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| 2. |
- Delsing, Jerker, et al.
(författare)
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Low-pressure gap discharge ultrasonic gas flowmeter
- 2010
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Ingår i: The 15th International Flow Measurement Conference. ; , s. 259-266
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Konferensbidrag (refereegranskat)abstract
- Low-pressure gas measurements are of increasing interest in the process industry for both control purposes and emission measurements. Industrial measurement environments include some very challenging components, such as:- Dust, particles, vapor, water droplets, etc.- Temperatures up to 1200°C- Pipe diameters of 1 to 10 mUltrasound flow measurement techniques have many advantages for such industrial measurement problems. Currently, a major problem is the lack of transducer technology that is sufficiently robust to operate in the presence of the above given industrial components. For the purpose of producing more robust technology, a gap discharge sound transmitter has been developed [1, 2]. Theoretical and experimental studies of the gap discharge transmitter indicate that flow measurement performances in the range of 1-2% of the actual flow is achievable [3]. Based on this gap discharge transmitter, an experimental ultrasound gas flowmeter was designed. The design features a gap discharge transmitter and piezo-based receivers. The design was tested in a real industrial environment. The test environment included heavy dust and water vapor in an exhaust pipe at a pelletization plant at LKAB, Kiruna, Sweden. The pipe diameter is 3 m, the pressure is ambient, and the gas flow speed is in the range of 5-20 m/s. The flow conditions were highly turbulent, using a straight pipe length ten times the pipe diameter in front of the experimental flowmeter. This paper presents the experimental gap discharge ultrasonic flowmeter design, the experimental setup and some measurement data. These data indicate that the gap discharge transmitter is feasible for operation in an industrial environment. Further preliminary flow measurement data demonstrate the feasibility of using a gap discharge transmitter as the sound-emitting source in an ultrasonic gas flowmeter.
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| 3. |
- Hagvall, Kristoffer, et al.
(författare)
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Spectroscopic characterization of the coordination chemistry and hydrolysis of gallium(III) in the presence of aquatic organic matter
- 2014
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Ingår i: Geochimica et Cosmochimica Acta. - : Elsevier BV. - 0016-7037 .- 1872-9533. ; 146, s. 76-89
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Tidskriftsartikel (refereegranskat)abstract
- Interactions between metals and natural organic matter (NOM) are of great environmental importance and one of the key factors influencing hydrolysis, solubility, and speciation of the metals. However, studying geochemically relevant metals like Al, Fe, and Cu is sometimes associated with analytical problems; for example Fe and Cu are both redox active. Gallium (Ga) is a non-redox active metal that usually occurs at very low concentrations in environmental samples and therefore a wide concentration range of metal(III)-NOM species can be explored by adding Ga(III) to such samples. This makes Ga(III) a good probe and analogue for other metal ions, in particular Al. In addition, due to the increased usage of Ga in society, a better understanding of how Ga interacts with NOM is of importance but such studies are scarce. In this work, Ga(III) interactions with two different organic materials (Suwannee River natural organic matter and Suwannee River fulvic acid) were studied using infrared (IR) and extended X-ray absorption fine structure (EXAFS) spectroscopy in a large experimental range (101-84,076 mu g Ga g(-1) dry weight; pH 3-8). Our IR spectroscopic results showed that Ga(III) is bonded mainly to carboxylic functional groups and suggested that only a fraction of the total number of carboxylic sites in the samples was actively involved in the bonding. Modeling of the EXAFS data revealed that Ga(III) formed mononuclear chelate complexes with NOM that strongly suppressed the hydrolysis and polymerization of Ga(III). At low Ga(III) concentrations (1675-16,649 mu g g(-1)) organic complexes, consisting of 1-3 chelate ring structures, were the dominating species in the entire pH range while at higher concentrations (67,673-84,076 mu g g(-1), pH 3.0-7.0) we detected mixtures of mononuclear organic Ga(III) complexes, Ga(III) (hydr) oxide, and free Ga(III) (here defined as the hydrated Ga(III) ion and its soluble hydrolysis products). Moreover, the EXAFS results showed significantly higher contribution from second-shell C atoms (9-11) for the Ga(III)-organic complexes at the lowest concentration (101-125 mu g g(-1), pH 4.9-5.1), indicating formation of cage-like structures similar to Ga(III)-EDTA. Our combined results showed that Ga(III)-NOM interactions can be of importance for the solubility and speciation of Ga in environmental systems. Furthermore, the similarities between Ga(III) and previous Fe(III) results demonstrate that Ga(III) can be utilized as a probe for metal(III)-NOM interactions over an extended experimental range (e. g., pH and metal concentration) and thereby improve our knowledge about these interactions in general. (C) 2014 Elsevier Ltd. All rights reserved.
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| 4. |
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| 5. |
- Holt, Kristoffer, 1976-, et al.
(författare)
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Edited participation : A comparative study of editorial influence on three online news media in Sweden
- 2010
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Konferensbidrag (refereegranskat)abstract
- Although participatory journalism often involves the publishing of content created by users, editorial influence is an important aspect of the emerging participatory online mediascape. The choices that editors make shape the conditions under which user generated content is produced, the immediate context of publication and the perceived prominence of the published content. The question is how this influence manifests itself, and how this can be related to the discussion about participatory media’s potential for revitalizing democracy. In this paper, three online news media in Sweden are analysed comparatively: Sourze – one of the first Swedish sites that invited citizens as primary contributors; Newsmill – a social media focusing on news and debate; and DN – the online version of the largest Swedish morning paper Dagens Nyheter. The question is how participation is affected by editorial influence.The findings suggest that participatory arenas to some extent are constrained by the logic of their context of production. Participation is not the same for everyone, and people from different categories in society participate on different terms. Furthermore, editors influence the agenda by suggesting topics, and by rewarding articles that follow their suggestions. These findings do not challenge assumptions about participatory newspapers as more accessible channels for citizens to publish content, and therefore interesting as possible means of allowing a more democratically involved citizenry, but it challenges assumptions about freedom from constraints related to traditional mass media, such as agenda setting, gate-keeping and media logic.
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| 6. |
- Holt, Kristoffer, 1976-, et al.
(författare)
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Edited participation comparing editorial influence on traditional and participatory online newspapers in Sweden
- 2011
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Ingår i: Javnost - The Public. - 1318-3222. ; 18:2, s. 19-36
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Tidskriftsartikel (refereegranskat)abstract
- Although participatory journalism involves publishing content created by users, editorial influence is an important aspect of participatory online media. Editors shape the conditions under which user generated content is produced, the context of publication and the perceived prominence of the content. It is still unclear how this influence manifests itself, and how it can be related to the discussion about participatory media’s potential for revitalising democracy. In this paper, three online news media in Sweden are analysed comparatively: Sourze – the first Swedish participatory newspaper; Newsmill – a social media focusing on news and debate; and DN – the online version of the largest Swedish morning paper Dagens Nyheter. The question is how participation is affected by editorial influence. The findings suggest that participatory arenas are constrained by the logic of their context of production. People from different categories in society participate on different terms. Furthermore, editors influence the agenda by suggesting topics, and by rewarding articles that follow their suggestions. These fi ndings do not challenge assumptions about participatory newspapers as more accessible channels for citizens and therefore interesting as possible means of allowing a more democratically involved citizenry, but it challenges assumptions about freedom from constraints related to traditional mass media, such as agenda setting, gate-keeping and media logic.
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| 7. |
- Holt, Kristoffer, et al.
(författare)
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How are citizen journalists telling news? The Swedish case
- 2013
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Konferensbidrag (refereegranskat)abstract
- Previous research on citizen journalism has an Anglo-Saxon bias and frequently studies specific cases that focus on conflict, crisis events or war creating a selection bias of existing and, at least modestly, successful examples. In this study, situated in Sweden, we reverse the process and examine how actual communities are served by digital citizen community journalism in an everyday context. The study has a particular focus on how events are portrayed in terms of news topics dimensions, framing, presentation style, geographical focus and the authorship of news items. Preliminary findings indicate that the citizen journalists’ only present one perspective, rarely refers to policy plans or talks to the actors involved and provide individual and episodic news frames. Their focus is mostly on the local level and they have embraced the impersonal and unemotional presentation style from mainstream news. Half of the news items are being written by citizens while representatives from organisations or politicians author a quarter of them. All in all, citizen journalism in general falls short from both traditional journalistic standards and many scholarly claims of being alternative.
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| 8. |
- Holt, Kristoffer, 1976-, et al.
(författare)
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How are citizen journalists telling the news? : An inventory of Swedish online citizen journalism sites
- 2013
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Ingår i: Nordmedia 2013.
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Konferensbidrag (refereegranskat)abstract
- In this study, situated in Sweden, we examine what actual communities that are served by digital citizen community journalism in an everyday context. The results show that there are very few cases of citizen journalism and that they are situated in the same legacy media logic that they allegedly should be an alternative to. Moreover, the study shows that the citizen journalists focus on business news, entertainment and sports and do not cover local authorities. When sources are used they are few and originate from social institutions such as business, media, authorities and politics rather than citizens. All in all, this empirical study suggests that the reality of citizen journalism fall very short from the expectations expressed in much of the scholarly debate.
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| 9. |
- Holt, Kristoffer, 1976-, et al.
(författare)
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Om journalistikens existentiella kris : behövs verkligen journalister när vem som helst kan bli publicist?
- 2014
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Ingår i: IKAROS tidskrift om människan och vetenskapen. - Åbo : Fbf. Folkets Bildningsförbund, Finland. - 1796-1998. ; 11:3-4, s. 5-7
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Aldrig förr har journalister tagit så mycket så mycket plats i offentligheten som i våra dagar. Exempel: Valrörelserna 2014 i Sverige prägla(de)s i högre utsträckning än någonsin tidigare av en ohejdad journalistisk kommentarlusta. Ett typiskt nyhetsinslag innehåller ofta ett kort uttalande av någon politiker, följt av en lång diskussion med kanalens politiska kommentatorer. Klyftan mellan de politiska partierna och den intet ont anande allmänheten fylls till bredden av journalistisk analys, tyckande, reflekterande och debatt med andra journalister. Många har frågat sig om vi medborgare verkligen får en chans att fundera själva över vad politikerna egentligen menar, innan en journalistisk expert har hunnit förklara det oss. Samtidigt pågår en annan utveckling journalistiken befinner sig 1 sedan cirka ett decennium tillbaka i en existentiell kris.2 Just nu pågår en fas som präglas av ett stort behov av att definiera vad en journalist egentligen är, varför de finns och vilken uppgift de förvänts fylla i samhället. Anledningen är att den teknologiska utveckingen, parallellt med stora ekonomiska svårigheter för många mediehus, skapat helt nya förutsättningar för en verksamhet som under decennier präglats av rutin och förutsägbarhet.3 Mitt i detta skeende dyker de sociala medierna upp, där bloggare och twittrare utan journalistisk skolning tävlar med de professionella journalisterna om att tycka och tänka – och inte minst att leverera nyheter.
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| 10. |
- Holt, Kristoffer, et al.
(författare)
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Participatory Journalism and Editorial Influence
- 2011
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Ingår i: Communication @ the Center. - : International Communication Association.
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Konferensbidrag (refereegranskat)abstract
- Although participatory journalism involves publishing content created by users, editors shape the conditions under which user generated content is produced; the context of publication and the perceived prominence of the content. In this paper, three online news media in Sweden are analysed comparatively: Sourze – the first Swedish participatory newspaper; Newsmill – a social media focusing on news and debate; and DN – the online version of the Dagens Nyheter. The question is how participation is affected by editorial influence.Findings suggest that participatory arenas are constrained by the logic of their context of production. People from different categories in society participate on different terms. Furthermore, editors influence the agenda by suggesting topics, and by rewarding articles that follow their suggestions. This challenges assumptions about freedom from constraints related to traditional mass media, such as agenda setting, gate-keeping and media logic.
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