4,792 research outputs found
Migration to Juba: a case study
This study represents the first stage in an examination of migration to Juba, the capital of the Southern Region of the Democratic Republic of the Sudan. Both the Region and the subject are largely unresearched and thus the work is mainly original, yet descriptive and analytical rather than hypothesis testing. Similarly the first and final sections provide necessary background material on the Sudan, the Region and the subject of migration, thereby placing the study in a relevant context. Since 1972, when a seventeen year civil war was terminated and Juba became capital of the Southern Region, the population of the town has grown enormously, and largely as a result of in-migration. The work on this movement is broadly divided into three sections. The first of these looks at the migratory movement as a whole and examines its directions, mechanisms and temporal aspects. The movement is largely rural to urban in direction, and there is some evidence of a stepped nature and of hierarchical organisation by distance rather than town size. The bulk of in-migration has occurred since 1972, and particularly in 1978 and 1979.The second section considers the socio-economic characteristics of the migrants and highlights the male bias, and the dominance of the 15-29 year cohort in the age structure. Economic reasons have been important in the decision making process, as have those of education and family connections. International migration is the subject of the third section, in which the relevant migratory aspects of the civil disturbances in Sudan and Uganda are examined. It is concluded that in-migration has been of great importance in the growth of the population of Juba and that there appear to be no reasons why it will not continue for the foreseeable future. This will raise very serious economic and infrastructural problems because the creation of employment opportunities is not keeping pace with demand nor are the existing services sufficient to cope with further increases in the population of the town
Master of Science
thesisA crushed, secondary sulfide copper ore was provided by a large mining company. The agglomeration of the ore was studied in three phases. In phase one, a series of scoping experiments were conducted to characterize agglomerates produced in terms of agglomerate size distribution, electrical conductivity, hydraulic conductivity, and a test of binding strength. Using these tools and visual appearance, optimum agglomeration conditions were determined to be 13.0% moisture determined on a wet basis, 60 g/L H2SO4, 30% critical speed, and 3 minute agglomeration time. Upon determination of agglomeration conditions, the study entered a second phase where agglomerates were subjected to leaching in order to determine the relation of leaching behavior to agglomeration conditions. Acid concentration was found to be important for the initial week of leaching. None of the agglomeration conditions affected copper recovery at 90 days of leaching. Following leaching, acid-resistant agglomeration aids were evaluated to identify those with a potential to improve agglomerate stability and potentially, leaching behavior. Two cationic polymers were selected from an assortment of potential binders. Both polymers greatly improved agglomerate strength and hydraulic conductivity when used during agglomeration at a dosage of 0.5 kg polymer per tonne of ore
New Perspectives: Technology Teacher Education and Engineering Design
Initiatives to integrate engineering design within the field of technology education are increasingly evident (Lewis, 2005; Wicklein, 2006). Alliances between technology education and engineering were prominent in the development of the Standards for Technological Literacy (International Technology Education Association, 2000), and leaders from both disciplines have expressed support for the outcomes described in the Standards (Bybee, 2000; Council of the National Academy of Engineering, 2000; Dugger, Meade, Delany, and Nichols, 2003; Gorham, Newberry, and Bickart, 2003). The National Science Foundation (NSF) has also encouraged and funded opportunities for technology educators and engineers to work collaboratively. The Bridges for Engineering Education projects and more recently the $10 million, 5-year funding for the National Center for Engineering and Technology Education exemplify the commitment of the NSF to support these activities.
The history of technology education is replete with trends and changes in curriculum, technical content, instructional materials and equipment, instructional strategies, and even identity (Lewis, 2004, 1999; Sanders, 2001). The profession has revised its name and made substantial efforts to affect public perceptions of the field. The historical benchmarks in technology education bear labels such as Industrial Arts Curriculum Project, Maryland Plan, Jacksonâs Mill, or Technology for All Americans. A movement to embrace engineering design as a focal element in technology education would be another significant event in the ongoing history of technology education and could become another benchmark in shaping the profession.
Perspectives regarding the role engineering should play within the discipline of technology education vary considerably. These positions range from advocating that technology education take on the role of pre-engineering for high school students to arguments in favor of retaining a broad focus for technology education in which it treats engineering design as simply one of many forms of creative activity. The perspective underlying the position presented here is that technology education should retain a general education role, providing hands-on learning activities for all students and encompassing approaches to design and problem-solving that extend beyond engineering to embrace aesthetics and artistic creativity. Engineering design, however, can provide a focus for the field of technology education that is applicable for students in all grade levels and career pathways.
Implementing an engineering design focus within technology education has significant ramifications. Classroom teachers, teacher educators, and support staff will need additional knowledge and skills to successfully shift the focus of the field toward engineering design. Changes will especially affect the preparation of technology teachers. Curriculum, educational philosophy, instructional strategies, and collaborative relationships are among the facets that will be influenced by this initiative. In each of these areas there are perhaps more questions than answers, and thoughtful discussion and research are needed to guide decision-making. It is essential that the field recognize the key issues so that steps are taken to provide and facilitate necessary professional development
Optimising chronotherapy for gastrointestinal cancers
Gastrointestinal cancers are some of the most common and deadly cancers in the world. The improvement of current treatments is of great importance to improve patients survival and quality of life and decrease the burden of these cancers. Within this thesis we will focus on two particular cancers: colorectal and pancreatic cancer, and their treatment by three cytotoxics oxaliplatin, 5-fluorouracil and irinotecan. The improvement of treatment will focus on the use of circadian rhythms. Circadian rhythms are the innate approximately 24 hour rhythms present in almost all living organisms. Treatments which take this innate rhythm into account is known as chronotherapy and has already been shown to improve patient outcomes. However, recent findings highlight the need of personalising drug timing to account for the patientâs gender, chronotype and genetic background. We will firstly look at potential improvements which can be made directly to current treatment protocols by using mathematical models. A model of the drug solution dynamics from an infusion pump to the patient blood will be developed and used to improve the accuracy of chronomodulated drug delivery. Subsequently, semi-mechanistic models of individual patient drug pharmacokinetics will be connected to the pump-to-patient model and used as a method of patient stratification in order to better personalise treatments. We will then use a multiscale approach- from in vitro to mouse studies- to build a physiologically-based whole body model of oxaliplatin pharamcokinetics to look at sexual dimorphism in the drug chronoefficacy and chronotoxicity. This model can then be used to connect differences in drug dynamics to measurable biomarkers and help inform future human trials. Overall, this thesis aims to develop mathematical tools to personalize chronotherapy treatments and further the knowledge available to biologists and clinicians working in this important area of cancer research
An evolutionary approach to the optimisation of autonomous pod distribution for application in an urban transportation service
For autonomous vehicles (AVs), which when deployed in urban areas are called âpodsâ, to be used as part of a commercially viable low-cost urban transport system, they will need to operate efficiently. Among ways to achieve efficiency, is to minimise time vehicles are not serving users. To reduce the amount of wasted time, this paper presents a novel approach for distribution of AVs within an urban environment. Our approach uses evolutionary computation, in the form of a genetic algorithm (GA), which is applied to a simulation of an intelligent transportation service, operating in the city of Coventry, UK. The goal of the GA is to optimise distribution of pods, to reduce the amount of user waiting time. To test the algorithm, real-world transport data was obtained for Coventry, which in turn was processed to generate user demand patterns. Results from the study showed a 30% increase in the number of successful journeys completed in a 24 hours, compared to a random distribution. The implications of these findings could yield significant benefits for fleet management companies. These include increases in profits per day, a decrease in capital cost, and better energy efficiency. The algorithm could also be adapted to any service offering pick up and drop of points, including package delivery and transportation of goods
The experience of disabled and non-disabled students on professional practice placements in the United Kingdom
Temperature Dependent Neutron Scattering Sections for Polyethylene
This note presents neutron scattering cross sections for polyethylene at 296
K, 77 K and 4 K derived from a new scattering kernel for neutron scattering off
of hydrogen in polyethylene. The kernel was developed in ENDF-6 format as a set
of S(alpha,beta) tables using the LEAPR module of the NJOY94 code package. The
polyethylene density of states (from 0 to sub eV) adopted to derive the new
kernel is presented. We compare our calculated room temperature total
scattering cross sections and double differential cross sections at 232 meV at
various angles with the available experimental data (at room temperature), and
then extrapolate the calculations to lower temperatures (77K and 4K). The new
temperature dependent scattering kernel gives a good quantitative fit to the
available room temperature data and has a temperature dependence that is
qualitatively consistent with thermodynamics.Comment: 6 page
High Reynolds Number Test of the Boeing TR77 Airfoil in the Langley 0.3-Meter Transonic Cryogenic Tunnel
A Boeing TR77 airfoil associated with the Advanced Technology Airfoil Test (ATAT) program was tested in the Langley 0.3 m Transonic Cryogenic Tunnel. Limited analysis of the data indicated that increasing Reynolds number for a fixed Mach number resulted in increased normal-force, nose-down pitching moment, and decreased drag coefficient. Increasing Mach number while keeping the Reynolds number constant yielded the expected increase in normal-force slopes, nose-down pitching moment coefficients, and decrease in angle of attack associated with maximum normal-force coefficient. Turbulent boundary layer flow was achieved over the airfoil at low Reynolds numbers for the test Mach number range using aluminum discs
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