What can possibly go wrong? Anticipatory work in space operations

This paper explores how different forms of anticipatory work contribute to reliability in high-risk space operations. It is based on ethnographic field work, participant observation and interviews supplemented with video recordings from a control room responsible for operating a microgravity greenhouse at the International Space Station (ISS). Drawing on examples from different stages of a biological experiment on the ISS, we demonstrate how engineers, researchers and technicians work to anticipate and proactively mitigate possible problems. Space research is expensive and risky. The experiments are planned over the course of many years by a globally distributed network of organizations. Owing to the inaccessibility of the ISS, every trivial detail that could possibly cause a problem is subject to scrutiny. We discuss what we label anticipatory work: practices constituted of an entanglement of cognitive, social and technical elements involved in anticipating and proactively mitigating everything that might go wrong. We show how the nature of anticipatory work changes between planning and the operational phases of an experiment. In the planning phase, operators inscribe their anticipation into technology and procedures. In the operational phase, we show how troubleshooting involves the ability to look ahead in the evolving temporal trajectory of the ISS operations and to juggle pre-planned fixes along these trajectories. A key objective of this paper is to illustrate how anticipation is shared between humans and different forms of technology. Moreover, it illustrates the importance of including considerations of temporality in safety and reliability research.     

Measuring information systems success: models,dimensions, measures,and interrelationships

Since DeLone and McLean (D&M) developed their model of IS success, there has been much research on the topic of success as well as extensions and tests of their model. Using the technique of a qualitative literature review, this research reviews 180 papers found in the academic literature for the period 1992–2007 dealing with some aspect of IS success. Using the six dimensions of the D&M model – system quality, information quality, service quality, use, user satisfaction, and net benefits – 90 empirical studies were examined and the results summarized. Measures for the six success constructs are described and 15 pairwise associations between the success constructs are analyzed. This work builds on the prior research related to IS success by summarizing the measures applied to the evaluation of IS success and by examining the relationships that comprise the D&M IS success model in both individual and organizational contexts.     

Open generification

To what extent can software ‘travel’ to organizations and countries for which it was not designed for, and how important are local contexts for a successful design and implementation of generic software? Information systems researchers have differing views on this, some emphasizing the strengths of the generic and others the importance of contextual aspects. Contributing to this debate, Pollock and Williams have coined the term generification in order to describe how large vendors succeed in globalizing software packages through management by community, content and social authority. In this paper, we explore an approach that we call open generification, which extends Pollock and Williams' work in the sense that we acknowledge the need for and the feasibility of generic software, but propose an alternative model for the governance of it. Open generification is not about managing the community of users attached to a software package by homogenization or segmentation but aims at addressing the diverse needs of the community the software is expected to serve. Our empirical basis is a longitudinal study of the development of an open‐source health information system software (District Health Information software version 2), which is being used in more than 47 countries. Its success is attributed to a continuous interplay between generic and specific software and continuous cycles of embedding (implementing the global in the local context) and disembedding (taking local innovations into the global). We identify and discuss the contingent mechanisms of this interplay.     

Accelerated climate ageing of building materials, components and structures in the laboratory

Building materials, components and structures have to fulfil many functional demands during the lifetime of a building. Therefore, it is important to require satisfactory durability of these materials, components and structures. In fact, one single material failure may jeopardize whole components as well as structures. Unfortunately, experience shows that building products too often do not satisfy the various requirements after a relatively short period of use, i.e. the expected service life is considerably shorter than foreseen. This results in increased and large costs due to increased maintenance, extensive replacements of the specific building products and any possible consequential building damages. In addition, health hazards with respect to both risk and consequence may also become an issue. To avoid this, the solution is to apply building products which have properly documented adequate and satisfactory long-term durability. That is, building products which have been subjected to long-term natural outdoor climate exposure or appropriate accelerated climate ageing in the laboratory. This study examines the main climate exposures and how these may be reproduced in the laboratory in various ways. Thus, crucial properties of building products and their durability towards climate strains may be investigated within a relatively short time frame compared with natural outdoor climate ageing. Examples of miscellaneous climate ageing laboratory apparatuses, ageing methods and building product properties to be tested before, during and after ageing are given. A calculation method for estimating acceleration factors is also discussed. Various ageing examples are shown and discussed. A special note is made towards accelerated climate ageing of new and advanced materials being developed. Hence, this study addresses durability and the versatile and powerful application of accelerated climate ageing which is an all too overlooked field within materials science and engineering.     

Built environment,causality and urban planning

Informed by critical realist philosophy of science, this paper aims to contribute to a better understanding of the issue of causality within urban and planning research. The concept of causality dominating within certain influential disciplinary and philosophical traditions is difficult to reconcile with research into influences of the built environment on human actions. This paper promotes a conceptualizing of causality in terms of generative mechanisms operating in different combinations in normally non-closed systems, and discusses in what sense the built environment can be said to exert causal influences on human actions. In order to integrate knowledge about causal influences at the level of the individual and at the city level, a combination of qualitative and quantitative research methods is recommended.     

Methanol Conversion to Hydrocarbons (MTH) Over H-ITQ-13 (ITH) Zeolite

Product flexibility is key to meeting fluctuating chemicals demands in the future. In this contribution, the methanol to hydrocarbons (MTH) reaction was investigated over two Ge-containing H-ITQ-13 samples, one with needle-like (H-ITQ-13(N), with (Si+Ge)/Al) = 42) and another with plate-like (H-ITQ-13(P), with (Si+Ge)/Al > 100) morphology. The samples were characterised using XRD, BET, SEM/EDS and FTIR spectroscopy, and their MTH performance was compared with the performance of H-ZSM-5 and H-ZSM-22. Similar specific surface areas (413 and 455 m² g^?1 for H-ITQ-13(N) and (P), respectively) and similar acid strength (Δν ~ ?327(?310) cm^?1) was observed for the two H-ITQ-13 samples. Testing of H-ITQ-13(N) at weight hourly space velocity (WHSV) = 2–8 h^?1 at 350–450 °C revealed that C₅₊ alkenes were the main products (35–45 % selectivity at 400 °C), followed by propene and butene. A low but significant selectivity for aromatic products was observed (6–8 % selectivity at 400 °C). Product selectivity was found to be independent of deactivation. The methanol conversion capacity of H-ITQ-13(N) was 120–150 g methanol g^?1 catalyst at 400 °C. Testing H-ITQ-13 at high (30 atm) and ambient pressure, respectively, at 350 °C showed that a high pressure led to enhanced C₅₊ selectivity, but close to a tenfold decrease in methanol conversion capacity. H-ITQ-13(P) was tested at 400 °C and 2 h^?1. It gave lower conversion than H-ITQ-13(N). Furthermore, when compared at the same conversion level, H-ITQ-13(P) gave higher C₅₊ alkene selectivity, lower aromatics selectivity, and a higher propene to ethene ratio than H-ITQ-13(N). The H-ITQ-13 samples yielded a product spectrum intermediate of H-ZSM-22 and H-ZSM-5. The effluent product cut-off of H-ITQ-13 was similar to that of H-ZSM-5 with tetramethylbenzene as the largest significant product, while H-ZSM-22 produced mainly linear and branched alkenes. The lifetime of H-ITQ-13(N) was clearly enhanced compared to H-ZSM-22, but inferior to H-ZSM-5.     

Disassembly and Mislocalization of AQP4 in Incipient Scar Formation after Experimental Stroke

There is an urgent need to better understand the mechanisms involved in scar formation in the brain. It is well known that astrocytes are critically engaged in this process. Here, we analyze incipient scar formation one week after a discrete ischemic insult to the cerebral cortex. We show that the infarct border zone is characterized by pronounced changes in the organization and subcellular localization of the major astrocytic protein AQP4. Specifically, there is a loss of AQP4 from astrocytic endfoot membranes that anchor astrocytes to pericapillary basal laminae and a disassembly of the supramolecular AQP4 complexes that normally abound in these membranes. This disassembly may be mechanistically coupled to a downregulation of the newly discovered AQP4 isoform AQP4ex. AQP4 has adhesive properties and is assumed to facilitate astrocyte mobility by permitting rapid volume changes at the leading edges of migrating astrocytes. Thus, the present findings provide new insight in the molecular basis of incipient scar formation.     

Development of large-scale hydrogen liquefaction processes from 1898 to 2009

This paper presents a review of the development of large-scale hydrogen liquefaction processes throughout the world from 1898 to 2009. First, there is a concise literature review including numerous past, present, and future designs given such as the first hydrogen liquefaction device, long time ago simple theoretical processes, today's actual plants with efficiencies 20–30%, a list of the capacity and location of every hydrogen liquefaction plant in the world, and some modern more efficient proposed conceptual plants with efficiencies 40–50%. After that, further information about the development and improvement potential of future large-scale liquid hydrogen liquefaction plants is given. It is found that every current plant is based on the pre-cooled Claude system, which is still the same as was 50 years ago with little improvement. Methods to resolve the challenges of the future plants include proposing completely new configurations and efficient systems coupled with improved efficiencies of the main system components such as compressors, expanders, and heat exchangers. Finally, a summary and comparison of the process efficiencies are described, including a newly proposed Multi-component Refrigerant (MR) system being developed by NTNU and SINTEF Energy Research AS.     

Designing Heterogeneous Catalysts by Incorporating Enzyme-Like Functionalities into MOFs

Everyone who works within the field of catalysis draws inspiration from the amazing functionality of nature’s catalysts, the enzymes. It is particularly the mild conditions that these catalysts are able to operate at and the selectivity that they demonstrate that make these materials dream targets for scientists involved in the art of synthesizing homogeneous and heterogeneous industrial catalysts. But enzymes also have their weak points; in particular their low thermal stability and their often too slow reaction rates for an economical industrial process are problems that have to be overcome. The obvious solution would be to copy the catalytic active center into a robust open framework. A key property of an enzyme is its selectivity; this property is partly regulated by steric constraints surrounding the catalytically active site. The microporous zeolite based catalysts in some cases show impressive selectivity based on the geometrical constraints imposed by the size and shape of the regular channels in these crystalline silicate and alumino-phosphate based structures, and enzyme-like properties have been claimed but the pure inorganic nature of the selective internal surface in these materials makes it impossible to mimic many important enzymatic properties. The new generation of microporous materials, Metal Organic Frameworks (MOFs) are hybrids of organic and inorganic structures. This dualistic nature offers an unprecedented flexibility in the possibility to incorporate both organic and metallic functional groups into the ordered crystalline lattice and thereby opening up for a much greater possibility to copy structural motifs known from enzymes into much simpler but also more stable open structures. Several groups are working on development of new catalysts by this approach. Here we will illustrate this approach with structures that mimic anhydrase and C–H activation.     

An evaluation of the Norwegian Salmonella surveillance and control program in live pig and pork

Population data and apparent prevalence data from the Salmonella surveillance and control program in pigs (NSSCP) from 1998 and 1999 were used in a simulation model to evaluate the efficacy of the program. The model consists of three parts: modelling of individual prevalence at the abattoir (abattoir part), modelling of the number of sampled herds of different sizes when carcasses are randomly sampled at the abattoir (sampling strategy part) and finally, modelling of the within herd prevalence (within herd part). A total of 136,550 sows and 2,866,550 finishing pigs slaughtered, 4446 herds and 11 herds positive for Salmonella in 1994/1995-2000 were included in the abattoir part, sampling strategy part and the within herd part of the model, respectively. The abattoir part showed an average estimated prevalence of Salmonella in sows and finishing pigs of (median) 0.4% (5-95 percentiles = 0.03-2%) and 0.1% (0.04-0.2%) respectively. The estimated number of infected sow carcasses that entered the market was 502 (37-2157) while the estimated number of finishing pig carcasses was 2919 (1218-5771). The probability of being sampled for the 10% smallest herds was (mean) 1.9% (1.6-2.2), to 25% (24.7-26.5%) for the 10% largest herds. The within herd prevalence was estimated to be from 1% to 4% for Norwegian pig herds. The conclusions drawn from this evaluation are that the NSSCP does not have any significant consumer protection effect, and that the documentation could be done more effectively using the herd rather than the individual animal as the unit of sampling. Sampling should focus on the larger herds supplying most of the meat on the market and on herds that produce breeding sows and piglets and thus can contribute to the spread of Salmonella among herds.