Census and ear-notching of black rhinos (Diceros bicornis michaeli) in Tsavo East National Park, Kenya

This paper updates the status of the black rhino population in Tsavo East National Park (NP). Data were acquired through aerial counts of the black rhino between 3 and 9 October 2010 using three fixed-wing husky aircrafts and a Bell 206L helicopter in an area of about 3,300 km2. Based on previous sightings of rhinos, the area was divided into 14 blocks, with each block subdivided into 400 m transects. An aircraft flying at about 500 m above the ground was assigned to carry out the aerial survey following these transects within each block. Observers scanned for rhinos about 200 m on either sides of the flight paths. Intensive searches in areas with dense vegetation, especially along the Galana and Voi Rivers and other known rhino range areas was also carried out by both the huskies and the helicopter. The count resulted in sighting of 11 black rhinos. Seven of these individuals were ear notched and fitted with radio transmitters and the horns were tipped off to discourage poaching. Three of the seven captured rhinos were among the 49 animals translocated to Tsavo East between 1993 and 1999. The other four animals were born in Tsavo East. Two female rhinos and their calves were not ear-notched or fitted with transmitters. It is recommended that another count be carried out immediately after the wet season as the rhinos spend more time in the open areas while the vegetation is still green. The repeat aerail count is to include blocks north of River Galana

MgH2 nanoparticles confined in reduced graphene oxide pillared with organosilica: a novel type of hydrogen storage material

Hydrogen is a promising energy carrier that can push forward the energy transition because of its high energy density (142 MJ kg-1), variety of potential sources, low weight and low environmental impact, but its storage for automotive applications remains a formidable challenge. MgH2, with its high gravimetric and volumetric density, presents a compelling platform for hydrogen storage; however, its utilization is hindered by the sluggish kinetics of hydrogen uptake/release and high temperature operation. Herein we show that a novel layered heterostructure of reduced graphene oxide and organosilica with high specific surface area and narrow pore size distribution can serve as a scaffold to host MgH2 nanoparticles with a narrow diameter distribution around ~2.5 nm and superior hydrogen storage properties to bulk MgH2. Desorption studies showed that hydrogen release starts at 50 {\deg}C, with a maximum at 348 {\deg}C and kinetics dependent on particle size. Reversibility tests demonstrated that the dehydrogenation kinetics and re-hydrogenation capacity of the system remains stable at 1.62 wt.% over four cycles at 200 {\deg}C. Our results prove that MgH2 confinement in a nanoporous scaffold is an efficient way to constrain the size of the hydride particles, avoid aggregation and improve kinetics for hydrogen release and recharging

Corrigendum: Three spatially separate records confirm the presence of and provide a range extension for the giant pangolin Smutsia gigantea in Kenya (Oryx (2022) DOI: 10.1017/S0030605322000126)

In the original publication of this article, the list of authors was incomplete, with only the following authors listed: Tommy Sandri, Claire Okell, Stuart Nixon, Naomi Matthews, Fred Omengo, James Mathenge, Stephen Ndambuki, Daniel W.S. Challender and Bradley Cain. The correct author list is: Tommy Sandri, Claire Okell, Stuart Nixon, Naomi Matthews, Fred Omengo, James Mathenge, Stephen Ndambuki, Daniel W.S. Challender, Richard Chepkwony, Patrick Omondi, Shadrack Ngene and Bradley Cain The article has been updated to include the correct author details and add the ORCID iD of Shadrack Ngene

Anomalous Impact of Mechanochemical Treatment on the Na-ion Conductivity of Sodium Closo-Carbadodecaborate Probed by X-Ray Raman Scattering Spectroscopy

Solid-state sodium ion conductors are crucial for the next generation of all-solid-state sodium batteries with high capacity, low cost, and improved safety. Sodium closo-carbadodecaborate (NaCB11H12) is an attractive Na-ion conductor owing to its high thermal, electrochemical, and interfacial stability. Mechanical milling has recently been shown to increase conductivity by five orders of magnitude at room temperature, making it appealing for application in all-solid-state sodium batteries. Intriguingly, milling longer than 2 h led to a significant decrease in conductivity. In this study, X-ray Raman scattering (XRS) spectroscopy is used to probe the origin of the anomalous impact of mechanical treatment on the ionic conductivity of NaCB11H12. The B, C, and Na K-edge XRS spectra are successfully measured for the first time, and ab initio calculations are employed to interpret the results. The experimental and computational results reveal that the decrease in ionic conductivity upon prolonged milling is due to the increased proximity of Na to the CB11H12 cage, caused by severe distortion of the long-range structure. Overall, this work demonstrates how the XRS technique, allowing investigation of low Z elements such as C and B in the bulk, can be used to acquire valuable information on the electronic structure of solid electrolytes and battery materials in general

Materials for hydrogen-based energy storage - past, recent progress and future outlook

Globally, the accelerating use of renewable energy sources, enabled by increased efficiencies and reduced costs, and driven by the need to mitigate the effects of climate change, has significantly increased research in the areas of renewable energy production, storage, distribution and end-use. Central to this discussion is the use of hydrogen, as a clean, efficient energy vector for energy storage. This review, by experts of Task 32, “Hydrogen-based Energy Storage” of the International Energy Agency, Hydrogen TCP, reports on the development over the last 6 years of hydrogen storage materials, methods and techniques, including electrochemical and thermal storage systems. An overview is given on the background to the various methods, the current state of development and the future prospects. The following areas are covered; porous materials, liquid hydrogen carriers, complex hydrides, intermetallic hydrides, electrochemical storage of energy, thermal energy storage, hydrogen energy systems and an outlook is presented for future prospects and research on hydrogen-based energy storage

Persistent maternal tachycardia: A clinical alert for healthcare professionals providing maternity care in South Africa

Cardiac disease is one of the commonest causes of indirect maternal deaths globally. This brief report is a reminder that isolated maternal tachycardia at rest is a clinical alert and warrants a detailed history in relation to cardiac disorders, thorough clinical examination of all organ systems, relevant investigations such as imaging, and expert advice to avoid serious adverse events. We reflect on a belatedly investigated persistent maternal tachycardia resulting in a fatal postpartum collapse due to mitral stenosis. The lost window of opportunity for appropriate investigation and management of the tachycardia provides an insight into many similar maternal deaths in South Africa. Key clinical messages regarding persistent maternal tachycardia are presented for midwives and doctors caring for pregnant women