Neškodljivost kalupnih pjesaka sa bentonitom i svijetlećim nositeljima ugljika

Procedures have been developed to determine the volume, rate and composition (particularly BTEX: benzene, toluene, ethylbenzene and xylenes and PAHs (polycyclic aromatic hydrocarbons)) of gas evolution from moulds and cores prepared with various binders as a means of harmfulness of moulding sands. The rate of gas evolution from green sands with four different lustrous carbon carrier and BTEX content were determined. The gas evolution rates are highest in the range of about 20 to 30 s after contact with molten metal. In practice during the first 200-250 s the total emission of gases generated in investigated samples occurred. The main emitted component from the BTEX group was benzene.Postupci su razvijeni za određivanje volumena, brzine i sastava (posebice BTEX: benzen, toluen, etilbenzen, xilana) i PAH (policiklički automatski hidrokarbonati) plina koji nastaje iz kalupa i jezgri na različitim nosačima u težnji za neškodljivost kalupnih pijesaka. Brzine nastajanja plina iz pripravljenih pijesaka sa 4 različita svijetleća nositelja ugljika i sadržajem BTEX su određeni. Brzine nastajanja plina su najveće u razini 20 do 30 s poslije dodira sa rastopljenim metalom. Praktično, tijekom prvih 200-250 s ostvaruje se ukupna emisija stvorenih plinova u istraživanim uzorcima. Iz BTEX skupine, benzen je glavna emitirajuća komponenta

A policy-based management architecture for flexible service deployment in active networks

This paper describes a dynamic, scalable and extensible policy-based network management (PBNM) system that is fully integrated with a service provisioning architectures for active networks. The key result is network customisation according to the needs of the different service providers and its end users. Our component-based service provisioning architecture enables us to render service- and user-specific requirements, across single/multiple administrative domains, at deployment time and to dynamically map service components onto the network using the corresponding management policies. The architecture presented in this paper describes the approach undertaken by the IST-FAIN research project as well as the main issues that we encounter in developing and integrating the PBNM with the service provisioning mechanism

Towards upgrading actively replicated servers on-the-fly

Change management is indispensable in most distributed software systems, which are continuously being modified throughout their life cycle. Managing the changes at runtime in highly available distributed systems is especially challenging as upgrade of a running system should not deteriorate its availability characteristics. We present a distributed algorithm that allows one to dynamically upgrade an actively replicated server so that the server is operational, even during the upgrade process. The algorithm makes use of the core functionality of an underlying group communication system that has been extended with a recovery mechanism. Its design enables dependable upgrades of replicated software in the presence of replica crashes. The presented mechanisms are part of the dynamic upgrade management framework aiming at supporting and managing dependable upgrades of distributed systems on the fly

Reference integrity in dynamic CORBA components

Change management is indispensable in distributed software systems where reliability and availability of system resources has to be maintained in the presence of potentially changing system requirements. In this paper we show how one aspect of change management can be addressed: namely, support for interface reference integrity in the presence of dynamic updating of CORBA components. In our approach, we show how it is possible using current technologies such as the CORBA Component Model and the Portable Object Adaptor, to achieve referentially safe dynamic updating. That is, updates that maintain the validity of the existing (i.e. pre-update) interface references. Hence the update should not adversely influence existing interaction possibilities