Study of molten aluminium cleaning process using physical modelling and CFD

Furnace treatment is an important step during molten aluminium production by which the dissolved hydrogen and solid impurity particles are removed. Conventionally, a chlorine/inert gas mixture is used for this purpose injected into the molten metal via a simple lance. In order to meet new requirements for furnace emissions and improve efficiency, mechanical agitation through an impeller is becoming more widely used. In this research, the homogenization behaviour of both lance bubbling and mechanical agitation by impeller has been investigated experimentally and numerically. It can be concluded that under the same mean specific energy dissipation rates, the velocity magnitude for mechanical agitation process is about ten times bigger than that for the lance bubbling process, and the mixing time for the mechanical agitation process are much lower than that for the lance bubbling process, so better cleaning or fluxing would be expected

Effects of thin film Pd deposition on the hydrogen permeability of Pd60Cu40 wt% alloy membranes

AbstractPd60Cu40 wt% (Pd47.3Cu52.7 at%) membranes were surface modified by depositing Pd thin films of three different thicknesses (~100, 800 and 1400nm) on to one side of a range of as-received Pd60Cu40 wt% cold-rolled foils via magnetron sputtering. The hydrogen permeability of the membranes was then measured and compared to the uncoated material. The Pd60Cu40 wt% membrane coated with a 1400nm thick Pd thin film positioned on the feed side (445kPa of hydrogen pressure) during hydrogen permeability measurements and cycled between 50 and 450°C achieved the highest hydrogen permeability of 1.09×10−8molm−1s−1Pa−0.5 at 450°C in the third cycle. This is a 58% increase on the value measured for the as-received Pd60Cu40 wt% membrane under the same conditions.This improvement can be attributed to a Pd-rich Pd–Cu face centred cubic (FCC) phase forming through interdiffusion between the Pd thin film and bulk Pd–Cu membrane as a result of the test conditions used during hydrogen permeability measurements. This introduces a larger hydrogen concentration gradient across the membrane due to the relatively high hydrogen solubility of the Pd-rich Pd–Cu FCC phase resulting in the observed increase in permeability.The Pd60Cu40 wt% membranes coated with a ~1400nm and ~800nm thick Pd thin film retained an almost pure Pd surface throughout cycling between 50 and 450°C with a feed and permeate hydrogen pressure of 445 and 100kPa, respectively. For the deposition technique and test conditions used throughout this work, these surface modified Pd–Cu membranes appear to stabilise the Pd thin films upon cycling across the critical temperature of 295 °;C

How and where to find NPS users: a cross national survey among current users of new psychoactive substances.

Use of new psychoactive substances (NPS) across Europe remains a public health challenge. The study describes potentials and limitations of methods in a transnational survey of recent marginalized, nightlife and online community NPS users in Germany, Hungary, Ireland, the Netherlands, Poland and Portugal (n=3023). In terms of demographic profile, drug use history and type of NPS, different methods reached different segments of the NPS-using population. Last year use of different NPS varied across countries and groups. Respondents used NPS in a variety of settings, with public spaces most common in marginalized group. The study suggests that prevalence rates can reveal a picture of the NPS market that significantly deviates from what law enforcement seizures indicate. Outreach in nightlife settings and peer education are recommended to inform users about health risks and to improve access to drug services and care

Lodz City Tour: The Changing Nature of the Urban Restructuring of a Post-Socialist Industrial City

This paper describes the restructuring of Poland’s third-largest city, Lodz (Łódź). Once a thriving metropolitan hub of textile and clothing manufacturing, Lodz was confronted with the closure of its numerous factories in the early 1990s with Poland’s transition from a planned to a global market economy. The city suffered an abrupt and dramatic decline followed by a redefinition of its economic, spatial and social structures. The paper focuses on the major economic and spatial phenomena taking place in the city in the three decades after the economic collapse. Using an evolutionary approach, it identifies and discusses the gradual shift of Lodz’s restructuring. We claim that the restructuring initially involved mostly organic and spontaneous initiatives of dynamic local and non-local actors, with minor and circumstantial involvement from the local authorities. However, over time, the restructuring of Lodz has become influenced and driven by nationally and EU-set objectives and targeted urban policies, with urban and infrastructural projects as driving vehicles.Jakub Zasina’s portion of this work was supported by the National Science Centre in Poland (grant agreement no. 2016/23/N/HS4/03390)

Three phase mixing Studies of geometry, viscosity and scale

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN036559 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Economic competitiveness of distributed generation in comparison to large centralised systems

W artykule przedstawiono wyniki badań nad źródłami energii elektrycznej i cieplnej, które to źródła byłyby stosowane w tzw. energetyce rozproszonej (ang. distributed generation - DG). Podstawowym elementem analizy jest porównanie systemów energetycznych opartych o rozproszone wytwarzanie z obecnymi systemami elektroenergetycznym i ciepłowniczymi. Autor przedstawił możliwe rozwiązania takich systemów z uwzględnieniem ogniw paliwowych, jako przyszłościowego źródła energii elektrycznej i ciepła.The article presents the results of research on sources of electricity and heat that would be used in distributed generation. The main element of the analysis is the comparison between energy systems based on distributed generation and the existing systems based on large centralized facilities. Solutions for distributed generation, including fuel cells as a future source of electricity and heat, are presented by the author

Wykorzystanie gazu w źródłach rozproszonych w dużych systemach ciepłowniczych

The aim of an investigation was to examine the heat sources, which can be used as a supplement for providing the heat for the users at the ends of extensive heating networks. The research was based on the technical and economic analysis that also included ecological effects. The integral element of the research was a comparative analysis of such distributed heat sources and the current heating systems regarding their mutual competitiveness factors or supplementation.W pracy zaprezentowano rozważania dotyczące ekonomicznej celowości instalacji zastosowania źródeł rozproszonych w ciepłownictwie. Pomysl zastosowania źródeł rozproszonych w ciepłownictwie podobny jest do tego obecnie szeroko dyskutowanego pomysłu źródeł rozproszonych do produkcji energii elektrycznej. Ze względu na obecne warunki ekonomiczne do rozważań wybrano źródła zasilane gazem ziemnym. Zaproponowano pięć sposób zasilania odbiorców na końcach rozległych sieci ciepłowniczych. Dla przedstawionych wariantów wykonano analizy ekonomiczne, których wyniki przedstawiona w pracy