The use of new generation geosynthetics in water treatment

The importance of clean drinking water in any community is absolutely vital if we as the consumers are to sustain a life of health and wellbeing. Suspended particles in surface waters not only provide the means to transport micro-organisms which can cause serious infections and diseases, they can also affect the performance capacity of a water treatment plant. In such situations pre-treatment ahead of the main plant is recommended. Previous research carried out using non-woven synthetic as a pre-filter materials for protecting slow sand filters from high turbidity showed that filter run times can be extended by several times and filters can be regenerated by simply removing and washing of the fabric ( Mbwette and Graham, 1987 and Mbwette, 1991). Geosynthetic materials have been extensively used for soil retention and dewatering in geotechnical applications and little research exists for the application of turbidity reduction in water treatment. With the development of new materials in geosynthetics today, it was hypothesized that the turbidity removal efficiency can be improved further by selecting appropriate materials. Two different geosynthetic materials (75 micron) tested at a filtration rate of 0.7 m/h yielded 30-45% reduction in turbidity with relatively minor head loss. It was found that the non-woven geotextile Propex 1701 retained the highest performance in both filtration efficiency and head loss across the varying turbidity ranges in comparison to other geotextiles tested. With 5 layers of the Propex 1701 an average percent reduction of approximately 67% was achieved with a head loss average of 4mm over the two and half hour testing period. Using the data collected for the Propex 1701 a mathematical model was developed for predicting the expected percent reduction given the ability to control the cost and as a result the number of layers to be used in a given filtration scenario.

The Media as Political Actors

This chapter provides a history of the media as political actors and identifies key principles that have shaped their role in both democratic and authoritarian polities (i.e., information, interpretation, participation, critical scrutiny). In addition, the chapter explores recent trends impacting on the performance of that role, such as the emergence of the Internet and, as a consequence of that process, a globalized public sphere of transnational news media outlets. It is argued that to make the Internet truly valuable as a political resource, democratic societies continue to require the work of skilled, professional journalists and their sense making, interpretative functions. Because of that journalists and their organizations remain crucial to the translation of content into meaningful messages.

Reproduction of an autographed portrait of Ludwig Bamberger seated holding paper Portraits; Men

Signed Ludwig Bamberger

Johanna Heymann with her ten children

Reproduction of a portrait of Johanna Heymann, wife of Aron Hirsch with her ten children (tallest boy is Gotthold Heymann) on the occasion of the 50th birthday of Aron Hirsch; Berlin

Hedwig Fischer with Tutti and Hilla Portraits Groups

Handwritten dedication: Fuer Paula und Richard Beer-Hofmann in gedanken und die Schoenen Tage von Jaakobs Traum

Passport portrait of Ruth Augusta Beatrice Goldschmidt Portraits Children

Born 1923?

Max and Martha Liebermann seated next to the lake; Wannsee Portraits Couples

Digital Image

Portrait of Paul Kraft; Stockholm Portraits Men

Digital Image

Alice Salomon with students on the roof garden of the Sozialen Frauenschule Portraits Groups

Including Hilde Caro, Lotte Lipschitz and Ellen Milch

Hedwig Fischer with Tutti and Hilla Portraits Groups

Handwritten dedication: Fuer Paula und Richard Beer-Hofmann in gedanken und die Schoenen Tage von Jaakobs Traum

Max and Martha Liebermann seated next to the lake; Wannsee Portraits Couples

Digital Image

Unser Haus Am Erlenweg : Weihnachten 1911.

Cloth covered, oversize album featuring photographs of a family home.

Hans Friedrich Kayser Collection 1877-1893

Photocopies of birth certificate (1877) and release from citizenship certificate (1893), Berlin.

Siegbert Springer Collection 1977-1984

Article about Siegbert Springer in Juristische Schulung, vol. 17, No. 7 and a report about a memorial plaque for Siegbert Springer in Berlin.

Deutsch-Boehm Family collection 1834-1938 Bulk: 1834-1892

The collection holds original official documents pertaining to the ancestors of Hermann Deutsch, such as his father, Hugo Deutsch, and his grandfather, Simon Deutsch, and the last will and testament of Abraham Nathan Meyer, great-grandfather of Hermann Deutsch. Also included are documents for Hermann Boehm. There is a printed obituary by Hugo Preuss for Hugo Deutsch and the copy of a 1938 document, declaring the end of the Simon Boehm company.