Today most ice rinks in Sweden use secondary refrigeration systems with a solution of calcium chloride and water as secondary refrigerant. Due to the large amount of energy such a system uses more efficient systems would be desired.An earlier study concluded in the possibilities of using carbon dioxide as secondary refrigerant with copper tubes as the loops in the ice rink. Since then 3 ice rink refrigeration systems has been built with carbon dioxide in copper tubes. Excluding the ones being direct involved in those projects there is still very little knowledge about how these system works. This study has been made primarily with the aim of adding to the knowledge concerning availability and cost and secondary to look at possibilities for improvement.A comparison between systems with carbon dioxide, calcium chloride respective ammonium solved in water has been made by using Decision Matrix.

The ÅF Group is a leader in technical consulting, with expertise founded on more than a century of experience. They offer highly qualified services and solutions for industrial processes, infrastructure projects and the development of products and IT systems. They are also one of the leading names in certified third-party testing and inspection work.Today the ÅF Group has approximately 4,000 employees. Their base is in Europe, but their business and clients are found all over the world.A part of ÅF-Engineerings business is programming different automation systems to clients. Another part is support in both telephone and personal visits.Because the number of clients is high and the flora of different automation systems is big the consequence is that the employees must have access to many licenses with programming tools.

The amount of web APIs that are open to the public is increasing fast. Both the free web APIs as well as the ones that cost money to access. Both bigger and smaller organizations, professional and non-professional developers use these web APIs to add value to their systems or use it to create new applications. This is an area study where alot of research has been done in the last few years. In spite of this there are still no user-centered evaluation methods for web APIs.

The aim with this study is to explore if and how linguistic learning takes places when four pairs ofstudents in grade one writes on the computer. Observations of eight students took place duringtwelve lessons to investigate what happened during their writing processes. This study isimportant because students? computer writing is a relatively new phenomenon in the Swedishprimary school.It is clear that the peer collaboration creates a complex interaction that becomes the platform, andalso the prerequisite, for successful language training. The method can clearly give students profitsin their linguistic development.

Ocean Thermal Energy Conversion, OTEC, is a sustainable energy conversion technology that is not yet commercialized. OTEC is a technology that utilizes the temperature difference in oceans between the warm surface water and the cold water at 1 000 m depth to run a Rankine Cycle. This technology can produce electricity and provide synergies like fresh water, air conditioning and aquaculture. A simulation program for three alternative OTEC systems has been created in order to decide which OTEC system is most profitable; closed, open or hybrid system. In this simulation a production cost analysis is performed in order to investigate and decide which one of the three systems that has the lowest production cost. The production cost analysis also analyzes if the profitability is affected by the size of the facility. After these analyzes, the most profitable of the three different OTEC-systems is expanded by an installation of solar collectors in order to see if the thermal efficiency is improved. The result shows that the most profitable system varies with the size of the facility.

In inhalation anesthesia life-support systems are used to provide gases to the patient and to monitor important parameters. These systems are used in dynamic and stressful situations where the information-load on the operators often is significant. This thesis presents a design concept of an anesthetic system. The design goal has been to keep the information-load on the operator low with the objective to minimize confusion and error.A number of contextual inquiries were made in the operating room during surgery at four hospitals in Sweden. The goal was to understand the actual use-situations when anesthetic systems are employed.

Modern IT systems tend to become more and more complex, while the number of active systems in companies increases. Furthermore, the number of security-related incidents is at an all-time high. These new conditions impose new demands on organizations. For example, it is no longer possible to manually collect and examine the systems log messages.The purpose of this thesis has been to make a comprehensive study of solutions for automated collecting and managing of log messages, analyze the Swedish Armed Forces specification for solutions for central log collection and management, and evaluating exis- ting solutions. The work consisted primarily of literature studies and evaluations of two of the Swedish Armed Forces of selected products: NetIQ Security Manager and Splunk.

The purpose of this literature review was to investigate how the rearing systems influence the behaviour of dairy calves. Calves are social animals that form groups within the herd where play and social licking between calves are important social activities. Suckling is a complex behaviour and essential for the calf's survival. In the modern rearing systems the calf is usually separated from its mother soon after birth. Calves are then kept in individual pens, group pens or, more rarely, with a foster cow.

When different type of programs are developed one wants to make these adjustable to future changes and requirements. It must be done a good design of the program from the beginning to make it possible to continue development of it without having to redo big parts of it to high costs. In the area of object orientation there are design pattern, which can be used to design systems that can be adjusted to new changes in an easier way. I have in this thesis chosen to take a closer look at how to design a program that sends SMS to cell phones through a system of an operator. One requirement on the program is that it has to be possible to change what operator to send though in an easy way.

Sweden is considered to have one of the world's highest animal welfare standards in agriculture. Despite this, there are shortcomings in animal husbandry. One example is overcrowding, which is a way to increase stock size without making costly investments in the buildings. It can be carried out systematically to increase profitability or due to, for example uneven calving during the year. The European Commission criticizes the fact that stocking density is not controlled under Swedish welfare inspections.

This master thesis examines the development of the two earlier independent IR protocols Z39.50 and SR (Search and Retrieve, ISO 10162/10163), now Z39.50/SR, from the beginning of the 80s to 1996 and their functionality in the client/server environment.Z39.50 applications in library systems will allow easy access to information regardless of platform or location. The use of Z39.50 will create a new user environment. Almost all the library systems of the market support the Z39.50 and surprisingly the use of it in Sweden lied on a very low leve! in 1996. This thesis was followed-up by an interview and a questioner among the Swedish Z39.50 users. They could see a huge potential of development concerning the future IR process.

Attacker och intrång på webbservrar är idag vanligt förekommande. Webben gör det lätt för hackare, knäckare och andra inkräktare att hitta sårbara servrar, och det finns gott om tips att hämta för den som vill lära sig hur man gör intrång. Det finns ett flertal olika intrångsmetoder som utnyttjar olika typer av svagheter i datorsystemen. Denna uppsats inriktar sig på svagheter i webbplatsernas serverskriptsystem, dess skriptkod och konfiguration. Syftet är att undersöka huruvida intrång kan göras med endast en webbläsare via webbplatsens offentliga webbsidor. Genom att kombinera tre olika metoder - litteraturundersökning, en enkät och ett experiment - undersöker uppsatsen hur serverskriptintrång fungerar.

The background to this thesis is the impact of information technology on libraries and librarywork. If information technology causes changes in the tasks and work of libraries, thenlibrary organisations should also change. It is important to engage and inform the staff if suchchanges are to succeed. This thesis investigates the notions about library tasks and librarywork among eight "middle-managers" at Linkopings universitetsbibliotek.The investigation is based on interviews and then analysed with Soft Systems Methodology(SSM). By identifying the "Weltanschauung" of the staff, the thesis tries to create logicallydesirable and culturally feasible models of systems relevant to the situation at Linkopingsuniversitetsbibliotek.

The aim of this paper is to find an algorithm to establish and maintain a virtual enclosure around a mobile unit. The area may take any form and should be scalable up to and including national borders. The enclosure is managed on the mobile unit. The target system is Android. Smartphones, tablets and more recently, cameras is examples of mobile units. A modern mobile unit is part of a computer network.

The implementation of large IT-systems is a complex area where many aspects have to be taken into account.KSU, Kärnkraftssäkerhet och Utbildning AB, is a small company in the Vattenfall group that is increasingly being urged to implement SAP, one of the largest ERP-systems on the market. Vattenfalls purpose with SAP is to centralize certain processes within economy that are common to all the companies in the group, this to gain benefits with economics of scale. However, KSU is not convinced that SAP is a suitable system and that the common processes apply to them.The purpose of this degree project is to investigate if SAP is a suitable system and if KSU will benefit from a transition to SAP. Three perspectives were applied to further specify important areas of the main question. From a technical point of view KSU:s demands on a system was mapped against SAP.