East African topography and volcanism explained by a single, migrating plume

Anomalous topographic swells and Cenozoic volcanism in east Africa have been associated with mantle plumes. Several models involving one or more fixed plumes beneath the northeastward migrating African plate have been suggested to explain the space-time distribution of magmatism in east Africa. We devise paleogeographically constrained global models of mantle convection and, based on the evolution of flow in the deepest lower mantle, show that the Afar plume migrated southward throughout its lifetime. The models suggest that the mobile Afar plume provides a dynamically consistent explanation for the spatial extent of the southward propagation of the east African rift system (EARS), which is difficult to explain by the northeastward migration of Africa over one or more fixed plumes alone, over the last ≈45 Myrs. We further show that the age-progression of volcanism associated with the southward propagation of EARS is consistent with the apparent surface hotspot motion that results from southward motion of the modelled Afar plume beneath the northeastward migrating African plate. The models suggest that the Afar plume became weaker as it migrated southwards, consistent with trends observed in the geochemical record

Modelling and Optimising of a Light-Weight Rockfall Catch Fence System

Rockfall catch fence is a mechanical barrier system that is used at the foot of cliffs to stop and retain falling rocks from reaching nearby infrastructures. A typical system comprises of a high tensile strength wire mesh that is anchored to the ground by rigid posts and strengthened to the lateral and upslope sides by anchoring tension cables. Additional components, such as shock absorbers, might be added to improve the system capacity to dissipate energy. This multi-component system characterises by geometrical complexity and high nonlinear response to impact loads. A light-weight catch fence system is a simple system that can be easily installed in a time efficient manner using manpower rather than heavy machinery, which makes it ideal for railways located in mountainous and difficult terrain regions where there is difficulty in accessing sites with limited workspaces and restricted installation times. However, this should be combined with a proper design to ensure that the system provides the required protection to impede falling rocks from reaching the train lines. In this paper, a parametric study based on finite element analysis is developed to optimise the design of a light-weight catch fence system that has an energy absorption capacity of up to 100 kJ

On Dirac Zero Modes in Hyperdiamond Model

Using the SU(5) symmetry of the 4D hyperdiamond and results on the study of 4D graphene given in "Four Dimensional Graphene" (L.B Drissi, E.H Saidi, M. Bousmina, CPM-11-01, Phys. Rev. D (2011)), we engineer a class of 4D lattice QCD fermions whose Dirac operators have two zero modes. We show that generally the zero modes of the Dirac operator in hyperdiamond fermions are captured by a tensor {\Omega}_{{\mu}}^{l} with 4\times5 complex components linking the Euclidean SO(4) vector {\mu}; and the 5-dimensional representation of SU(5). The Bori\c{c}i-Creutz (BC) and the Karsten-Wilzeck (KW) models as well as their Dirac zero modes are rederived as particular realizations of {\Omega}_{{\mu}}^{l}. Other features are also given. Keywords: Lattice QCD, Bori\c{c}i-Creutz and Karsten-Wilzeck models, 4D hyperdiamond, 4D graphene, SU(5) Symmetry.Comment: LaTex, 28 pages, To appear in Phys Rev

Polynomial bounds for the solutions of parametric transmission problems on smooth, bounded domains

We consider a \emph{family} $(P_\omega)_{\omega \in \Omega}$ of elliptic second order differential operators on a domain $U_0 \subset \mathbb{R}^m$ whose coefficients depend on the space variable $x \in U_0$ and on $\omega \in \Omega,$ a probability space. We allow the coefficients $a_{ij}$ of $P_\omega$ to have jumps over a fixed interface $\Gamma \subset U_0$ (independent of $\omega \in \Omega$). We obtain polynomial in the norms of the coefficients estimates on the norm of the solution $u_\omega$ to the equation $P_\omega u_\omega = f$ with transmission and mixed boundary conditions (we consider ``sign-changing'' problems as well). In particular, we show that, if $f$ and the coefficients $a_{ij}$ are smooth enough and follow a log-normal-type distribution, then the map $\Omega \ni \omega \to \|u_\omega\|_{H^{k+1}(U_0)}$ is in $L^p(\Omega)$, for all $1 \le p < \infty$. The same is true for the norms of the inverses of the resulting operators. We expect our estimates to be useful in Uncertainty Quantification.Comment: We fixed a small .tex problem in the abstract on the site (the manuscript has not changed

Examining the Land Use Act of 1978 and Its Effects on Tenure Security in Nigeria: A Case Study of Ekiti State, Nigeria

The Land Use Act of 1978 (LUA) has failed to achieve some of its objectives. The rural poor and the vulnerable are those most affected. The failure is ascribed to problems inherent in the Act and poor implementation. This paper discusses the effect of the LUA on the customary ownership of land and its effect on the tenure security of the rural poor. Using a conceptual framework for guiding cadastral systems development, the critical areas of the LUA as pertains to tenure security are analysed for the degree of their success, sustainability, and significance. The framework looks at the underlying theory, the drivers of change, the change process, and the land administration system. A mixed methodology approach was adopted for the study, using a single case study. Three groups of respondents contributed to the study: land professionals, civil servants and students. The study found that securing title to land is difficult, compensation provisions need to be reviewed, formal land registration is not in the interest of the poor, land is not available at an affordable rate, land speculators are still active in Nigerian land markets, the composition of the two committees is inadequate, and the refusal to grant certificates to people below the age of 21 is age biased. It further revealed that the power granted to the governor is enormous and unnecessary. The findings showed that the LUA is both effective in some areas and dysfunctional in others. This is because of the age of the Act and the lack of a pro-poor policy focus. Based on these findings recommendations were made, including that a new policy be enacted that includes pro-poor policies and customary laws. The LUA is found to be useful in urban areas, but not in solving land-related problems in rural areas. This study provides an understanding of the legal holding of land in Nigeria. &nbsp

Capacitance-Based Sensor with Layered Carbon-Fiber Reinforced Polymer and Titania-Filled Epoxy

Advances in intelligent infrastructure can be achieved through the use of novel materials for increased system-level efficiency and multifunctionality. Carbon Fiber-Reinforced Polymer (CFRP) has been widely used in strengthening, rehabilitating, and retrofitting of existing structures because of its speed of deployment, low maintenance requirement, and high strength-to-weight ratio. In this work, the authors propose a novel method to augment CFRP with self-sensing capabilities. The sensor consists of two CFRP layers separated by a titania-filled epoxy dielectric layer, therefore forming a parallel plate capacitor. Sensing capability can be achieved through variations in the sensor’s capacitance provoked by strain, therefore providing an additional function that could be leveraged for structural health monitoring and structural health management purposes. Comprehensive testing, including (1) sensing properties on sensors with and without titania-doped epoxy and (2) electromechanical test on tension specimens subjected to both static and dynamic loading, was conducted. The test results show that doping the titania filler within the epoxy matrix can improve the sensor’s sensitivity. The gauge factor is 0.92 under static load and decreases with the increasing frequency up to 1 Hz. Therefore, it can be concluded that CFRP can be used as a self-sensing sensor without affecting its mechanical properties

Development of a questionnaire to evaluate practitioners' confidence and knowledge in primary care in managing chronic kidney disease

Background: In the UK, chronic disease, including chronic kidney disease (CKD) is largely managed in primary care. We developed a tool to assess practitioner confidence and knowledge in managing CKD compared to other chronic diseases. This questionnaire was part of a cluster randomised quality improvement interventions in chronic kidney disease (QICKD; ISRCTN56023731). Methods: The questionnaire was developed by family physicians, primary care nurses, academics and renal specialists. We conducted three focus groups (n = 7, 6, and 8) to refine the questionnaire using groups of general practitioners, practice nurses and trainees in general practice. We used paper based versions to develop the questionnaire and online surveys to test it. Practitioners in a group of volunteer, trial practices received the questionnaire twice. We measured its reliability using Cohen’s Kappa (K). Results: The practitioners in the focus groups reached a consensus as to the key elements to include in the instrument. We achieved a 73.1% (n = 57/78) initial response rate for our questionnaire; of these 57, 54 completed the questionnaire a second time. Family physicians made up the largest single group of respondents (47.4%, n = 27). Initial response showed more female (64.9%, n = 37) than male (35.1%, n = 20) respondents. The reliability results from retesting showed that there was moderate agreement (k > 0.4) on all questions; with many showing substantial agreement (k > 0.6). There was substantial agreement in the questions about loop diuretics (k = 0.608, CI 0.432-0.784, p < 0.001), confidence in managing hypertension (k = 0.628, 95%CI 0.452-0.804, p < 0.001), diastolic blood pressure treatment thresholds in CKD (k = 0.608, 95%CI 0.436-0.780, p < 0.001) and the rate of decline of eGFR that would prompt referral (k = 0.764, 95%CI 0.603-0.925, p < 0.001). Conclusion: The QICKD-CCQ is a reliable instrument for measuring confidence and knowledge among primary care practitioners on CKD management in the context of UK primary care

Resonant Inductive Coupling Power Transfer for Mid-Sized Inspection Robot

This paper presents a wireless power transfer (WPT) for a mid-sized inspection mobile robot. The objective is to transmit 100 W of power over 1 meter of distance, achieved through lightweight Litz wire coils weighing 320 g held together with a coil structure of 3.54 kg. The Wireless Power Transfer System (WPTS) is mounted onto an unmanned ground vehicle (UGV). The study addresses an investigation of coil design, accounting for misalignment and tolerance issues in resonance coupled coils. In experimental validation, the system effectively transmits 109.7 W of power over a 1-meter distance, with obstacles present. This achievement yields a system efficiency of 47.14%, a value that is remarkably close to the maximum power transfer point (50%) when the WPTS utilises the full voltage allowance of the capacitor. The paper shows the WPTS charging speed of 5 minutes for 12 V, 0.8 Ah lead acid batteries

East African topography and volcanism explained by a single, migrating plume

Anomalous topographic swells and Cenozoic volcanism in east Africa have been associated with mantle plumes. Several models involving one or more fixed plumes beneath the northeastward migrating African plate have been suggested to explain the space-time distribution of magmatism in east Africa. We devise paleogeographically constrained global models of mantle convection and, based on the evolution of flow in the deepest lower mantle, show that the Afar plume migrated southward throughout its lifetime. The models suggest that the mobile Afar plume provides a dynamically consistent explanation for the spatial extent of the southward propagation of the east African rift system (EARS), which is difficult to explain by the northeastward migration of Africa over one or more fixed plumes alone, over the last ≈45 Myrs. We further show that the age-progression of volcanism associated with the southward propagation of EARS is consistent with the apparent surface hotspot motion that results from southward motion of the modelled Afar plume beneath the northeastward migrating African plate. The models suggest that the Afar plume became weaker as it migrated southwards, consistent with trends observed in the geochemical record

Assessment of climate change effects on vegetation and river hydrology in a semi-arid river basin

Climate change plays a key role in changing vegetation productivity dynamics, which ultimately affect the hydrological cycle of a watershed through evapotranspiration (ET). Trends and correlation analysis were conducted to investigate vegetation responses across the whole Upper Jhelum River Basin (UJRB) in the northeast of Pakistan using the normalized difference vegetation index (NDVI), climate variables, and river flow data at inter-annual/monthly scales between 1982 and 2015. The spatial variability in trends calculated with the Mann-Kendall (MK) trend test on NDVI and climate data was assessed considering five dominant land use/cover types. The inter-annual NDVI in four out of five vegetation types showed a consistent increase over the 34-year study period; the exception was for herbaceous vegetation (HV), which increased until the end of the 1990s and then decreased slightly in subsequent years. In spring, significant (p<0.05) increasing trends were found in the NDVI of all vegetation types. Minimum temperature (Tmin) showed a significant increase during spring, while maximum temperature (Tmax) decreased significantly during summer. Average annual increase in Tmin (1.54°C) was much higher than Tmax (0.37°C) over 34 years in the UJRB. Hence, Tmin appears to have an enhancing effect on vegetation productivity over the UJRB. A significant increase in NDVI, Tmin and Tmax during spring may have contributed to reductions in spring river flow by enhancing evapotranspiration observed in the watershed of UJRB. These findings provide valuable information to improve our knowledge and understanding about the interlinkages between vegetation, climate and river flow at a watershed scale