Validation and application of a multiparameter model for the densification of biochar

Densification is generally addressed to improve both the mechanical properties and the energy density of biomass feedstock. For such reason, it can also be used for biochar. However, the investigation of larger scales production by smaller academic equipment is not straightforward. It is therefore relevant to have access to models to facilitate a reliable comparison between the two different scales. In 2011, Holm et al. provided and validated a multiparameter model for analyzing industrial wood pelleting by a lab-scale single pellet press1. In 2017, the model was further verified for torrefied wood pelleting by Puig-Arnavat et al2. The intention of the authors of the present study was to prove the suitability of this model for pyrolyzed wood. It may help to understand how the densification process can be optimized at larger scales, especially regarding the forces that act through the pelleting channel, which are often cause of damages. Theoretically the model links the pelleting pressure , that the pellets undergo when ejected out of the channel, to the compression ratio c = x / 2r (where x is the length of the channel and r is its radius) 1. This is described by the equation: Please click Additional Files below to see the full abstract

A study of densified biochar as carbon source in the silicon and ferrosilicon production

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Avstivningsevnen til sammensatte veggelementer av limtre

In recent years, the use of timber in large structures has increased, partly because of its good environmental properties. One wood-based product that has emerged is the HBE-element, which practically is a 580mm high glulam beam. By stacking these on top of each other and screwing them into columns, HBE-elements can be used to build wall structures. It is, however, unknown how to document the bracing effect of such walls if they are to maintain the global stability of a building. In order to achieve global stability, a structure needs to resist horizontal loads and lead them to the foundation. This master’s thesis aims to investigate what bracing effect can be obtained when using HBE-elements in walls, as well as how to document this effect. FEM-analyzes and other analytical calculations have been conducted, as well as literature studies. Results revealed that a bracing effect can be obtained from HBE-elements if the connections to the columns are moment stiff, as this activates the bending stiffness of the elements. Such connections proved to be difficult to obtain using screws. Other mechanisms with a bracing effect were caused by contact forces between the elements, but the contribution from these mechanisms was either insignificantly small or too uncertain to be used for documentation

Avstivningsevnen til sammensatte veggelementer av limtre

In recent years, the use of timber in large structures has increased, partly because of its good environmental properties. One wood-based product that has emerged is the HBE-element, which practically is a 580mm high glulam beam. By stacking these on top of each other and screwing them into columns, HBE-elements can be used to build wall structures. It is, however, unknown how to document the bracing effect of such walls if they are to maintain the global stability of a building. In order to achieve global stability, a structure needs to resist horizontal loads and lead them to the foundation. This master’s thesis aims to investigate what bracing effect can be obtained when using HBE-elements in walls, as well as how to document this effect. FEM-analyzes and other analytical calculations have been conducted, as well as literature studies. Results revealed that a bracing effect can be obtained from HBE-elements if the connections to the columns are moment stiff, as this activates the bending stiffness of the elements. Such connections proved to be difficult to obtain using screws. Other mechanisms with a bracing effect were caused by contact forces between the elements, but the contribution from these mechanisms was either insignificantly small or too uncertain to be used for documentation

Improved language modeling by unsupervised acquisition of structure

The perplexity of corpora is typically reduced by more than 30% compared to advanced n-gram models by a new method for the unsupervised acquisition of structural text models. This method is based on new algorithms for the classification of words and phrases from context and on new sequence finding procedures. These procedures are designed to work fast and accurately on small and large corpora. They are iterated to build a structural model of a corpus. The structural model can be applied to recalculate the scores of a speech recognizer and improves the word accuracy. Further applications such as preprocessing for neural networks and (hidden) markov models in language processing, which exploit the structure finding capabilities of this model, are proposed. 1. CLASSIFYING ENTITIES FROM CONTEXT VIA ITERATED REESTIMATION The most widespread criterion for the classification of words and phrases in linguistics is the replacement test, which states, that two linguistic entities are the same..

A Statoil Project : merger, agents and power

This master thesis investigates a case study of the experiences of eighteen Statoil project workers in terms of working in a large scale project as a unit in relation to other parts of the organization. Moreover, contextual conditions influence the experiences of the informants, such as the Statoil and Hydro merger of 2007. The informants are of both ex-Hydro and ex-Statoil background. The data is collected by qualitative interviews of each of the informants in collaboration with two other students of organizational psychology. The interviews were conducted by an open interview guide. The research questions emerged as a result of the analysis of the collected data from the interviews. Relevant theoretical background for the analysis of the data is first of all Mintzberg's (1983) structures in five of organization. Mintzberg's theory is used to describe the various agents of the case, such as the various forms of structuring in the organization that the project informants have to relate to in their work. Hernes' (1975) model of power is further described and used to discuss what characterizes these various relations in terms of interests, dependency and control. Finally, Martins' (2002) perspectives on organizational culture and other perspectives on the merger of organizations are elaborated. The theory on organizational culture and mergers is relevant in order to discuss the various perceptions and experiences of the informants, which are also characterized by conflicting interest. The introduction and chapter four elaborates on some of the organizational differences of the former Hydro and Statoil organizations which were investigated in a previous study on the merger. The analysis investigates three main research questions evolved around the informants. experiences of the project work. The first research question investigates if the informants still are concerned about the merger. Furthermore, the analysis seeks to disclose if there are any direct or indirect influences of the merger expressed by the informants. Finally, the analysis investigates given the tensions, what are the effects of the informant's organizational background. The merger as a concern emerged out the interviews of the informants. First of all they expressed different views on the structure of the organization and the project in relation to their previous organizational background. Mostly the ex-Hydro informants present concern on the organizational structure and system, which appears to be related to the fact the much of the present organizational system are parts kept from ex-Statoil. In relation to this, there appears to be some indirect and direct influences of the merger, such as collegiums and networks. Those informants of an ex-Statoil background express to have more of a network to relate to in other parts of the organization, something which seems also related to how the present system is in many ways parts from the former Statoil organization. The project is an organizational unit dependent and related to many other organizational parts, such as the operative organization, support units, governing documents and the organizational values and strategies. Hence, these relations are characterized by interests, control and dependency. However, how these relations are experienced do also differ between the informants, and particularly between ex-Hydro and ex-Statoil informants. Nevertheless, the informants do not present these conflicts of interests as social identities or in "us versus "them" like manners, which is more typical in merged organizations. The conflicts of interests are rather aspects which emerge when the informants express their concerns on the way of doing things in the project and in terms of what they express as most appropriate. The conflicts of interests or diverging perspectives on the organizational system, such as the governing documents and values seem rooted in a cultural difference of perceptions, expectations and habits. Especially, there appears to be a conflict in terms of the focuses and values, such as safety versus efficiency and cost. Thus, some of the diverging perspectives on the organizational culture seem also to reinforce each other as they are perceived as contradictory

Environmental Assessment of Bus Transport in the Trondheim Region - Evaluation of Relevant Bus and Fuel Technologies and their Potential for Mitigating Emissions from Passenger Transportation

The overall aim of this thesis is to assess the carbon footprint of transport by bus in the Trondheim region. Bus transportation is promoted as a strategy both to combat local pollution problems in urban areas and to mitigate global greenhouse gas emissions from passenger transport. Still, the environmental impacts of bus transport have received fairly limited attention in research. The environmental impacts of bus transport are calculated through life cycle assessment. A model is developed for the bus and fuel technologies included in the bus fleet in Trondheim. The analysis is limited to city buses, which in Trondheim comprise hybrid, natural gas and biodiesel buses. All life cycle phases of bus transport are included. The environmental impacts are measured by the impact categories climate change, fossil depletion, eutrophication, acidification, particulate matter formation and land occupation. The thesis draws on previous LCA studies of cars to compare GHG emissions per passenger kilometer between different bus routes. A comparison is also made for work travels in Trondheim to investigate the effect of climate mitigation measures implemented the later years. The results shows that the hybrid bus performs best in terms of greenhouse gas emissions and fossil depletion per vehicle kilometer, while the natural gas bus had lower emissions in the remaining five impact categories. By switching to biogas, it is found that this bus technology achieved similar impacts to the hybrid bus also in the two former categories. Looking at specific bus routes, it is found that buses with 5-10 passengers had lower GHG emissions than a car with 1-2 persons, depending on the bus technology. Both technology advancements and modal shifts are promoted by national authorities as ways to reduce the overall emissions from passenger transportation. Comparing the carbon footprint of work travels between 2009 and 2014 shows that the modal shift had the largest mitigation effect. The largest reduction potential per vehicle kilometer is identified in the operation phase of the buses. With the use of biofuels, these emissions can be reduced significantly. The mitigation potential is however dependent on the type of biofuels, thus policy makers should be aware of problem shifting

Keeping the peace together? Joint Russian-Western peace operations in the Commonwealth of Independent States

The purpose of this report is to discuss the conditions for future multinational peace operations in the Commonwealth of Independent States, including both Russian and Western forces. The aim and scope of this study are based on a positive attitude to challenges in general, in other words, a will to see opportunities and solutions instead of obstacles and insolvable problems. Problem: What are the possible options for multinational peace operations including Russian and Western forces in the Commonwealth of Independent States? I will focus on investigating possibilities for CPOs in the CIS area. Content: The report will consist of an initial discussion focusing on various Russian approaches that influence thinking on combined peace operations. The focus on Russia is an inevitable consequence of my West/NATO origin, but in order to give a more balanced view of the problem it will also be necessary to look at some other factors influencing this potential co-operation. Further, I will discuss three generic options for combined peace operations in the Commonwealth of Independent States. The main goal of this study is a detailed discussion of various possible scenarios for future Russian-Western co-operation in the field of peace-keeping on the territory of the former Soviet Union. In order to place the topic in a proper context the author takes a closer look at various political, mental, historical and not least purely technical determinants limiting the potential scope of the joint peace-keeping. The study contains a detailed analysis of international (UN), Western (NATO, Canada) and Russian peace-keeping terminology. It also discusses the importance and relevance of various international frameworks determining the field, the scope and the geographical dimension of the potential Russian-Western co-operation, as well as the practical experience from the joint peace-keeping missions in the former Yugoslavia. The study gives a good insight in the history and practice of joint Russian-Western peacekeeping efforts. It also outlines and analyses various practical and political challenges linked with development of this relatively new and still challenging field of co-operation between Russia and the West. As such, it is relevant for both theoreticians of peace-keeping and for those who work with peace-keeping in the field

Rådgivning - et mulighetsrom: En kvalitativ studie av rådgiveres opplevelse av egen kreativitet i møte med klient

The topic of this study is creativity within counseling. The purpose has been to look closer at how counselors experience themselves as creative in meeting with clients. The term counselor refers to a person who works with non-clinical clients, but who supports individuals in an inquiry into a problem, as in career counseling. The methodological basis for this study has been a qualitative approach, inspired by phenomenological research. The data gathering consisted of individual interviews with four informants. In the analysis features from The Constant Comparative Method have been used. The results from the analysis consist of five main categories or themes: ”Presence”,”Looking for possibilities”, ” Variations in approach and method”, ”Experiences that inspire or challenge oneself”, and ”Persons in relation”. Furthermore, ”To use oneself” is a subcategory of ”Presence”. The study draws mainly on theories by Joseph Zinker, Rollo May, Carl Rogers and Allgood og Kvalsund. Additional theorists are presented within the paper. Theory from the Gestalt orientation is central. The study points to how counselors’ creativity is an interesting and important theme to further investigate, a theme that has seldom been explored in scientific literature. Central results are how counselors experience their creativity as closely interchanged with the meeting with a client, and how the nature of the meeting is essential. Furthermore, the counselor’s attitudes emerge as an important theme, in which the ability to create an approach or method in meeting with the client is important. Additionally, presence is seen as a key to opening up one’s own creativity