All building materials can be affected by microbiological agents during their lifecycle. The presence of microorganisms changes the appearance of the surface, degrading it, and they can even cause health problems to the residents. The biological susceptibility is dependent on the content of nutrient based on organic compounds. Thus one of the most susceptible of those materials are earthen construction materials. The degree of fungal growth is influenced by the chemical composition and plant fibres additives as well as the external conditions such as temperature and relative humidity.
The earth plastering mortar has started to gain more attention recently as it is considered to have a low environmental impact and to increase the indoor air quality. Mechanical and physical characteristics of earth materials were studied by a number of authors but the knowledge about the biological resistance of the material is scarce.
This study intends to look into the issue of the biological colonisation of earth plasters depending on the relative humidity. The samples, made of four types of earth plasters with different plant fibres, were placed to an environment of the relative humidity ranging from 33% to 100%. During a period of 4 weeks the extent of fungal growth was observed.
This paper integrates a Real Power Differential Scheme (RPDS) for power transformer protection. The suggested RPDS for power transformer computes the active power loci during normal operation, switching, normal, and internal, involves turn to turn, and external faults at varied load angles. The proposed RPDS concept is based on monitoring and comparing the transformers primary and secondary active and reactive powers. The dynamic response of the proposed RPDS is tested 300 MVA, 220/66 kV, Y/Δ transformer. Furthermore, the suggested scheme is simulated with the use of Matlab/Simulink then tested for various fault and switching conditions. Moreover, the RPDS is checked for inter turn fault conditions at primary and secondary sides. The evaluation of the suggested scheme confirms the superiority of the proposed scheme to distinguish internal and external faults as well as magnetizing inrush currents with good selectivity, high speed, sensitivity, stability limits and high accuracy response of the power differential scheme. Finally, the suggested scheme is able to detect correctly the turn to turn faults for wide range of fault resistances but fails at very low values.
Authors:H. Coutinho, J. Costa, V. Falcão-Silva, J. Siqueira-Júnior and E. Lima
, E.O., Falcão-Silva, V.S. & Siqueira-Júnior, J.P. (2009b): Potentiating effect of Mentha arvensis and chlorpromazine in the resistance to aminoglycosides of methicillin-resistant Staphylococcus aureus . In Vivo , 23 , 287
, Parekh A. ( 2015 ), Assessing long term thermal resistance (LTTR) of vacuum insulation panel (VIP) –Review of challenges and way forward . Proc. of 12th International Vacuum Insulation Symposium , September 19
Authors:G. Lizia Thankam and Neelakantan Thurvas Renganathan
out resistance was enhanced when steel fibers were introduced. 4.3 Chloride resistivity In order to determine the chloride resistivity of concrete, the electrical conductance of concrete is performed by allowing the chloride ions to penetrate into it