933 resultados para Four-Point Bending
Resumo:
Whilst the topic of soil salinity has received a substantive research effort over the years, the accurate measurement and interpretation of salinity tolerance data remain problematic. The tolerance of four perennial grass species (non-halophytes) to sodium chloride (NaCl) dominated salinity was determined in a free-flowing sand culture system. Although the salinity tolerance of non-halophytes is often represented by the threshold salinity model (bent-stick model), none of the species in the current study displayed any observable salinity threshold. Further, the observed yield decrease was not linear as suggested by the model. On re-examination of earlier datasets, we conclude that the threshold salinity model does not adequately describe the physiological processes limiting growth of non-halophytes in saline soils. Therefore, the use of the threshold salinity model is not recommended for non-halophytes, but rather, a model which more accurately reflects the physiological response observed in these saline soils, such as an exponential regression curve.
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Physical and psychological decline is common in the post-treatment breast cancer population, yet the efficacy of concurrent interventions to meet both physical- psychosocial needs in this population has not been extensively examined. PURPOSE: This study explores the effects of a combined exercise and psychosocial intervention model on selected physiological-psychological parameters in post-treated breast cancer. METHODS: Forty-one breast cancer survivors were randomly assigned to one of four groups for an 8-week intervention: exercise only [EX, n=13] (aerobic and resistance training), psychosocial therapy only [PS, n=11] (biofeedback), combined EX and PS [EX+PS, n=11], or to control conditions [CO, n=6]. Mean delta score (post-intervention - baseline) were calculated for each of the following: body weight, % body fat (skin folds), predicted VO2max (Modified Bruce Protocol), overall dynamic muscular endurance [OME] (RMCRI protocol), static balance (Single leg stance test), dynamic balance (360° turn and 4-square step test), fatigue (Revised Piper Scale), and quality of life (FACT-B). A one-way ANOVA was used to analyze the preliminary results of this on-going randomized trial. RESULTS: Overall, there were significant differences in the delta scores for predicted VO2max, OME, and dynamic balance among the 4 groups (p<0.05). The EX+PS group showed a significant improvement in VO2max compared with the PS group (4.2 ± 3.8 vs. -0.9 ± 4.2 mL/kg/min; p<0.05). Both the EX+PS and EX groups showed significant improvements in OME compared with the PS and CO groups (44.5 ± 23.5 and 43.4 ± 22.1 vs. -3.9 ± 15.2 and 2.7 ± 13.7 repetitions; p<0.05). All 3 intervention groups showed significant improvements in dynamic balance compared with the CO group (-0.8 ± 0.6, -0.6 ± 0.8, and -0.6 ±1.0 vs. 0.6 ± 0.6 seconds; p<0.05). Overall, changes in fatigue tended towards significance among the 4 groups (p = 0.08), with decreased fatigue in the intervention groups and increased fatigue in the CO group. CONCLUSIONS: Our preliminary findings suggest that EX and PS seem to produce greater positive changes in the outcome measures than CO. However, at this point no definite conclusions can be made on the additive effects of combining the EX and PS interventions.
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The self-similar solution of the unsteady laminar compressible boundary-layer flow with variable properties at a three-dimensional stagnation point with mass transfer has been obtained when the free-stream velocity varies inversely as a linear function of time. The resulting ordinary differential equations have been solved numerically using an implicit finite-difference scheme. The results are found to be strongly dependent on the parameter characterizing the unsteadiness in the free-stream velocity. The velocity profiles show some features not encountered in steady flows.
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The effectiveness of the neonicotinoid insecticide imidacloprid was evaluated against four psocid pests of stored grain. This research was undertaken because of the growing importance of psocids in stored grain and the need to identify methods for their control. The mortality and reproduction of adults of Liposcelis bostrychophila Badonnel, L. entomophila (Enderlein), L. decolor (Pearman) and L. paeta Pearman in wheat treated with imidacloprid were determined. There were five application rates (0.5, 1, 2, 5 and 10 mg AI kg -1 grain) and an untreated control. There were significant effects of application rate on both adult mortality and reproduction for all four species, but the effect of imidacloprid was sometimes more pronounced on reproduction. Imidacloprid was most effective against L. bostrychophila, with 100% adult mortality after 7 d at 5 mg AI kg-1, 14 d at 2 mg AI kg-1 and 28 d at 0.5 and 1 mg AI kg-1. No live progeny were produced at 2 mg AI kg-1. For L. decolor, there was 100% adult mortality after 28 d at 10 mg AI kg-1 and no live progeny were produced at 2 mg AI kg-1. For L. entomophila, there was 100% adult mortality after 14 d at 10 mg AI kg-1 and 28 d at 2 and 5 mg AI kg-1. No live progeny were produced at 10 mg AI kg-1. At 10 mg AI kg-1 there was 100% mortality of L. paeta adults after 28 d exposure and no live progeny developed. Because reproduction at some application rates occurred only in the first 14 d of exposure, it is concluded that the application rate leading to population extinction was 1 mg AI kg-1 for L. bostrychophila, 2 mg AI kg-1 for L. decolor and L. entomophila and 5 mg AI kg -1 for L. paeta. This study shows that imidacloprid has potential as a grain protectant to control all four Liposcelis species in stored grain.
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Non-governmental organisations (NGOs) have gained an important role in development co-operation during the last two decades. The development funding channelled through NGOs has increased and the number of NGOs engaged in development activities, both North and South, has been growing. Supporting NGOs has been seen as one way to strengthen civil society in the South and to provide potential for enhancing more effective development than the state, and to exercise participatory development and partnership in their North-South relationships. This study focuses on learning in the co-operation practices of small Finnish NGOs in Morogoro, Tanzania. Drawing on the cultural-historical activity theory and the theory of expansive learning, in this study I understand learning as a qualitative change in the actual co-operation practices. The qualitative change, for its part, emerges out of attempts to deal with the contradictions in the present activity. I use the concept of developmental contradiction in exploring the co-operation of the small Finnish NGOs with their Tanzanian counterparts. Developmental contradiction connects learning to actual practice and its historical development. By history, in this study I refer to multiple developmental trajectories, such as trajectories of individual participants, organisations, co-operation practices and the institutional system in which the NGO-development co-operation is embedded. In the empirical chapters I explore the co-operation both in the development co-operation projects and in micro-level interaction between partners taking place within the projects. I analyse the perceptions of the Finnish participants about the different developmental trajectories, the tensions, inclusions and exclusions in the evolving object of co-operation in one project, the construction of power relations in project meetings in three projects, and the collision of explicated partnership with the emerging practice of trusteeship in one project. On the basis of the empirical analyses I elaborate four developmental contradictions and learning challenges for the co-operation. The developmental contradictions include: 1) implementing a ready-made Finnish project idea vs. taking the current activities of Tanzanian NGO as a starting point; 2) gaining experiences and cultural interaction vs. access to outside funding; 3) promoting the official tools of development co-operation in training vs. use of tools and procedures taken from the prior activities of both partners in actual practice; and 4) asymmetric relations between the partners vs. rhetoric of equal partnership. Consequently, on the basis of developmental contradictions four learning challenges are suggested: a shift from legitimation of Finnish ideas to negotiation, transcending the separate objects and finding a partly joint object, developing locally shared tools for the co-operation, and identification and reflection of the power relations in the practice of co-operation. Keywords: activity theory; expansive learning; NGO development co-operation; partnership; power
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Black point in wheat has the potential to cost the Australian industry $A30.4 million a year. It is difficult and expensive to screen for resistance, so the aim of this study was to validate 3 previously identified quantitative trait loci (QTLs) for black point resistance on chromosomes 2B, 4A, and 3D of the wheat variety Sunco. Black point resistance data and simple sequence repeat (SSR) markers, linked to the resistance QTLs and suited to high-throughput assay, were analysed in the doubled haploid population, Batavia (susceptible) × Pelsart (resistant). Sunco and Pelsart both have Cook in their pedigree and both have the Triticum timopheevii translocation on 2B. SSR markers identified for the 3 genetic regions were gwm319 (2B, T. timopheevii translocation), wmc048 (4AS), and gwm341 (3DS). Gwm319 and wmc048 were associated with black point resistance in the validation population. Gwm341 may have an epistatic influence on the trait because when resistance alleles were present at both gwm319 and wmc048, the Batavia-derived allele at gwm341 was associated with a higher proportion of resistant lines. Data are presented showing the level of enrichment achieved for black point resistance, using 1, 2, or 3 of these molecular markers, and the number of associated discarded resistant lines. The level of population enrichment was found to be 1.83-fold with 6 of 17 resistant lines discarded when gwm319 and wmc048 were both used for selection. Interactions among the 3 QTLs appear complex and other genetic and epigenetic factors influence susceptibility to black point. Polymorphism was assessed for these markers within potential breeding material. This indicated that alternative markers to wmc048 may be required for some parental combinations. Based on these results, marker-assisted selection for the major black point resistance QTLs can increase the rate of genetic gain by improving the selection efficiency and may facilitate stacking of black point resistances from different sources.
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The aim of this research was to explore how issues of power manifest themselves in bringing up children at home. The starting point for the study was a phenomenon centered, power focused, and theoretically orientated view which also included an empirical part as well. The most common aim of the research was to find out and theoretize of power which is suitable for bringing up children at home. Power was defined and researched on the basis of existing power theories, mostly those presented in anglo-american research on power. For closer investigation I chose the most common categorizations and theories of power, namely, the nature of power, the four dimensions of power, and forms of power. The empirical part of the research consisted of 22 thematic interviews with mothers, fathers and 14 – 16-year-old teenagers from 11 different families. The interviewees were found through snowball sampling. The questions for the interviews were based on power theories. The result of the research was that the most common categorizations and theories of power were useful but not satisfactory in the study of power in bringing up children at home. The nature of authority in bringing up children at home appears to have same characteristics as the categorization of authority put forward by Weber but in addition it included extra categories called moral authority and ontological-existential authority. Theoretically the most challenging problem concerns the conflict between modern and postmodern views of power. None of them alone is able to describe power in bringing up children at home. The best solution appeared to be to add an assumption about the inner relation to the modern power view and an assumption about the Popperian three worlds to the postmodern view of power. The relationship between the parent and the child is necessary the inner power relation where the relation itself modifies the parties’ identities. In that case positive and productive elements are also included in the power relationship. Parents use many forms of power in bringing up children at home. Manipulative and violent forms of power are not justifiable but other forms of power and their open exercise is sometimes necessary. The important criteria to use in order to determine the most suitable forms of power and the most appropriate ways of exercising that power is to see how they improve the development of the identity and internalization of values of the child. An ethically justified exercise of power in bringing up children at home is based on a dialogical, pedagogical relationship between the parent and the child, focuses on the relationship between the parent and the child, orientates itself further than present, aspires to promote the good of the child, and comes true in a caring atmosphere.
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An on-line algorithm is developed for the location of single cross point faults in a PLA (FPLA). The main feature of the valgorithm is the determination of a fault set corresponding to the response obtained for a failed test. For the apparently small number of faults in this set, all other tests are generated and a fault table is formed. Subsequently, an adaptive procedure is used to diagnose the fault. Functional equivalence test is carried out to determine the actual fault class if the adaptive testing results in a set of faults with identical tests. The large amount of computation time and storage required in the determination, a priori, of all the fault equivalence classes or in the construction of a fault dictionary are not needed here. A brief study of functional equivalence among the cross point faults is also made.
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When recapturing satellite collared wild dogs that had been trapped one month previous in padded foothold traps, we noticed varying degrees of pitting on the pads of their trapped paw. Veterinary advice, based on images taken of the injuries, suggests that the necrosis was caused by vascular compromise. Five of six dingoes we recaptured had varying degrees of necrosis restricted only to the trapped foot and ranging from single 5 mm holes to 25% sections of the toe pads missing or deformed, including loss of nails. The traps used were rubber-padded, two–coiled, Victor Soft Catch #3 traps. The springs are not standard Victor springs but were Beefer springs; these modifications slightly increase trap speed and the jaw pressure on the trapped foot. Despite this modification the spring pressure is still relatively mild in comparison to conventional long spring or four-coiled wild dog traps. The five wild dogs developing necrosis were trapped in November 2006 at 5-6 months of age. Traps were checked each morning so the dogs were unlikely to have been restrained in the trap for more than 12 hours. All dogs exhibited a small degree of paw damage at capture which presented itself as a swollen paw and compression at the capture point. In contrast, eight wild dogs, 7-8 month-old, were captured two months later in February. Upon their release, on advice from a veterinarian, we massaged the trapped foot to get blood flow back in to the foot and applied a bruise treatment (Heparinoid 8.33 mg/ml) to assist restoring blood flow. These animals were subsequently recaptured several months later and showed no signs of necrosis. While post-capture foot injuries are unlikely to be an issue in conventional control programs where the animal is immediately destroyed, caution needs to be used when releasing accidentally captured domestic dogs or research animals captured in rubber-padded traps. We have demonstrated that 7-8 month old dogs can be trapped and released without any evidence of subsequent necrosis following minimal veterinary treatment. We suspect that the rubber padding on traps may increase the tourniquet effect by wrapping around the paw and recommend the evaluation of offset laminated steel jaw traps as an alternative. Offset laminated steel jaw traps have been shown to be relatively humane producing as few foot injuries as rubber-jawed traps.
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This study examined the fundamental question of what really matters when selecting a new employee. The study focused on tacit knowledge used by personnel recruiters when interviewing employees. Knowledge was defined as the best view available, which helps one not to act haphazardly. Tacit knowledge was also defined as a positive concept, and it was seen as a part of personnel recruiters` improving proficiency. The research topic was chosen based on the observed increase in the amount of employment interviews and their importance in society. As recruiting is becoming a more distinct profession, it was reasonable to approach the topic from an educational point of view. The following research problems guided the examination of the phenomenon: 1) Where does the interviewer seek tacit knowledge from during the employment interview? 2) How is tacit knowledge achieved during the employment interview? 3) How does the interviewer defend the significance of the tacit knowledge gained as knowledge that has influence on the selection decision? The research data was collected by interviewing six personnel recruiters who conduct and evaluate employment interviews as part of their work responsibilities. The interview themes were linked to some recently made selection decision in each organization and the preceding employment interview with the selected candidate. In order to conceptualize tacit knowledge, reflective consideration of the interview event was used in the study. The lettered research data was analyzed inductively. As a result of the study, the objects of tacit knowledge in the context of an employment interview culminated into three areas: the applicant s verbal communication, the applicant s non-verbal communication and the interaction between interview participants. Observations directed toward those objects were shown to be intentional and three schemes were found behind them: experiences from previous interviews, applicant s application papers and the aptitude for the work responsibilities. The question of gaining knowledge was answered with the concept of procedural knowledge. Personnel recruiters were found to have four different, but interconnected ways to encounter knowledge during an employment interview: understanding, evaluative, revealing, and approving knowing. In order to explain the importance given to tacit knowledge, it was examined in connection with the most prevalent practices in the personnel selection industry. The significance of knowledge as the kind of knowledge that has an impact on the decision was supported by references to collective opinion (other people agree with it), circumstance (interview s short duration), or using some instrument (structured interview). The study revealed new aspects of employment selection process through examining tacit knowledge. The characteristics of the inductive analysis of the research data may also be utilized, when applicable, in tacit knowledge research within other contexts.
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Short-time analytical solutions of temperature and moving boundary in two-dimensional two-phase freezing due to a cold spot are presented in this paper. The melt occupies a semi-infinite region. Although the method of solution is valid for various other types of boundary conditions, the results in this paper are given only for the prescribed flux boundary conditions which could be space and time dependent. The freezing front propagations along the interior of the melt region exhibit well known behaviours but the propagations along the surface are of new type. The freezing front always depends on material parameters. Several interesting results can be obtained as particular cases of the general results.
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We discuss the consistency, unitarity and Lorentz invariance of an anomalous U(1) gauge theory in four dimensions. Our analysis is based on an effective low-energy action valid in the chiral symmetry broken phase. The allegedly bad properties of anomalous theories (except non-renormalizability) are examined. It is shown that, in the low-energy context, the theory can be consistently and unitarily quantised, and is formally Lorentz covariant.
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This study reports on the realisation of multicultural education in a multicultural pre-school group of one kindergarten. The research questions were: 1) what multicultural goals and contents did the kindergarten´s own pre-school curriculum contain? and 2) how did the pre-school educators´ views on multicultural education appear in their actions in a multicultural pre-school group? The research was conducted by analysing the curricula, interviewing the educators, and observing of the preschool groups. Pre-school education is seen as part of institutionalised education which is defined through culture. Education is considered from the point of view of critical multicultural education, paying special attention to the role of society in the definition of education. The research is a case study, and it concentrates on the interpretation of the working philosophy of one preschool group with respect to its implementation. The target group consisted of 20 6-year-old pre-school pupils in a kindergarten and their four pre-school educators. The research results showed that the kindergarten´s own pre-school curriculum (1997) was in structure and form consistent with the structure and form of the National Core Curriculum for Pre-School Education from 1996. The only difference was in the classification of the various subject fields and objectives. The contents of the two curricula showed hardly any variation, and both of them contained only few goals and contents for multicultural education. According to the interviews, the educational views and learning philosophy of the pre-school educators represented a child-centred point of view that takes into consideration the individual pupil´s needs and skills. This is also one of the basic principles of multicultural education. The principle was not, however, realised in the directed activities of the pre-school group. The heterogeneity of the pre-school group was dealt with by dividing the children into smaller groups, but the contents of the tuition were not differentiated. All children were provided with the same goals and contents. Multicultural education was seen as remote and separate from the overall educational philosophy. The contents of multicultural education were interpreted by the educators as teaching Finnish as a second language and teaching the children their own mother tongue and religion. After the evaluation of the state of the kindergarten´s multicultural education using four different models, I determined that the kindergarten emerged as a representative of the model where multicultural education is seen as something meant for immigrants only. The aim of the model is a rapid integration of the immigrant children with the majority population. Keywords: education, pre-school education, multicultural education, critical multicultural education, language, culture
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The study examines one case of students' experiences from the activity in a collaborative learning process in a networked learning environment, and explores whether or not the experiences explain the participation or lack of participation in the activities. As a research task the students' experiences in the database of the networked learning environment, participating in its construction, and the ways of working needed to build the database, were examined. To contrast the students' experiences, their actual participation in the building of the database was clarified. Based on actual participation, groups more active and more passive than average were separated, and their experiences were compared to each other. The research material was collected from the course Cognitive and Creative Processes, which was offered to studentsof the Department of Textile Teacher Education in University of Helsinki, and students of the Departments of Teacher Education Units giving textile education in Turku, Rauma and Savonlinna in the beginning of 2001. In this course, creativity was examined from a psychological and sosiocultural context with the aim of realizing a collaborative progressive inquiry process. The course was held in a network-based Future Learning Environment (Fle 2) except for the starting lecture and training the use of the learning environment. This study analyzed the learning diaries that the students had sent to the tutor once a week for four weeks, and the final thoughts written into the database of the learning environment. Content analysis was applied as the research method. The case was enriched from another point of view by examining the messages the students had written into the learning environment with the social network analysis. The theoretical base of the study looks at the research of computer-supported collaborative learning, the conceptions of learning as a process of participation and knowledge building, and the possibilities and limitations of network-based learning environments. The research results show, that both using the network-based learning environment and collaborative ways of studying were new to the students. The students were positively surprised by the feedback and support provided by the community. On the other hand, they also experienced problems with facelessness and managing the information in the learning environment. The active students seemed to be more ready for a progressive inquiry process. It can be seen from their attitudes and actions that they have strived to participate actively and invested into the process both from their own and the community's point of view. The more passive students reported their actions to get credits and they had a harder time of perceiving the thoughts presented in the net as common progression. When arranging similar courses in the future, attention should be paid to how to get the students to act in ways necessary for knowledge building, and different from more traditional ways of studying. The difficulties of students used to traditional studying methods to adapt to collaborative knowledge building were evident on the course Cognitive and Creative Processes. Keywords: computer supported collaborative learning, knowledge building, progressive Inquiry, participation