Thermal reactions of the major hydrocarbon components of biomass gasification gas

Gasification of biomass is an efficient method process to produce liquid fuels, heat and electricity. It is interesting especially for the Nordic countries, where raw material for the processes is readily available. The thermal reactions of light hydrocarbons are a major challenge for industrial applications. At elevated temperatures, light hydrocarbons react spontaneously to form higher molecular weight compounds. In this thesis, this phenomenon was studied by literature survey, experimental work and modeling effort. The literature survey revealed that the change in tar composition is likely caused by the kinetic entropy. The role of the surface material is deemed to be an important factor in the reactivity of the system. The experimental results were in accordance with previous publications on the subject. The novelty of the experimental work lies in the used time interval for measurements combined with an industrially relevant temperature interval. The aspects which are covered in the modeling include screening of possible numerical approaches, testing of optimization methods and kinetic modelling. No significant numerical issues were observed, so the used calculation routines are adequate for the task. Evolutionary algorithms gave a better performance combined with better fit than the conventional iterative methods such as Simplex and Levenberg-Marquardt methods. Three models were fitted on experimental data. The LLNL model was used as a reference model to which two other models were compared. A compact model which included all the observed species was developed. The parameter estimation performed on that model gave slightly impaired fit to experimental data than LLNL model, but the difference was barely significant. The third tested model concentrated on the decomposition of hydrocarbons and included a theoretical description of the formation of carbon layer on the reactor walls. The fit to experimental data was extremely good. Based on the simulation results and literature findings, it is likely that the surface coverage of carbonaceous deposits is a major factor in thermal reactions.

Market Opportunity Analysis of the Finnish Mineral Wool Market

Tutkimuksen tarkoituksena on tutkia markkinamahdollisuuksia Suomeneristevillamarkkinoilla. Tutkimuksessa on sekä teoreettinen, että käytännön osuus. Teoreettisessa osiossa luodaan pohja empiiriselle tutkimukselle tutkimalla markkinamahdollisuusanalyysin eri komponenttien sisältöä. Empiirisessä osiossa haastatellaan markkinoiden suurimpia asiakkaita, jotka vastaavat valtaosasta markkinoiden ostovolyymista. Näiden haastattelujen pohjalta pyritään löytämään ne mahdollisuudet mitä eristevillamarkkinoilla on. Tutkimus osoittaa, että markkinamahdollisuusanalyysin eri komponentit ovat tiiviissä keskinäisessä suhteessa. Kattavalla tutkimuksella kyetään osoittamaan eri mahdollisuuksia markkinoilla. Empiirisessä osiossa kyetään osoittamaan, että Suomen eristevillamarkkinoilla on mahdollisuuksia uudelle toimittajalle. Tutkimuksessa esitetään myös joitakin toimenpide-ehdotuksia näiden havaittujen mahdollisuuksien hyödyntämiseksi.

Asleep or not asleep? Evaluation of the Quality of Patients’ Sleep in Critical Care Nursing

Sleep is important for the recovery of a critically ill patient, as lack of sleep is known to influence negatively a person’s cardiovascular system, mood, orientation, and metabolic and immune function and thus, it may prolong patients’ intensive care unit (ICU) and hospital stay. Intubated and mechanically ventilated patients suffer from fragmented and light sleep. However, it is not known well how non-intubated patients sleep. The evaluation of the patients’ sleep may be compromised by their fatigue and still position with no indication if they are asleep or not. The purpose of this study was to evaluate ICU patients’ sleep evaluation methods, the quality of non-intubated patients’ sleep, and the sleep evaluations performed by ICU nurses. The aims were to develop recommendations of patients’ sleep evaluation for ICU nurses and to provide a description of the quality of non-intubated patients’ sleep. The literature review of ICU patients’ sleep evaluation methods was extended to the end of 2014. The evaluation of the quality of patients’ sleep was conducted with four data: A) the nurses’ narrative documentations of the quality of patients’ sleep (n=114), B) the nurses’ sleep evaluations (n=21) with a structured observation instrument C) the patients’ self-evaluations (n=114) with the Richards-Campbell Sleep Questionnaire, and D) polysomnographic evaluations of the quality of patients’ sleep (n=21). The correspondence of data A with data C (collected 4–8/2011), and data B with data D (collected 5–8/2009) were analysed. Content analysis was used for the nurses’ documentations and statistical analyses for all the other data. The quality of non-intubated patients’ sleep varied between individuals. In many patients, sleep was light, awakenings were frequent, and the amount of sleep was insufficient as compared to sleep in healthy people. However, some patients were able to sleep well. The patients evaluated the quality of their sleep on average neither high nor low. Sleep depth was evaluated to be the worst and the speed of falling asleep the best aspect of sleep, on a scale 0 (poor sleep) to 100 (good sleep). Nursing care was mostly performed while the patients were awake, and thus the disturbing effect was low. The instruments available for nurses to evaluate the quality of patients’ sleep were limited and measured mainly the quantity of sleep. Nurses’ structured observatory evaluations of the quality of patients’ sleep were correct for approximately two thirds of the cases, and only regarding total sleep time. Nurses’ narrative documentations of the patients’ sleep corresponded with patients’ self-evaluations in just over half of the cases. However, nurses documented several dimensions of sleep that are not included in the present sleep evaluation instruments. They could be classified according to the components of the nursing process: needs assessment, sleep assessment, intervention, and effect of intervention. Valid, more comprehensive sleep evaluation methods for nurses are needed to evaluate, document, improve and study patients’ quality of sleep.