961 resultados para cold work hardening
Resumo:
Educators who are currently beginning their professional career at any level of the educationalsystem and who will likely have to work during the next thirty to forty years will be takingpart in the education of individuals who, with the permission of prophets and doomsayers,will live part of their lives in the 22nd century. That long but simple statement causes a bit ofvertigo as well as a good amount of reflection on the part of we educators who were trainedin the 20th century, are working in the 21st century, and are responsible for preparing peopleto build a tomorrow that is already today (Millán and Sancho, 1995). This is the starting pointof our research groups’ interest in exploring how men and women who have graduated fromteacher education programs with specializations in infant and primary education learn to beteachers, and how they establish and position themselves as teachers during their university studies and the first years of their professional life...
Resumo:
Educators who are currently beginning their professional career at any level of the educationalsystem and who will likely have to work during the next thirty to forty years will be takingpart in the education of individuals who, with the permission of prophets and doomsayers,will live part of their lives in the 22nd century. That long but simple statement causes a bit ofvertigo as well as a good amount of reflection on the part of we educators who were trainedin the 20th century, are working in the 21st century, and are responsible for preparing peopleto build a tomorrow that is already today (Millán and Sancho, 1995). This is the starting pointof our research groups’ interest in exploring how men and women who have graduated fromteacher education programs with specializations in infant and primary education learn to beteachers, and how they establish and position themselves as teachers during their university studies and the first years of their professional life...
Resumo:
Educators who are currently beginning their professional career at any level of the educationalsystem and who will likely have to work during the next thirty to forty years will be takingpart in the education of individuals who, with the permission of prophets and doomsayers,will live part of their lives in the 22nd century. That long but simple statement causes a bit ofvertigo as well as a good amount of reflection on the part of we educators who were trainedin the 20th century, are working in the 21st century, and are responsible for preparing peopleto build a tomorrow that is already today (Millán and Sancho, 1995). This is the starting pointof our research groups’ interest in exploring how men and women who have graduated fromteacher education programs with specializations in infant and primary education learn to beteachers, and how they establish and position themselves as teachers during their university studies and the first years of their professional life...
Resumo:
This is a study of team social networks, their antecedents and outcomes. In focusing attention on the structural configuration of the team this research contributes to a new wave of thinking concerning group social capital. The research site was a random sample of Finnish work organisations. The data consisted of 499 employees in 76 teams representing 48 different organisations. A systematic literature review and quantitative methods were used in conducting the research: the former primarily to establish the current theoretical position on the relationships among the variables and the latter to test these relationships. Social network analysis was the primary method used in identifying the social-network relations among the work-team members. The first and key contribution of this study is that it relates the structuralnetwork properties of work teams to behavioural outcomes, attitudinal outcomes and, ultimately, team performance. Moreover, it shows that addressing attitudinal outcomes is also important in terms of team performance; attitudinal outcomes (team identity) mediated the relationship between the team’s performance and its social network. The second contribution is that it examines the possible antecedents of the social structure. It is thus one response to Salancik’s (1995) call for a network theory in that it explains why certain network characteristics exist. Itdemonstrates that irrespective of whether or not a team is heterogeneous in terms of age or gender, educational diversity may protect it from centralisation. However, heterogeneity in terms of gender turned out to have a negative impact on density. Thirdly, given the observation that the benefits of (team) networks are typically theorised and modelled without reference to the nature of the relationships comprising the structure, the study directly tested whether team knowledge mediated the effects of instrumental and expressive network relationships on team performance. Furthermore, with its focus on expressive networks that link the workplace to a more informal world, which have been rather neglected in previous research, it enhances knowledge of teams andnetworks. The results indicate that knowledge sharing fully mediates the influence of complementarities between dense and fragmented instrumental network relationships, thus providing empirical validation of the implicit understanding that networks transfer knowledge. Fourthly, the study findings suggest that an optimal configuration of the work-team social-network structure combines both bridging and bonding social relationships.
Resumo:
One of the methodological resources that teachers use in a generalised way in Physical Education classes is the game. Inthis article we define the concept of game and analyse the characteristics of their internal structure. On the other hand welook at the concepts of physical condition and conditional skills and describe the objectives of its work in Primary Education.Finally, we relate these concepts and propose two practical examples of modifying the internal structure of the game so asto produce variations in the implied conditional skills
Resumo:
Mercury is a toxic metal used in a variety of substances over the course history. One of its more dubious uses is in dental amalgam restorations. It is possible to measure very small concentrations of this metal in the urine of exposed subjects by the cold vapor atomic absorption technique. The present work features the validation as an essential tool to confirm the suitability of the analytical method chosen to accomplish such determination. An initial analysis will be carried out in order to evaluate the environmental and occupational levels of exposure to mercury in 39 members of the auxiliary dental staff at public consulting rooms in the city of Araguaína (TO).
Resumo:
The purpose of the present study was to validate a method for organic Hg determination in sediment. The procedure for organic Hg was adapted from literature, where the organomercurial compounds were extracted with dichloromethane in acid medium and subsequent destruction of organic compounds by bromine chloride. Total Hg was performed according to 3051A USEPA methodology. Mercury quantification for both methodologies was then performed by CVAAS. Methodology validation was verified by analyzing certified reference materials for total Hg and methylmercury. The uncertainties for both methodologies were calculated. The quantification limit of 3.3 µg kg-1 was found for organic Hg by CVAAS.
Resumo:
This master’s thesis was done for Andritz Inc. Atlanta Georgia. The purpose of the thesis was to develop a new trolley for a small portal log yard crane. In the beginning of the thesis the basic principles of the systematic design processes have been described, along which the design work of the trolley has proceeded. The second literature part consists of the design and dimensioning of the welded steel structures under fatigue loading. The design work of the trolley consists of the engineering and the selection of the mechanical components and the design of the load carrying structure for the trolley. The realization of the steel structure of the trolley is based on the fatigue and static dimensioning. The fatigue dimensioning is grounded in the life expectations estimated for the trolley and the static dimensioning is based on the CMAA guidelines. The computer aided element method was utilized in the design of the steel structure. The effective notch method and the hot spot method were used in the fatigue calculations. The trolley structure was carried out by using the sheet metal parts in order to manufacture the structure as effective and low cost way as possible. The corner stone of the dimensioning of the trolley structure was the utilization of the open profiles made of welded or cold formed sheet metals, which provide better weldability, weld inspection, access for repairs and corrosion protection. As a last part of the thesis a new trolley traveling system was developed. The distribution of the wheel loads of the trolley bogies on the main girder was also studied, which led to an innovative suspension arrangement between the trolley leg and the bogie. The new bogie solution increases the service life of the main girder of the crane and improves the stability of the bogies. The outcome of the thesis is an excellent trolley structure from the weight and the service life point of view.
Resumo:
In this thesis three experiments with atomic hydrogen (H) at low temperatures T<1 K are presented. Experiments were carried out with two- (2D) and three-dimensional (3D) H gas, and with H atoms trapped in solid H2 matrix. The main focus of this work is on interatomic interactions, which have certain specific features in these three systems considered. A common feature is the very high density of atomic hydrogen, the systems are close to quantum degeneracy. Short range interactions in collisions between atoms are important in gaseous H. The system of H in H2 differ dramatically because atoms remain fixed in the H2 lattice and properties are governed by long-range interactions with the solid matrix and with H atoms. The main tools in our studies were the methods of magnetic resonance, with electron spin resonance (ESR) at 128 GHz being used as the principal detection method. For the first time in experiments with H in high magnetic fields and at low temperatures we combined ESR and NMR to perform electron-nuclear double resonance (ENDOR) as well as coherent two-photon spectroscopy. This allowed to distinguish between different types of interactions in the magnetic resonance spectra. Experiments with 2D H gas utilized the thermal compression method in homogeneous magnetic field, developed in our laboratory. In this work methods were developed for direct studies of 3D H at high density, and for creating high density samples of H in H2. We measured magnetic resonance line shifts due to collisions in the 2D and 3D H gases. First we observed that the cold collision shift in 2D H gas composed of atoms in a single hyperfine state is much smaller than predicted by the mean-field theory. This motivated us to carry out similar experiments with 3D H. In 3D H the cold collision shift was found to be an order of magnitude smaller for atoms in a single hyperfine state than that for a mixture of atoms in two different hyperfine states. The collisional shifts were found to be in fair agreement with the theory, which takes into account symmetrization of the wave functions of the colliding atoms. The origin of the small shift in the 2D H composed of single hyperfine state atoms is not yet understood. The measurement of the shift in 3D H provides experimental determination for the difference of the scattering lengths of ground state atoms. The experiment with H atoms captured in H2 matrix at temperatures below 1 K originated from our work with H gas. We found out that samples of H in H2 were formed during recombination of gas phase H, enabling sample preparation at temperatures below 0.5 K. Alternatively, we created the samples by electron impact dissociation of H2 molecules in situ in the solid. By the latter method we reached highest densities of H atoms reported so far, 3.5(5)x1019 cm-3. The H atoms were found to be stable for weeks at temperatures below 0.5 K. The observation of dipolar interaction effects provides a verification for the density measurement. Our results point to two different sites for H atoms in H2 lattice. The steady-state nuclear polarizations of the atoms were found to be non-thermal. The possibility for further increase of the impurity H density is considered. At higher densities and lower temperatures it might be possible to observe phenomena related to quantum degeneracy in solid.
Resumo:
Sea buckthorn (Hippophaë) berries are ingredients of the Chinese traditional medicine. In addition to China, they are nowadays cultivated for food in several European countries, Russia, Canada, the USA, and Japan. Sea buckthorn berries are a rich source of flavonoids, mainly flavonol glycosides and proanthocyanidins. Depending on the genetic background, growth conditions, and ripeness of the berries, vitamin C concentrations up to over 1 g/100 ml juice, have been reported. Sea buckthorn berries contain inositols and methyl inositols, components of messenger molecules in humans. Sea buckthorn seed oil is rich in essential aplha-linolenic and linoleic acids, whereas the most abundant fatty acids in the berry oil are palmitoleic, palmitic and oleic acids. Other potentially beneficial lipophilic compounds of sea buckthorn seeds and berries include carotenoids, phytosterols, tocopherols and tocotrienols. The effects of sea buckthorn fractions on inflammation, platelet aggregation, oxidation injuries, the liver, skin and mucosa, among others, have been reported. The aim of the thesis work was to investigate the health effects of sea buckthorn berries and oil in humans. The physiological effects of sea buckthorn berries, berry components, and oil have mostly been studied in vitro and in animal models, leaving a demand for more clinical trials. In the first randomized, placebo-controlled trial of this thesis healthy adults consumed 28 g/day of sea buckthorn berries for three months. The main objective was to investigate the effects on the common cold. In addition, effects on other infections, inflammation and circulating lipid markers associated with cardiovascular disease risk were studied. In the second randomized, placebocontrolled trial participants reporting dry eye symptoms consumed 2 g/day of sea buckthorn oil from the seeds and berries for three months. The effects on symptoms and clinical signs of dry eye were monitored. In addition, the effects on circulating markers of inflammation and liver functions were analyzed. Sea buckthorn berries did not affect the common cold or other infections in healthy adults. However, a decrease in serum C-reactive protein was detected, indicating effects on inflammation. Fasting concentrations of serum flavonols, typical to sea buckthorn berry, increased without affecting the circulating total, HDL, LDL cholesterol, or triacylglycerol concentrations. Tear film hyperosmolarity and activation of inflammation at the ocular surface are among the core mechanisms of dry eye. Combined sea buckthorn berry and seed oil attenuated the rise in tear film osmolarity taking place during the cold season. It also positively affected some of the dry eye symptoms. Based on the tear film fatty acid analysis, the effects were not mediated through direct incorporation of sea buckthorn oil fatty acids to tear film lipids. It is likely that the fatty acids, carotenoids, tocopherols and tocotrienols of sea buckthorn oil affected the inflammation of the ocular surface, lacrimal and/or meibomian glands. The effects on the differentiation of meibomian gland cells are also possible. Sea buckthorn oil did not affect the serum concentrations of inflammation markers or liver enzymes investigated. In conclusion, this thesis work suggests positive effects of sea buckthorn berries and oil on inflammation and dry eye, respectively, in humans.
Resumo:
År 1974 började den finska regeringen kanalisera pengar för utvecklingssamarbete genom medborgarorganisationer. Tre år senare och fram till år 1988 beviljade regeringen ett speciellt anslag specifikt för missionsorganisationers utvecklingsprojekt. De finska pingstvännerna, lutheranerna och de ortodoxa utvidgade samtliga sitt sociala arbete i Kenya med statens stöd. Deras projekt var likadana: alla byggde läroanstalter, utvecklade Kenyas hälsoservice och sysselsatte kenyaner. Olikheterna mellan pingstvännerna, lutheranerna och de ortodoxa blev tydliga genom diverse problem som de mötte inom ramen för utvecklingssamarbetet. Den finska pingströrelsen bestod av självständiga församlingar, och pingstvännerna måste omvandla sin takorganisation, Suomen Vapaa Ulkolähetys, så att utvecklingsprojekt blev en viktig gren av dess verksamhet. Lutheranerna som till en början hade sänt missionärer för att arbeta i den kenyanska kyrkans tjänst började i medlet av 1970-talet i ökande grad bygga sociala anstalter med statens pengar. Ett problem var att statens stöd varade endast för en begränsad tid och att den lutherska kyrkan i Kenya inte hade råd att överta dessa anstalter och täcka deras löpande kostnader i framtiden. De finska ortodoxa, för sin del, igångsatte sociala projekt i samarbete med de ortodoxa i Kenya. Under några år fick de dock lära sig att de inte kunde driva självständiga utvecklingsprojekt i Patriarkens i Alexandria maktsfär. Den finska ortodoxa missionen blev tvungen att underkasta sig ärkebiskopen i Nairobi. År för år beviljade den finska regeringen större anslag för missionsorganisationernas utvecklingsprojekt och statens ansvar för kostnaderna ökade från 50% till 60% år 1984. Intressant nog mottog både lutheranerna och de ortodoxa mindre statliga pengar för utvecklingssamarbete år 1989 än 1984. Däremot växte pingstvännernas utvecklingssamarbete i Kenya under hela 1980-talet. Eftersom pingstvännerna inte ville använda sina medlemmarnas pengar (som var avsedda för missionsverksamhet) till sociala projekt täckte de sin andel i utvecklingskostnaderna med pengar från utanförstående. Pingstvännerna utvecklade en omfatttande komersiell och även industriell verksamhet för att samla in pengar för sina utvecklingsprojekt.
Resumo:
Mark 4:11-12 innehåller en av Jesu mest gåtfulla utsagor. När Jesus citerar Jes 6:9-10, ser det ut som om han skulle mena att han använder liknelserna för att hindra vissa människor att förstå vad han säger, ända därhän att de därigenom utesluts från möjligheten att göra bättring och att få förlåtelse av Gud. Men utryckte Jesus sig verkligen på detta sätt? Formulerades inte utsagan snarare av den tidiga kyrkan eller evangelisten? Eller gav utsagan - vare sig den härstammade från Jesus eller kyrkan - från början alls uttryck åt tanken att liknelserna hade en förstockande funktion? Under mera än ett århundrade har forskarna ställt frågor av detta slag. Denna forskning syftar till att undersöka om man kan finna en plausibel jesuansk mening hos utsagan. Den utgår från förutsättningen att den mening och funktion som man gav åt Jes 6:9-10 i den palestinska, judiska kontexten under andra Templets period är avgörande för att hitta en jesuansk mening hos utsagan.