Machine vision for the automatic classification of images acquired from Non-destructive tests

This project is based on Artificial Intelligence (A.I) and Digital Image processing (I.P) for automatic condition monitoring of sleepers in the railway track. Rail inspection is a very important task in railway maintenance for traffic safety issues and in preventing dangerous situations. Monitoring railway track infrastructure is an important aspect in which the periodical inspection of rail rolling plane is required.Up to the present days the inspection of the railroad is operated manually by trained personnel. A human operator walks along the railway track searching for sleeper anomalies. This monitoring way is not more acceptable for its slowness and subjectivity. Hence, it is desired to automate such intuitive human skills for the development of more robust and reliable testing methods. Images of wooden sleepers have been used as data for my project. The aim of this project is to present a vision based technique for inspecting railway sleepers (wooden planks under the railway track) by automatic interpretation of Non Destructive Test (NDT) data using A.I. techniques in determining the results of inspection.

Energy Analysis within Industrial Hydraulics and Correspondent Solar PV System Design

Energy efficiency and renewable energy use are two main priorities leading to industrial sustainability nowadays according to European Steel Technology Platform (ESTP). Modernization efforts can be done by industries to improve energy consumptions of the production lines. These days, steel making industrial applications are energy and emission intensive. It was estimated that over the past years, energy consumption and corresponding CO2 generation has increased steadily reaching approximately 338.15 parts per million in august 2010 [1]. These kinds of facts and statistics have introduced a lot of room for improvement in energy efficiency for industrial applications through modernization and use of renewable energy sources such as solar Photovoltaic Systems (PV).The purpose of this thesis work is to make a preliminary design and simulation of the solar photovoltaic system which would attempt to cover the energy demand of the initial part of the pickling line hydraulic system at the SSAB steel plant. For this purpose, the energy consumptions of this hydraulic system would be studied and evaluated and a general analysis of the hydraulic and control components performance would be done which would yield a proper set of guidelines contributing towards future energy savings. The results of the energy efficiency analysis showed that the initial part of the pickling line hydraulic system worked with a low efficiency of 3.3%. Results of general analysis showed that hydraulic accumulators of 650 liter size should be used by the initial part pickling line system in combination with a one pump delivery of 100 l/min. Based on this, one PV system can deliver energy to an AC motor-pump set covering 17.6% of total energy and another PV system can supply a DC hydraulic pump substituting 26.7% of the demand. The first system used 290 m2 area of the roof and was sized as 40 kWp, the second used 109 m2 and was sized as 15.2 kWp. It was concluded that the reason for the low efficiency was the oversized design of the system. Incremental modernization efforts could help to improve the hydraulic system energy efficiency and make the design of the solar photovoltaic system realistically possible. Two types of PV systems where analyzed in the thesis work. A method was found calculating the load simulation sequence based on the energy efficiency studies to help in the PV system simulations. Hydraulic accumulators integrated into the pickling line worked as energy storage when being charged by the PV system as well.

A study of slag corrosion of oxides and oxide-carbon refractories during steel refining

The use of ceramic material as refractories in the manufacturing industry is a common practice worldwide. During usage, for example in the production of steel, these materials do experience severe working conditions including high temperatures, low pressures and corrosive environments. This results in lowered service lives and high consumptions of these materials. This, in turn, affects the productivity of the whole steel plant and thereby the cost. In order to investigate how the service life can be improved, studies have been carried out for refractories used in the inner lining of the steel ladles. More specifically, from the slag zone, where the corrosion is most severe. By combining thermodynamic simulations, plant trails and post-mortem studies of the refractories after service, vital information about the behaviour of the slagline refractories during steel refining and the causes of the accelerated wear in this ladle area has been achieved. The results from these studies show that the wear of the slagline refractories of the ladle is initiated at the preheating station, through reduction-oxidation reactions. The degree of the decarburization process is mostly dependent on the preheating fuel or the environment. For refractories without antioxidants, refractory decarburization is slower when coal gas is used in ladle preheating than when a mixture of oil and air is used. In addition, ladle preheating of the refractories without antioxidants leads to direct wear of the slagline refractories. This is due to the total loss of the matrix strength, which results in a sand-like product. Thermal chemical changes that take place in the slagline refractories are due to the MgO-C reaction as well as the formation of liquid phases from impurity oxides. In addition, the decrease in the system pressure during steel refining makes the MgO-C reaction take place at the steel refining temperatures. This reduces the refractory’s resistance to corrosion. This is a serious problem for both the magnesia-carbon and dolomite-carbon refractories. The studies of the reactions between the slagline refractories and the different slag compositions showed that slags rich in iron oxide lead mostly to the oxidation of carbon/graphite in the carbon-containing refractories. This leads to an increased porosity and wettability and therefore an enhanced penetration of slag into the refractory structure. If the slag contains high contents of alumina and or silica (such as the steel refining slag), reactions between the slag components and the dolomite-carbon refractory are promoted. This leads to the formation of low-temperature melting phases such as calcium-aluminates and silicates. The state of these reaction products during steel refining leads to an accelerated wear of the dolomite-carbon refractory. The main products of the reactions between the magnesia-carbon refractory and the steel refining slag are MgAl2O4 spinels, and calcium-aluminates, and silicates. Due to the good refractory properties of MgAl2O4 spinels, the slag corrosion resistance of the magnesiacarbon refractory is promoted.

Letters, authority and secrecy : The case of Karagwe in Tanzania

This paper aims to show how letters, as a genre of literacy, are used in Karagwe in Tanzania, in relation to authority and secrecy. It is shown that literacy, in the form of letters, plays an important role in the negotiation of authority. Authorities as well as ordinary people use letters according to official norms to claim or manifest authority, while grassroots forms of literacy, dominated forms, are used to resist authorities. Through secret messages and letters people find opportunities to resist that are less dangerous than open rebellion, although the effects may be limited because of the secrecy. It is also shown how children are socialized into this pattern of secrecies through literacy as they are used as messengers. When delivering secret letters and messages, they may be said to exercise a passive voice through literacy.

Sportdykaren och den ”rätta” manligheten

The Scuba Diver and “Proper” Masculinity Based on ethnographic fieldwork on scuba diving, this article explores the social homogeneity characterizing this specific sport activity regarding questions on how deviance is treated within a group and on what grounds. The consequences of the dangerous context on the Dyad (one is always diving together with a “Buddy”) in which the activity is performed, is analysed with the help of Georg Simmel (1950) and Erving Goffman (1967). The loyalty of the diving partner (the Buddy) towards the “right attitude” which governs the activity may be turned against the scuba diver who does not adapt. The Buddy is transformed from a friend into an opponent, who, by spreading anecdotes or rumours, questions the character of the scuba diver, which eventually may exclude him or her from the activity. The article discusses how the “right attitude” in scuba diving is related to the so-called predominant masculine identity (Connell 1995) in a Swedish context.

Projekt Norrliden : Om småstadspressens etnifiering och genderisering av en förort

The Norrliden project. Genderisation and ethnification of a low status residential area in the local press Media often contributes to segregation by constructing low status residential areas as “different” from what is “normal” and “Swedish”. Research into media representations of these residential areas often focuses big city contexts. Furthermore, research tends to be preoccupied with the construction of ethnic differences, paying little attention to the relationship between construction processes of gender and ethnicity. This article is a critical analysis of how the local daily newspapers in a medium sized town, Kalmar, construct stereotypes of immigrants and gendered identities in the low status residential area Norrliden. Two newspapers were studied in search for articles related to the area, published during the year 2005. Despite the newspapers’ claim that they want to contribute to a more nuanced and less stereotyped image of the residential area the consequences of their work seem to be the opposite. The representation sof the area are coded with stereotypes suggesting that the area is unsafe and dangerous and that the people who live there are motivated by affect and emotions rather than by successful socialisation. These representations are also characterised by notions of ethnicity and gender, as well as class. Norrliden is described as an area in need of change and improvement, as an unfinished project dependent upon aid from the outside. A reading of the 2005 media representations of Norrliden exposes an example of “symbolic violence” in that texts and photographs repeatedly degrade the area and its inhabitants.

The effects of attitudes and personality traits on mode choice

We hypothesise that differences in people's attitudes and personality traits lead them to attribute varying importance to environmental considerations, safety, comfort, convenience and flexibility. Differences in personality traits call be revealed not only in the individuals' choice of transport, but also in other actions of their everyday lives-such as how much they recycle, whether they take precautions or avoid dangerous pursuits. Conditioning on a set of exogenous individual characteristics, we use indicators of attitudes and personality traits to form latent variables for inclusion in an, otherwise standard, discrete mode choice model. With a sample of Swedish commuters, we find that both attitudes towards flexibility and comfort, as well as being pro-environmentally inclined, influence the individual's choice of mode. Although modal time and cost still are important, it follows that there are other ways, apart from economic incentives, to attract individuals to the, from society's perspective, desirable public modes of transport. Our results should provide useful information to policy-makers and transportation planners developing sustainable transportation systems.