831 research outputs found
Solar Energetic Particles and their Measurement with Space Borne Instruments
The study of our Sun and its various modes of activity is an important area of research in the field of space physics and heliophysics. These active phenomena such as solar flares and Coronal Mass Ejections are associated with energetic particles (protons, electrons, ions, etc.) which are released into our solar system and possess high speed. Some of these energetic particles are likely to reach Earth. In this work, I looked into the various types of solar particle events and their characteristics as well as how these energetic particle properties are measured using space borne instruments. Different instruments using different measurement techniques were also studied, which gives us information about the kind of energetic particles that are measured or detected by these different instruments. A design of a particle telescope, which employs the use of multiple detectors was studied in this work. The telescope had three Si-detectors, a foil material (Kapton polyimide film) and a caesium iodide (CsI) detector. The detector thicknesses were optimised in order to achieve a desired result. Thus in total the design had four detectors and an entrance foil. The thicknesses of the foil material and CsI detector were as well converted into their respective silicon range equivalence in order to optimise the layer thicknesses in the design. Particles are measured at different angles of incidence but for the purpose of this work, I looked at particles penetrating the detectors at 0â° and 25â° as the limiting values. The results show that the minimum energies a particle needs to penetrate the foil material at 0â° and 25â° are 4.97 MeV and 5.27 MeV respectively. The effective threshold energy of protons detected in the first detector (D1) is between these values. Furthermore the results give us the information that as the angle of incidence is increasing, the energy also increases steadily. The energy channel resolution for protons stopping in D1, D2 and D3 were 0.386, 0.355 and 0.374 respectively which was close to the desired value (0.4) set as a target of the design
How effective are farmer-based organisations in Ghana's smallholder agriculture?
Recent years have witnessed renewed interest in farmer-based organisations (FBOs) as important local institutions for promoting smallholder agriculture and improving rural livelihoods. Many believe that the establishment of FBOs would, amongst other things, strengthen the ability of smallholder farmers to access agricultural services such as extension services and inputs, as well as reduce their risks and transaction costs of accessing these services. This thesis examines the extent to which FBOs improve smallholder farmersâ access to extension services, inputs and credit in Ghana. Central to this thesis is to understand whether, and to what extent, smallholder farmersâ participation in FBOs improves their access to extension services, inputs and credit, with special attention to understanding the factors that shape their performance in this process. The study employs a mixed-methods approach to data collection and analysis. The data collection involved structured questionnaires to 240 smallholder farmers; semi-structure interviews with 90 smallholder farmers, 12 government officials and four NGO officials. It also used a variety of secondary sources, such as documentation from FBOs, survey data, and project data from government agencies and NGOs. The data analysis utilised both quantitative and qualitative approaches, namely descriptive and inferential statistics, thematic analysis and descriptions. The analysis in the thesis shows that while smallholder farmersâ participation in FBOs improves their access to extension services, inputs and credit, their access to these services is on a limited basis. The thesis argues that the limited roles that FBOs play in improving smallholder farmersâ access to extension services, inputs and credit relate largely to their governance and management structure and their internal collective capabilities, as well as the smallholder farmersâ motivations for participating in the FBOs. The study argues that when external institutions (e.g. government and NGOs) do not invest in building FBOsâ organisational structure and leadership capacities, the results are FBOs that are passive and have weak leadership with regard to mobilising their members for the purpose of accessing agricultural services. Contrary to the empirical and theoretical arguments that FBOs and related organisations with homogenous and small memberships should have a positive collective outcome, this thesis argues that collective activities will remain limited in FBOs if their leaders do not have the experience and skills to mobilise their members for such activities. Developing sound organisational structures, such as suitable rules and regulations, would contribute to ensuring that FBOs invest time and resources into collective activities, such investment is a significant factor in their success. (ACCESS RESTRICTED TO ABSTRACT ONLY
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Analysing the requirements for monitoring and switching: A problem-oriented approach
Context-aware applications monitor changes in their environment and switch their behaviour in order to continue satisfying requirements. Specifying monitoring and switching in such applications can be difficult due to their dependence on varying environmental properties. Two problems require analysis: the detection of changes in the operating environment to assess their impact on requirements satisfaction, and the adaptation of application behaviour to ensure requirements satisfaction.
This thesis borrows from the world of problem-oriented software system development and product-lines to analyse monitoring and switching problems on one hand and contextual changes on the other. It proposes a shift of focus from treating monitoring and switching as activities to be analysed as part of the design, to treating them as part of the problem whose requirements are analysed. We claim three novel contributions: (1) we provide concepts and mechanisms for analysing monitoring and switching problems in context; (2) we formulate and prove two theorems for monitoring and switching, which define the necessary and sufficient conditions for monitoring a contextual variable and for switching application behaviour to restore requirements satisfaction when they are violated; and (3) we provide a tool for automated derivation of the conditions for monitoring and switching.
Our approach is evaluated using two case studies of a proof of concept mobile phone productline and a logistics company that delivers and monitors products across the UK. We found the applications of the approach to be effective in analysing unforeseen requirements violations caused by changes in the systems operating environments. Furthermore, the monitoring and switching mechanisms derived from the analysis enabled the software to become, to some extent, context-aware
ENGINEERING FUNGAL-MYCELIA FOR SOIL IMPROVEMENT
Most of the conventional materials, processes and techniques used by geotechnical engineers for ground improvement are associated with the emission of greenhouse gases. Global targets for reducing carbon emissions therefore pose a direct challenge to research and practice in the field of geotechnical engineering and has led to the development of interdisciplinary approaches seeking alternative low carbon technologies that are resilient to climate change. This thesis presents a novel, potentially low-carbon technique involving the use of fungal hyphal networks of Pleurotus ostreatus (P. ostreatus) for ground engineering applications.
An investigation was carried out to understand the range of environmental conditions suitable for growth of P. ostreatus in sand. Subsequently, the influence of the growth of P. ostreatus on the hydraulic and mechanical behaviour of sand was explored, in particular the influence on soil wettability, soil water retention curve, infiltration behaviour, saturated hydraulic conductivity and the stress-strain behaviour of sands. In addition, the influence of growth of P. ostreatus on the erodibility of sand was assessed using the Jet erosion test.
The results presented in this thesis demonstrate that the treatment of sand with P. ostreatus (i) induced extreme water repellency, (ii) caused a shift of the soil water retention curve increasing the air entry value from ~0.6 to 6 kPa (iii) reduced the rate of infiltration of water into sand (iv) lowered saturated hydraulic conductivity by one order of magnitude from 1.3 x 10-4 to 3.0 x 10-5 ms-1 (v) inhibited the development of dilatancy during shearing with an associated loss of peak shear strength and (vi) significantly improved the resistance of sand to erosion.
These results provide for the first time, evidence of the influence of the growth of fungal hyphae on the hydro-mechanical behaviour of soils within a geotechnical engineering context. The findings of this thesis implies that there is the potential to deploy fungal hyphal networks as a low carbon technique in areas of ground improvement where resistance of surface erosion and/or the creation of a semi-permeable barrier is require
Challenges in the Posting and Transfer of Teachers to Rural Community Schools in the Sissala East Municipality
The effective posting and transfer of teachers is a linchpin in getting teachers to rural school locations. This study explored the challenges faced by the Sissala East Municipal Education Directorate in posting and transfer of teachers to rural schools. It further looks at the effects of inadequate teachers in rural schools and proposes strategies to engender the posting and transfer of teachers to rural schools. The concurrent triangulation design type of the mixed method research paradigm was employed for the study. Both qualitative and quantitative data were collected simultaneously. Two hundred and sixty (260) respondents were sampled for the study through simple random, stratified and purposive sampling techniques. The data were collected using a questionnaire (five-point Likert scale) and a semi-structured interview guide. The collected data sets were analysed using SPSS software version 20. The study found that teacher accommodation, professional development needs, perceived ignorance about rural dwellers and condition as well as branding rural teachers as âvillage teachersâ, teachers desire to live in urban areas, Ministry of Education recruitment practices, the desire of graduate teachers to teach in senior high and urban schools, contribute significantly to the challenge of posting and transfer of teachers to rural schools. On the effects of inadequate teachers, the study found the practice of multigrade teaching, heavy workload on teachers, the presence of unqualified teachers and the inability to cover the curriculum On strategies in attracting and retaining teachers in rural schools, the study found the following strategies: recruiting teachers from targeted rural areas, induction of new teachers, provision of financial incentives and siting of teacher training institutions in rural areas. The study, contrary to previous research findings found that force transfer of teachers should be enforced. The study concluded that the Sissala East Municipal Education Directorate is challenged in the posting and transfer of teachers to rural schools. The study recommended the provision of decent accommodation for teachers, giving priority to rural teachers in granting of study leave, provision of social amenities in rural areas, decentralizing recruitment of teachers, provision of financial incentives and induction of new teachers. Keywords: posting, transfer, urban, rural and community DOI: 10.7176/JEP/11-36-13 Publication date: December 31st 202
The Impact of Crop Rotation and Nutrient Levels on Nutrition Quality, Yield and Yield Components of Maize (Zea maize L)
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Formulating an Effective Means of Bringing More Adult Males into Active Participation in the Church
The purpose of this Major Applied Project (MAP) is to interview active Lutheran male adults to discover why men perceive Christianity as a âWhite manâs religionâ and further discuss how to effectively teach people about what Christ has done for all mankind. This study, I strongly hope, will provide resources to teach Kusasi men why they should stop their worship of idols or ancestors, fear witchcraft, and also accept monogamy as the God pleasing design of marriage
Supervising the Teacher in Ghana: Implications for Pupilsâ Academic Performance in the Sissala East District
The purpose of the study, which employed qualitative and quantitative design, was to assess the core roles of supervisors in the Ghana Education Service (GES) and how effective these roles are discharged as well as the effects of the core roles of teachers on pupilsâ academic performance. The data was gathered and analysed using one hundred and fifty (150) respondents. This included twenty (20) GES officials, forty (40) teachers, forty (40) parents and fifty (50) pupils in the Sissala East District. Random and stratified sampling techniques were used in the selection of respondents. A semi-structured questionnaire and an interview guide were used in collecting data for the study. The data were analysed using the Statistical Product and Service Solutions (SPSS) based on which frequency tables were generated. It emerged from the study that bodies such as the National Inspectorate Board, the Regional Monitoring Team, the District Education Oversight Committee, School Management Committees and Parent-Teacher Associations have not been effective in discharging their supervisory roles and responsibilities. The study further revealed that the core roles of teachers impact greatly on pupilsâ academic performance. It is recommended that bodies responsible for supervising teachers are given the need logistics, education and training on their roles to ensure that teachers discharge their core roles and responsibilities. There is the need to institute stiffer sanctions such as placing embargo on teachersâ salary who fail to carry out their roles and responsibilities. Keywords: roles, data, effective, education and GE
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