In all process industries, the process variables like flow, pressure, level, concentration
and temperature are the main parameters that need to be controlled in both set point
and load changes.
A control system of propylene glycol production in a non isothermal (CSTR) was
developed in this work where the dynamic and control system based on basic mass
and energy balance were carried out.
Inlet concentration and temperature are the two disturbances, while the inlet
volumetric flow rate and the coolant temperature are the two manipulations. The
objective is to maintain constant temperature and concentration within the CSTR.
A dynamic model for non isothermal CSTR is described by a first order plus dead
time (FOPDT).
The conventional PI and PID control were studied and the tuning of control
parameters was found by Ziegler-Nichols reaction curve tuning method to find the
best values of proportional gain (Kc), integral time ( I) and derivative time ( D).
The conventional controller tuning is compared with IMC techniques in this work and
it was found that the Ziegler –Nichols controller provides the best control for the
disturbance and the worst for the set-point change, while the IMC controller results
show satisfactory set-point responses but sluggish disturbance responses because the
approximate FOPTD model has relatively small time delay.
Feedforward and feedforward combined with feedback control systems were used as
another strategy to compare with above strategies. Feedforward control provides a
better response to disturbance rejection than feedback control with a steady state
deviation (offset). Thus, a combined feedforward-feedback control system is preferred
in practice where feedforward control is used to reduce the effects of measurable
disturbances, while feedback trim compensates for inaccuracies in the process model,
measurement error, and unmeasured disturbances. Also the deviation (offset) in
feedforward control was eliminated.
The present study was conducted to determined the action of several levels of cytokinis (N6-benzyladenine (BA), 6-furfurylaminopurine (kinetin), N6-(∆-isopentyladenine) (2,ip) on buds proliferation of Phoenix dactylifera L..3 ml explants of the heart of 3 years old offshoot were cultured on Murashige and Skoog medium (1962) containing 3 mg/L activated charcoal, 10 mg/L Naphthalene acetic acid proposed by (1) as a control. Other explants were cultured on this medium supplemented with 0.1, 0.5, 1 mg/L BA. 0.1, 0.5, 1, 2, 3, 4 mg/L Kinetin. 0.1, 0.5, 1 mg/L 2,ip. Best number of buds proliferated has occurred on control medium containing 3 mg/L. 2ip.
Background: Mineral Trioxide Aggregate (MTA) and BiodentineTM cements are new materials with numerous exciting clinical applications. Both have appreciable properties which include good physical properties and the ability to stimulate tissue regeneration as well as good antibacterial effects. The aim of this study was to investigate and compare the antibacterial effects of MTA and BiodentineTM, when they were mixed with different concentrations of aqueous solutions of Black Seed extract, against Enterococcus faecalis. Materials and methods: MTA and BiodentineTMwere prepared according to the manufacturer’s instructions. The method of Mawlood was followed to prepare the Black Seed aqueous solution. Agar diffusion method on Brain Heart
... Show MoreThis experiment was conducted to evaluate the effect of foliar spraying with gibberellic acid concentrations (0,50,100)mg.L¹ and proline acid concentrations (0, 25, 50)mg.L¹ and their interactions on some growth parameters of pea plant using clay pots in the botanical garden of Biology Department College of Education for pure science Ibn –Al-Haitham ,Baghdad University, for the growing season 2012-2013 the experiment involved the studing of some growth parameters as plant?s height, dry weight, wt. of pods.plant¹, biology yield and the concentration of some major elements (nitrogen, phosphorus and calcium) in plant?s seeds. The experiment was designed according to Completely Randomized Desig(CRD) with three replications. R
... Show MoreThe subject of the Internet of Things is very important, especially at present, which is why it has attracted the attention of researchers and scientists due to its importance in human life. Through it, a person can do several things easily, accurately, and in an organized manner. The research addressed important topics, the most important of which are the concept of the Internet of Things, the history of its emergence and development, the reasons for its interest and importance, and its most prominent advantages and characteristics. The research sheds light on the structure of the Internet of Things, its structural components, and its most important components. The research dealt with the most important search engines in the Intern
... Show MoreIn the case where a shallow foundation does not satisfy with design requirements alone, the addition of a pile may be suitable to improve the performance of the foundation design. The lack of in-situ data and the complexity of the issues caused by lagging in the research area of pile foundations are notable. In this study, different types of piles were used under the same geometric conditions to determine the load-settlement relationships with various sandy soil relative densities. The ultimate pile capacity for each selected pile is obtained from a modified California Bearing Ratio (CBR) machine to be suitable for axial pile loading. Based on the results, the values of Qu for close-ended square pile were increased by 15
... Show MoreIn this study, a simulation model inside a channel of rectangular section with high of (0.16 m) containing two rectangular obstruction plates were aligned variable heights normal to the direction of flow, use six model of the obstructions height of (0.059, 0.066, 0.073, 0.08 and 0.087 m) were compared with the flow behavior of the same duct without obstructions. To predict the velocity profile, pressure distribution, pressure coefficient and turbulence kinetic energy flow of air, the differential equations which describe the flow were approximated by the finite volumes method for two dimensional, by using commercial software package (FLUENT) with standard of k-ε model two dimensions turbulence flow.
... Show MoreFG Mohammed, HM Al-Dabbas, Iraqi journal of science, 2018 - Cited by 6
This paper presents theoretical parametric study of the curvature ductility capacity for reinforced concrete column sections. The study considers the behavior of concrete and reinforcing steel under different strain rates. A computer program has been written to compute the curvature ductility taking into account the spalling in concrete cover. Strain rate sensitive constitutive models of steel and concrete were used for predicting the moment-curvature relationship of reinforced concrete columns at different rate of straining. The study parameters are the yield strength of main reinforcement, yield strength of transverse reinforcement, compressive strength of concrete, spacing of ties and the axial load. The results indicated that hi
... Show MoreDigital Elevation Model (DEM) is one of the developed techniques for relief representation. The definition of a DEM construction is the modeling technique of earth surface from existing data. DEM plays a role as one of the fundamental information requirement that has been generally utilized in GIS data structures. The main aim of this research is to present a methodology for assessing DEMs generation methods. The DEMs data will be extracted from open source data e.g. Google Earth. The tested data will be compared with data produced from formal institutions such as General Directorate of Surveying. The study area has been chosen in south of Iraq (Al-Gharraf / Dhi Qar governorate. The methods of DEMs creation are kriging, IDW (inver
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