Open Access

Social networking technologies such as social media, crowd concepts, or gamification represent key resources for the integration of customers, value network partners, and the community into sustainable business models. However, there is a lack of understanding of how sustainable enterprises apply such technologies. To close this gap, we propose a taxonomy of design options for social networking technologies in sustainable business models. Our taxonomy comprises eight dimensions that deal with relevant questions of the design of social networking technologies. When creating our taxonomy, we built on existing literature and use cases and involved experienced practitioners in the field of sustainable business models for the validation of our taxonomy. In this way, our study contributes to knowledge on the use of social networking technologies in sustainable business models and how such technologies influence the boundaries of sustainable business models. Likewise, we provide practical insights into the use of social networking technologies in sustainable business models.

Vanadium carbide (VC) reinforced FeCrVC hardfacings have become important to improving the lifetime of tools suffering abrasive and impressive loads. This is because the microstructural properties of such hardfacings enable the primary VCs to act as obstacles against the penetrating abrasive. Because dilution is supposed to be the key issue influencing the precipitation behaviour of primary carbides during surfacing, the development of deposit welding processes exhibiting a reduced thermal impact, and hence lower dilution to the base material, is the primary focus of the current research. By inserting an additional hot wire in the melt, an approach was developed to separate the material and energy input during gas metal arc welding (GMAW) and hence realised low dilution claddings. The carbide content could be increased, and a grain refinement was observed compared with conventional GMAW. These effects could be attributed to both the reduced dilution and heterogeneous nucleation.

Injection of slurry or digestate below maize seeds is a relatively new technique developed to improve nitrogen use efficiency. However, this practice has the major drawback of increasing nitrous oxide (N2O) emissions. The application of a nitrification inhibitor (NI) is an effective method to reduce these emissions. To evaluate the effect of the NI 3,4‐dimethypyrazole phosphate (DMPP) on N2O emissions and the stabilization of ammonium, a two‐factorial soil‐column experiment was conducted. PVC pipes (20 cm diameter and 30 cm length) were used as incubation vessels for the soil‐columns. The trial consisted of four treatments in a randomized block design with four replications: slurry injection, slurry injection + DMPP, digestate injection, and digestate injection + DMPP. During the 47‐day incubation period, N2O fluxes were measured twice a week and cumulated by linear interpolation of the gas‐fluxes of consecutive measurement dates. After completion of the gas flux measurement, concentration of ammonium and nitrate within the soil‐columns was determined. DMPP delayed the conversion of ammonium within the manure injection zone significantly. This effect was considerably more pronounced in treatment digestate + NI than in treatment slurry + NI. Regarding the cumulated N2O emissions, no difference between slurry and digestate treatments was determined. DMPP reduced the release of N2O significantly. Transferring the results into practice, the use of DMPP is a promising way to reduce greenhouse gas emissions and nitrate leaching, following the injection of slurry or digestate.

Organic pot-based production of basil (Ocimum basilicum L.) often has lower biomass yield than conventional cultivation. Previous investigations indicate that this growth impairment is related to high ammonium (NH4+) concentrations in the growing media released by the mineralization of organic nitrogen (N) fertilizers. However, as a result of this ammonification process substrate pH may also increase. Under neutral to alkaline conditions NH4+ is converted to ammonia (NH3), which is known to be phytotoxic even at low concentrations. Therefore, we investigated the impact of both ammonical N species on basil grown in a peat substrate. In total, three fertilization pot experiments were conducted in a greenhouse in order to compare the effect of different organic base dressings [250 and 750 mg N (L substrate)-1 mainly supplied by a liquid amino acid fertilizer (AAF)] and two initial substrate pH levels (5.5 and 6.5). In two treatments, 5% (v/v) mature compost was mixed into the peat 1 day and 12–days before the substrate was used for sowing, respectively. The aim of this procedure was to stimulate nitrification in this way to reduce ammonical N concentration. Ammonia concentration in the aerial plant surrounding environment was measured by using NH3 detector tubes in combination with an open-top chamber method. The results showed that the growth of basil (number of plants, fresh matter yield, plant height) was significantly inhibited in the second and third week of cultivation by rising NH3 and NH4+ exposure, as well as by a substrate pH ≥ 7.0. These adverse effects were reduced by lowering the organic base dressing rate and adjusting the initial substrate pH to 5.5. Furthermore, the addition of mature compost to peat in combination with a 12-day storage was proven to be effective for promoting nitrification in the organically fertilized substrate. As a result, plant growth was improved by both lower NH3 and NH4+ exposure as well as a faster supply of nitrate (NO3-) as an additional N source. Using this approach, it was possible to feed organically fertilized basil right from the seedling stage with a NO3--N/NH4+-N-balanced and later on providing a predominant NO3--N supply.

Der vorliegende Beitrag thematisiert den Umgang mit digitalen Medien im Berufsalltag hinsichtlich Strategien zur reduzierten oder reflektierten Mediennutzung. Konkret wurde folgender Forschungsfrage nachgegangen: Inwiefern erachten Beschäftigte eine Begrenzung der Nutzung von digitalen Medien im Arbeitskontext als sinnvoll? Der bisherige Forschungsstand ist von einer quantitativen Herangehensweise und dem Fokus auf die Unternehmensperspektive geprägt. Zur Annäherung an die Beantwortung der Forschungsfrage wurden im Rahmen einer Masterarbeit sieben qualitative, telefonische Leitfadeninterviews geführt. Befragt wurden Beschäftigte aus verschiedenen Großunternehmen in Deutschland, in denen die genannten Strategien zur Anwendung kommen. Den Antworten ist zu entnehmen, dass unter Arbeitnehmenden grundsätzlich Bedarf und Interesse an Strategien der reduzierten oder reflektierten Nutzung digitaler Medien besteht. Die meisten Befragten kritisieren jedoch insbesondere solche unternehmerischen Vorhaben, durch die ihnen die Autonomie genommen wird, flexibel zu entscheiden, wann und in welcher Form sie ihre Mediennutzung einschränken. Eine klare Handlungsempfehlung für Unternehmen ist deshalb, vorrangig Strategien einzusetzen, welche die Beschäftigten in ihrer individuellen und selbstbestimmten Arbeitsweise nicht behindern und mit denen sie sich daher identifizieren können.