Zum Einfluß des Ofengasschwefels auf die Glasschmelze Teil II. Diskussion der Meßergebnisse

Im Anschluß an die im ersten Teil dieser Arbeit mitgeteilte Methode zur Meßwertermittlung werden nunmehr die experimentellen Meßergebnisse in ihrem komplexen Zusammenhang gedeutet, wobei vor allem der korrespondierende Einfluß vom Schwefelgehalt des Brennstoffes und von der Gas- bzw. Schmelzentemperatur hervorzuheben ist. Abschließend werden die Versuchsergebnisse im Vergleich mit Ergebnissen früherer Laborversuche diskutiert

Zum Einfluß des Ofengasschwefels auf die Glasschmelze Teil I. Experimentelle Untersuchungsmethodik und Meßwertermittlung

Die in zunehmendem Maße eingeführte Beheizung der Glasschmelzöfen durch Verbrennung von schwefelhaltigen Heizölen und von Kohlenwasserstoffgasen läßt in der Praxis die Frage nach dem möglichen Einfluß des Ofengasschwefels auf die Glasschmelze nicht verstummen. Da die Ergebnisse diesbezüglicher Laboruntersuchungen erheblich von der gewählten Versuchsmethodik beeinflußt werden können, wurde eine möglichst praxisnahe Beaufschlagung der Glasschmelze mit realen Ofenabgasen bekannter Zusammensetzung angestrebt. Über die angewandte Versuchsmethodik und Meßwertermittlung zur Untersuchung des Einflusses des Ofengasschwefels auf die Glasschmelze wird berichtet. Der experimentelle Teil der Untersuchungen wurde im Institut für Brennstoffchemie der Rheinisch-Westfälischen Technischen Hochschule Aachen durchgeführt

Zum Einfluß des Ofengasschwefels auf die Glasschmelze Teil III. Zeitlicher Verlauf der SO3-Aufnahme

In praxisorientierten Laborversuchen wurde in Ergänzung früherer Untersuchungen zur Problematik der sekundären Gallebildung der zeitliche Verlauf des SO3-Übergangs aus der Ofengasphase in die Schmelzenoberfläche bzw. der Sulfatbildung in der oberflächennahen Schmelzenschicht ermittelt. Um eine einheitliche Auswertung der Meßergebnisse mit denen der früheren Untersuchungen zu gewährleisten, wurde ein stark vereinfachtes Modell diffusiven Transportprozesses angewendet, welches gleichzeitig eine grafische Darstellung näherungsweise zu erwartender Konzentrationsprofile in der oberflächennahen Schmelzenschicht erlaubt

About Cooperation, Selfishness and Joint Risks in Clusters

This study introduces an entirely novel way to study the cooperative and noncooperative nature of clusters by looking at the selfish, profit-seeking interests of the actors within cluster initiatives. The approach provides a game theory inspired framework to study the dilemma of cluster actors between the fruitful cooperation with other actors and their own selfish – and possibly short-term – interests at three levels: intensity focussing on the overall cooperation effort; structure looking at the network of cooperation and balance discussing good ways to allocate resources. Characteristic models of cluster behaviour have been developed for all these aspects. Interviews have been conducted among cluster actors of two cluster initiatives. Both were quite matured and well managed with similar core objectives. The methodology applied has revealed that the nature of cooperation among the actors and how the cluster initiative is managed is of surprisingly different nature although both cluster initiatives provide high added value by the cluster actors perspective. One cluster initiative can be characterised as a “managed cooperation cluster”, where the management has a central role to match actors, while the nature of the other cluster initiative is more “a peer-to-peer cooperation cluster” where cooperation emerges directly between cluster actors and the cluster management has another role. The results of the study lead to conclusions that there is not one ideal way how to manage cluster initiative. Furthermore the cluster actors cannot be seen as a homogenous group. Even if all of them have similar objectives like increased innovation capabilities, higher competitiveness, higher profitability etc. their intension why joining a cluster initiative and the readiness to contribute or just to benefit is very different. The cluster management has to understand what are the particular interests and to what extent a dedicated cluster is ready to contribute. Applying the game theory inspired analytical approach helps to gain important inside views for cluster management. Furthermore the study shows that the way how cluster initiatives are set up and supported by public authorities does have a strong implication on the nature of cooperation and selfishness among the cluster actors. The conclusion from the study is, among others, that high public funding facilitates the creation of cluster initiatives, but also attracts free riders to join since the barriers to enter are quite low. Having such an interest group “on board” within a cluster initiative hampers further trust building and cooperative framework conditions since selfish actors dominate. Low public funding at the beginning of the life of a cluster initiative leads to higher barriers due to higher mandatory investments of cluster participants, but creates a cooperative environment since mainly those actors have joint that are really interested to cooperate and take common risks. However, the study has shown that good cluster managements can deal with different cooperative natures among cluster participants, if they are aware of this and implement proper actions

Regionale Transformationsprozesse verstehen und gestalten - Neue Instrumente der regionalen Strategieentwicklung

REGIONALE TRANSFORMATIONSPROZESSE VERSTEHEN UND GESTALTEN - NEUE INSTRUMENTE DER REGIONALEN STRATEGIEENTWICKLUNG Regionale Transformationsprozesse verstehen und gestalten - Neue Instrumente der regionalen Strategieentwicklung / Nögel, Lukas (Rights reserved) ( -

Promoting SME cooperative aggregations: main criteria and contractual models

Collaboration is considered an effective solution to improve business strategies. However, small and medium enterprises (SMEs) often lack common principles and common forms of contractual coordination. Several policies implemented by the EU have addressed the set-up of a comprehensive SME policy framework, but European institutions seem to have focused more on organisational devices to conduct business activities rather than on contractual forms of coordination. In April 2009, Italy adopted a law in network contract to promote the development of inter-firm cooperation strategies to foster enterprises' innovation and growth. Even if this law represents a novelty in Europe and may offer new challenges and hints, it still presents some lacks in its formulation. The current research aims at presenting the Italian law for network contract and a comparison with other models of SME aggregations adopted in EU countries. A formal model to support the design of an SME network was proposed, by providing both an ontology-based model to help the definition of the contract in a structured way, and a basic workflow to identify the important phases of the network design, i.e. the feasibility study and the negotiatio

Autonomous measurement system for photovoltaic and radiometer soiling losses

Soiling can greatly reduce both the efficiency of photovoltaic (PV) installations and the signals of radiometers. The knowledge of the current soiling losses of a PV installation can be used to optimize the cleaning schedule and to avoid false alarms related to other issues that might cause underperformance. Underperformance can be detected by comparing measured to modeled PV production derived using pyranometer or reference cell measurements. Soiled pyranometers or reference cells lead to too low modeled PV production so that PV soiling or other errors might not be detected. So far, soiling sensors either require frequent cleaning or they use indirect measurements to derive the soiling loss (e.g., analysis of backscattering signal or imaging of dust on a glass surface). Currently, the soiling loss of pyranometers or outdoor reference cells uses the comparison to another frequently cleaned device of the same model. To avoid time-consuming maintenance of the sensors and to avoid additional sensors as much as possible, we developed a new method for measuring PV and radiometer soiling losses. The method makes use of a characterized lamp that is protected from soiling by a collimator and that illuminates the pyranometer or reference cell each night for some time. Comparing the signals of one night to the signal obtained at a night shortly after the last cleaning of the sensor, its soiling loss can be derived. To validate the measurements of soiling losses for the pyranometer and the reference cell, the soiling losses of the devices are also derived by comparing their signals to those of a clean sensor of the same type. These reference instruments are calibrated relative to the test devices so that deviations indicate the soiling loss of the test sensors. The first outdoor tests with 4 months of data show a good agreement with the reference measurements of the soiling losses. The accuracy of the method is estimated to be similar to that of the reference method, which involves the daily cleaning of the reference devices