Säätömenetelmien suunnittelu ja toteutus lämmitysprosessiin

Tiivistelmä. Diplomityön tavoitteena oli kehittää ja tutkia säätömenetelmiä itsenäiseen, ja avoimen lähdekoodin ratkaisuja käyttävään säätöjärjestelmään. Tarkasteltaviksi säätömenetelmiksi valittiin perinteinen PID-säätö, sumea säätö ja mallipohjainen säätö. Työn tavoitteena oli myös toteuttaa ensimmäinen versio järjestelmästä. Työn kirjallisuusosa sisältää esittelyn ylätason säätöön ja säätöjärjestelmiin liittyvistä käsitteistä ja periaatteista. Teollisuudessa yleisien hajautettujen ohjausjärjestelmien rakenne ja ylätason optimoinnin merkitys automaatiossa on sisällytetty kirjallisuusosaan lyhyesti. Kirjallisuusosassa esitellään myös kokeellisessa osiossa toteutetut säätömenetelmät, sekä etsittiin niiltä vaadittavia ominaisuuksia skaalautuvuuden ja joustavuuden mahdollistamiseksi. Säätömenetelmien suorituskykyä arvioitiin testausympäristössä toteutetuissa säätötesteissä. Järjestelmä toimi testeissä hyvin, ja jatkokehityksen jälkeen sen siirtämistä tuotantoon voidaan suunnitella. Kolmen toimi- ja mittalaitteen prosessissa testausympäristön lämmitysvastusten tuottama ristikkäisvaikutus vaikuttaa takaisinkytkettyjen säätimien toimintaan. Mallipohjaisen säätimen sisältämä järjestelmän dynamiikkaa kuvaava malli mahdollistaa ristikkäisvaikutusten huomioimisen yksinkertaisella tavalla, joka ilmenee muita säätömenetelmiä pienempinä ylityksinä. Säätömenetelmien vertailuluku kolmen toimi- ja mittalaitteen säätötestissä PI-säätimellä keskineliövirhe oli 188,56 ºC2, sumealla PI-säätimellä keskineliövirhe oli 170,24 ºC2 ja mallipohjaisella säätimellä keskineliövirhe oli 166,37 ºC2.Design of control methods and implementation in the heating process. Abstract. The goal of this master’s thesis was to develop and study control methods for independent control system that uses open source solutions. The control methods studied were traditional PID control, fuzzy control and model predictive control. Another goal was also to implement the first version of this control system. In theory part of the thesis, concepts and principles related to advanced process control and controls systems are reviewed. The structure of distributed control systems common in industry and the importance of upper-level optimization related to process automation are briefly discussed in the theory. Required characteristics of the control methods and control system were examined to enable scalability and flexibility. Also, theory of the control methods implemented in experimental part of the thesis are included. The performance of the developed control methods was evaluated in the testing process. The control system performed successfully in the tests and after further development it can be planned to be used in production. In the process of three controlled and manipulated variables, the coupling effect related to the heating resistances of the testing environment affects the operation of the feedback controllers. The dynamic model used in the model predictive controller enables coupling effects between process variables to be taken into account in a simple way. The model predictive control manifests itself as a smaller overshoot than other tested control methods. The mean squared error values for the control methods in the control test of three controlled and manipulated variables were 188,56 ºC2, 170,24 ºC2 and 166,37 ºC2 for the PI controller, the fuzzy PI controller and the model predictive controller, respectively

Spodumeenirikasteen liuotusta edeltävä lämpökäsittely

Tiivistelmä. Työssä tutkittiin spodumeenin lämpökäsittelyn aikana tapahtuvaa faasimuutosta. Spodumeenirikasteen faasimuutos on tärkeä litiumin liuostuksen mahdollistamiseksi. Työn tavoitteena on määrittää faasimuutoslämpötila sekä seurata faasimuutoksesta aiheutuvaa tilavuuden kasvua lämpökäsittelyn aikana. Työssä suoritettiin kaksi erilaista koetta. Hehkutusuunikokeissa tarkasteltiin näytteessä tapahtuneita visuaalisia muutoksia lämpökäsittelyn jälkeen ja optisessa dilatometrissa tilavuuden muutosta lämpökäsittelyn aikana. Tuloksena huomattiin spodumeenin tilavuuden kasvavan voimakkaasti 1025 °C:n lämpötilassa. Tilavuuden kasvu on merkki faasimuutoksesta. Optisesta dilatometrista nähtiin faasimuutoksen alkavan noin 980 °C:n lämpötilasta ja puhtaan spodumeenin mahdollisuus laajentua lähes kaksinkertaiseksi faasimuutoksen aikan

Association between dog ownership and type 2 diabetes in later life : the Helsinki birth cohort study

Dog ownership has been reported to have beneficial effects on physical activity and emotional well-being, both known to reduce the risk for type 2 diabetes (T2D). The aim of this study was to evaluate the association between dog ownership during the whole life course and having T2D in later life. The study subjects consisted of 731 people (307 men and 424 women) from the Helsinki Birth Cohort Study. We assessed dog ownership with questionnaires, for every decade of life as well as current dog ownership. We investigated the associations between dog ownership and T2D with generalised estimating equation models and with generalised linear models. At a mean age of 71.0 (standard deviation [SD] 2.6) years, 13% of the participants had T2D. Dog ownership prior to the clinical examination was not associated with T2D (p >= 0.51). In men, but not in women, current dog owners had greater odds of having T2D compared with the non-owners when adjusted for age when clinically examined, socio-economic status, smoking, leisure-time physical activity, chronic diseases (OR = 3.32, 95% confidence interval 1.25-8.79, p = 0.016). In the age group of people around 70 years, dog ownership is not associated with reduced odds for developing T2D.Peer reviewe

Effect of maternal weight during pregnancy on offspring muscle strength response to resistance training in late adulthood

Purpose: Maternal obesity can unfavorably influence offspring body composition, muscle strength, and possibly muscle's adaptability to training, but the human studies are scarce. Therefore, we aimed to investigate the effect of maternal obesity on offspring muscle strength responses to resistance training intervention in elderly frail women. Materials/methods: Recruited participants were elderly frail women offspring of lean/normal weight mothers (n = 19, mean body mass index (BMI): 22.8 kg/m2, range: 19.9-24.5) or overweight/obese mothers (n = 16, mean BMI: 29.7 kg/m2, range: 28.2-34.2). Information on maternal BMI immediately prior to delivery was collected from the birth registers. All women participated in a 4-month supervised progressive resistance training intervention three times a week for 60 min. Predicted 1-RM of abdominal crunch, hip abduction, leg curl, leg press, seated row, and total strength were measured at baseline and after each month of training. Results: According to rANOVA, strength increased significantly in both groups (p for time 0.072). On average, muscle strength of the women offspring of overweight/obese mothers tended to be lower than in women offspring of lean/normal weight mothers, but the only significant difference was found in leg curl (p = 0.006). No significant differences between the groups were found in relative strength changes from baseline to 4-months. Conclusions: Muscle strength response to supervised resistance training is not modulated by maternal adiposity in late pregnancy in elderly frail female offspring.Peer reviewe

Amiodarone disrupts cholesterol biosynthesis pathway and causes accumulation of circulating desmosterol by inhibiting 24-dehydrocholesterol reductase

Background We have earlier reported that amiodarone, a potent and commonly used antiarrhythmic drug increases serum desmosterol, the last precursor of cholesterol, in 20 cardiac patients by an unknown mechanism. Objective Here, we extended our study to a large number of cardiac patients of heterogeneous diagnoses, evaluated the effects of combining amiodarone and statins (inhibitors of cholesterol synthesis at the rate-limiting step of hydroxy-methyl-glutaryl CoA reductase) on desmosterol levels and investigated the mechanism(s) by which amiodarone interferes with the metabolism of desmosterol using in vitro studies. Methods and Results We report in a clinical case-control setting of 236 cardiac patients (126 with and 110 without amiodarone treatment) that amiodarone medication is accompanied by a robust increase in serum desmosterol levels independently of gender, age, body mass index, cardiac and other diseases, and the use of statins. Lipid analyses in patient samples taken before and after initiation of amiodarone therapy showed a systematic increase of desmosterol upon drug administration, strongly arguing for a direct causal link between amiodarone and desmosterol accumulation. Mechanistically, we found that amiodarone resulted in desmosterol accumulation in cultured human cells and that the compound directly inhibited the 24-dehydrocholesterol reductase (DHCR24) enzyme activity. Conclusion These novel findings demonstrate that amiodarone blocks the cholesterol synthesis pathway by inhibiting DHCR24, causing a robust accumulation of cellular desmosterol in cells and in the sera of amiodarone-treated patients. It is conceivable that the antiarrhythmic potential and side effects of amiodarone may in part result from inhibition of the cholesterol synthesis pathway.Peer reviewe

Body composition as a predictor of physical performance in older age : A ten- year follow-up of the Helsinki Birth Cohort Study

Background: This study assessed how different measures of body composition predict physical performance ten years later among older adults. Methods: The participants were 1076 men and women aged 57 to 70 years. Body mass index (BMI), waist circumference, and body composition (bioelectrical impedance analysis) were measured at baseline and physical performance (Senior Fitness Test) ten years later. Linear regression analyses were adjusted for age, education, smoking, duration of the follow-up and physical activity. Results: Greater BMI, waist circumference, fat mass, and percent body fat were associated with poorer physical performance in both sexes (standardized regression coefficient [beta] from -0.32 to -0.40, p <0.001). Lean mass to BMI ratio was positively associated with later physical performance (beta = 0.31 in men, beta = 0.30 in women, p <0.001). Fat-free mass index (lean mass/height(2)) in both sexes and lean mass in women were negatively associated with later physical performance. Lean mass residual after accounting for the effect of height and fat mass was not associated with physical performance. Conclusions: Among older adults, higher measures of adiposity predicted poorer physical performance ten years later whereas lean mass was associated with physical performance in a counterintuitive manner. The results can be used when appraising usefulness of body composition indicators for definition of sarcopenic obesity.Peer reviewe

Glucose regulation and physical performance among older people: the Helsinki Birth Cohort Study

Aims To assess whether disturbances in glucose regulation are associated with impairment in physical performance during a 10-year follow-up. Methods 475 Men and 603 women from the Helsinki Birth Cohort Study were studied. Glucose regulation was evaluated with a 2-h 75-g oral glucose tolerance test (OGTT) in 2001-2004. Subjects were categorised as having either impaired fasting glucose (IFG), impaired glucose tolerance (IGT), newly diagnosed diabetes or previously known diabetes. Physical performance was assessed approximately 10 years later using the validated senior fitness test (SFT). The relationship between glucose regulation and the overall SFT score was estimated using multiple linear regression models. Results The mean age was 70.8 years for men and 71.0 years for women when physical performance was assessed. The mean SFT score for the whole population was 45.0 (SD 17.5) points. The SFT score decreased gradually with increased impairment in glucose regulation. Individuals with previously known diabetes had the lowest overall SFT score in the fully adjusted model (mean difference compared to normoglycaemic individuals -11.56 points, 95% CI - 16.15 to - 6.98, p <0.001). Both individuals with newly diagnosed diabetes and individuals with IGT had significantly poorer physical performance compared to those with normoglycaemia. No significant difference in physical performance was found between those with IFG and those with normoglycaemia. Conclusions Among older people, impaired glucose regulation is strongly related with poor physical performance. More severe disturbances in glucose regulation are associated with a greater decrease in physical function, indicating the importance of diagnosing these disturbances at an early stage.Peer reviewe

Telomere Length and Frailty : The Helsinki Birth Cohort Study

Objectives: Telomere length is associated with aging-related pathologies. Although the association between telomere length and frailty has been studied previously, only a few studies assessing longitudinal changes in telomere length and frailty exist. Design: Longitudinal cohort study. Setting and participants: A subpopulation of the Helsinki Birth Cohort Study consisting of 1078 older adults aged 67 to 79 years born in Helsinki, Finland, between 1934 and 1944. Measures: Relative leukocyte telomere length (LTL) was measured using quantitative real-time polymerase chain reaction at the average ages of 61 and 71 years, and at the latter the participants were assessed for frailty according to Fried criteria. Results: The mean +/- SD relative LTLs were 1.40 +/- 0.29 (average age 61 years) and 0.86 +/- 0.30 (average age 71 years) for the cohort. A trend of shorter mean relative LTL across frailty groups was observed at 61 years (P =.016) and at 71 years (P =.057). Relative LTL at age 61 years was significantly associated with frailty: per 1-unit increase in relative LTL, the corresponding relative risk ratio (RRR) of frailty was 0.28 (95% confidence interval [CI] 0.08-0.97), adjusting for several confounders. Also, LTL at age 71 years was associated with frailty (RRR 0.18, 95% CI 0.04-0.81) after adjustment for sex, age, and adult socioeconomic status, but further adjustment attenuated the association. No associations between telomere shortening and frailty were observed during the 10-year follow-up. Conclusions: Shorter relative LTL was associated with frailty in cross-sectional and longitudinal analyses, but telomere shortening was not, suggesting that short LTL may be a biomarker of frailty. (C) 2018 AMDA - The Society for Post-Acute and Long-Term Care Medicine. This is an open access article under the CC BY-NC-ND license.Peer reviewe

A pilot application of risk-informed methods to establish inservice inspection priorities for nuclear components at Surry Unit 1 Nuclear Power Station. Revision 1

As part of the Nondestructive Evaluation Reliability Program sponsored by the US Nuclear Regulatory Commission, the Pacific Northwest National Laboratory has developed risk-informed approaches for inservice inspection plans of nuclear power plants. This method uses probabilistic risk assessment (PRA) results to identify and prioritize the most risk-important components for inspection. The Surry Nuclear Power Station Unit 1 was selected for pilot application of this methodology. This report, which incorporates more recent plant-specific information and improved risk-informed methodology and tools, is Revision 1 of the earlier report (NUREG/CR-6181). The methodology discussed in the original report is no longer current and a preferred methodology is presented in this Revision. This report, NUREG/CR-6181, Rev. 1, therefore supersedes the earlier NUREG/CR-6181 published in August 1994. The specific systems addressed in this report are the auxiliary feedwater, the low-pressure injection, and the reactor coolant systems. The results provide a risk-informed ranking of components within these systems

Telomere length and physical performance among older people – the Helsinki Birth Cohort Study

Telomere length has been suggested a biomarker of aging and is associated with several chronic diseases. However, the association between telomere length and physical performance is not well known. Using both cross-sectional and longitudinal data, we studied 582 women and 453 men from the Helsinki Birth Cohort Study at two time-points; a baseline examination in 2001-2004 at a mean age of 61 years and a follow-up examination approximately 10 years later in 2011-2013. Telomere length was measured both at baseline and at follow-up using real-time quantitative polymerase chain reaction. Physical performance was evaluated only at follow-up using the Senior Fitness Test (SFT), which assesses strength, flexibility and endurance. In women, shorter telomere length at follow-up (p = 0.044) and greater telomere attrition during follow-up time (p = 0.022) were associated with poorer physical performance after adjusting for covariates (age at baseline, smoking status, body mass index at baseline, follow-up time and educational attainment). No similar associations were found for men. This indicates that, at least in women, telomere length could potentially be used as a biomarker for physical performance, however, more longitudinal studies are needed to confirm this association.Peer reviewe