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

Pd–Cu alloys have great potential as hydrogen separation membranes due to their relatively low cost and excellent durability compared to commercial dense metal membranes such as Pd and Pd–Ag alloys. At a composition of Pd60Cu40 wt% the body centred cubic (bcc) phase possesses the highest hydrogen permeability of the Pd–Cu alloy system. Furthermore, a Pd–Cu membrane containing a Pd-rich Pd–Cu fcc phase exhibits improved resistance to hydrogen sulphide (H2S) contamination.The basis of this study was to modify the surface composition of bcc Pd60Cu40 wt% membranes through deposition of a Pd thin film onto one side to produce a stable Pd-rich fcc layer and to investigate its effects on hydrogen permeability. The hydrogen permeability of two as-received Pd60Cu40 wt% membranes (Membranes 1 and 2) was measured in addition to two Pd coated Pd60Cu40 wt% membranes (Membranes 3 and 4) for comparison. A Pd-rich Pd–Cu fcc phase with an approximate composition of Pd70Cu30 wt% was formed as a result of Cu interdiffusion between the Pd–Cu bulk membrane and the Pd thin film during hydrogen permeability testing. This new phase was responsible for the reduction in hydrogen permeability shown in the Samples 3 and 4.Using variable temperature in-situ X-ray diffraction(XRD), it was observed that Cu interdiffusion occurred from the Pd–Cu bulk membrane and into the Pd thin film between 300 and 600 °C under 445 kPa of flowing helium. Under 445 kPa of flowing hydrogen the Pd thin film readily formed the β-palladium hydride (β-PdH) phase at room temperature and gradually formed the α-interstitial hydrogen solid solution (α-PdH) phase at around 200 °C with Cu interdiffusion also occurring between 300 and 600 °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)

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

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

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