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Krzysztof Lubkowski

Abstract

This paper presents the most important issues relating to the influence of mineral fertilizers on both the natural environment and human and animal health. The physiological, environmental and economic impact of fertilizer production and application, resulted from a low assimilation of mineral components by crops, has been described. The research on the development and production of a large and diverse group of materials with slow-release properties that can increase the effectiveness of nutrient uptake, alleviate the negative influence of fertilizers on the environment and reduce labor and energy consumption associated with the use of conventional fertilizers, has been reviewed.

Open access

Krzysztof Lubkowski and Barbara Grzmil

Controlled release fertilizers

The efficiency of nitrogen assimilation by plants is rather low and this is a serious problem in view of environmental protection. Improvement of nitrogen absorption can be carried out through the developing, producing and applying the controlled release fertilizers. Biodegradable chitosan has been proposed as an alternative material in the production of controlled release fertilizers.

Open access

Mariann Hauge, Lars Landmark, Piotr Łubkowski, Marek Amanowicz and Krzysztof Maślanka

Abstract

Tactical ad-hoc networks are evolving today towards complex heterogeneous networks in terms of architecture, protocols and security. Due to the difference in network resources and reliability, end-to-end quality of service provisioning becomes very challenging. If we also take into account communication issues such as unpredictable connectivity, preferential forwarding for special traffic classes, intermittency due to node or communication link failure, the problem is further aggravated. In this article, we examine the major challenges that must be solved in order to provide efficient QoS provisioning in the heterogeneous network. Finally we describe QoS-aware mechanisms for inter-domain and intra-domain heterogeneous networks, also including real-time services provision in highly mobile environments.

Open access

Ewa Ekiert, Rafał Pelka, Krzysztof Lubkowski and Walerian Arabczyk

The possibility of implementation of spent iron catalyst for ammonia synthesis

An iron catalyst used in the ammonia synthesis is pyrophoric in its reactive, reduced form. Before further use the catalyst has to be passivated. Results of the research on the iron catalyst - its passivation, re-use as a catalyst in other processes and implementation as a substrate to obtain new nanocrystalline materials have been presented in the paper.

Open access

Krzysztof Lubkowski, Aleksandra Smorowska, Marta Sawicka, Elwira Wróblewska, Alicja Dzienisz, Małgorzata Kowalska and Marcin Sadłowski

Abstract

Ethylcellulose polymer was used as a coating material in the preparation of controlled release fertilizers. The materials have been prepared with the use of an immersion method. The mass ratio of polymer to fertilizer was in the range of 0.165–0.285 and the layer thickness was in the range of 204–244 μm. Mechanical properties of the prepared materials were significantly better in comparison with the initial fertilizer. Measurements of time and the degree of release of mineral components from the obtained materials were determined with a standard method. Ethylcellulose-coated materials have met the requirements of controlled release fertilizers.