Deltack, Blanket Study

There are two objectives of this study.The first one was to study the new instrument Deltack fromPrufbau, and with the new knowledge, study the interaction between blanket and paper.Deltack is a new instrument to measure the ink splitting force. Blankets from an earlier study doneby GATF have been montered on 12 different Deltack print forms and those have together with Deltackbeen the base for this project.This study together with information from GATF’s study shows that some of the blankets have ahigher capability to adsorb ink. Those blankets generate a sharper shape on the force curve, they havea lower dot gain, but they print not as good solid.

Combined solar and pellet heating systems for single-family houses : How to achieve decreased electricity usage, increased system efficiency and increased solar gains

In Sweden, there are about 0.5 million single-family houses that are heated by electricity alone, and rising electricity costs force the conversion to other heating sources such as heat pumps and wood pellet heating systems. Pellet heating systems for single-family houses are currently a strongly growing market. Future lack of wood fuels is possible even in Sweden, and combining wood pellet heating with solar heating will help to save the bio-fuel resources. The objectives of this thesis are to investigate how the electrically heated single-family houses can be converted to pellet and solar heating systems, and how the annual efficiency and solar gains can be increased in such systems. The possible reduction of CO-emissions by combining pellet heating with solar heating has also been investigated. Systems with pellet stoves (both with and without a water jacket), pellet boilers and solar heating have been simulated. Different system concepts have been compared in order to investigate the most promising solutions. Modifications in system design and control strategies have been carried out in order to increase the system efficiency and the solar gains. Possibilities for increasing the solar gains have been limited to investigation of DHW-units for hot water production and the use of hot water for heating of dishwashers and washing machines via a heat exchanger instead of electricity (heat-fed appliances). Computer models of pellet stoves, boilers, DHW-units and heat-fed appliances have been developed and the parameters for the models have been identified from measurements on real components. The conformity between the models and the measurements has been checked. The systems with wood pellet stoves have been simulated in three different multi-zone buildings, simulated in detail with heat distribution through door openings between the zones. For the other simulations, either a single-zone house model or a load file has been used. Simulations were carried out for Stockholm, Sweden, but for the simulations with heat-fed machines also for Miami, USA. The foremost result of this thesis is the increased understanding of the dynamic operation of combined pellet and solar heating systems for single-family houses. The results show that electricity savings and annual system efficiency is strongly affected by the system design and the control strategy. Large reductions in pellet consumption are possible by combining pellet boilers with solar heating (a reduction larger than the solar gains if the system is properly designed). In addition, large reductions in carbon monoxide emissions are possible. To achieve these reductions it is required that the hot water production and the connection of the radiator circuit is moved to a well insulated, solar heated buffer store so that the boiler can be turned off during the periods when the solar collectors cover the heating demand. The amount of electricity replaced using systems with pellet stoves is very dependant on the house plan, the system design, if internal doors are open or closed and the comfort requirements. Proper system design and control strategies are crucial to obtain high electricity savings and high comfort with pellet stove systems. The investigated technologies for increasing the solar gains (DHW-units and heat-fed appliances) significantly increase the solar gains, but for the heat-fed appliances the market introduction is difficult due to the limited financial savings and the need for a new heat distribution system. The applications closest to market introduction could be for communal laundries and for use in sunny climates where the dominating part of the heat can be covered by solar heating. The DHW-unit is economical but competes with the internal finned-tube heat exchanger which is the totally dominating technology for hot water preparation in solar combisystems for single-family houses.

Study of ink mileage and print through

This report contains a study of ink mileage, show through and other mechanisms that are important inthe study of substrate printability. These mechanisms have an impact on how ink will react on paper.To develop a substrate that provides good ink mileage and less show through requires a closer studyof substrate characteristics.Substrates with different characteristics have been tested by a technique developed for this projectcalled modified ink mileage. Ink mileage is a method to determine how much ink that is required for acertain target density. Further tests on the same substrates have been done including print throughand surface roughness measurements.

Wear of coated and uncoated PCBN cutting tool used in turning and milling

This licentiate thesis has the main focus on evaluation of the wear of coated and uncoated polycrystalline cubic boron nitride cutting tool used in cutting operations against hardened steel. And to exam the surface finish and integrity of the work material used. Harder work material, higher cutting speed and cost reductions result in the development of harder and more wear resistance cutting tools. Although PCBN cutting tools have been used in over 30 years, little work have been done on PVD coated PCBN cutting tools. Therefore hard turning and hard milling experiments with PVD coated and uncoated cutting tools have been performed and evaluated. The coatings used in the present study are TiSiN and TiAlN. The wear scar and surface integrity have been examined with help of several different characterization techniques, for example scanning electron microscopy and Auger electron spectroscopy.   The results showed that the PCBN cutting tools used displayed crater wear, flank wear and edge micro chipping. While the influence of the coating on the crater and flank wear was very small and the coating showed a high tendency to spalling. Scratch testing of coated PCBN showed that, the TiAlN coating resulted in major adhesive fractures. This displays the importance of understanding the effect of different types of lapping/grinding processes in the pre-treatment of hard and super hard substrate materials and the amount and type of damage that they can create. For the cutting tools used in turning, patches of a adhered layer, mainly consisting of FexOy were shown at both the crater and flank. And for the cutting tools used in milling a tribofilm consisting of SixOy covered the crater. A combination of tribochemical reactions, adhesive wear and mild abrasive wear is believed to control the flank and crater wear of the PCBN cutting tools. On a microscopic scale the difference phases of the PCBN cutting tool used in turning showed different wear characteristics. The machined surface of the work material showed a smooth surface with a Ra-value in the range of 100-200 nm for the turned surface and 100-150 nm for the milled surface. With increasing crater and flank wear in combination with edge chipping the machined surface becomes rougher and showed a higher Ra-value. For the cutting tools used in milling the tendency to micro edge chipping was significant higher when milling the tools steels showing a higher hard phase content and a lower heat conductivity resulting in higher mechanical and thermal stresses at the cutting edge.

Life situations and the care burden for stroke pa­tients and their informal caregivers in a prospective cohort study

Background. The purpose of this study was to analyse whether the parallel life situation between stroke patients and their informal caregivers (dyads) shown in cross-sectional studies prevails also in a longitudinal perspective. Methods. A total of 377 Swedish stroke patients, aged ‡65 years, and their 268 informal caregivers were followed from hospital admission and one year on. Analyses were based on patient interviews, functional ability (MMSE) score, Nottingham Health Profile (NHP) score, Hospital Anxiety and Depression (HAD) score, self-rated health score, and the Gothenburg Quality of Life (GQL) activity score. Similar information was obtained by postal questionnaires from informal caregivers, also including information on the nature and amount of assistance provided and on Caregiver Burden (CB) score. Results. Before index admission informal caregivers provided care on average 5 h per week and after discharge 11 h per week (P < 0.0001). Support volume was associated with patient sex (more for men), low patient’s functional ability, low received municipal social service support, closeness of patient–caregiver relation, and short distance to patient’s home. Significant positive associations within the dyads were found for HAD anxiety score (P < 0.0001), total NHP score (P < 0.0001), and GQL activity score (P < 0.0001) after adjustment for patient’s age, sex, functional ability, and patient–caregiver relationship. CB score increased with amount of informal caregiver support, patient’s age, and with low functional ability and low amount of municipal social service support. All these associations were constant across time. Conclusions. There was an association within the dyads regarding anxiety score, NHP score, and activity score. CB score was generally high.