Moodley S.,University of KwaZulu - Natal |
Johansson E.,University of KwaZulu - Natal |
Bolton K.,University of Bors |
Ramjugernath D.,University of KwaZulu - Natal
Molecular Simulation | Year: 2012
This paper reports the effects of varying the cross-energy parameter, via a multiplying factor in each phase, on the fluid phase equilibrium compositions of a binary monatomic Lennard-Jones-based mixture (methane/xenon) using constant pressure Gibbs ensemble Monte Carlo simulations. Homogeneous () increases in within the two-phase region resulted in monotonic enrichment of methane in the liquid phase; decreasing had the opposite effect. This was valid only within a certain interval (the two-phase region) at each simulation state point because below the lower bound a single vapour phase was observed and above the upper bound a single liquid phase was observed. Homogeneous were effective at several state points for satisfactory predictions of experimental compositions. At other states, such predictions were not possible with homogeneous but it is demonstrated that perturbing the energy parameter independently in each phase () results in the experimental compositions being predicted satisfactorily. Different combinations of heterogeneous energy cross-parameters do not necessarily result in unique compositions. Variations in revealed that several minima are present on the composition error surface in the - plane and also the existence of a temperature-dependent homogeneous, which has slopes of opposite sign on either side of the critical temperature of pure methane. © 2012 Copyright Taylor and Francis Group, LLC.
Magnusson L.,University of Bors |
Magnusson L.,Linnaeus University |
Hanson E.,Corresponding Author Elizabeth Hanson |
Hanson E.,Linnaeus University |
Hanson E.,University of Sheffield
Technology and Disability | Year: 2012
ACTION (Assisting Carers using Telematics Interventions to meet Older people's Needs) stemmed from an EU-funded project (1997-2000). It is an Information and Communication Technology (ICT) based support service designed together with frail older people and their family carers to help empower them in their daily lives by providing access to web-based educational programmes, support from other ACTION families and dedicated care practitioners via the use of an integrated videophone system. It is currently running as a mainstream service in Bors municipality in West Sweden and as implementation projects in an additional twenty-five municipalities across Sweden. It is well recognised that there are relatively few examples of telecare projects that have successfully managed the transfer to a mainstream service. Based on our fourteen years of experience with the design and implementation of ACTION, we reflect on the major lessons learned. This paper highlights the user centred design model developed and refined during this period, including the range of methods for working in partnership with a variety of stakeholder groups at all stages of the technology transfer process of the ACTION service. © 2012 - IOS Press and the authors. All rights reserved.
Rolandsson B.,University of Bors |
Bergquist M.,Gothenburg University |
Ljungberg J.,Gothenburg University
Research Policy | Year: 2011
Opening up firms to open source has changed professional programmers' work in software development. In their work practice they must cope with two modes of software production: one based on proprietary, closed work situations, the other built around open source community ways of cooperation and knowledge sharing. In this article we present a study of how programmers cope with the co-existence of an industrial/commercial and a community/commons based mode of production. We analyze how they develop strategies to handle tensions that arise from contradictions between these two modes, and how it changes programmers' approach towards open source software development in the company. The study covers proprietary companies that have gradually incorporated open source software (hybrid companies) and SMEs entirely built around open source business concepts (pure-play companies). Four strategies are elaborated and discussed in-depth: Engineering in the lab, Market driven tailoring, Developing the community consortium and Peer-production. At a more general level, the study contributes to our understanding of how the transformation of proprietary production processes into a more open mode of knowledge work is not only associated with company strategies, but also with tensions and new demands on how work is strategically handled by knowledge workers. © 2010 Elsevier B.V. All rights reserved.
Lennartsson P.R.,University of Bors |
Lennartsson P.R.,Chalmers University of Technology |
Ylitervo P.,University of Bors |
Ylitervo P.,Chalmers University of Technology |
And 3 more authors.
Process Biochemistry | Year: 2012
The capability of two zygomycetes strains, Mucor indicus and an isolate from tempeh (Rhizopus sp.), to grow on orange peel hydrolysate and their tolerance to its antimicrobial activity, was investigated. Both fungi, in particular M. indicus, tolerated up to 2% d-limonene in semi-synthetic media during cultivation in shake flasks, under aerobic as well as anaerobic conditions. The tolerance of M. indicus was also tested in a bioreactor, giving rise to varying results in the presence of 2% limonene. Furthermore, both strains were capable of consuming galacturonic acid, the main monomer of pectin, under aerobic conditions when no other carbon source was present. The orange peel hydrolysate was based on 12% (dry w/v) orange peels, containing d-limonene at a concentration of 0.6% (v/v), which no other microorganism has been reported to be able to ferment. However, the hydrolysate was utilised by M. indicus under aerobic conditions, resulting in production of 410 and 400 mg ethanol/g hexoses and 57 and 75 mg fungal biomass/g sugars from cultivations in shake flasks and a bioreactor, respectively. Rhizopus sp., however, was slow to germinate aerobically, and neither of the zygomycetes was able to consistently germinate in orange peel hydrolysate, under anaerobic conditions. The zygomycetes strains used in the present study demonstrated a relatively high resistance to the antimicrobial compounds present in orange peel hydrolysate, and they were capable of producing ethanol and biomass in the presence of limonene, particularly when cultivated with air supply. © 2012 Elsevier Ltd. All rights reserved.
Jeihanipour A.,University of Bors |
Jeihanipour A.,Chalmers University of Technology |
Niklasson C.,Chalmers University of Technology |
Taherzadeh M.J.,University of Bors
Process Biochemistry | Year: 2011
Hydrolysis is widely acknowledged as the rate-limiting step in anaerobic digestion of solid cellulose to biogas (methane), and pretreatment is generally considered to facilitate the process. However, few studies have investigated how such pretreatment may affect the rest of this complex process. The present study compared the solubilization rate in anaerobic digestion of cotton linter (high crystalline cellulose), with that of regenerated cellulose (amorphous cellulose), using pretreatment with NMMO. Batch digestions were performed, with the initial cellulose concentrations ranging between 5 and 40 g/l, and during 30 days of incubation, biogas and VFAs production as well as pH and COD changes were measured. The lag time before digestion started was longer for the high crystalline cellulose than for the amorphous one. The maximum solubilization rates of treated cellulose were 842 and 517 mg sCOD/g cCOD/day at the initial cellulose concentration of 5 and 30 g/l, respectively, while the solubilization rate of untreated cellulose never exceeded 417 mg sCOD/g cCOD/day. The difference between the two cellulose types was a direct result of the high rate of hydrolysis inhibiting the acetogenesis/methanogenesis microorganisms, a drawback to the rest of the process. © 2011 Elsevier Ltd.