As an essential principle in contract law, Indonesia has regulated good faith in the Indonesian Civil Code (the Dutch Civil Code that the Indonesian government uses based on the principle of concordance). However, the definition and benchmarks are not yet clear. There are no further provisions regarding the meaning and concept of this principle in the Indonesian Civil Code or other regulations. This absence of a single understanding of good faith principle in contract causes different opinions and legal certainty, whether from the business actor who signs the agreement or the judge as the third party who resolves contract disputes between parties. Therefore, future Indonesian contract law needs to regulate the definition and benchmarks for good faith principle. In order to find out the meaning and clear benchmarks for the good faith principle, the authors use a normative juridical method with a statute and conceptual approach. This research finds that the definition and benchmarks for the good faith principle is possible to be developed and regulated in Indonesian contract law. It shall set that good faith principle is based on honesty, decency, and fairness, which covers every agreement stage, from pre-agreement, agreement implementation, and after the agreement is completed.

Control of key technological and benchmark flows of polymer fluids poses a number of challenges. Some of them are nowadays under active investigation and rather far from complete under­stan­ding. This review considers such phenomena as both practically important and governed by funda­mental laws of rheology and non-linear fluid mechanics. We observe, shear bands in polymeric and other complex structured fluids (like wormlike micellar solutions or soft glassy materials), birefrigerent strands, peculiarities of stress and pressure losses in fluids moving through com­plex shape domains. These and other processes involve in­ho­mo­geneity, in­stabilities and tran­sient modes creeping in flow fields. In practical aspect this is of interest in such industrial process as polymer flooding for Enhanced Oil Recovery (EOR), where a flow inhomogeneity affects a poly­mer solution injectivity and residual oil saturation. The value of viscoelasticity in the polymer flooding is estimated. The obser­va­tion is con­clu­ded by some new results on relation between polymer concentration in solutions and viscoelastic traits of benchmark flows.