The research problem of the thesis undertakes psychological aspects of carrying an infant on a mother's body using a sling or carrier. The research question states: What are the motives of mothers to carry their infant in carrying aid, according to opinions of mothers who carry their babies? The theoretical part discusses psychological findings about an early mother-child relationship in terms of contact and emerging bonds (attachment) from a prenatal period, through perinatal period, and up to one year of an infant's age. More attention has been paid to biological, behavioural, anthropological, and especially psychological assumptions for carrying an infant by its mother. A qualitative research method has been chosen for the emphirical part of the thesis. The data has been obtained by means of semi-structured interview conducted with nineteen respondents that have had experiences with carrying an infant. The respondents have been selected by an improbability selection method. The recorded interviews have been transcribed verbatim and analysed using a grounded theory. Among the most common motives for carrying a child include pleasurable feelings and experiences of mothers; especially feelings of naturalness, tranquillity, security, and freedom. Furthermore, the mothers appreciate the practicality...

In this thesis, we are addressing new method of object transportation using multi-robot system. The new method of object transportation is called A grid-based cyclic robot allocation (GCRA) method which consists multiple spherical robots. The object is placed on top of group of spherical robots before the transportation. The rotation of the multiple spherical robots cause the displacement of the object and reach the goal location based on the direction and speed of the rotation of the robots. The GCRA method for spherical robots is proposed along with specific stability criterion, which designs the formation of the multi-robot system. The formation is created based on the customized grid which is to be modified based on the properties of the object. The shape and the center of gravity of the shape define the horizontal gap, $g_x$ and vertical gap, $g_y$. All the possible locations of spherical robots is the cross points of grid which implies that $g_x$ and $g_y$ defines the distance between the robots and based on the boundary of the robots placed underneath the object, the condition of the stability is defined. It also identifies minimum number of robots required based on the arbitrary shape of an object for stable omni-directional translation of the object on a 2 dimensional space. The desired positions and formation of the robots is identified based goal position of the object. Under centralized system, position control is applied to drive the robots to the desired positions. The position control simultaneously makes the object mobile and maintain the stability of the object. Mathematical proof of the proposed method is shown verifying the stability of the transportation process with the assumptions of no slip between the robots and the object. 2 Dimensional Simulation results of robot allocation using GCRA for several arbitrary shapes certify the proposed method.

Alkali-kiselsyrareaktionen (AKR) är en kemisk reaktion som medför att spänningar uppstår i betongen då den bildade silikatgelen expanderar. Reaktionen kräver tillräcklig hög alkalihalt, reaktiv ballast samt vatten. På grund av de AKR-inducerade spänningarna är det av intresse att få kunskap i hur reaktionen påverkar betongens böjmomentkapacitet, förankring samt skjuvnings- och genomstansningskapacitet. För att besvara frågeställningen har därför en omfattande litteraturinventering tillsammans med tre kompletterande intervjuer utförts. Resultat som har erhållits, påvisar att två huvudsakliga effekter fås av AKR. Utöver en reducerad hållfasthet på grund av expansioner och sprickbildningar, erhålls även en gynnsam förspänningseffekt när armering motverkar expansioner. Med hänsyn till dessa huvudeffekter påverkas betongs bärighet i olika stor utsträckning beroende på expansionens storlek samt armeringens läge och typ i tvärsnittet. Resultaten tyder på att draghållfastheten reduceras till 40 % medan tryckhållfastheten reduceras till 60 % vid 5 mm/m expansion. För böjkapaciteten har ingen större reduktion uppmäts då expansioner understiger 6 mm/m. Emellertid har en reduktion på 25 % observerats vid expansioner större än 6 mm/m. Skjuvkapaciteten i AKR-skadad betong beror till stor del av byglars närvaro samt expansionens omfattning. I balkar utan byglar reduceras skjuvkapaciteten med 15-25 % för slät armering och 20-30 % för räfflad armering. Genomstansningskapaciteten i ett dubbelarmerat betongtvärsnitt reduceras obetydande till dess att expansionen överstiger 6 mm/m varpå en mer påtaglig reduktion fås. Hållfastheten för vidhäftning minskar med ca 40 % då täckande betongskikt understiger 1.5Æ och/eller att inga byglar är närvarande. Om byglar är närvarande samt om täckande betongskikt överstiger 4Æ visas inga tecken på försämrad vidhäftningshållfasthet. Utöver en minskad bärighet, öppnar AKR upp betong och skapar gynnsammare förutsättningar för rost-och frostangrepp. / Alkali-silica reaction (ASR) is a chemical reaction that causes stresses in concrete when the produced alkali silica gel expands. The reaction requires sufficiently high alkali content, reactive aggregates and water. Due to ASR-induced stresses it is of interest to gain insight in how ASR affects the concrete’s bending capacity, anchoring together with shear- and punching shear capacity. An extensive literature review was therefore carried out together with three complementary interviews in order to answer the question at issue. Obtained results show two main effects of ASR. In addition to a reduced strength because of cracking and expansion, an advantageous pre-stress is gained due to restraint to expansion. Thus, the load-carrying capacity of concrete is affected in various extents depending on the size of expansion and location and type of the reinforcement. The results indicate that the tensile strength is reduced to 40 % whereas the compressive strength is reduced to 60 % at 5 mm/m expansions. While expansions lesser than 6 mm/m has not shown a greater reduction of the bending capacity, a reduction of 25 % has been observed in concrete with expansions greater than 6 mm/m. The shear capacity of an ASR-affected concrete structure depends mainly on the presence of links and the extent of expansions. In beams without links, shear capacity is reduced to 15-25 % for smooth bars and 20-30 % for ribbed bars. The punching strength of a concrete structure reinforced in both faces is not reduced until expansions exceed 6 mm/m, whereas a more significant reduction is obtained. The bond strength decreases by about 40 % if the concrete cover is less than 1.5 Æ and/or if no links are present. Meanwhile if links are present and if concrete cover is more than 4Æ, no signs of reduction of the bond strength has been observed. Additionally, to a reduced load-carrying capacity, ASR also opens up the concrete and consequently creates beneficial circumstances for corrosion and frost attacks.

By investigating the scope of future wind turbine projects in north Swedish coastal regions and Lapland inland, identification of especially sensitive areas and the effect of wind farm location for the white- tailed sea eagles (WSE) Haliaeetus albicilla at these sites were evaluated. Since the 1980s the WSE the population growth has been stable and intensified in the last two decades, the upgoing trend is evident especially at coastal areas of the Bothnian Sea and Lapland inland, these regions are also considered suitable for wind farm projects. The scope of this analysis consists of an investigation of the density-dependent effect and interference regarding WSE population for each concerned wind farm by using an option with 4 MW wind turbines and a 6 MW alternative. The purpose with this comparison was to identify where wind turbines impact is most critical for WSEs and to which extent wind farms affected land area usage as well as the carrying capacity levels.One of the key findings was in Norrbotten where the 6 MW wind turbines reduced land area usage by 37,59%. In Västerbotten the highest concentration of WSEs was found and where the interference was most severe, in one of the wind farms three WSEs were observed inside the WF area which was the highest number noticed for this category in the study.Based on the low occurrence of WSEs and the accessible land area in the north-east part of Sweden (Pajala), it was considered the least critical area in terms of risk mitigation for WSE interference. A similar scenario was noticed in the southern part of Gävleborg, however in this case it was mainly a slowdown of population growth related to issues with habitat preference that enabled further possibilities for wind power investments.

This thesis presents a reanalysis of data collected between 1999 and 2006 by the Institute for Outdoor Recreation and Tourism (IORT) at Utah State University. These data concern a variety of outdoor recreation sites in Utah, Idaho, and South Dakota, and were collected via intercept, mail, and, to a very limited extent, telephone surveys. Survey instruments contained questions related to visitor perceptions of crowding, overall satisfaction, support for use limits/rationing, and estimates of use density, in addition to other conceptually related factors. Analyses consisted of multiple regression models for both perceived crowding and visitor support for use limits dependent variables for each suitable data set. These were intended to ascertain the dependent variables' relationships with various factors hypothesized to contribute to both crowding perceptions and a perceived need for use limits--notably variations in use level. This thesis also incorporated bivariate and univariate analyses intended to investigate the relationship between perceived crowding and satisfaction, reasons for respondent support for use limits, and the potential of displacing visitors to similar recreation sites via use rationing. Side-by-side comparison of results yielded several interesting findings. First, use level was the variable most consistently showing a statistically significant association with perceived crowding. However, the amount of variation explained by use level variables was small, particularly from a managerial perspective. Results suggested support for use limits may have more to do with fears about potential changes in future conditions than actual on-site crowding. Results were not suggestive of a strong or consistent relationship between perceived crowding and satisfaction. Apprehensions about crowding were the most prevalent stated reason for respondents' support of use rationing, but concerns about safety at motorized (land- and water-based) sites were also a major factor, as was recreational conflict, though to a lesser extent. Results of all analyses highlighted the uniqueness of each study area. Overall, results suggested crowding-based recreational carrying capacities may lack utility as a generalized management framework and are perhaps best reserved for sites specifically managed for low use levels or solitude experiences. Results also support calls for regional scale, rather than site-specific, recreation planning.

Outdoor recreation participation has increased during the Covid-19 pandemic and the Jämtland mountains have felt the impacts like many other geographical areas. Increased pressure from outdoor recreation risks of decreasing visitor experience and the physical conditions of the recreational landscape. The focused area of this study (the mountain area of the Jämtland triangle) experienced problems already before the Covid-19 pandemic hit due to increasing pressure from visitors as well as from differing interests among stakeholders. The pandemic has especially increased the visitor numbers and pressure from them. This study focused on the viewpoints of the visitors in relation to outdoor recreation impacts and their landscape and land-use perspectives. Moreover, their views on the possible future planning and management of the area, with emphasis on the management practices. Methods used to achieve the objectives were of embedded mixed methods (concurrent nested design): observations, contact cards and semi-structured interviews with the emphasis on qualitative data. Visible impacts in the landscape (crowding, litter, tear, and wear as well as impacts on the fauna) were discovered and that they were also experienced by the visitors to different degrees. In general, their experiences from the contact cards identified higher experiences on tear and wear of the trails as well as crowdedness. This was supported by the interview participants experiences, where each participant experienced erosion (tear and wear) and crowdedness to some degree, and numerous also noticed littering. Noise in both quantitative and qualitative aspect was only experienced to minor degree. The experiences of the visitors differed based on how many times the visitor had been in the area (besides their personal perspectives and values). In general people saw less impacts in the social and physical aspects during their first visit.The eco-strategies framework assisted the analysis of different users and user groups perspectives on the landscape, the land-use of the landscape and conflicts between different types of users (passive use “admire and enjoy the landscape” to the other end of spectrum “factory” of activities). Moreover, carrying capacity was used as a support of the analysis in combining the visitor experience, physical landscape, and the social limits. Besides viewing the public right of access as necessity, stronger restrictions and management practices were viewed as beneficial if these would help the nature recover from the outdoor recreation impacts. Inclusion of visitors and as many stakeholders as possible in the planning process was seen as beneficial. At the end, the results are reflected on in regard to future necessities planned by Länsstyrelsen Jämtlands län (2018). / <p>2022-01-22</p>

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Many species naturally occupy discrete habitat patches within a mosaic of habitats that vary in quality. The Florida scrub-jay (Aphelocoma coerulescens) is endemic to Florida scrub, a habitat that is naturally patchy and greatly reduced in area over recent decades owing to development and urbanization. Because of this habitat loss, future management of Florida scrub-jays will focus on smaller, fragmented tracts of land. My study examines such a tract, Lyonia Preserve, southwest Volusia County, FL. This preserve was unoccupied by scrub-jays prior to habitat restoration. The preserve is now frequently managed exclusively for scrub-jays as a habitat island surrounded by development. Management of the preserve includes roller chopping, root raking, timbering, and "oak stripping" where islands of oak patches are left intact while the rest of the area is roller chopped. I investigate what, if any, demographic consequences may be associated with the habitat management and the spatial setting of the preserve. I used population data collected in this area since 1992 to examine population growth and responses to habitat restoration within the preserve and habitat destruction outside the preserve. I mapped territories and measured survival and recruitment of scrub-jays, and dispersal into and out of the study area, for two and a half years. Since restoration, the population has shown logistic growth, with the area supporting higher than average densities of scrub-jay family groups. Observed density of the population and territory size varied between study years. Breeder survival values were positively related to territory size and significantly lower during periods of highest observed density. However, recruitment (yearling production) showed no relationship to territory size. Dispersal to isolated habitat patches was observed; likewise, several failed dispersal events were noted. No immigration into the study area was observed; however these data may be underrepresented since not all scrub-jays in and outside of the preserve were banded, and data collection was limited during the initial colonization period. High densities inside the preserve may therefore be both a result of frequent habitat management in the form of mechanical treatment as well as crowding of individuals due to outside habitat destruction. The results indicate that carrying capacity of habitat for scrub-jays may be raised by frequent, mechanical management; however, if the area is isolated, management may result in high densities and negative demographic consequences, e.g., reduced breeder survival. Negative effects of management may be avoided by subjecting smaller areas to mechanical treatment with increased time between treatments. Land managed for Florida scrub-jays should be contiguous or connected with other scrub habitats so that surplus birds from the managed areas have a refuge and do not contribute to increased densities. Regulatory officials should use caution when allowing for "take" of scrub-jay habitat as the effects may extend beyond the local habitat being destroyed.

No description available.

No description available.