University of Wollongong

About: University of Wollongong is a education organization based out in Wollongong, New South Wales, Australia. It is known for research contribution in the topics: Population & Context (language use). The organization has 15674 authors who have published 46658 publications receiving 1197471 citations. The organization is also known as: UOW & Wollongong University.

International migration at the beginning of the twenty-first century: global trends and issues

Abstract: Globalisation leads to increases in all kinds of cross-border flows, including movements of people. In recent years international migrationhas grown in volume, and is now an important factor of social transformation in all regions of the world. States classify migrants into certain categories, and seek to encourage certain types of mobility while restricting others. However,control measures are often ineffective if they are not based on understanding of the economic, social and cultural dynamics of migration. The article reviews causes and patterns of migration, and discusses some key issues: migration anddevelopment, international cooperation, settle-ment and ethnic diversity, and migration as a challenge to the nation-state. It is argued that most national governments have taken a short-term and reactive approach to migration. Effortsat international regulation are also relatively under-developed. There is a need for long-term cooperative strategies to achieve agreed goals such as: ensuring orderly migration and preventing exploitation by agents and recruiters;safeguarding the human rights of migrants; making migration an instrument of sustainable development; avoiding conflicts with populations of migrant-receiving areas, and maximising positive aspects of social and culturalchange.

A mobile robot exploration algorithm

Abstract: An algorithm for path planning to a goal with a mobile robot in an unknown environment is presented. The robot maps the environment only to the extent necessary to achieve the goal. Mapping is achieved using tactile sensing while the robot is executing a path to the specified goal. Paths are generated by treating unknown regions in the environment as free space. As obstacles are encountered en route to a goal, the model of the environment is updated and a new path to the goal is planned and executed. Initially the paths to the goal generated by this algorithm will be negotiable paths. However, as the robot acquires more knowledge about the environment, the length of the planned paths will be optimized. The optimization criteria can be modified to favor or avoid unexplored regions in the environment. The algorithm makes use of the quadtree data structure to model the environment and uses the distance transform methodology to generate paths for the robot to execute. >

Grain-orientation-engineered multilayer ceramic capacitors for energy storage applications.

Abstract: Dielectric ceramics are highly desired for electronic systems owing to their fast discharge speed and excellent fatigue resistance. However, the low energy density resulting from the low breakdown electric field leads to inferior volumetric efficiency, which is the main challenge for practical applications of dielectric ceramics. Here, we propose a strategy to increase the breakdown electric field and thus enhance the energy storage density of polycrystalline ceramics by controlling grain orientation. We fabricated high-quality -textured Na0.5Bi0.5TiO3–Sr0.7Bi0.2TiO3 (NBT-SBT) ceramics, in which the strain induced by the electric field is substantially lowered, leading to a reduced failure probability and improved Weibull breakdown strength, on the order of 103 MV m−1, an ~65% enhancement compared to their randomly oriented counterparts. The recoverable energy density of -textured NBT-SBT multilayer ceramics is up to 21.5 J cm−3, outperforming state-of-the-art dielectric ceramics. The present research offers a route for designing dielectric ceramics with enhanced breakdown strength, which is expected to benefit a wide range of applications of dielectric ceramics for which high breakdown strength is required, such as high-voltage capacitors and electrocaloric solid-state cooling devices. The energy density of dielectric ceramic capacitors is limited by low breakdown fields. Here, by considering the anisotropy of electrostriction in perovskites, it is shown that -textured Na0.5Bi0.5TiO3–Sr0.7Bi0.2TiO3 ceramics can sustain higher electrical fields and achieve an energy density of 21.5 J cm−3.

Ultrafine SnO2 nanoparticle loading onto reduced graphene oxide as anodes for sodium-ion batteries with superior rate and cycling performances

Abstract: A structured SnO2–reduced graphene oxide (RGO) nanocomposite has been synthesized with SnO2 nanoparticles (∼5 nm) anchored on a RGO framework. It has been successfully applied as an anode material in sodium-ion batteries. The electrode delivers a reversible Na-storage capacity of 330 mA h g−1 with an outstanding capacity retention of 81.3% over 150 cycles. Moreover, it possesses a relatively good rate capability, exhibiting a capacity retention of 25.8% at high rate (1000 mA h g−1). With its combined advantages of low cost and environmental benignity, the SnO2–RGO nanocomposite would be a promising anode for Na-ion batteries.