Si/SiC-Ceramic low process shrinkage - high temperature material for the Laser Sinter process

Actual RP-systemsare very limited in producing adequate ceramic prototypes. In the presented process, the SiC..green part manufacturing bythe laser sintering process in combination with special postprocessing allows the fast production of SUSiC prototypes. A mixture of SiC powder and a reactive polymer binder system is used in the Laser Sinter process. In the following postprocessing the porous green part has to be .infiltrated with a precursor resin, carbonised and finally infiltrated withimolten silicon.•Incontrast to cold isostatic moulding or slip casting the shrinkage is very low (2-4 0/0).• Experiments with suitable materials/and process conditions were successful. This paper will show the state of and the possible further investigation into process.Mechanical Engineerin

Some limit results for Markov chains indexed by trees

We consider a sequence of Markov chains $(\mathcal X^n)_{n=1,2,...}$ with $\mathcal X^n = (X^n_\sigma)_{\sigma\in\mathcal T}$, indexed by the full binary tree $\mathcal T = \mathcal T_0 \cup \mathcal T_1 \cup ...$, where $\mathcal T_k$ is the $k$th generation of $\mathcal T$. In addition, let $(\Sigma_k)_{k=0,1,2,...}$ be a random walk on $\mathcal T$ with $\Sigma_k \in \mathcal T_k$ and $\widetilde{\mathcal R}^n = (\widetilde R_t^n)_{t\geq 0}$ with $\widetilde R_t^n := X_{\Sigma_{[tn]}}$, arising by observing the Markov chain $\mathcal X^n$ along the random walk. We present a law of large numbers concerning the empirical measure process $\widetilde{\mathcal Z}^n = (\widetilde Z_t^n)_{t\geq 0}$ where $\widetilde{Z}_t^n = \sum_{\sigma\in\mathcal T_{[tn]}} \delta_{X_\sigma^n}$ as $n\to\infty$. Precisely, we show that if $\widetilde{\mathcal R}^n \to \mathcal R$ for some Feller process $\mathcal R = (R_t)_{t\geq 0}$ with deterministic initial condition, then $\widetilde{\mathcal Z}^n \to \mathcal Z$ with $Z_t = \delta_{\mathcal L(R_t)}$.Comment: 12 page

Virtual personal assistant

Abstract This report discusses ways in which new technology could be harnessed to create an intelligent Virtual Personal Assistant (VPA) with a focus on user-based information. It will look at examples of intelligent programs with natural language processing that are currently available, with different categories of support, and examine the potential usefulness of one specific piece of software as a VPA. This engages the ability to communicate socially through natural language processing, holding (and analysing) information within the context of the user. It is suggested that new technologies may soon make the idea of virtual personal assistants a reality. Experiments conducted on this system, combined with user testing, have provided evidence that a basic program with natural language processing algorithms in the form of a VPA, with basic natural language processing and the ability to function without the need for other type of human input (or programming) may already be viable

LawSync: Collaboration in Action

A presentation about collaboration, itself the product of a collaboration, looking at a collaborative project as an example of the value of people from different teams working together! That was us at BIALL 2014 in Glasgow, a conference which took as its theme ‘law as a business.

Markovian embedding of non-Markovian superdiffusion

We consider different Markovian embedding schemes of non-Markovian stochastic processes that are described by generalized Langevin equations (GLE) and obey thermal detailed balance under equilibrium conditions. At thermal equilibrium superdiffusive behavior can emerge if the total integral of the memory kernel vanishes. Such a situation of vanishing static friction is caused by a super-Ohmic thermal bath. One of the simplest models of ballistic superdiffusion is determined by a bi-exponential memory kernel that was proposed by Bao [J.-D. Bao, J. Stat. Phys. 114, 503 (2004)]. We show that this non-Markovian model has infinitely many different 4-dimensional Markovian embeddings. Implementing numerically the simplest one, we demonstrate that (i) the presence of a periodic potential with arbitrarily low barriers changes the asymptotic large time behavior from free ballistic superdiffusion into normal diffusion; (ii) an additional biasing force renders the asymptotic dynamics superdiffusive again. The development of transients that display a qualitatively different behavior compared to the true large-time asymptotics presents a general feature of this non-Markovian dynamics. These transients though may be extremely long. As a consequence, they can be even mistaken as the true asymptotics. We find that such intermediate asymptotics exhibit a giant enhancement of superdiffusion in tilted washboard potentials and it is accompanied by a giant transient superballistic current growing proportional to $t^{\alpha_{{\rm eff}}}$ with an exponent $\alpha_{\rm eff}$ that can exceed the ballistic value of two

The Tasaki-Crooks quantum fluctuation theorem

Starting out from the recently established quantum correlation function expression of the characteristic function for the work performed by a force protocol on the system [cond-mat/0703213] the quantum version of the Crooks fluctuation theorem is shown to emerge almost immediately by the mere application of an inverse Fourier transformation

A lower bound for the density of states of the lattice Anderson model

We consider the Anderson model on the multi-dimensional cubic lattice and prove a positive lower bound on the density of states under certain conditions. For example, if the random variables are independently and identically distributed and the probability measure has a bounded Lebesgue density with compact support, and if this density is essentially bounded away from zero on its support, then we prove that the density of states is strictly positive for Lebesgue-almost every energy in the deterministic spectrum.Comment: 7 pages, typos corrected in v2, to appear in Proc. Amer. Math. So

Student engagement with self-instructional course materials : a thesis presented in partial fulfilment of the requirements for the degree of Master of Education in Distance and On-line Learning at Massey University, Extramural, New Zealand

This study is concerned with understanding how students engage with self-instructional materials on campus and at a distance within the context of the hybrid course offered at ABC College. This study examines the interrelationship of (a) time engaged with course materials, (b) the perceived value of course materials, (c) student approaches to engagement and (d) the integration of the course materials into the student learning experience in order to construct an understanding of student engagement with course materials. This study employed multiple case studies which formed a holistic collective case study. Data on student engagement with the course materials was collected using a questionnaire instrument. The resulting data was analysed using descriptive statistics to create a picture of how students engaged with the course materials. Correlation statistics were used to identify possible relationships between the items. Emerging themes were then explored in focus groups. Subsequent analysis of the focus group data explored the causation and interrelationships between themes resulting in an understanding of student engagement with the course materials. The findings from this study suggests that student engagement with self-instructional course materials (readings, learning guide, multimedia, etc.) are the result of complex interactions between a student's preferred approach to engagement, their locus of control and the method of integration of the course materials. The majority of participants preferred to engage with the course materials using a deep approach. Participants with an external locus of control reflected the assumptions and approaches they perceived from the method of integration. Participants with an internal locus of control engaged with the course materials using their preferred approach unless they were convinced that another approach served their needs better. The majority of participants exhibited an external locus of control. When a presentation or supplemental method of integrating was used, participants were more likely to engage with the course materials using a surface approach to engagement. They were also more likely to spend less time engaging with the course materials and place a lower value on the course materials. When a discussion or springboard method of integration was used participants were more likely to engage the course materials using a deep approach to engagement. They were also more likely to spend more time engaging with the course materials and place a higher value on the course materials