Assessment of P-Delta Effect on High Rise Buildings

P-delta effect is secondary effect on structure .it is also known as ‘Geometric nonlinearity effect’. As number of stories increases, P-delta effect becomes more important. If the change in bending moments and displacements is more than 10%, P-delta effect should be considered in design. In this study the P-delta effect on high rise building is studied. Linear static analysis (without P-delta effect) on high rise building having different number of stories is carried out. For the analysis G+14, G+19, G+24, (i.e 15, 20, and 25storey) R.C.C. framed building are modeled. Earthquake load is applied on model of structure as per IS-18939(2002) for zone III in E-Tab software. Load combination for analysis is set as per IS-456(2000).All analysis is carried out in software ETAB. Bending moment, story displacement with and without p-delta effect is calculated and compared for all the models. Then by trial and error method suitable cross-section are provided for unsafe building to bring within acceptable limit by increasing stiffness of a building. The result shows that it is essential to consider the P-delta effect for 25storey building. So buildings having height more than or equal to 75m, should be designed considering P-delta effect. Also we can say that up to 25storey building, it is not necessary to consider P-delta effect in design and primary or first order analysis is sufficient for design. By increasing stiffness of building by providing suitable cross section or by increasing stiffness building can bring within acceptable limit.[7] DOI: 10.17762/ijritcc2321-8169.150515

Feasibility of hydraulic separation in a novel anaerobic-anoxic upflow reactor for biological nutrient removal

ABSTRACT : This contribution deals with a novel anaerobic-anoxic reactor for biological nutrient removal (BNR) from wastewater, termed AnoxAn. In the AnoxAn reactor, the anaerobic and anoxic zones for phosphate removal and denitrification are integrated in a single continuous upflow sludge blanket reactor, aiming at high compactness and efficiency. Its application is envisaged in those cases where retrofitting of existing wastewater treatment plants for BNR, or the construction of new ones, is limited by the available surface area. The environmental conditions are vertically divided up inside the reactor with the anaerobic zone at the bottom and the anoxic zone above. The capability of the AnoxAn configuration to establish two hydraulically separated zones inside the single reactor was assessed by means of hydraulic characterization experiments and model simulations. Residence time distribution (RTD) experiments in clean water were performed in a bench-scale (48.4 L) AnoxAn prototype. The required hydraulic separation between the anaerobic and anoxic zones, as well as adequate mixing in the individual zones, was obtained through selected mixing devices. The observed behaviour was described by a hydraulic model consisting of continuous stirred tank reactors and plug-flow reactors. The impact of the denitrification process in the anoxic zone on the hydraulic separation was subsequently evaluated through model simulations. The desired hydraulic behaviour proved feasible, involving little mixing between the anaerobic and anoxic zones (mixing flowrate 40.2% of influent flowrate) and negligible nitrate concentration in the anaerobic zone (less than 0.1 mgN L-1) when denitrification was considered

Chemically Synthesized Sn Doped Polyaniline Hydrochloride for Carbon Dioxide Gas Sensing

The polyaniline (PANi) has been subject of many studies due to their case of synthesis, environmental stability and simple doping /dedoping chemistry. Sn doped PANI hydrochloride was synthesized using the monomer of aniline hydrochloride and insitu varying concentration of SnCl4 by chemically oxidative polymerisation in presence of oxidant ammonium peroxidase. Four samples were prepared by varying the concentration of SnCl4 from 0.01-0.04 M. The sensors of each sample were prepared using screen-printing on glass substrate. The sensors were investigated for CO2 gas sensing at different concentration (ppm) at room temperature (313 K) and compare sensing response with pure PANI hydrochloride. The sensing response (sensitivity) of sensors was found to be improved with the concentration of SnCl4. It is higher for 0.04 M concentration of Sn doped PANI hydrochloride film. Material was characterized by XRD and FTIR

Gas Sensors Based on Inorganic Materials: An Overview

In present article, typical 3S parameters of gas sensors that are sensitivity, selectivity and stability of metal oxides are discussed. Metal oxide gas sensors are considered as one of the basic technology for identification and measuring concentration of gases in atmosphere. Research on sensing materials has been focused on design higher performance and elevated efficiency gas sensing materials. Various experimental methodologies associated with gas sensors are discussed for their screening in this article. In present review we confined our dissection with inorganic materials. Factors deals with sensitivity and selectivity are discussed including inorganic materials such as Transition-metal oxides and Non-transition-metal oxides

Molecular interactions in CdCl₂/H₂C₂O₄ nanofluid using acoustical studies at room temperature

670-674Nanofluids have been prepared by dispersing nanometer size particles in base fluid. The very essence of nanofluids research and development has to enhance the fluid macroscopic and mega scale properties such as thermal conductivity through manipulating microscopic physics. The acoustical properties of rhombohedral symmetry CdCl2/H2C2O4 nanofluids have been studied using ultrasonic technique at room temperature (303 K). The ultrasonic velocity, density and viscosity of nanofluids have been measured to manipulate the acoustical parameters such as specific acoustic impedance, adiabatic compressibility, internal pressure, viscous relaxation time, relative association, Gibbs free energy, intermolecular free length to know the molecular interaction. The particle size of CdCl2/H2C2O4 fluid was estimated by using UV-Vis analysis. The results were discussed and compared with experimental and theoretical facts