In this chapter, the sustainability of journalism is explored with interest in how users express trust and distrust towards professional news media. The challenges to the sustainability of journalism have social, financial and environmental tenets. The center of attention here is the social aspect of how users negotiate the end of journalism in society. Users have conflicting views on how professional news media perform, oscillating between if the responsibility of news media should be extended to coverage of conflicting issues or to enable citizens to share a common ground imprinted by solidarity. These aspects merge and manifest in news related to issues of xenophobia and solidarity. The changed financial prospects of the news industry coincide with the timing of globalization’s effects on the local scene, where people experience increasing hurdles across the world. The sustainability of journalism—considered crucial for democracy—is currently under substantial pressure. At the same time, living conditions are deteriorating around the world. People need to migrate to other societies that are becoming ever more polarized between xenophobia and solidarity. News covering this process is constructed within a professional value system that—for the sustainability of journalism—needs to be perceived as legitimate.

This study investigates the types of information that users of a local news site share on Facebook. This issue relates to the idea of "churnalism", which concerns a form of weakened journalism that diminishes the ability to perform expected tasks in a democratic society. As a major social media platform, Facebook has acquired substantial influence over news dissemination, and therefore, scholarly focus needs to be directed to users as news disseminators. The manners by which users share news on Facebook indicate whether churnalism is promoted or abated through users’ interaction with online news. In this study, a quantitative content analysis illustrates how 348 news articles published on a local news site were shared 7266 times. The results show that concerns related to churnalism should be directed primarily to the fact that the news outlet only rarely provides users with opportunities to interact with serious or hard news, while lightweight news is frequently offered. Despite this, users abate churnalism in the sense that the news they prefer to share is news from in-house sources rather than from external sources. The news extensively shared covers changes in the vicinity, and health care, and has emerged from local and regional events.

Social plugins for sharing news through Facebook and Twitter have become increasingly salient features on news sites. Together with the user comment feature, social plugins are the most common way for users to contribute. The wide use of multiple features has opened new areas to comprehensively study users’ participatory practices. However, how do these opportunities to participate vary between the participatory spaces that news sites affiliated with local, national broadsheet and tabloid news constitute? How are these opportunities appropriated by users in terms of participatory practices such as commenting and sharing news through Facebook and Twitter? In addition, what differences are there between news sites in these respects? To answer these questions, a quantitative content analysis has been conducted on 3,444 articles from nine Swedish online newspapers. Local newspapers are more likely to allow users to comment on articles than are national newspapers. Tweeting news is appropriated only on news sites affiliated with evening tabloids and national morning newspapers. Sharing news through Facebook is 20 times more common than tweeting news or commenting. The majority of news items do not attract any user interaction.

The development of social media applications, such as blogs, Facebook, and Twitter, has offered new participatory opportunities for everyday media users. This article contributes to research by looking into one specific aspect of the increasingly more participatory media ecology—the news comment feature. Drawing on a quantitative content analysis of 1,100 news pieces, as well as spaces for user comments, the article reveals both how this emerging public space is shaped by the media company and, later, appropriated by their participating users. Our analysis reveals, for instance, that the online newspaper prefers to allow users to comment on lightweight news such as sports and entertainment. The users, however, prefer to post comments on news covering changes in proximity space, politics, and health care, while also clearly ignoring the most available news pieces (sport and entertainment). In the concluding section, the discrepancy in preferences is discussed.

This thesis deals with the preparation of chemically and/or enzymatically modified cellulose. This modification can be either irreversible or reversible. Irreversible modification is used to prepare cellulose derivatives as end products, whereas reversible modification is used to enhance solubility in the preparation of regenerated cellulose.

The irreversible modification studied here was the preparation of carboxymethyl cellulose (CMC) using extended mercerization of a spruce dissolving pulp. More specifically the parameters studied were the effect of mercerization at different proportions of cellulose I and II in the dissolving pulp, the concentration of alkali, the temperature and the reaction time. The parameters evaluated were the degree of substitution, the filterability and the amount of gel obtained when the resulting CMC was dissolved in water. Molecular structures of CMC and its gel fractions were analysed by using NIR FT Raman spectroscopy. It was found that the alkali concentration in the mercerization stage had an extensive influence on the subsequent etherification reaction. FT Raman spectra of CMC samples and their gel fractions prepared with low NaOH concentrations (9%) in the mercerization stage indicated an incomplete transformation of cellulose to Na-cellulose before carboxymethylation to CMC. Low average DS values of the CMC, i.e. between 0.42 and 0.50 were obtained. Such CMC dissolved in water resulted in very thick and semi solid gum-like gels, probably due to an uneven distribution of substituents along the cellulose backbone. FT Raman spectra of CMC samples and their gel fractions mercerized at higher alkaline concentration, i.e. 18.25 and 27.5% in the mercerization stage, indicated on the other hand a complete transformation of cellulose to Na-cellulose before carboxymethylation to CMC. Higher average DS values of the CMC, i.e. between 0.88 and 1.05 were therefore obtained. When dissolved in water such CMC caused gel formation especially when prepared from dissolving pulp with a high fraction of cellulose II.

The reversible modification studied was the dissolution of cellulose in NaOH/ZnO. Here the effect of enzyme pretreatment was investigated by using two mono-component enzymes; namely xylanase and endoglucanase, used in consecutive stages. It was found that although the crystallinity and the specific surface area of the dissolving pulp sustained minimal change during the enzymatic treatment; the solubility of pulp increased in a NaOH/ZnO solution from 29% for untreated pulp up to 81% for enzymatic pretreated pulp.

Carboxymethyl cellulose (CMC) is produced commercially in a two-stage process consisting of a mercerization stage, where the pulp is treated with alkali in a water alcohol solution, followed by an etherification stage in which monochloroacetic acid is added to the pulp slurry. In this thesis an extended mercerization stage of a spruce ether pulp was investigated where the parameters studied were the ratio of cellulose I and II, concentration of alkali, temperature and retention time. The influence of the mercerization stage conditions on the etherification stage, were evaluated as the degree of substitution (DS) of the resulting CMC and the filterability of CMC dissolved in water at a concentration of 1%. The DS results suggested that the NaOH concentration in the mercerization stage was the most important of the parameters studied. When the NaOH concentration in the mercerization step was low (9%), a high cellulose II content in the pulp used was found to have no negative impact on the DS of the resulting CMC compared with pulps with only cellulose I. However, when the NaOH concentration was high (27.5%), pulps with high content of cellulose II showed a lower reactivity than those with only cellulose I with respect to the DS of the CMC obtained after a given charge of NaMCA.

The results obtained from the filtration ability study of CMC water solutions suggested that both the amount of cellulose II in the original pulp and the temperature had a negative influence on the filtration ability whereas the NaOH concentration in the mercerization stage had a positive influence. The filtration ability was assumed to be influenced highly by the presence of poorly reacted cellulose segments. A retention time between 1-48 h in the mercerization stage had no effect on either the DS or the filtration ability of the CMC.

Using NIR FT Raman spectroscopy molecular structures of CMC and its gel fraction were analyzed with respect to the conditions used in the extended mercerization stage. Here it was found that the alkaline concentration had a very strong influence on the following etherification reaction. FT Raman spectra of CMC samples and their gel fractions prepared with low NaOH concentrations (9%) in the mercerization stage indicated an incomplete transformation of cellulose to Na-cellulose before carboxymethylation to CMC. Low average DS values of the CMC, i.e. between 0.42 and 0.50, were yielded. Such CMC dissolved in water caused very thick and semi solid gum-like gels, probably due to an uneven distribution of substituting groups along the cellulose backbone. FT Raman spectra of CMC mercerized with alkaline concentrations at 18.25 and 27.5% in the mercerization stage indicated, however, that all of the cellulose molecules were totally transferred to CMC of high DS, i.e. between 0.88 and 1.05. When dissolved in water such CMC caused gels when they were prepared from ether pulp with a high fraction of cellulose II.

Carboxymethyl cellulose (CMC) is produced commercially in a two stage process consisting of a mercerization stage in which the pulp is treated with alkali in a water alcohol solution and a second etherification stage whereby monochloro-acetic acid is added to the pulp slurry. In this study, the influence of the conditions of an extended mercerization stage was evaluated on the etherification stage concerning the degree of substitution (DS) and the filterability of the resulting CMC. The parameters studied were: (1) the ratio of cellulose I and cellulose II in the original pulp, (2) the concentration of alkali, (3) the temperature and (4) the retention time in the mercerization stage. The DS results indicate that the NaOH concentration in the mercerization stage is the most important among the parameters studied. When the NaOH concentration in the mercerization stage was high (27.5%), cellulose II showed a lower reactivity than cellulose I with respect to the DS obtained in the resulting CMC. The results from the filtration ability of CMC water solutions are interpreted that the amount of cellulose II in the original pulp and the temperature has a negative influence, while the NaOH concentration in the mercerization stage has a positive influence on the filtration ability. Retention time between 1 h–48 h in the mercerization stage had no effect on the DS or the filtration value. The filtration ability was assumed to be highly influenced by the presence of poorly reacted cellulose segments. The CMC samples with the lowest filtration ability at a given DS can be assumed to have the highest degree of unevenly substituted segments.

The adhesive properties of Fe(110)/Fe(110) and Fe3C(001)/Fe(110) countersurfaces have been investigated by using classical molecular dynamics simulations. The simulation results show that Fe3C/Fe exhibits a relatively lower adhesion compared to the Fe/Fe. Additionally, the temperature dependence of the adhesive properties between 300–700 K has been examined. The results demonstrate that, with increasing the temperature, the values of the adhesion force and the work of adhesion continuously decrease in the case of Fe3C/Fe; they initially slightly increase up to 500 K then decrease in the case of Fe/Fe. Furthermore, the effect of lattice coherency between Fe/Fe has been examined and found to slightly reduce the adhesion. These results explain how carbides improve galling resistance of tool steel observed during dry sliding. 

Using embedded atom method potential, extensive large-scale molecular dynamics (MD) simulations of nanoindentation/nanoscratching of nanocrystalline (nc) iron have been carried out to explore grain size dependence of wear response. MD results show no clear dependence of the frictional and normal forces on the grain size, and the single-crystal (sc) iron has higher frictional and normal force compared to nc-samples. For all samples, the dislocation- mediated mechanism is the primary cause of plastic deformation in both nanoindentation/nanoscratch. However, secondary cooperative mechanisms are varied significantly according to grain size. Pileup formation was observed in the front of and sideways of the tool, and they exhibit strong dependence on grain orientation rather than grain size. Tip size has significant impact on nanoscratch characteristics; both frictional and normal forces monotonically increase as tip radii increase, while the friction coefficient value drops by about 38%. Additionally, the increase in scratch depth leads to an increase in frictional and normal forces as well as friction coefficient. To elucidate the relevance of indentation/scratch results with mechanical properties, uniaxial tensile test was performed for nc-samples, and the result indicates the existence of both the regular and inverse Hall-Petch relations at critical grain size of 110.9 angstrom. The present results suggest that indentation/scratch hardness has no apparent correlation with the mechanical properties of the substrate, whereas the plastic deformation has.

In the present work, molecular dynamics simulations were used to investigate the impact of the tool microstructure on the wear behavior of ferrite workpiece during nanoscratching. The tool microstructure was modified by varying the carbide (cementite) contents. The simulation results show that dislocations are the primary mechanism for plastic deformation of the workpiece material. It is found that total dislocation length varies significantly depending on the carbide content in the tool. Furthermore, other tribological phenomena were also observed to depend on the carbide contents. For example, the average value of frictional forces decreased while the normal force increases with increasing carbide contents, and hence the friction coefficient was decreased. Additionally, the shape and size of lateral and frontal pileups are lowered. The structural analysis of the pileup region reveals the loss of long range order and start of amorphisation. The temperature distribution of the pileup regions showed an increase of the pileup temperature when carbide is added into tool. The wear volume is considerably reduced when the carbide content increases. The average scratch hardness was found to decrease and the result was analyzed with the theoretical Taylor hardening model.

- In sheet metal forming operations, adhesive wear is the main causeof tool damage as sheet material is transferred to the tool surface during the forming operation. Means of reducing adhesive wear are of high interest for the metal forming industry.In the present work, molecular dynamics simulations were used to investigate influence of alloying iron with vanadium on adhesive properties in contact with iron. The results showed that adhesion, quantified by the work of adhesion, decreased as the vanadium content increased. Highest reduction was obtained for 10 at.% vanadium which corresponded to a decrease in adhesive work of approximately 10%.

Molecular dynamics simulations are applied to investigate the wear/friction behavior of a ferrite/austenite iron bi-crystal, as a model system for duplex stainless steels. The plasticity of the ferrite phase is dominated by dislocations while both dislocations and stacking faults are the primary cause of plastic deformation of the austenite phase. Interestingly, the responses of tribological parameters vary depending on the scratch direction. For instance, the scratch hardness is increased by about 46% whereas the friction coefficient is reduced by about 22% when scratch starts from austenite to ferrite. At the interface, a local softening/hardening occurs because of dislocation-interface interaction. The present results demonstrate that martensitic phase transformation is responsible for experimentally observed high amount of ferrite of the pile-up.