A bibliometric tale of two cities: Hong Kong and Singapore

A research evaluation of the leading research universities globally using the curated bibliometric data from Shanghai Rankings Global Ranking of Academic Subjects 2018 shows Hong Kong at the top position. A X/GDP productivity criteria is used where each country’s scientific wealth is represented by X, a second-order bibliometric indicator, and its nominal Gross Domestic Product (GDP) is taken as a measure of its economic wealth. Singapore appears at the fifth position. This brief communication looks at the anatomy of this exceptional performance of the two city states, which are similar in many ways and yet dissimilar in many other ways. Hong Kong has the slight edge over Singapore in translating economic wealth to scientific wealth.

     

Durability studies of surface-modified coir geotextiles

Coir (Cocos nucifera) is a natural fibre known to retain its strength and resist biodegradation far better than other industrial natural fibres. However, systematic studies in this discipline are scarce. Geotextiles are usually exposed to diverse pH, salinity, moisture, and microbial association conditions. In the present work, specific surface modifications of coir geotextiles using a natural agent (cashew nut shell liquid) have been carried out to enhance their long-term performance depending on the end applications. The modified and unmodified geotextiles were subjected to acidic, alkaline, and neutral pH conditions, saline conditions, alternate wetting and drying cycles, and thermal cycles for the assessment of their durability, measured in terms of tensile strength. In situ soil burial studies in a tropical climate were conducted in specially prepared soil to follow the biodegradation behaviour of geotextiles at various depths. The surface-modified geotextiles were found to resist adverse chemical, physical, and biological conditions much better than the unmodified geotextiles. Alkaline conditions marginally accelerated the degradation rates when compared to acidic environments. The saline conditions, as well as alternate wetting and drying conditions, resulted in marginal loss of tensile strength (<7%). The surface-modified geotextiles buried within lower depths of soil under field conditions retained 70–80% of their initial tensile strength after 12 months, whereas the unmodified geotextiles lost 88% strength in four months. The positive impact of surface modification on durability is confirmed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The results indicate the excellent potential of suitably surface-modified coir geotextiles for long-term use in adverse conditions.     

All-solid-state lithium secondary batteries using a layer-structured LiNi0.5Mn0.5O2 cathode material

All-solid-state cells of In/LiNi_0.5Mn_0.5O₂ using a superionic oxysulfide glass with high conductivity at room temperature of 10⁻³ S cm⁻¹ as a solid electrolyte were fabricated and the cell performance was investigated. Although a large irreversible capacity was observed at the 1st cycle, the solid-state cells worked as lithium secondary batteries and exhibited excellent cycling performance after the 2nd cycle; the cells kept charge–discharge capacities around 70 mAh g⁻¹ and its efficiency was almost 100%. This is the first case to confirm that all-solid-state cells using manganese-based layer-structured cathode materials work as lithium secondary batteries.     

Letter to the editor: Revisiting the h-index and the p-index

Scientometrics - In this Letter to the Editor we revisit the h-index, which is a heuristic construction and the mock h-index (also known as the p-index) which is derived from analytical...     

Hybrid Nanostructures for Energy Storage Applications

Materials engineering plays a key role in the field of energy storage. In particular, engineering materials at the nanoscale offers unique properties resulting in high performance electrodes and electrolytes in various energy storage devices. Consequently, considerable efforts have been made in recent years to fulfill the future requirements of electrochemical energy storage using these advanced materials. Various multi‐functional hybrid nanostructured materials are currently being studied to improve energy and power densities of next generation storage devices. This review describes some of the recent progress in the synthesis of different types of hybrid nanostructures using template assisted and non‐template based methods. The potential applications and recent research efforts to utilize these hybrid nanostructures to enhance the electrochemical energy storage properties of Li‐ion battery and supercapacitor are discussed. This review also briefly outlines some of the recent progress and new approaches being explored in the techniques of fabrication of 3D battery structures using hybrid nanoarchitectures.     

Some issues in sintering science and technology

Various sintering theories based on two-particle model are no longer valid. Apart from this the basic properties and data of materials are also much more accurate in the present date, thus casting doubt in the previous theories. The role of electronic structure of additives in activating sintering processes has been convincingly put forth. In the field of sintering practice still a gap is apparent with the theory. Various techno-economic factors including the nature of starting powders have, of late, given good impetus in tackling this challenge.     

Letter to the Editor: Comments on the paper of Batagelj—on fractional approach to analysis of linked networks

Scientometrics - We examine the role of count conservation when derived network matrices are obtained from linked network matrices using an outer product decomposition. It is seen that a full...     

Scale-dependent stratification: a skyline–shoreline scatter plot

Scientometrics - Most performance exercises help identify size-dependent and size-independent indicators which separately represent quantity and quality proxies. A good example is the evaluation of...