34 resultados para tensile well
Resumo:
One of the aims of the study was to clarify the reliability and validity of the Job Diagnostic Survey (JDS) and the Eigenzustand (EZ) method as measures of the objective characteristics of work and short-term mental work load in the Finnish data. The reliability and validity were examined taking into consideration the theoretical backgrounds of the methods and the reliability of the measurements. The methods were used for finding out the preconditions for organisational development based on self-improvement and clarifying the impacts of working environment (organisational functioning and job characteristics) on a worker’s mental state and health. The influences were examined on a general level - regardless of individual personal or specific contextual factors. One aim was also to clarify how cognitions and emotions are intertwined and how they influence a person’s perception of the working environment. The data consisted of 15 blue-collar organisations in the public sector. The organisations were divided in target and comparison groups depending on the research frames. The data was collected by questionnaires by post. The exploratory and confirmatory factor analyses (Lisrel) were used as the main statistical methods in examining the structures of the methods and impacts between the variables. It was shown that it is possible for organisations to develop their working conditions themselves on specific preconditions. The advance of the development processes could be shown by the amount of the development activity as well as by the changes of the mental well-being (ability to act) and sick absenteeism of the personnel. It was found that the JDS and the EZ methods were reliable and valid measures in the Finnish data. It was shown that, in addition to the objective working environment (organisational functioning and job characteristics), also such a personal factor as selfesteem influences a person’s perception of mental work load. However, the influence did not seem to be direct. The importance of job satisfaction as a general indicator of perceived working conditions was emphasised. Emotional and cognitive factors were found to be functionally intertwined constituting a common factor. Organisational functioning and the characteristics of work had connections with a person’s health measured by sick absenteeism.
Resumo:
ELY Centres strategy brocshure.
Resumo:
Connectivity depends on rates of dispersal between communities. For marine soft-sediment communities continued small-scale dispersal as post-larvae and as adults can be equally important in maintaining community composition, as initial recruitment of substrate by pelagic larvae. In this thesis post-larval dispersal strategies of benthic invertebrates, as well as mechanisms by which communities are connected were investigated. Such knowledge on dispersal is scarce, due to the difficulties in actually measuring dispersal directly in nature, and dispersal has not previously been quantified in the Baltic Sea. Different trap-types were used underwater to capture dispersing invertebrates at different sites, while in parallel measuring waves and currents. Local community composition was found to change predictably under varying rates of dispersal and physical connectivity (waves and currents). This response was, however, dependent on dispersal-related traits of taxa. Actively dispersing taxa will be relatively better at maintaining their position, as they are not as dependent on hydrodynamic conditions for dispersal and will be less prone to be passively transported by currents. Taxa also dispersed in relative proportions that were distinctly different from resident community composition and a significant proportion (40 %) of taxa were found to lack a planktonic larval life-stage. Community assembly was re-started in a large-scale manipulative field experiment over one year across several sites, which revealed how patterns of community composition (α-, β- and λ-diversity) change depending on rates of dispersal. Results also demonstrated that in response to small-scale disturbance, initial recruitment was by nearby-dominant species after which other species arrived from successively further away. At later assembly time, the number of coexisting species increased beyond what was expected purely by local niche requirements (species sorting), transferring regional differences in community composition (β-diversity) to the local scale (α-diversity, mass effect). Findings of this thesis complement more theoretical studies in metacommunity ecology by demonstrating that understanding how and when individuals disperse relative to underlying environmental heterogeneity is key to interpreting how patterns of diversity change across different spatial scales. Such information from nature is critical when predicting responses to, for example, different types of disturbances or management actions in conservation.
Resumo:
The aim of this study is to analyze and understand a well-being service brand. Brands most definitely are a hot topic of today’s business world. Companies have started to realize the importance of branding, especially when talking about product related industries. Branding of services is a relatively new concept, which has gained less attention within academic literature. Though there is no legal distinction between product and service brands, they both have their own characteristics and qualities. The focus of the study is especially on the current brand images of both internal and external stakeholder groups. Understanding these brand perceptions will help in managing and developing the brand, so that it becomes even stronger, more recognized, and unified. This study is a quantitative, semi hypothetic-deductive single case study. The data for this study was collected throughout an online survey. The respondents represent both internal stakeholders, in direct contact with the service, as well as external stakeholders, who have no previous history with the service brand. The respondents represent a wide age spread, and are also geographically diverse. The study relies on a Finnish context. The study provides numerous managerial takeaways, especially because of its wide scope, on a topic that has never before been studied. All findings strongly reflected existing service brand theory, in addition with making the findings implementable for the case company.
Resumo:
Brittleness is a well-known material characteristic but brittleness of paper is vaguely covered. The objective of this thesis was to characterize the phenomenon and causes around brittleness of paper and to clarify if it is a measurable property. Brittleness of paper was approached from the perspectives of paper physics and paper mills. Brittleness is a property of dry paper and it causes problems at the finishing stages of paper machine. According to paper physics, brittle materials fail in the elastic regime, while ductile materials can locally accumulate a plastic deformation prior to the fracture and they are often able to withstand higher stresses. Brittleness of paper is vastly affected by the surrounding conditions: paper as a hygroscopic material tries to get to the equilibrium. It is also affected by the quality of the pulp used. Measurement techniques can be divided into two categories: based on the viscoelastic behavior of paper and on the exposure to the mechanical stress of sort. The experimental part of the thesis was based on the trials with brittle and non-brittle mill-made LWC papers. It is divided into three parts: strength testing of the brittle and non-brittle papers, analysis of the conditions that may contribute the brittleness and the experimental methods to evaluate brittle behavior. The strength measurements confirmed the influence of the moisture content, but only tensile energy absorption and the fracture toughness measurements provided modest differences between the brittle and non-brittle papers. Versatile analysis of the possible contributing factors resulted into speculation, while the brittle papers contained higher amount of starch, triglycerides and steryl esters. The experimental research proved that the formation, the sensory impression and the variation of local strains may contain the crucial information of paper brittleness.
Resumo:
This monograph dissertation looks into the field of ICT-mediated health and well-being services. Through six chapters that extend the work done in the reviewed and published articles, the dissertation focuses on new and emerging technologies, and to impact of their use on the beneficiary; the individual who eventually derives advantage from the services. As the field is currently going through major changes particularly in the OECD countries, the focus is on shortterm developments in the field and the analysis on the long term developments is cursory by nature. The dissertation includes theoretical and empirical elements. Most of the empirical elements are linked to product development and conceptualization performed in the national MyWellbeing project that ended in 2010. In the project, the emphasis was on conceptualization of a personal aid for the beneficiary that could be used for managing information and services in the field of health and well-being services. This work continued the theme of developing individual-centric solutions for the field; a work that started in the InnoElli Senior program in 2006. The nature of this thesis is foremost a conceptual elaboration based on a literature review, illustrated in empirical work performed in different projects. As a theoretical contribution, this dissertation elaborates the role of a mediator, i.e. an intermediary, and it is used as an overarching theme. The role acts as a ‘lens’ through which a number of technology-related phenomena are looked at, pinned down and addressed to a degree. This includes introduction of solutions, ranging from anthropomorphic artefacts to decision support systems that may change the way individuals experience clinical encounters in the near-future. Due to the complex and multiform nature of the field, it is impractical and effectively impossible to cover all aspects that are related to mediation in a single work. Issues such as legislation, financing and privacy are all of equal importance. Consideration of all these issues is beyond the scope of this dissertation and their investigation is left to other work. It follows from this that the investigation on the role is not intended as inclusive one. The role of the mediator is also used to highlight some of the ethical issues related to personal health information management, and to mediating health and well-being related issues on behalf of another individual, such as an elderly relative or a fellow member of a small unit in the armed forces. The dissertation concludes in a summary about the use and functions of the mediator, describing some potential avenues for implementing such support mechanisms to the changing field of ICT-mediated health and well-being services. The conclusions also describe some of the limitations of this dissertation, including remarks on methodology and content.
Resumo:
0-meridiaani: Lontoo. - Koordinaattiasteikko: N90°-55°[50°].
Resumo:
Työn tavoitteena oli kehittää menetelmä, jolla voitaisiin arvioida veto-ominaisuuksien avulla konvertointikoneen prässäysnopeuden ja muottien lämpötilan vaikutuksia kartongin muovautuvuuteen. Kirjallisuusosassa käsiteltiin kartongin muovautuvuuteen vaikuttavia ominaisuuksia sekä vetolujuuteen vaikuttavia tekijöitä. Lisäksi käsiteltiin kosteuden vaikutusta muovautuvuuteen sekä esiteltiin vuokakonvertointiprosessin periaate ja muovin sekä kartongin käyttäytymisen erot konvertointiprosessissa. Kokeellinen osa jakaantui kolmeen osaan. Esikokeissa tutkittiin laboratoriomittauksilla vetonopeuden ja kosteuden muutosten vaikutusta erilaisten kaupallisten kartonkimateriaalien vetolujuuteen ja murtovenymään. Tulosten perusteella valittiin prässäysnopeudet ja kosteustaso 2D- testauslaitteella suoritettuihin esi-pilot-mittakaavan kokeisiin sekä varsinaiseen pilot-koeajoon. Pilot-koeajossa pyrittiin arvioimaan prässäysnopeuden ja muottien lämpötilan vaikutuksia muovautuvuuteen vetolujuusarvojen avulla. Prässäysnopeudella ja vetolujuuslaitteen nopeudella ei havaittu yhteneväisyyksiä, jotta voitaisiin arvioida kartongin muovautuvuutta. Muovautuvuutta voidaan kuitenkin arvioida epäonnistuneisuusluvulla, jonka laskentapa kehitettiin työn aikana. Epäonnistuneisuusluku kuvaa hyvin kartongin muovautuvuutta ja on menetelmänä helppo, mutta sen heikkoutena on repeämien mittaamisen aiheuttama epätarkkuus. Esikokeissa havaittiin myös muovipäällysteiden veto-ominaisuuksien vastaavan kartongin ominaisuuksia 65 %:n suhteellisessa kosteudessa, jonka valittiin siten olevan optimaalinen olosuhde pilot-mittakaavan koeajoihin.
Resumo:
Laser cutting implementation possibilities into paper making machine was studied as the main objective of the work. Laser cutting technology application was considered as a replacement tool for conventional cutting methods used in paper making machines for longitudinal cutting such as edge trimming at different paper making process and tambour roll slitting. Laser cutting of paper was tested in 70’s for the first time. Since then, laser cutting and processing has been applied for paper materials with different level of success in industry. Laser cutting can be employed for longitudinal cutting of paper web in machine direction. The most common conventional cutting methods include water jet cutting and rotating slitting blades applied in paper making machines. Cutting with CO2 laser fulfils basic requirements for cutting quality, applicability to material and cutting speeds in all locations where longitudinal cutting is needed. Literature review provided description of advantages, disadvantages and challenges of laser technology when it was applied for cutting of paper material with particular attention to cutting of moving paper web. Based on studied laser cutting capabilities and problem definition of conventional cutting technologies, preliminary selection of the most promising application area was carried out. Laser cutting (trimming) of paper web edges in wet end was estimated to be the most promising area where it can be implemented. This assumption was made on the basis of rate of web breaks occurrence. It was found that up to 64 % of total number of web breaks occurred in wet end, particularly in location of so called open draws where paper web was transferred unsupported by wire or felt. Distribution of web breaks in machine cross direction revealed that defects of paper web edge was the main reason of tearing initiation and consequent web break. The assumption was made that laser cutting was capable of improvement of laser cut edge tensile strength due to high cutting quality and sealing effect of the edge after laser cutting. Studies of laser ablation of cellulose supported this claim. Linear energy needed for cutting was calculated with regard to paper web properties in intended laser cutting location. Calculated linear cutting energy was verified with series of laser cutting. Practically obtained laser energy needed for cutting deviated from calculated values. This could be explained by difference in heat transfer via radiation in laser cutting and different absorption characteristics of dry and moist paper material. Laser cut samples (both dry and moist (dry matter content about 25-40%)) were tested for strength properties. It was shown that tensile strength and strain break of laser cut samples are similar to corresponding values of non-laser cut samples. Chosen method, however, did not address tensile strength of laser cut edge in particular. Thus, the assumption of improving strength properties with laser cutting was not fully proved. Laser cutting effect on possible pollution of mill broke (recycling of trimmed edge) was carried out. Laser cut samples (both dry and moist) were tested on the content of dirt particles. The tests revealed that accumulation of dust particles on the surface of moist samples can take place. This has to be taken into account to prevent contamination of pulp suspension when trim waste is recycled. Material loss due to evaporation during laser cutting and amount of solid residues after cutting were evaluated. Edge trimming with laser would result in 0.25 kg/h of solid residues and 2.5 kg/h of lost material due to evaporation. Schemes of laser cutting implementation and needed laser equipment were discussed. Generally, laser cutting system would require two laser sources (one laser source for each cutting zone), set of beam transfer and focusing optics and cutting heads. In order to increase reliability of system, it was suggested that each laser source would have double capacity. That would allow to perform cutting employing one laser source working at full capacity for both cutting zones. Laser technology is in required level at the moment and do not require additional development. Moreover, capacity of speed increase is high due to availability high power laser sources what can support the tendency of speed increase of paper making machines. Laser cutting system would require special roll to maintain cutting. The scheme of such roll was proposed as well as roll integration into paper making machine. Laser cutting can be done in location of central roll in press section, before so-called open draw where many web breaks occur, where it has potential to improve runability of a paper making machine. Economic performance of laser cutting was done as comparison of laser cutting system and water jet cutting working in the same conditions. It was revealed that laser cutting would still be about two times more expensive compared to water jet cutting. This is mainly due to high investment cost of laser equipment and poor energy efficiency of CO2 lasers. Another factor is that laser cutting causes material loss due to evaporation whereas water jet cutting almost does not cause material loss. Despite difficulties of laser cutting implementation in paper making machine, its implementation can be beneficial. The crucial role in that is possibility to improve cut edge strength properties and consequently reduce number of web breaks. Capacity of laser cutting to maintain cutting speeds which exceed current speeds of paper making machines what is another argument to consider laser cutting technology in design of new high speed paper making machines.
Resumo:
The aim of this work was to calibrate the material properties including strength and strain values for different material zones of ultra-high strength steel (UHSS) welded joints under monotonic static loading. The UHSS is heat sensitive and softens by heat due to welding, the affected zone is heat affected zone (HAZ). In this regard, cylindrical specimens were cut out from welded joints of Strenx® 960 MC and Strenx® Tube 960 MH, were examined by tensile test. The hardness values of specimens’ cross section were measured. Using correlations between hardness and strength, initial material properties were obtained. The same size specimen with different zones of material same as real specimen were created and defined in finite element method (FEM) software with commercial brand Abaqus 6.14-1. The loading and boundary conditions were defined considering tensile test values. Using initial material properties made of hardness-strength correlations (true stress-strain values) as Abaqus main input, FEM is utilized to simulate the tensile test process. By comparing FEM Abaqus results with measured results of tensile test, initial material properties will be revised and reused as software input to be fully calibrated in such a way that FEM results and tensile test results deviate minimum. Two type of different S960 were used including 960 MC plates, and structural hollow section 960 MH X-joint. The joint is welded by BöhlerTM X96 filler material. In welded joints, typically the following zones appear: Weld (WEL), Heat affected zone (HAZ) coarse grained (HCG) and fine grained (HFG), annealed zone, and base material (BaM). Results showed that: The HAZ zone is softened due to heat input while welding. For all the specimens, the softened zone’s strength is decreased and makes it a weakest zone where fracture happens while loading. Stress concentration of a notched specimen can represent the properties of notched zone. The load-displacement diagram from FEM modeling matches with the experiments by the calibrated material properties by compromising two correlations of hardness and strength.
Resumo:
The parents of premature infants, especially the mothers, are at increased risk for distress. Infants born prematurely are at risk for developmental problems. The aim of this study was to investigate whether the psychological well-being of both parents is associated with child development in very low birth weight (VLBW, ≤1500g) children. The burden of prematurity-related morbidity to the children and to the family was also assessed. A cohort of 201 VLBW infants born during 2001–2006 in the Turku University Hospital, Finland, and their parents were studied (I–IV). One study included a control group (n=166) of full-term infants (IV). The psychological well-being of the parents was evaluated by assessments of depressive symptoms, parenting stress, the sense of coherence and general family functioning. Cognitive, behavioral, and socio-emotional development, and the health-related quality of life (HRQoL) of the children were determined when the children were 2 to 8 years old. The psychological well-being of the parents was associated with the cognitive, behavioral and social development of the VLBW children. The VLBW infants with prematurity-related morbidities had a poorer HRQoL and the general functioning of the family was inferior compared to the control children and their families. 64.5% of the VLBW children survived without morbidities. Most of the VLBW children did not have significant behavior problems (93%), had normal social skills (63%), had no emotional problems (64%), and had no problems in executive functioning (62%). Only 3% of the surviving VLBW infants had significant cognitive delay. In conclusion, the depressive symptoms and stress of the parents can be risk factors for disadvantageous child development, while a strong sense of coherence can be protective. Parents of the premature children with developmental delays might also experience more depressive symptoms and stress than other parents. Prematurity-related morbidities were a burden to the VLBW child as well as to the family.