Gully Erosion of Coastal Plain Sediments of SE Nigeria - Final Summary Technical Report

Coastal plain sediments of SE Nigeria are prone to rapid and extensive gullying. Gully advances of 157m in length, 50m in width, and 5m in depth per year have been measured, and have cut through road, isolated villages, disrupted water supplies, and caused major landslides. The gullying rates have increased in recent years because of increased population pressures and resultant vegetative cover denudation and poor drainage channelization. Studies were carried out in nine different sites over four different gully-prone formations. The gully-prone areas are underlain by lateritic coastal sands of very specific geotechnical properties, such as similar grain size distribution, uniformity, and dispersivity. Correlations indicate that the gully advance and dispersion rate is governed mostly be the sands' grain size distribution and uniformity. The Ca0, K20, Mn0 and Mg0 content of the weak lateritic cements also have a significant statistical relationship to the gullying process

The Large Observatory for x-ray timing

The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final down-selection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supra-nuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m2 effective area, 2-30 keV, 240 eV spectral resolution, 1° collimated field of view) and a WideField Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). The WFM is equipped with an on-board system for bright events (e.g. GRB) localization. The trigger time and position of these events are broadcast to the ground within 30 s from discovery. In this paper we present the status of the mission at the end of its Phase A study

Strategic water resource management, Nigeria

The research project, Gully erosion, Nigeria, involved cooperation between the geology departments of the University of Windsor and the Nnamdi Azikiwe University, Awka, Anambra State, and the University of Port Harcourt, Port Harcourt, Rivers State. Research teams from the universities worked in partnership with rural people in Abia, Anambra, Enugu, and Imo States from 1993 to 1997. Political events intervened and the project participants next were reunited in 1999. The extended project term came to an end in 2000. The goal was to reduce gully erosion in southeastern Nigeria. The purpose was to discover reasons for the large numbers of gullies in the region and to design a strategy for the control and prevention of gully erosion. The funding agency was the International Development Research Centre, Ottawa. Hudec et al. (1998) described the geological engineering properties of those materials that are especially susceptible to gully erosion. The present account relates some aspects of project research to concepts of water resource management. Use of “strategic” in the title draws attention to the importance of this to the national security of Nigeria

Stabilization of the Solid-Electrolyte-Interphase Layer and Improvement of the Performance of Silicon–Graphite Anodes by Nanometer-Thick Atomic-Layer-Deposited ZnO Films

Silicon (Si) is a promising anode material due to its high theoretical capacity and abundant presence as the second most common element in the earth’s crust. However, the formation of an unstable solid-electrolyte interphase (SEI) and significant volume expansion during lithiation result in structural degradation, leading to a decrease in the cycle life for Si-based anodes. This paper reports on the electrochemical performance of the silicon/graphite (Si/Gr) electrodes coated with nanometer-thick ZnO layers prepared by atomic layer deposition (ALD). In our study, ZnO layers were deposited using 5–40 ALD cycles on Si/Gr electrodes of ∼20 μm thickness. Electrochemical measurements such as galvanostatic charging/discharging at different C-rates and electrochemical impedance spectroscopy were performed utilizing the pristine and 5–40 ALD cycles of ZnO on Si/Gr electrodes in a half-cell configuration. The Si/Gr electrodes (pristine and ZnO-coated) were analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy (XPS) before and after electrochemical cell cycling. The ZnO-coated samples showed a better electrochemical rate performance than the uncoated pristine Si/Gr sample. The reversible conversion of the ZnO ALD films was demonstrated through dQ/dV plots and XPS analysis during (de)lithiation. The ultrathin ZnO layers passivate the underlying Si/Gr electrodes, help in the formation of a stable SEI layer, and facilitate lithium-ion transport through the SEI layer