Universal deformation rings of modules for algebras of dihedral type of polynomial growth

Let k be an algebraically closed field, and let \Lambda\ be an algebra of dihedral type of polynomial growth as classified by Erdmann and Skowro\'{n}ski. We describe all finitely generated \Lambda-modules V whose stable endomorphism rings are isomorphic to k and determine their universal deformation rings R(\Lambda,V). We prove that only three isomorphism types occur for R(\Lambda,V): k, k[[t]]/(t^2) and k[[t]].Comment: 11 pages, 2 figure

Higher-Order Calculus of Variations on Time Scales

We prove a version of the Euler-Lagrange equations for certain problems of the calculus of variations on time scales with higher-order delta derivatives.Comment: Corrected minor typo

A supersonic crowdion in mica: Ultradiscrete kinks with energy between 40^{40}K recoil and transmission sputtering

In this chapter we analyze in detail the behaviour and properties of the kinks found in an one dimensional model for the close packed rows of potassium ions in mica muscovite. The model includes realistic potentials obtained from the physics of the problem, ion bombardment experiments and molecular dynamics fitted to experiments. These kinks are supersonic and have an unique velocity and energy. They are ultradiscrete involving the translation of an interstitial ion, which is the reason they are called 'crowdions'. Their energy is below the most probable source of energy, the decay of the $^{40}$K isotope and above the energy needed to eject an atom from the mineral, a phenomenon that has been observed experimentallyComment: 28 pages, 15 figure

Micromixing and microchannel design: Vortex shape and entropy

This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.In very recent years microdevices, due to their potency in replacing large-scale conventional laboratory instrumentation, are becoming a fast and low cost technology for the treatment of several chemical and biological processes. In particular microfluidics has been massively investigated, aiming at improving the performance of chemical reactors. This is because of the fact that reaction is often an interface phenomenon where the greater the surface to volume ratio, the higher the reaction speed, and microscale mixing increases the interfacial area (in terms of mixing-induced-by-vortices generation). However, microfluidic systems suffer from the limitation that they are characterized mostly by very low Reynolds numbers, with the consequence that (i) they cannot take advantage from the turbulence mixing support, and (ii) viscosity hampers proper vortex detection. Therefore, the proper design of micro-channels (MCs) becomes essential. In this framework, several geometries have been proposed to induce mixing vortices in MCs. However a quantitative comparison between proposed geometries in terms of their passive mixing potency can be done only after proper definition of vortex formation (topology, size) and mixing performance. The objective of this study is to test the ability of different fluid dynamic metrics in vortex detection and mixing effectiveness in micromixers. This is done numerically solving different conditions for the flow in a classic passive mixer, a ring shaped MC. We speculate that MCs design could take advantage from fluidic metrics able to rank properly flow related mixing

Interestingness of traces in declarative process mining: The janus LTLPf Approach

Declarative process mining is the set of techniques aimed at extracting behavioural constraints from event logs. These constraints are inherently of a reactive nature, in that their activation restricts the occurrence of other activities. In this way, they are prone to the principle of ex falso quod libet: they can be satisfied even when not activated. As a consequence, constraints can be mined that are hardly interesting to users or even potentially misleading. In this paper, we build on the observation that users typically read and write temporal constraints as if-statements with an explicit indication of the activation condition. Our approach is called Janus, because it permits the specification and verification of reactive constraints that, upon activation, look forward into the future and backwards into the past of a trace. Reactive constraints are expressed using Linear-time Temporal Logic with Past on Finite Traces (LTLp f). To mine them out of event logs, we devise a time bi-directional valuation technique based on triplets of automata operating in an on-line fashion. Our solution proves efficient, being at most quadratic w.r.t. trace length, and effective in recognising interestingness of discovered constraints

Clinical Processes - The Killer Application for Constraint-Based Process Interactions?

For more than a decade, the interest in aligning information systems in a process-oriented way has been increasing. To enable operational support for business processes, the latter are usually specified in an imperative way. The resulting process models, however, tend to be too rigid to meet the flexibility demands of the actors involved. Declarative process modeling languages, in turn, provide a promising alternative in scenarios in which a high level of flexibility is demanded. In the scientific literature, declarative languages have been used for modeling rather simple processes or synthetic examples. However, to the best of our knowledge, they have not been used to model complex, real-world scenarios that comprise constraints going beyond control-flow. In this paper, we propose the use of a declarative language for modeling a sophisticated healthcare process scenario from the real world. The scenario is subject to complex temporal constraints and entails the need for coordinating the constraint-based interactions among the processes related to a patient treatment process. As demonstrated in this work, the selected real process scenario can be suitably modeled through a declarative approach.Ministerio de Economía y Competitividad TIN2016-76956-C3-2-RMinisterio de Economía y Competitividad TIN2015-71938-RED

Care of patients fitted with an external fixation device.

Severe lower limb fractures may be stabilized by an External Fixation Device such as the DENHAM BAR, which is a single-sided Fixator. The feasibility of detecting healing in tibial shaft fractures using this device as a transducer was investigated The Bar was instrumented with strain gauges and calibrated in two modes to determine its reliability as a transducer. Further experimentation was carried out on a Bone / Fixator configuration to determine the limits of detectable strain in the Bar which results from firstly, a complete break, and secondly, when the bone is fully healed. The experimental work was fraught with practical difficulties and the results indicated that the bar did not behave as a reliable transducer. This suggested that direct instrumentation of the bar is not a suitable technique for clinical application. A lack of response from the strain gauges was found when the bar was in situ with fully healed bone indicating that the device behaved as a redundant structure at this stage. The Denham Bar is, however, a clinically popular device but subject to wide variation in its application. Using the device as a basis for a theoretical analysis, strain energy techniques were employed to determine whether intermediary stages of healing could be detected by related changes in the level of strain. The extent of this analysis indicated that as healing bone reaches 10 - 15% of normal strength changes in the level of healing are not detectable by the bar. The motion at the fracture site, that the device permits, was also determined from a further analysis using Beam Deflection techniques. These results were compared with an analysis of the same configuration using the PRIME STRESS PROGRAM. A number of Fixator and Physiological variables were identified, which were then selected for further analysis by the Prime Stress program to determine their relative importance and contribution to overall stiffness. From this final investigation the maximum and minimum criteria for stability were established. The analysis included a consideration of healing bone and the changes in fracture site motion which occur as the strength of CALLUS (Healing bone) approaches that of normal bone

A model for uphill droplet motion

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.This paper focuses on the behaviour of a liquid droplet over the surface of a treated solid substrate. It deals with the use of surface tension forces induced by setting up a gradient of wettability to allow the evacuation of the dispersed phase. The main aim is to present a new model capable of predicting the motion of a droplet of known volume over a surface with a wettability gradient that explicitly takes contact angle hysteresis into account. Several authors have established a phenomenological footprint radius, from which the droplet starts moving. Our model, provides a relationship to find this critical droplet size. The results show that the contact angle hysteresis parameter appears to be a key issue in droplet dynamics and in the accurate prediction of droplet motion

Application of Information and Communication Technologies (ICTs) to Library Operations and Routines in Selected Nigerian Federal University Libraries

Digital media have revolutionized information sources and advances in Information and Communication Technologies (ICTs) and have dramatically enhanced information provision. The process of library operations and routines has become very challenging and complex. Libraries as centres for learning, teaching and research can no longer cope with the use of traditional methods. To this end, the study examines the Application of Information and Communication technologies (ICTs) to Library Operations and Routines in Selected Nigerian Federal University Libraries. Survey research method was adopted for the study; six (6) academic libraries in Federal Universities in the six geo-political zones of Nigeria were selected for this study. Area or cluster probability sampling was used for this study. Questionnaire was instrument used for data collection. A total of 336 (92.3 %) copies of the questionnaire were returned duly completed and found usable for this study, Data were analysed descriptively, to further clarified the researchers interviewed one staff each from the selected academic libraries. The study found among others that ICT facilities are frequently applied in cataloguing and classification of information resources with a score of 250 (74%) and selection of information resources with a score of 244 (73%) while statistical records with the least score of 44%, computers was the most often used IC facilities in the library studied. The study concluded that digital media have revolutionized information resources and the advances in ICT have dramatically enhanced information provision not only in the selection, ordering, acquisition, processing, storage and retrieval of library information resources but also improved staff productivity. It is expected that the NFUL can fully utilize the benefit of ICT facilities, especially, the digitization of local contents, institutional repository and functioning websites. The challenges of ICT utilization in the libraries if not properly handled will reduce their potentials to achieve the goals and objectives of their parent institutions. The study recommended among others that, the NFUL should use Open-source library information management software and DSpace content management system and document management to manage the library