vector
(the {\sf rational Kirkman numbers}). We define \Ass(a,b) via {\sf rational
Dyck paths}: lattice paths from (0,0) to (b,a) staying above the line y =
\frac{a}{b}x. We also use rational Dyck paths to define a rational
generalization of noncrossing perfect matchings of [2n]. In the case (a,b) =
(n, mn+1), our construction produces the noncrossing partitions of [(m+1)n] in
which each block has size m+1.Comment: 21 pages, 8 figure
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