Measurement of O and Ti atom displacements in TiO2 during flash sintering experiments

In‐situ flash experiments on rutile TiO₂ were performed at the synchrotron at the Brookhaven National Laboratory. Pair distribution function analysis of total X‐ray scattering measurements yielded mean‐square atomic displacements of oxygen and titanium atoms during the progression of the 3 stages of flash. The displacements are measured to be far greater for oxygen atoms than for titanium atoms. These large displacements may signal an “elastic softening” of the lattice, which, recently, has been predicted as a precursor to the onset of flash.     

Digital inverse model control using Generalised holds with extensions to the adaptive case

In this paper, a digital implementation of an inverse-model based control scheme is proposed using Generalised Sampling and Hold Functions. The implementation of the controller using this kind of holds allows overcoming the difficulties related to the presence of unstable zeros in the continuous-time model and the usual appearance of unstable discretisation zeros in the discrete model when a ZOH is applied. The Generalised Sampling and Hold Functions allows obtaining a discrete model of the plant with all its zeros stable which allows realizing an exact inverse model of the plant in comparison to the use of a classical ZOH which only allows, in general, an approximate inversion of the plant. The proposed approach is then extended to the adaptive case where the stability and tracking properties of the general scheme are fully proved. Simulation examples showing the scope and application of the method are also presented.     

The shortest path in a simply-connected domain having a curved boundary

Given two distinct points S and E on a closed parametric curve forming the boundary of a simply-connected domain (without holes), this paper provides an algorithm to find the shortest interior path (SIP) between the two points in the domain. The SIP consists of portions of curves along with straight line segments that are tangential to the curve. The algorithm initially computes point-curve tangents and bitangents using their respective constraints. They are then analyzed further to identify potential tangents. A region check is performed to determine the tangent that will form part of the SIP. Portions of the curve that belong to the SIP are also identified during the process. The SIP is identified without explicitly computing the length of the curves/tangents. The curve is represented using non-uniform rational B-splines (NURBS). Results of the implementation are provided.     

Inhibition in multiclass classification

The role of inhibition is investigated in a multiclass support vector machine formalism inspired by the brain structure of insects. The so-called mushroom bodies have a set of output neurons, or classification functions, that compete with each other to encode a particular input. Strongly active output neurons depress or inhibit the remaining outputs without knowing which is correct or incorrect. Accordingly, we propose to use a classification function that embodies unselective inhibition and train it in the large margin classifier framework. Inhibition leads to more robust classifiers in the sense that they perform better on larger areas of appropriate hyperparameters when assessed with leave-one-out strategies. We also show that the classifier with inhibition is a tight bound to probabilistic exponential models and is Bayes consistent for 3-class problems. These properties make this approach useful for data sets with a limited number of labeled examples. For larger data sets, there is no significant comparative advantage to other multiclass SVM approaches.     

Protein modeling and active site binding mode interactions of myrosinase-sinigrin in Brassica juncea--an in silico approach

Myrosinase, the only known S-glycosidase, occurs particularly in Cruciferae family. It is responsible for the hydrolysis of glucosinolates and serves as a vital element of plant defense system. The biological and chemical properties of myrosinase catalyzed products of glucosinolates are well characterized. The myrosinase-protein-sequence of Brassica juncea was retrieved from NCBI database and its 3-D model was generated on the basis of crystal structure of 1MYR-A, 1E4M-M and 1DWA-M chains of myrosinase from Sinapis alba by employing Modeller9v7 program. Homolog templates from S. alba exhibited 72% identity with target sequence. The model was optimized by using molecular dynamics (MD) approach together with simulated annealing (SA) methods in the same Modeller program, and eventually verified and validated on SAVES (Structure Analysis and Verification Server) and PROCHECK programs, respectively. Ramachandran plot obtained through PROCHECK program depicted that 99.8% of total residues were confined to the allowed region while only one residue (Thr92) was restrained to the disallowed region. Additionally, B. juncea myrosinase contains three disulphide bridges which were found to be conserved in S. alba homologs as well. Further, overlapping of B. juncea myrosinase with that of template protein 1MYR-A from S. alba stipulates the amino acid residues Arg115, Gln207, Thr210, Asn350, Tyr352 and Glu429 that constitute active site of the enzyme. Active site analysis also speculates the presence of a hydrophobic pocket in addition to seven N-glycosylation sites. Docking studies of enzyme and substrate illuminate the interactions of various active site residues with diverse groups of sinigrin. Therefore, the present study furnishes the first significant, in silico insight into the 3-D structure, active site machinery, and enzyme-substrate interactions of B. juncea myrosinase.     

Awareness marks: adaptive services through user interactions with augmented objects

The ambient intelligence paradigm involves one important challenge: to be adaptive to users and context through simple and natural interactions. To meet this goal, it is important to associate data with relevant everyday objects in the environment, including users themselves, and to enable interaction mechanisms between these objects. Following this premise, in this paper, we present a conceptual model to link contextual information with augmented elements acquired from user interactions in an implicit and transparent way. In this way, it is possible to personalize and enhance offered services in order to facilitate daily user activities. We call this contextual data “awareness marks”, and these awareness marks make it possible to offer novel services adapted from past events that were captured as they happened. Moreover, we have developed and evaluated a set of prototypes using Near Field Communication technology, which follows the presented model.     

Ultrasound as a tool for the preparation of gels: effect on the textural properties of TiO2-SiO2 aerogels

TiO₂-SiO₂ aerogels have been prepared by hydrolysis and polycondensation of alkoxides following two different methods: the classic one, using ethanol as a solvent, and the sonic one, by means of activation with ultrasound. The work is focused on the comparison of the textural properties of gels obtained by both synthetic routes. Nitrogen physisorption, mercury pycnometry and transmission electron microscopy have been used as characterization techniques. The sonogels present higher values of specific surfaces and apparent densities, lower pore volumes, finer and sharper pore-size distributions and lower average particle size. These properties are discussed and related to the preparation techniques.     

Radiative heat transfer in participating media — A review

This paper presents an overview of various exact analytic and approximate numerical methods for the solution of radiative heat transfer problems in participating media. Review of each method is followed by its strengths and limitations. Importance of radiative heat transfer analysis and difficulties in the solution of radiative transfer problems have been emphasized.