Suchergebnisse

The properties of sub-base filling materials in highway construction are essential, as they can determine the performance of the road in service. Normally, the existing materials are removed and replaced with new materials that have adequate load-bearing capacity. Rising environmental concern and new environmental legislations have made construction professionals consider other methods. These methods include stabilizing the existing materials with other additives to improve their performance. Additives can be waste materials generated by different industries. In this work, the existing excavated soil is stabilized with waste materials. The wastes consisted of fly ash, marble dust and waste sand. The percentage addition of waste materials was 5%, 10%, 15% and 20% (by mass) of the existing soil. The soil/waste specimens were cured for 1, 7, 28, 56, 90 and 112 days before testing. Testing included the dry unit weight and unconfined compressive strength (q(u)) as well as X-ray diffraction analysis and scanning electron microscopy observation. Also, the California Bearing Ratio values were obtained and are reported in this investigation. The results showed that the q(u) values increased with the increase in waste materials content. Also, there is tendency for the dry unit weight to increase with the increase in waste materials.

Mit der partiellen Einbringung von keramischen Partikeln in der Pulvermatrix lassen sich die lokalen Eigenschaften gezielt einstellen. Der Einsatz unterschiedlicher und heterogen verteilter Materialien in einem Werkstück wirkt sich auf den induktiven Erwärmungsprozess aus. Dieser Fachbeitrag beschäftigt sich mit Erwärmungsuntersuchungen an partiell partikelverstärkten Pulverpresslingen aus Stahl in den thixotropen Temperaturbereich für den anschließenden Schmiedeprozess.
 
Due to the partial incorporation of ceramic particles, locally improved properties can be achieved in powder metallurgy of metal matrix composites. The use of various and heterogeneous distributed materials in one workpiece has an effect on the inductive heating process. This article deals with investigations on heating at thixotropic temperature range of partially particle-reinforced powder compacts made of steel for the subsequent forging process.

Zunehmende Variantenvielfalt und schwankende Stückzahlen führen zu hohen Effizienzverlusten in abgetakteten starr verketteten Linien. Eine flexible Alternative sind modulare Produktionsstrukturen aus frei anfahrbaren Prozessmodulen. Der Fachartikel ergründet, wie leistungsfähig diese Strukturen für die personalisierte Serienproduktion im volatilen Marktumfeld sind und zeigt, unter welchen Bedingungen sie eine konkurrenzfähige Alternative zur Linienmontage darstellen.
 
Increasing numbers of product variants and changing production volumes cause high losses of efficiency in rigidly linked synchronized assembly lines. Modular production structures of flexibly linked process modules present an alternative to such lines. This paper explores the ability of such modular structures to produce personalized products in high volumes with high performance and determines the conditions for their competitiveness compared to the classic line.

Human-wildlife conflicts have escalated in semi-arid lands because of changes in various aspects, including land use, arable farming and sedentary life style of pastoralists in semi-arid lands, inadequate wildlife control and ban on hunting of wild animals. The objective of the study was to assess the impact of human-wildlife conflicts on wildlife conservation as an alternative source of income to improve the welfare of the pastoralists. The study was carried out in Kirisia, Lorroki and Baragoi divisions. Survey was conducted among households and the data gathered were analysed using Statistical Package for the Social Sciences (SPSS). The results indicated that human-wildlife conflicts have great impact on wildlife conservation and socioeconomic welfare of pastoralists. The study highlighted the need for the government to revise existing policies on wildlife conservation and management in Kenya.

Das Buch begleitet den Übergang von der analogen zur digitalen Energiewirtschaft und gibt dem Leser wertvolle Impulse für die Erschließung neuer, lukrativer Betätigungsfelder. Autoren aus Wissenschaft und Praxis liefern ausgewählte Antworten auf die enormen Herausforderungen angesichts von Digitalisierung und Dezentralisierung im Energiesektor. Insofern soll das Buch Mut machen, die digitale Transformation zügig anzugehen und den Veränderungsprozess insgesamt als Chance zu begreifen. Die Debatte um die Ausgestaltung und Zukunft von Utility 4.0 hat damit gerade erst begonnen. Der Inhalt Energiewirtschaft im digitalen Zeitalter Konzepte und Technologien Digitale Geschäftsmodelle Die Zielgruppen Manager, Praktiker und Berater aus der Energiewirtschaft Mitglieder von Verbänden und Institutionen des Energiesektors Dozierende und Studierende energiewirtschaftlicher Ausrichtung Der Herausgeber Oliver D. Doleski ist Unternehmensberater und Autor zahlreicher Fachpublikationen. Die Autoren P.-V. Abs, C. Aichele, J. Anthonijsz, C. Arnold, M. Bachmann, M. Bartsch, E. Böhme, O. Budde, T. Clees, T. Dell, B. Deppe, S. Dieper, C. Doetsch, R. A. Dudenhausen, T. Dürr, S. Ebert, T. Egeler, D. Elsner, M. R. Esser, M. Felsmann, P. Fett, S. Frey, S. Fritsch, J. D. Golovatchev, H. Hahn, V. Herbort, J.-C. Heyne, N. Hofstetter, M. Irlbeck, T. Kaiser, J. Klaus, M. Köster, O. Krone, P. Küller, H. Lehmann, T. Mache, R. Mackensen, B. Mildebrath, H. Ostermann, W. Pell, R. Pflaum, D. Phillipp, M. Postina, K. Reiche, V. Rieger, D. Schallmo, M. Schönberger, K. Schüller, H. Schweinfurth, I. Spiecker gen. Döhmann, E. Thyen, K. Vortanz, W. M. Walter, S. Weber, S. Weiße, P. Zayer

T e spatial variability of the content of granulometric fraction d>0,25 mm in the arable layer of soddy-podzolic cultivated soil on an area of 18 hectares was studied. T e soil formed in the loess-like loam, underlain by moraine deposits. Samples were taken from the upper (0-10 cm) and lower parts of the arable layer (10-20 cm) following a random-stratif ed sampling scheme. T e total number of samples was 350 cores. T e average fraction content was about 22%, the coef cient of variation was 39-41%, the distributions were approximated by a logarithmically normal distribution. T e Spearman correlation coef cient between values at dif erent depths equaled to 0,87. T e spatial distribution cartograms were constructed by the ordinary kriging method using a spherical variogram model. It is shown that preliminary censoring of high sample values (quantile 0,95) gives better results when constructing a cartogram than removing a linear spatial trend and logarithm of the original data. Spatial structures with reduced and increased values were found on the site, the average linear sizes of which was about 100 m. Presumably, they were associated with the heterogeneity of soil-forming material.