in this paper, optimization and control of a tubular reactor for thermal bulk post-polymerization of styrene have been investigated. by using the reactor mathematical model, static and dynamic simulations are carried out. based on an objective function including polymer conversion and polydispersity, reactor optimal temperature profile has been obtained. in the absence of model mismatch, desire...

In the continuous gas lift operation, compressed gas is injected into the lower section of tubing through annulus. The produced liquid flow rate is a function of gas injection rate and injection depth. All the equations to determine depth of injection assumes constant density for gas based on an average temperature of surface and bottomhole that decreases the accuracy of gas lift design. Also g...

a theoretical solution is presented for the forced convection heat transfer of a viscoelastic fluid obeying the giesekus constitutive equation in a concentric annulus under steady state, laminar, and purely tangential flow. a relative rotational motion exists between the inner and the outer cylinders, which induces the flow. a constant temperature was set in both cylinders, in this study. the f...

The final hot strip profile is a superposition of the roll initial crown, the roll bending and flattening crown, the roll wearing crown and the roll thermal crown. In this research, linear regression models are proposed to predict the roll force, the roll wearing crown and the roll thermal crown using experimental data provided by Mobarake Steel Complex (MSC). The short beam theory based on ela...

The shape of wake behind a wind turbine is normally assumed to have a hat shape for the models used in wind farm layout optimization purposes; however, it is know from experimental tests and numerical simulations that this is not a real assumption. In reality, the results of actual measurements and detailed numerical simulation show that the velocity in wake region has a S-shape profile. The pr...

We examine the systematics affecting the X-ray mass estimators applied to a set of five galaxy clusters resolved at high resolution in hydrodynamic simulations, including cooling, star formation and feedback processes. These simulated objects are processed through the X-ray Map Simulator, X-MAS , to provide Chandra -like long exposures that are analyzed to reconstruct the gas temperature, densi...

precision forging process is widely used for the production of spur gears due to its advantages such asimproved strength and surface finish, little waste of materials and reduction in the machining time ofthe gear. an important aspect of precision forging process is the load required to perform the processsuccessfully and design the forging tools. in this research, a new kinematically admissibl...

Errors in navigational instruments can significantly affect flight safety. Airspeed is a key piece of navigational data that depends on accurately measured air pressure, which in turn depends on accurately measured air temperature. Instead of measuring the outside air temperature in real time, cockpit instruments are preprogramed with standard air temperature values for different flight altitud...

Previous analyses of ASCA data of clusters of galaxies have found conflicting results regarding the slope of the temperature profile of the hot X-ray gas within clusters, mainly because of the large, energy-dependent point spread function (PSF) of the ASCA mirrors. We present a summary of all ASCA-determined cluster temperature profiles found in the literature, and find a discrepancy in the rad...

AIM To describe self-perceived health status and quality of life in noninstitutionalized persons older than 65 years in two health care districts in Madrid (central Spain). DESIGN Descriptive study based on home interviews by investigators trained in the administration of the questionnaires. SETTING Health care districts 2 and 4 in Madrid; community level. PARTICIPANTS Of a sample of 2002...