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Micic T.,City University London | Asenov M.,Nis
Safety and Reliability of Complex Engineered Systems - Proceedings of the 25th European Safety and Reliability Conference, ESREL 2015

In this paper we investigate probabilistic modelling and analysis options for sample RC solid slab. Variations in slab material, geometric and load slab parameters have been reviewed and set as input variables for the particular sample probabilistic model. Subsequently, FE probabilistic analysis is carried out using Monte-Carlo method and Latin Hypercube sampling technique whereas yield-line probabilistic simulations are conducted using FOSM method. Based on the resulting lower bound solution in the form cumulative distribution functions for the stress and displacement at particular location and probability of slab failure, we are able to identify the most appropriate and most efficient probabilistic structural analysis. © 2015 Taylor & Francis Group, London. Source

Hasan E.H.,Nis | Haucke G.,PTB | Kumme R.,PTB
21st Conference on Measurement of Force, Mass and Torque Together with HARDMEKO 2010 and 2nd Meeting on Vibration Measurement, IMEKO TC3, TC5 and TC22 Conferences

The creep and creep recovery are important characteristics of force transducers. Thus, this study is focused on the measurements of creep and creep recovery for transducers of different capacities. Creep measurements are carried out according to three different loading schemes, revealed that the creep values measured at maximum loads and reached after time intervals from 30 to 300 seconds like proposed in a new draft of ISO 376 from the moment of load application. The effect was higher in direct loading (one step to reach the maximum load) than those obtained from the two other schemes (chosen loading steps distributed all over the full range up to maximum load and according to automatic machine calibration (M/C) software that designed to cover all the range up to maximum load). Effect of creep on hysteresis value is also investigated. Source

Olneva T.V.,Gazpromneft | Milei E.,Nis
2nd Conference on Forward Modelling of Sedimentary Systems: From Desert to Deep Marine Depositioned Systems

There are several approaches of interpretation fluvial depositional environment sediments based on seismic and well data. This work show some examples of interpretation deposits from the west Siberia and Pannonian Basin which have the same geological settings. Due to the seismic attribute analysis, the integration of spectral decomposition with log analysis was defined in the investigated interval and facies boundaries were established. The most perspective part of the pay is the channel deposits which location were identified more precisely after spectral decomposition interpretation in the interval of interest. The lithological model obtained as a result of this project differs qualitatively from all previous models of the investigated formation, due to the following: using the predictive facies boundaries derived from the complex dynamic interpretation of the seismic data to detect geological characteristics more precisely; reconstructing the formation heterogeneity, which is very important for the well position planning and its hydrodynamic studies. © 2016, European Association of Geoscientists and Engineers, EAGE. All rights reserved. Source

Kruger O.,NMISA | Hungwe F.,NMISA | Farid N.,Nis | Schreve K.,SUN
International Journal of Metrology and Quality Engineering

At NMISA the SI unit for length is realised by an iodine stabilised He-Ne laser, an optical measurement. In industry most measurements are performed by mechanical probing. Gauge blocks are the link between the optical measurements and the mechanical measurements, and are therefore critical in disseminating traceability. The gauge block length is currently determined by wringing the gauge block onto a platen. This is laborious, requires skill and causes contact errors. Since around 1943, there have been efforts to build a double ended interferometer where gauge block length can be determined without wringing it onto a platen. While there has been a lot of progress in building DEIs, to date, there is still no commercially available DEI. We present a collaboration project between the National Metrology Institute of South Africa (NMISA), the National Institute of Standards (NIS Egypt) and Stellenbosch University (SUN) in South Africa to build a double ended interferometer for use at the respective National Metrology Institutes. We investigate improvements to the interferometric calibration of gauge blocks and recent developments. The different systems currently in use in the national metrology laboratories are described and various designs are investigated. Lastly the expected outcome of the project will be discussed. © 2014 EDP Sciences. Source

Korasie C.,NMISA | Eltawil A.,Nis
PTB - Mitteilungen Forschen und Prufen

- This paper will look at the process, developing NMI's in Africa go through to establish an NMI from mostly Trade and or Legal Metrology requirements. The aim is to investigate the challenges countries are faced with in obtaining traceability and eventually accreditation. A case study will be made of the roadmap followed by NMI's that has successfully entered CMC's in the BIPM database. With limited resources the tools required to maintain these newly formed NMI's and how to increase capability in various parameters will be scrutinized. Source

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