Teräksen jatkuvavalun hallinta

Tiivistelmä. Tämän kandidaatintyön aiheena on teräksenvalmistuksessa käytettävä jatkuvavaluprosessi ja sen hallinta. Työn tavoitteena on esitellä jatkuvavaluprosessi osana nykyaikaista teräksenvalmistusta, sekä tuoda esille jatkuvavalukoneen ohjauksessa käytettyjä automaatioratkaisuja. Työ on toteutettu kirjallisuuskatsauksena tarkastellen aiheesta aiemmin tehtyjä julkaisuja ja valukoneen säätöratkaisuja tarjoavien yritysten internetsivuja. Jatkuvavalun hallinta perustuu nykypäivänä jo suurelta osin matemaattisten mallien käyttöön. Monimutkainen teräksen jähmettymisprosessi on haastava mallinnettava, mutta se parantaa olennaisesti prosessin toimintaa. Tässä työssä pohditaan nykypäivän jatkuvavalun haasteita ja esitellään tulevaisuuden näkymiä ja ratkaisuja valukoneiden automaation ja hallinnan osalta.Control of continous casting in steelmaking. Abstract. This bachelor’s thesis presents the continuous casting process and automation solutions related to its control. The thesis is implemented as a literature review by examining previous studies on the subject and the websites of companies offering casting machine control solutions. Mathematical models play a major role in controlling today’s continuous casting process. The complex solidification process of steel poses challenges to the modelling, but it also substantially improves its operation. In this work, these challenges have been considered, as well as the future of casting machines and their automation

Particle filter-based estimation of instantaneous frequency for the diagnosis of electrical asymmetries in induction machines

"© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.” Upon publication, authors are asked to include either a link to the abstract of the published article in IEEE Xplore®, or the article’s Digital Object Identifier (DOI).Fault diagnosis of induction machines operating under variable load conditions is still an unsolved matter. Under those regimes, the application of conventional diagnostic techniques is not suitable, since they are adapted to the analysis of stationary quantities. In this context, modern transient-based methodologies become very appropriate. This paper improves a technique, based on the application of Wigner Ville distribution as time frequency decomposition tool, using a particle filtering method as feature extraction procedure, to diagnose and quantify electrical asymmetries in induction machines, such as wound- rotor induction generators used in wind farms. The combination of both tools allows tracking several variable frequency harmon- ics simultaneously and computing their energy with high accu- racy, yielding magnitudes and values similar to those obtained by the application of the fast Fourier transform in stationary operation. The experimental results show the validity of the approach for rapid speed variations, independently of any speed sensor.Climente Alarcon, V.; Antonino Daviu, JA.; Haavisto, A.; Arkkio, A. (2014). Particle Filter-Based Estimation of Instantaneous Frequency for the Diagnosis of Electrical Asymmetries in Induction Machines. IEEE Transactions on Instrumentation and Measurement. 63(10):2454-2463. doi:10.1109/TIM.2014.231011324542463631

Finnish and Swedish prehospital emergency care providers' knowledge and attitudes towards pressure ulcer prevention

Background: Despite the knowledge that transportation by emergency medical services may increase the risk of pressure ulcers (PU), there is still lack of knowledge about the possibility of prehospital emergency care providers to be a part of preventing and reducing the risk of PUs. Methods: A survey was carried out during 2017 in Finland and Sweden. Validated questionnaires were used. Results: A total of 179 (72.7%) Finnish and 188 (28.8%) Swedish prehospital emergency care providers participated in the study. The overall rate of correct answers and the mean total knowledge score was 58.8% (SD 21.8), 20/34, in the Finnish group and 70.5% (SD 15.7), 24/34, in the Swedish group (p < 0.000). The percent of the total and the mean attitude score was in the Finnish group 71.3% (SD 0.48), 37.1/52, and in the Swedish group 69.4% (SD 0.77), 36.1/52 (p < 0.813). Half of the Finnish and most of the Swedish participants felt they needed more education about PUs (Fin 50.2% & Swe: 76.0%). Conclusions: Prehospital emergency care providers don't see themselves as responsible for PU prevention. Therefore, there is a need for increasing the level of knowledge on PU prevention and classification among prehospital emergency care providers. They could play a key role in developing methods to improve PU prevention and identifying patients in risk of developing PUs.Peer reviewe

Diagnosis of Induction Motors Under Varying Speed Operation by Principal Slot Harmonic Tracking

© 1972-2012 IEEE. A detailed study on the energy content of a principal slot harmonic (PSH) in an induction motor operating at variable slip is carried out. The machine is tested under different faulty conditions, namely, broken rotor bar, mixed eccentricity, and interturn short circuit. The use of a combined time-frequency analysis and particle filtering feature extraction procedure allows tracking the evolution of a PSH under different load profiles and integrating its energy. The proposed fault indicator provides values that are equivalent with the traditional one for stationary operation even in the case of pulsating load. The results show that the energy in the PSH reflects the overall state of the machine under these conditions. Furthermore, procedures to discern the different faults in real applications are proposed

Accuracy of echocardiographic area-length method in chronic myocardial infarction: comparison with cardiac CT in pigs

Background: We evaluated echocardiographic area-length methods to measure left ventricle (LV) volumes and ejection fraction (EF) in parasternal short axis views in comparison with cardiac computed tomography (CT) in pigs with chronic myocardial infarction (MI).Methods: Male farm pigs with surgical occlusion of the left anterior descending coronary artery (n = 9) or sham operation (n = 5) had transthoracic echocardiography and cardiac-CT 3 months after surgery. We measured length of the LV in parasternal long axis view, and both systolic and diastolic LV areas in parasternal short axis views at the level of mitral valve, papillary muscles and apex. Volumes and EF of the LV were calculated using Simpson's method of discs (tri-plane area) or Cylinder-hemiellipsoid method (single plane area).Results: The pigs with coronary occlusion had anterior MI scars and reduced EF (average EF 42 +/- 10%) by CT. Measurements of LV volumes and EF were reproducible by echocardiography. Compared with CT, end-diastolic volume (EDV) measured by echocardiography showed good correlation and agreement using either Simpson's method (r = 0.90; mean difference -2, 95% CI -47 to 43 mL) or Cylinder-hemiellipsoid method (r = 0.94; mean difference 3, 95% CI -44 to 49 mL). Furthermore, End-systolic volume (ESV) measured by echocardiography showed also good correlation and agreement using either Simpson's method (r = 0.94; mean difference 12 ml, 95% CI: -16 to 40) or Cylinder-hemiellipsoid method (r = 0.97; mean difference: 13 ml, 95% CI: -8 to 33). EF was underestimated using either Simpson's method (r = 0.78; mean difference -6, 95% CI -11 to 1%) or Cylinder-hemiellipsoid method (r = 0.74; mean difference -4, 95% CI-10 to 2%).Conclusion: Our results indicate that measurement of LV volumes may be accurate, but EF is underestimated using either three or single parasternal short axis planes by echocardiography in a large animal model of chronic MI

Mediation and the Best Interests of the Child from the Child Law Perspective

What is the best interests of the child in family mediation and is mediation in the best interests of the child? In this article, I use child law and the United Nations Convention on the Rights of the Child combined with mediation theory to discuss these questions. Both mediation and the best interests of the child are open for multiple interpretations. Using facilitative and evaluative mediation theory and the legal concept ‘the best interests of the child’, I explore and compare the understandings of these concepts as they apply to family mediation. This includes a discussion of the advantages and disadvantages of facilitative as well as evaluative mediation orientations in terms of protecting the best interests of the child. Finnish court-connected family mediation is a combination of both mediation orientations, and the mediator is obliged to secure the best interests of the child. From a theoretical point of view, this seems to be a challenging combination.Peer reviewe

A Genome-Wide SNP Scan Reveals Novel Loci for Egg Production and Quality Traits in White Leghorn and Brown-Egg Dwarf Layers

Availability of the complete genome sequence as well as high-density SNP genotyping platforms allows genome-wide association studies (GWAS) in chickens. A high-density SNP array containing 57,636 markers was employed herein to identify associated variants underlying egg production and quality traits within two lines of chickens, i.e., White Leghorn and brown-egg dwarf layers. For each individual, age at first egg (AFE), first egg weight (FEW), and number of eggs (EN) from 21 to 56 weeks of age were recorded, and egg quality traits including egg weight (EW), eggshell weight (ESW), yolk weight (YW), eggshell thickness (EST), eggshell strength (ESS), albumen height(AH) and Haugh unit(HU) were measured at 40 and 60 weeks of age. A total of 385 White Leghorn females and 361 brown-egg dwarf dams were selected to be genotyped. The genome-wide scan revealed 8 SNPs showing genome-wise significant (P<1.51E-06, Bonferroni correction) association with egg production and quality traits under the Fisher's combined probability method. Some significant SNPs are located in known genes including GRB14 and GALNT1 that can impact development and function of ovary, but more are located in genes with unclear functions in layers, and need to be studied further. Many chromosome-wise significant SNPs were also detected in this study and some of them are located in previously reported QTL regions. Most of loci detected in this study are novel and the follow-up replication studies may be needed to further confirm the functional significance for these newly identified SNPs

Physiological and autonomic stress responses after prolonged sleep restriction and subsequent recovery sleep in healthy young men

Purpose Sleep restriction is increasingly common and associated with the development of health problems. We investigated how the neuroendocrine stress systems respond to prolonged sleep restriction and subsequent recovery sleep in healthy young men. Methods After two baseline (BL) nights of 8 h time in bed (TIB), TIB was restricted to 4 h per night for five nights (sleep restriction, SR, n = 15), followed by three recovery nights (REC) of 8 h TIB, representing a busy workweek and a recovery weekend. The control group (n = 8) had 8 h TIB throughout the experiment. A variety of autonomic cardiovascular parameters, together with salivary neuropeptide Y (NPY) and cortisol levels, were assessed. Results In the control group, none of the parameters changed. In the experimental group, heart rate increased from 60 +/- 1.8 beats per minute (bpm) at BL, to 63 +/- 1.1 bpm after SR and further to 65 +/- 1.8 bpm after REC. In addition, whole day low-frequency to-high frequency (LF/HF) power ratio of heart rate variability increased from 4.6 +/- 0.4 at BL to 6.0 +/- 0.6 after SR. Other parameters, including salivary NPY and cortisol levels, remained unaffected. Conclusions Increased heart rate and LF/HF power ratio are early signs of an increased sympathetic activity after prolonged sleep restriction. To reliably interpret the clinical significance of these early signs of physiological stress, a follow-up study would be needed to evaluate if the stress responses escalate and lead to more unfavourable reactions, such as elevated blood pressure and a subsequent elevated risk for cardiovascular health problems.Peer reviewe