Dissertation (PhD)--Stellenbosch University 2000. / ENGLISH ABSTRACT: It is indeed possible for agricultural institutions to render optimum services to farmers provided that such services meet the requirements of the farmers. Insofar as the agricultural extension and information arm of these services operated in the past, the emphasis was on keeping abreast - on a scientific basis - of the needs of commercial farming. The reason for this was that over the years a clear picture of the commercial farmer as individual and his particular needs had emerged and the focus was on this. The opposite is true of developing agriculture. It is evident from available literature that there are substantial differences between them, and that these may well have a very real influence on the nature of their information requirements. Inadequate knowledge and information concerning the developing farmer - mainly as a result of very little personal contact at grassroots level - therefore create a gap in the armour of the National Department of Agriculture (NDA) as a service organisation. This study is aimed at making a contribution to this inadequate - often totally lacking - pool of knowledge and to formulate a strategy that could narrow this gap. To gain an insight into and become conversant with the world of small farmers and subsistence farmers and the influence that the realities of their lifestyle may ultimately have on their ultimate information requirements and the implementation thereof, a profile was compiled of traditional small-scale farmers in several Rural Areas of the Western Cape Province. This information was acquired from recent surveys and studies carried out in these areas. Using this profile as background, an attempt was made to describe the information environment by using a qualitative investigation method known as the focus group data collection technique. The findings of the investigation show that the very real need for land ownership and the availability of financial assistance are primary needs. Before these problems are solved to the satisfaction of small farmers, it can not be expected that they will identify information as a high priority. As regards the utilisation of specific channels of information, fellow-farmers and agricultural extension officers are identified as the most important personal channels, with the radio and printed media as the major mass-media channels. In the absence of a departmental communication strategy, development support communication (DSC) is put forward as a potential strategy to bridge the shortcomings that emerged form the investigation. In fact, DSCis the liaison between interest groups with a view to reaching consensuswhich leads to action in which the interests, needs and abilities of all role players are taken into account. The role of the go-between to act as mediator between ground-level communities and institutions such as the NDA's Directorate of Communication, and extension and research would also be vital. / AFRIKAANSE OPSOMMING: Institusionele dienslewering in die landbou kan optimaal geskied mits dit aan die behoeftes van boere voldoen. Sover dit landbouvoorligting en -inligting as die ondersteuningsarm daarvan betref, is in die verlede op wetenskaplike grondslag tred gehou met die behoeftes van die kommersiële boerdery aangesien 'n kennispoeloor tyd opgebou is oor dié boer as persoon en sy besondere behoeftes. In ontwikkelingslandbou geld die teendeel. Uit die literatuur blyk dit dat daar aansienlike verskille tussen kommersiële en kleinboere bestaan wat 'n wesentlike invloed op hul inligtingsbehoeftes mag uitoefen. 'n Onvoldoende kennispoel van die ontwikkelende landbouer, grootliks as gevolg van weinige grondvlakkontak, skep gevolglik 'n gaping in die mondering van die Nasionale Departement van Landbou (NDL) as diensleweringsorganisasie. Die studie is daarop gerig om 'n bydrae te lewer tot die gebrekkige en dikwels algehele ontbrekende kennispoel en 'n strategie voor te hou ten einde die gaping te vernou. Ten einde op hoogte te kom met die leefwêreld van kleinboere en bestaansboereen die invloed wat die gegewe mag uitoefen op hul uiteindelike inligtingsbehoeftes en -benutting, is 'n profiel saamgestel van tradisionele kleinboere in verskeie Landelike Gebiede van die Provinsie Wes- Kaap. Die inligting is bekom uit resente opnames en studies wat in die Gebiede uitgevoer is. Met die profiel as agtergrond, is voortgegaan om kleinboere in Landelike Gebiede se inligtingsomge_wingte beskryf deur gebruik te maak van 'n kwalitatiewe ondersoekmetode bekend as die fokusgroepdata-insamelingstegniek. Die bevindings van die ondersoek toon dat die behoefte aan grondbesit en die beskikbaarheid van finansiële hulpbronne primêre behoeftes is. Alvorens dit tot bevrediging van kleinboere opgelos word, kan nie verwag word dat inligting as 'n hoë prioriteit deur hulle beleef sal word nie. Wat die benutting van spesifieke inligtingskanale betref, word medeboere en landbouvoorligters as die belangrikste persoonlike kanale gemeld, met die radio en die gedrukte media as die belangrikste massamediakanale. By gebrek aan 'n departementele kommunikasiestrategie word ontwikkelingsteunkommunikasie (aSK) as 'n potensiële strategie voorgehou om die leemtes te oorbrug wat in die ondersoek aangetoon is. aSK is in wese die skakeling tussen belangegroepe met die oog op konsensusbereiking wat oorgaan tot aksie en waarin die belange, behoeftes en vermoëns van alle rolspelers in berekening gebring word. Van groot belang in die aSK-strategie is die rol van die tussenganger wat bemiddelend optree tussen grondvlakgemeenskappe en instellings soos die NDL se direktoraat Kommunikasie, landbouvoorligters en selfs navorsers.

The UK has an abundant offshore wind resource with offshore wind farming set to grow rapidly over the coming years. Optimisation of energy production is of the utmost importance and accurate estimates of wind speed distributions are critical for the planning process. Synthetic aperture radar (SAR) data can provide synoptic, wide area wind field estimates at resolutions of a few kilometres and has great potential for wind resource assessment. This thesis addresses the key challenges for the operational implementation of SAR in this context; namely the accuracy of SAR wind retrievals and the ability of SAR to characterise the mean wind speed and wind power density. We consider the main stages of SAR wind retrieval; the retrieval algorithm; sources of a priori information; the optimal configuration of the retrieval system; and the challenges for and accuracy of SAR wind resource estimation. This study was conducted for the eastern Irish Sea in the UK, a region undergoing significant offshore wind energy development. A new wind retrieval algorithm was developed that implements a maximum a posterior probability (MAP) method drawn from Bayesian statistics. MAP was demonstrated to be less sensitive to input errors than the standard direction-based wind speed algorithm (DWSA) and provides a simple retrieval quality check via the error reduction ratio. Retrieval accuracy is strongly influenced by the quality of a priori information. The accuracy of two operationally viable a priori sources, mesoscale numerical weather prediction (NWP) data and WISAR image directions, was evaluated by comparison against in-situ wind observations and WERA coastal data. Results show that NWP wind speeds produce good wind speed and direction estimates with standard deviations of ¬±2 ms-1 and ±16o respectively. WISAR directions were less accurate producing standard deviations ranging from ±20o to ±29o, but were preferable when strong differences between NWP timesteps were observed. The accuracy of SAR wind retrievals was evaluated by comparison against in-situ wind observations. The MAP algorithm was found to provide modest improvements in retrieval accuracy over DWSA. Highest quality retrievals achieved using the CMOD5 forward model, producing wind speeds with a RMSE of 1.83 ms-1. Regarding the ability of SAR to estimate offshore wind resources, dataset density was found to be a controlling parameter. With 103 scenes available mean wind speeds were well characterised by comparison against in-situ observations and Wind Atlas results, while wind power density showed considerable errors. The accuracy of wind speed maps was further improved by accounting for wind direction and fetch effects upon the SAR wind distribution. A key strength of the SAR wind fields is their ability to identify the effect of mesoscale structures upon the surface wind field with atmospheric gravity waves observed in 30% of the images. These structures are shown to introduce wind speed fluctuations of up to ±2 ms-1 at scales of 5 to 10 km and may have significant implications for wind power prediction. These findings show that SAR may provide an important source of wide area wind speed observations as a complement to existing wind resource estimation techniques. SAR may be of particular use in coastal areas where complex wind fields are observed.

2009 metais devyniolikoje (su padaliniais dvidešimt viename) Lietuvos žuvininkystės ūkių buvo vykdomi gulbių nebylių sankaupų gausos, formavimosi sezoninės dinamikos ir pasiskirstymo ypatumų tyrimai. Tyrimai užpildo eilę spragų ankstesniuose tyrimuose apie gulbių nebylių sankaupų formavimąsi žuvų tvenkiniuose. Sankaupų formavimosi laikotarpiu žuvų auginimo tvenkiniais naudojasi apie tris tūkstančius neperinčių gulbių nebylių. Paukščiai čia apsistoja sezoninių migracijų metu. Taip pat čia susirenka šertis nesiveisiantys individai. Gulbių buvimo žuvininkystės ūkių tvenkiniuose trukmę apsprendžia tvenkinių pripildymo (balandžio mėn.) ir nuleidimo (intensyviausiai rugsėjo antroje - spalio pirmoje pusėje) laikotarpiai. Sankaupos gausiausios pavasario pabaigoje - vasaros pradžioje, visų pirma birželio mėnesį, tačiau jų dydis atskiruose ūkiuose ženkliai svyruoja ir gali piką pasiekti ir kitais sezono laikotarpiais, ypač rudeniop. Stabiliai pagrindiniu, sankaupų dydį konkrečiuose žuvų ūkiuose apsprendžiančiu, veiksniu yra bendras tvenkinių, kuriuose buvo beriami žuvų pašarai, plotas. Ūkiuose (jų grupėse), kuriuose šio faktoriaus skaitinė reikšmė didelė, gulbių nebylių sankaupos taip pat didelės ir atvirkščiai. Tačiau atsitiktinė natūralių buveinių su gausiomis gulbių nebylių sankaupomis (pavyzdžiui Kuršių Marių) kaimynystė (geografinis faktorius), gali nusverti anksčiau minėto faktoriaus poveikį. Gulbės sankaupose naudoja didžiąją dalį konkretaus, ūkio tvenkinių (paprastai 50-70 %) –... [toliau žr. visą tekstą] / In 2009, research was carried out on abundance of mute swan flocks, its formation, seasonal dynamics and distribution characteristics in nineteen (with branches in twenty-one) fish farms in Lithuania. This research fills-in a number of gaps of previous studies on mute swan flocks formation in fish farm ponds. Around three thousand non breeding mute swans are using fish farming ponds during flock’s formation season. Birds stay here during seasonal migrations. Also non breeding swans gather here to moult. The duration of stay of swans in fish farm ponds is determined by the time of filling up (in April) and draining (most intensive in the second half of September and in the first half of October) of ponds. The most numerous flocks are at late spring - early summer, particularly in June, but the size of individual flocks vary considerably and may reach peak during other periods of the season, especially in autumn. The most stable factor determining size of the specific flock in fish farm ponds is area of the pond where fish are fed. Flocks are more numerous in farms (or groups of farms) in which value of this factor is higher and vice versa. However, random natural dwellings of mute swan flocks with large populations (for example neighborhood of Kuršių Marios – geographical factor) may outweigh the above factor’s impact on mute swans flock size in fish ponds. Flocks of mute swans cluster during the mobilization period and use most part of the fish farm pond (usually 50-70%) –... [to full text]

This study examines change in the family farming sector through the lens of succession. It explores empirically the succession expectations and intentions of farmers and their children in a changing contextual landscape. The research is underpinned by two theoretical concepts: the ‘farm adjustment strategy’ facilitated the development of structural reference points in respect of the family farm business and household; and application of tenets of van der Ploeg’s (1994) ‘styles’ work enabled analysis of structural change in the farm business to be viewed through a qualitative succession lens. A ‘pragmatist’ mixed-methods approach comprised a farmer survey and next generation in-depth interviews. The analytical approach accommodated issues of temporality and facilitated the linkage and study of multiple components of change. It was found that immense variability exists in terms of how succession is managed in practice. The structural characteristics and capacity of the farm business clearly impact upon succession choices and positions, but intrinsic drivers also have a very significant bearing on succession and its potential outcome. The research revealed three broad outcomes of next generation succession intention, each forming the basis of a succession style: a desire and intention to succeed to the family farm, reflected in more traditional succession modes; an intention to leave the family farm, thus opting out of farming per se; and part-time succession, characterised by off-farm professional work, flexibility and a lifestyle preference that encompasses aspects of farming and non-farming worlds. The findings presented in this thesis suggest that, through succession, forms of farm management and operation are evolving. Family farming entities are adapting and becoming increasingly heterogeneous. Through a contemporary succession lens, the notion of the family farm now comprises an assortment of family-owned and family-managed businesses with an array of diversified business, amenity and farming interests.

Growing concerns about the environmental impact of fossil fuel energy and improvements in both the cost and performance of wind turbine technologies has spurred a sharp expansion in wind energy generation. However, both the increasing size of wind farms and the increased contribution of wind energy to the overall electricity generation market has created new challenges. As wind farms grow in size and power density, the aerodynamic wake interactions that occur between neighboring turbines become increasingly important in characterizing the unsteady turbine loads and power output of the farm. Turbine wake interactions also impact variability of farm power generation, acting either to increase variability or decrease variability depending on the wind farm control algorithm. In this dissertation, both the unsteady vortex wake loading and the effect of wake interaction on farm power variability are investigated in order to better understand the fundamental physics that govern these processes and to better control wind farm operations to mitigate negative effects of wake interaction. The first part of the dissertation examines the effect of wake interactions between neighboring turbines on the variability in power output of a wind farm, demonstrating that turbine wake interactions can have a beneficial effect on reducing wind farm variability if the farm is properly controlled. In order to balance multiple objectives, such as maximizing farm power generation while reducing power variability, a model predictive control (MPC) technique with a novel farm power variability minimization objective function is utilized. The controller operation is influenced by a number of different time scales, including the MPC time horizon, the delay time between turbines, and the fluctuation time scales inherent in the incident wind. In the current research, a non-linear MPC technique is developed and used to investigate the effect of three time scales on wind farm operation and on variability in farm power output. The goal of the proposed controller is to explore the behavior of an "ideal" farm-level MPC controller with different wind, delay and horizon time scales and to examine the reduction of system power variability that is possible in such a controller by effective use of wake interactions. The second part of the dissertation addresses the unsteady vortex loading on a downstream turbine caused by the interaction of the turbine blades with coherent vortex structures found within the upstream turbine wake. Periodic, stochastic, and transient loads all have an impact on the lifetime of the wind turbine blades and drivetrain. Vortex cutting (or vortex chopping) is a type of stochastic load that is commonly observed when a propeller or blade passes through a vortex structure and the blade width is of the same order of magnitude as the vortex core diameter. A series of Navier-Stokes simulations of vortex cutting with and without axial flow are presented. The goal of this research is to better understand the challenging physics of vortex cutting by the blade rotor, as well as to develop a simple, physics-based, validated expression to characterize the unsteady force induced by vortex

This thesis provides an analytical case study of Huerta del Valle Community Garden as a successful model of redefining social capital through not only providing healthy, affordable, high quality produce to a community subjected to the disproportionate consequences of systemic inequality, but also in incorporating a food justice education framework to underlie all development at the garden. Located in the city of Ontario, Southern California – the heart of the Inland Empire, known for its prominence within the nation’s goods movement industry and its landscape of sprawling warehouses – local residents face high rates of poverty, obesity, and a lack of food access. This research identifies the socio-economic, historical factors that led to Ontario as we know it today. I argue that Ontario was founded upon institutionally racist principles, which set the region up for a future of economic disparity. It is through ‘bottom-up,’ grassroots community organizing that deeply engrained structural barriers are most successfully challenged.

The aim of this diploma thesis is to suggest the best locality in the CEE region for a prospective investment in wind farms for an undisclosed Czech company. This goal is to be achieved by comparison of generic projects that have the same technical specification, capital expenditures and operating expenses. These projects are investigated from different perspectives including wind conditions, financing terms, technology constraints and mainly the legal aspects of each respective country -- namely the regulatory environment for wind power-offtake either feed-in tariff or green certificate support schemes. The NPV of FCF and IRR (MIRR) are to be used for evaluation of these projects. Sensitivity analysis for key drivers will complement prior assumptions.

En France, le recours à de la main-d’œuvre salariée a fortement augmenté en agriculture ces quarante dernières années, notamment les salariés permanents non familiaux. Les principales raisons de ce développement sont de profondes transformations structurelles dans le secteur agricole, comme l’agrandissement des exploitations et la diminution de la main-d’œuvre familiale. Maintenir ces salariés dans les exploitations, et ainsi réduire le turnover, est devenu un défi pour la pérennité des élevages. Notre hypothèse est qu’il est nécessaire de rendre compte du travail et de comprendre le rôle des salariés dans les exploitations d’élevage, ainsi que de comprendre les changements au cours du temps, pour identifier des leviers qui pourraient aider les éleveurs et les salariés à relever ce défi. Ainsi, notre objectif est de proposer un cadre d’analyse qui articule le travail en élevage et le développement de la carrière des salariés afin de rendre compte des évolutions de leur travail, que nous appelons « trajectoire ». Pour cela les concepts proposés en gestion de ressources humaines ont été mobilisés. Ils constituent des contributions pertinentes concernant l’organisation du travail et le développement de la carrière des salariés dans les organisations. Le cadre d’analyse a été construit à partir des concepts d’attribution de tâches, de polyvalence/spécialisation et d’autonomie. Il a été implémenté avec des données empiriques issues d’entretiens individuels auprès de 14 salariés permanents non familiaux et de huit éleveurs (leurs employeurs), dans des exploitations d’élevage bovin laitier en Auvergne. Le cadre d’analyse est composé de 8 variables (19 modalités), 3 types de temporalités des changements et de 12 moteurs de changements liés à l’exploitation d’élevage, au collectif de travail et au salarié. Une représentation graphique du cadre d’analyse est proposée en exposant les articulations entre ses composants. Nos résultats montrent que le cadre d’analyse proposé est pertinent pour analyser le travail des salariés en prenant en compte la dynamique d’évolution temporelle. Cinq grands types de trajectoires d’évolution du travail des salariés ont été identifiés, à partir de la combinaison des 8 variables descriptives de l’évolution des tâches attribuées, de la tendance vers la polyvalence vs. la spécialisation et de l’évolution du niveau d’autonomie. Ces trajectoires identifiées qualifient la place des salariés dans les collectifs de travail. Connaître les trajectoires du travail des salariés permettra aux éleveurs, aux salariés et aux conseillers de réfléchir à la carrière des salariés dans les exploitations, et ainsi aux moyens de les pérenniser. Les perspectives de ce travail sont de discuter ces résultats avec les éleveurs, les salariés et les conseillers, afin d’évaluer leur utilité dans un processus réflexif sur l’organisation du travail des salariés en élevage. / In France, hiring employees in agriculture has become more common during the last forty years, especially non-familiar permanent employees. The progress of employees is related to strong structural transformations in agriculture, such as the enlargement of farms and the decrease of family workforce. Decreasing employees’ turnover is a challenge for farms’ sustainability. Thereby, our hypothesis is that take into account the role of employees in farm teamwork and understanding changes over time is a fundamental condition to identify ways to support farmers and employees to face this challenge. The aim of this thesis is to build a framework which associates both the approach to the work in livestock farms and the career development of employees to analyze how their works evolve. For this reason, the concept of human resources management has been used, in order to bring valuable contributions concerning work planning and career development inside organisations.The framework was built with the concepts of tasks assignment, versatility, specialization and autonomy. It was implemented with and empirical data from individual interview with 14 non-familiar permanent employees and 8 farmers (their employers), on dairy farms in Auvergne, a center region of France. The framework is composed by 8 variables, 19 categories, 3 rhythm of changes and 12 drivers of changes related to the farm, the farm teamwork and the employee. A conceptual representation of framework was built by linking its content. Results show that our framework is pertinent to analyze the evolutions on employees’ work from a dynamic perspective. Five pathways were identified based on eight variables that describe the evolution of task assignment, the trend toward versatility vs. specialization, and the evolution of autonomy. These pathways qualify the role of employees in farm teamwork. They could be useful for farmers, employees and agricultural advisors to plan employees’ career, thus to keep employees in farms. The longer-term goal is to discuss these results with farmers, employees and agricultural advisors to validate the framework and to assess its usefulness for a reflexive process concerning employees work organization in livestock farms.

In the archaeological research about the Baltic Sea island of Gotland during Roman Iron Age, 0–400 AD, two different approaches are visible: One that sees the community life on Gotland as different from the one on the main land with a relative stabile development, based on the family and kin, where no higher elite separate itself. The other perception emanates from the changes in southern Scandinavia, where an elite steadily grows and finally isolate itself as an aristocracy with unlimited power over others, the development on Gotland is no exception. This paper is about describing, investigating and explaining these two points of view. By using a selection of written sources the paper tries to answer three questions: What archaeological argumentations are there for that Gotland should be particular? What support the views that the island was a part of an over-regional development when it comes to struggle for power? What lies behind these very diverse positions among archaeological scholars? Two scholars, Kerstin Cassel and Frands Herschend, represents the two opposite standpoints and the three questions are to be answered by a comparison with two of their main archaeological works. This comparison, based on the other written sources and my own understanding, will show that the two different views on the gotlandish development can be traced to, more than anything, the two writers pre-understanding of their own scientific argumentations.

A thesis submitted to the Faculty of Humanities, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirement of the degree of Master of Arts in Sociology (Coursework and Research) JOHANNESBURG / The advent of the Fast Track Land Reform Programme influenced a major shift of small scale farmers from subsistence cereal cropping to the commercial growing of tobacco. Smallholder tobacco farmers enjoyed economic prosperity in the tobacco farming sector but that prosperity was short lived. Smallholder farmers face a lot of marketing, production and policy problems within the tobacco farming industry and these problems are increasingly rendering them unproductive. Most smallholder tobacco farmers are entrapped in a ‘vulnerability context’ in which they are exposed to food and income insecurity owing to the problems which they face. However, despite the challenges which they face, smallholder tobacco farmers are largely resilient; they formulate and reformulate their livelihoods on a daily basis in endeavours to cushion themselves against the overwhelming odds. It was against this background that this qualitative study sought to explore the adaptive strategies that are pursued by smallholder tobacco farmers in response to the effects posed by tobacco mono-cropping. This study also sought to examine the factors that influenced the choice of the adaptive strategies that were pursued by those farmers as well as the factors that constrained their adaptive capacity. To meet the aims of this study, a purely qualitative methodology was adopted in which unstructured interviews and focus group discussions with smallholder farmers who were purposively selected were conducted in Hurungwe district. The study found out that smallholder tobacco farmers were highly adaptive and agricultural intensification, migration, and micro-enterprise activities were found out to be the main activities that were pursued by those farmers. The study also found out gender, income levels, educational levels, infrastructure and equipment ownership as the main factors that either determined or constrained the adaptive capacity of those farmers. Based on key findings, the researcher recommended the government and non-governmental organisations to enhance rural people’s education and credit facilities access, ensure infrastructural development in rural areas and encourage peer to peer sharing of vocational skills. / MT2017