PASSION Runtime Library for the Intel Paragon

We are developing a runtime library which provides a number of routines to perform the I/O required in parallel applications in an efficient and convenient manner. This is part of a project called PASSION, which aims to provide software support for high-performance parallel I/O at the compiler, runtime and file system levels. The PASSION Runtime Library uses a high-level interface which makes it easy for the user to specify the I/O required in the program. The user only needs to specify what portion of the data structure needs to read from or written to the file, and the PASSION routines will perform all the necessary I/O efficiently. This paper gives an overview of the PASSION Runtime Library and describes in detail its high-level interface

Common challenges and requirements

Research infrastructures available for researchers in environmental and Earth science are diverse and highly distributed; dedicated research infrastructures exist for atmospheric science, marine science, solid Earth science, biodiversity research, and more. These infrastructures aggregate and curate key research datasets and provide consolidated data services for a target research community, but they also often overlap in scope and ambition, sharing data sources, sometimes even sites, using similar standards, and ultimately all contributing data that will be essential to addressing the societal challenges that face environmental research today. Thus, while their diversity poses a problem for open science and multidisciplinary research, their commonalities mean that they often face similar technical problems and consequently have common requirements when addressing the implementation of best practices in curation, cataloguing, identification and citation, and other related core topics for data science. In this chapter, we review the requirements gathering performed in the context of the cluster of European environmental and Earth science research infrastructures participating in the ENVRI community, and survey the common challenges identified from that requirements gathering process

Breakage Assessment of Lath-Like Crystals in a Novel Laboratory-Scale Agitated Filter Bed Dryer

Agitated filter bed dryer is often the equipment of choice in the pharmaceutical industry for the isolation of potent active pharmaceutical ingredients (API) from the mother liquor and subsequent drying through intermittent agitation. The use of an impeller to promote homogeneous drying could lead to undesirable size reduction of the crystal product due to shear deformation induced by the impeller blades during agitation, potentially causing off-specification product and further downstream processing issues. An evaluation of the breakage propensity of crystals during the initial development stage is therefore critical. A new versatile scale-down agitated filter bed dryer (AFBD) has been developed for this purpose. Carbamazepine dihydrate crystals that are prone to breakage have been used as model particles. The extent of particle breakage as a function of impeller rotational speed, size of clearance between the impeller and containing walls and base, and solvent content has been evaluated. A transition of breakage behaviour is observed, where carbamazepine dihydrate crystals undergo fragmentation first along the crystallographic plane [00l]. As the crystals become smaller and more equant, the breakage pattern switches to chipping. Unbound solvent content has a strong influence on the breakage, as particles break more readily at high solvent contents. The laboratory-scale instrument developed here provides a tool for comparative assessment of the propensity of particle attrition under agitated filter bed drying conditions

Assessment of impact breakage of carbamazepine dihydrate due to aerodynamic dispersion

Acicular crystals are very common in pharmaceutical manufacturing. They are very prone to breakage, causing unwanted particle size degradation and problems such as segregation and lump formation. We investigate the breakage pattern of carbamazepine dihydrate, an acicular and platy crystal with cleavage planes. It readily undergoes attrition during isolation and drying stage, causing processing difficulties. We use the aerodynamic dispersion of a very small quantity of powder sample to induce breakage by applying a pulse of pressurised air. The dispersion unit of Morphologi G3 is used for this purpose. The broken particles settle in a chamber and are subsequently analysed using the built-in image analysis software. The shift in the particle size and shape distributions is quantified through which the extent of breakage is determined as a function of the dispersion pressure. The analysis reveals a change of breakage mechanism as the dispersion pressure is increased from primarily snapping along the crystal length to one in which chipping has also a notable contribution. The breakage data are analysed using a modified impact-based breakage model and the breakability index of the carbamazepine dihydrate is determined for the two breakage regimes. The method provides a quick and easy testing of particle breakability, a useful tool for assessing attrition in process plant and grindability in milling operations

Understanding stress-induced disorder and breakage in organic crystals: beyond crystal structure anisotropy

Crystal engineering has advanced the strategies for design and synthesis of organic solids with the main focus being on customising the properties of the materials. Research in this area has a significant impact on large-scale manufacturing, as industrial processes may lead to the deterioration of such properties due to stress-induced transformations and breakage. In this work, we investigate the mechanical properties of structurally related labile multicomponent solids of carbamazepine (CBZ), namely the dihydrate (CBZ·2H2O), a cocrystal of CBZ with 1,4-benzoquinone (2CBZ·BZQ) and the solvates with formamide and 1,4-dioxane (CBZ·FORM and 2CBZ·DIOX, respectively). The effect of factors that are external (e.g. impact stressing) and/or internal (e.g. phase transformations and thermal motion) to the crystals are evaluated. In comparison to the other CBZ multicomponent crystal forms, CBZ·2H2O crystals tolerate less stress and are more susceptible to breakage. It is shown that this poor resistance to fracture may be a consequence of the packing of CBZ molecules and the orientation of the principal molecular axes in the structure relative to the cleavage plane. It is concluded, however, that the CBZ lattice alone is not accountable for the formation of cracks in the crystals of CBZ·2H2O. The strength and the temperature-dependence of electrostatic interactions, such as hydrogen bonds between CBZ and coformer, appear to influence the levels of stress to which the crystals are subjected that lead to fracture. Our findings show that the appropriate selection of coformer in multicomponent crystal forms, targetting superior mechanical properties, needs to account for the intrinsic stress generated by molecular vibrations and not solely by crystal anisotropy. Structural defects within the crystal lattice, although highly influenced by the crystallisation conditions and which are especially difficult to control in organic solids, may also affect breakage

Disk-based management of interaction graphs

In our increasingly connected and instrumented world, live data recording the interactions between people, systems, and the environment is available in various domains, such as telecommunciations and social media. This data often takes the form of a temporally evolving graph, where entities are the vertices and the interactions between them are the edges. An important feature of this graph is that the number of edges it has grows continuously, as new interactions take place. We call such graphs interaction graphs. In this paper we study the problem of storing interaction graphs such that temporal queries on them can be answered efficiently. Since interaction graphs are append-only and edges are added continuously, traditional graph layout and storage algorithms that are batch based cannot be applied directly. We present the design and implementation of a system that caches recent interactions in memory, while quickly placing the expired interactions to disk blocks such that those edges that are likely to be accessed together are placed together. We develop live block formation algorithms that are fast, yet can take advantage of temporal and spatial locality among the edges to optimize the storage layout with the goal of improving query performance. We evaluate the system on synthetic as well as real-world interaction graphs, and show that our block formation algorithms are effective for answering temporal neighborhood queries on the graph. Such queries form a foundation for building more complex online and offline temporal analytics on interaction graphs. © 1989-2012 IEEE

A Unified Tiling Approach for Out-Of-Core Computations

This paper describes a framework by which an out-of-core stencil program written in a data-parallel language can be translated into node programs in a distributed-memory message-passing machine with explicit I#O and communication. We focus on a technique called Data Space Tiling to group data elements into slabs that can #t into memories of processors. Methods to choose legal tile shapes under several constraints and deadlock-free scheduling of tiles are investigated. Our approachisuni#ed in the sense that it can be applied to both FORALL loops and the loops that involve#ow-dependences. 1 Introduction and Related Work Since, today, almost every processor has some kind of memory hiearachy organized into layers with di#erent costs, compiler optimizations to reduce memory access costs are important. Tiling, one such optimization, was #rst used by Abu-Sufah et al.#Abu81# in order to optimize loop nests in a paging-memory system. The later applications were generally on cache memorie..

Optimizing Out-of-Core Computations in Uniprocessors

Abstract Programs accessing disk-resident arrays perform poorly in generaldue to excessive number of I/O calls and insufficient help from compilers. In this paper, in order to alleviate this problem, wepropose a series of compiler optimizations. Both the analytical approach we use and the experimental results provide strong evidencethat our method is very effective on uniprocessors for out-of-core nests whose data sizes far exceed the size of available memory