1,918 research outputs found
Stamina of a non-gasketed flange joint under combined internal pressure, axial and bending loading : an experimental study
The performance of a bolted flange joint is characterized mainly by its 'strength' and 'sealing capability'. A number of numerical and experimental studies have been conducted to study these characteristics under internal pressure loading conditions alone. However, limited work is found in the literature under conditions of combined internal pressure and axial loading. The effect of external, axial loading pressure being unknown, the optimal performance of the bolted flange joint cannot be achieved. Current design codes do not address the effects of axial loading on structural integrity and sealing ability. To study joint strength and sealing capability under combined loading conditions, an extensive experimental and numerical study of a non¬gasketed flange joint was carried out. Actual joint load capacity was determined at both design and test stages with the maximum external axial loading that can be applied for safe joint performance. Experimental and numerical results have been compared and overall joint performance and behaviour is discussed in detail
Determination of load capacity of a nongasketed flange joint under combined internal pressure, axial and bending loading for safe strength and sealing
Performance of a bolted flange joint is characterized mainly due to its ‘strength’ and ‘sealing capability’. A number of analytical and experimental studies have been conducted to study these characteristics only under internal pressure loading. A very limited work is found in literature under combined internal pressure and bending loading. Due to the ignorance of external loads i.e. bending and axial in addition to the internal pressure loading, an optimized performance of the bolted flange joint can not be achieved. The present design codes do not address the effects of combined loading on the structural integrity and sealing ability. To investigate joint strength and sealing capability under combined loading, an extensive comparative experimental and numerical study of a non-gasketed flange joint with two different taper angles on the flange surface and with different load combinations is carried out and overall joint performance and behavior is discussed. Actual joint load capacity is determined under both the design and proof test pressures with maximum additional external loading (axial and bending) that can be applied for safe joint performance
Effect of torch angle on arc properties and weld pool shape in stationary GTAW
In this paper, a three dimensional numerical simulation is performed on a stationary arc to study the effect of torch angle in gas tungsten arc welding (GTAW) of SS304 stainless steel. A comparison has been made to investigate 90o and 70o torch angles and analyze the effect on arc and weld pool shape. Current density, heat flux and gas shear stress are calculated in the arc region and are used as input to the workpiece to determine the weld pool. Buoyancy and Marangoni shear also affect the weld pool shape and are taken into account. The computed and experimental results are observed symmetric for 90o torch angle. For 70o torch angle, current density and hence the heat flux due to electron contribution is found the maximum behind and heat flux due to conduction and convection is found the maximum ahead of the electrode tip in the welding direction. This makes the maximum of total heat flux symmetric along the arc center. Heat flux due to conduction and convection decreases as the torch angle decreases resulting in a shallow weld pool. The nonsymmetric “w” shaped weld pool is developed by the combined effect of the gas shear and Marangoni convection. It is found that for 70o torch angle, the weld pool becomes non-symmetric, shallow and wide ahead of the electrode tip in the welding direction. The numerical weld pool shapes are verified through experiments
Another characterization of warped product submanifolds of nearly cosymplectic manifolds
In this paper, we study warped product pseudo-slant submanifolds of nearly cosymplectic manifolds. First, we derive the integrability conditions of the distributions and then, we investigate the geometry of the leaves of both distributions. Also, we prove a characterization theorem for a pseudo-slant submanifold to be locally a warped product manifold
Antitumour activity of adenovirus-12 structural proteins against Moloney sarcoma tumours in mice.
When purified fibre and hexon proteins of adenovirus 12 were given intramuscularly to 4-week-old BALB/c mice (250-300 mug/mouse) 2 h prior to inoculation with mouse sarcoma virus (0.05 ml of 10(4) FFU/ml) at the same site, significant suppression of tumour growth (P less than 0.001), and rapid regression in tumour size (P less than 0.001) were noted. As a rule, the survival rate in treated mice was also significantly higher than in untreated mice. Furthermore, the disease process in treated mice as compared to untreated mice was far less extensive as judged by the scarcity of sarcoma lesions on the spleens. Preliminary evidence suggested that treatment with fibre could lead to increased cellular immunity in mice. Whether this may be a secondary consequence of events whereby fibre inhibited tumour growth rather than first order mechanism of the inhibition is not known
CMC Determination and Thermodynamic Micellisation Of NPE Surfactant In Aqueous And CH3OH – H2O Solvents
The critical micelle concentration (CMC) of nonylphenolethoxylate (NPE) surfactant has been determined by measuring the surface tension as a function of the molar concentration of the surfactant in aqueous and binary mixture of water + methanol solutions at a temperature range from 20?C to 35?C. The interfacial parameters ?max, Amin, ?cmc and ?G?ads were calculated. The results indicate that the CMC increases as the temperature increases and that the addition of methanol the CMC decreases. The thermodynamic parameters such as standard Gibbs free energy (?G?), enthalpy (?H?), and entropy (?S?) of micellization were estimated using the change of CMC with temperature. The enthalpy – entropy compensation behavior of the surfactant was evaluated and a good linearity in the compensation plot has been observed
Capacity of Control for Stochastic Dynamical Systems Perturbed by Mixed Fractional Brownian Motion with Delay in Control
In this paper, we discuss the relationships between capacity of control in
entropy theory and intrinsic properties in control theory for a class of finite
dimensional stochastic dynamical systems described by a linear stochastic
differential equations driven by mixed fractional Brownian motion with delay in
control. Stochastic dynamical systems can be described as an information
channel between the space of control signals and the state space. We study this
control to state information capacity of this channel in continuous time. We
turned out that, the capacity of control depends on the time of final state in
dynamical systems. By using the analysis and representation of fractional
Gaussian process, the closed form of continuous optimal control law is derived.
The reached optimal control law maximizes the mutual information between
control signals and future state over a finite time horizon. The results
obtained here are motivated by control to state information capacity for linear
systems in both types deterministic and stochastic models that are widely used
to understand information flows in wireless network information theory.
The contribution of this paper is that we propose some new relationships
between control theory and entropy theoretic properties of stochastic dynamical
systems with delay in control. Finally, we present an example that serve to
illustrate the relationships between capacity of control and intrinsic
properties in control theory.Comment: 17 pages, 2 example
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