The main aim of the contribution is to present a possible approach to design of simple Proportional-Integral (PI) robust controllers and subsequently to demonstrate their applicability during control of a laboratory m...
The main aim of the contribution is to present a possible approach to design of simple Proportional-Integral (PI) robust controllers and subsequently to demonstrate their applicability during control of a laboratory model with uncertain parameters through the Programmable Logic Controller (PLC) SIMATIC S7–300 by Siemens Company. The proposed and utilized synthesis consists of two steps – the former one is a determination of controller parameters area, which ensures the robustly stable control loop and which is based on the computing/plotting the stability boundary locus while the latter one lies in the final choice of the controller itself relying on algebraic techniques. The basic theoretical parts are followed by laboratory experiments in which the 3rd order nonlinear electronic model has been successfully controlled in various working points.
It is common for small tandem peptide multimer genes to be indirectly inserted into expression vectors and fused with a protein tag. In this study, a multimer of the tandem angiotensin I-converting enzyme inhibitory p...
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Nonequilibrium statistical mechanics helps to estimate corrections to the entropy and energy of the fluid with heat flux in terms of the nonequilibrium distribution function, f. This leads to the coefficients of wave ...
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Nonequilibrium statistical mechanics helps to estimate corrections to the entropy and energy of the fluid with heat flux in terms of the nonequilibrium distribution function, f. This leads to the coefficients of wave model of heat: relaxation time, propagation speed and thermal inertia. With these data a quadratic Lagrangian and a variational principle of Hamilton's type follows for the fluid in the field representation of fluid's motion. We analyze canonical conservation laws and show the satisfaction of the second law under the constraint of these conservation laws.
作者：
McCarthy, AliceMain Text
“In June 2003
the scientific and medical communities at MIT Harvard University and its affiliated hospitals and the Whitehead Institute banded together as collaborating partners to form the Eli and Edythe L. Broad Institute based in Cambridge MA. The Broad Institute established with initial funding from a $100 million philanthropic donation from the Los Angeles-based Broad family was primarily viewed as a marriage between the Whitehead Institute's Center for Genome Research (WICGR) and the Harvard Institute of Chemistry and Cell Biology (ICCB). Eli Broad founder and chairman of AIG SunAmerica Inc. explained “the purpose of the Broad Institute is to create a new type of research institute to build on the accomplishments of the human genome project and to move to clinical applications to both prevent and cure diseases.”
Every Thursday morning we meet with perhaps 20 faculty members and 100 other researchers to discuss what we're all doing and should be doing next. -David Altschuler
This paragraph was written five years ago when the Broad Institute was in its very earliest days as a life science research community (McCarthy 2005). Since that time “the Broad” as it's known has kept true to Eli Broad's vision having attracted a talented group of researchers faculty trainees and professional staff. This 1600 person research community known internally as “Broadies” includes faculty staff and students from throughout the MIT and Harvard biomedical research communities and beyond with collaborations spanning over a hundred private and public institutions in more than 40 countries worldwide.
“What is special about the Broad is that we have people from Harvard MIT and the Harvard hospitals come together and work on problems of shared interest that could not be solved in their own individuals labs” explains David Altshuler M.D. Ph.D. Deputy Director and one of the Broad's six core faculty members. “These problems require expertise beyond any one principal investigator and in
Problem statement: One of the main factors influenced the bacterial productivity and total yield of hydrogen is the nitrogen source and its concentration. Approach: Using different nitrogen source with different conce...
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Exergy-based efficiency for devices producing work is usually defined as a ratio of obtained useful work to the maximum feasible work which is a difference between stream of exergy provided to device and stream of exe...
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ISBN:
(纸本)9788392238140
Exergy-based efficiency for devices producing work is usually defined as a ratio of obtained useful work to the maximum feasible work which is a difference between stream of exergy provided to device and stream of exergy leaving this device. For devices producing no work (e.g. heat exchangers) commonly accepted definition of an exergy-based efficiency doesn't exist so the efficiency is defined by various ways [1]. In these studies two definitions of exergy-based efficiency are considered. The first definition bases on balance of exergy. Hence the exergy-based efficiency is determined as a ratio of exergy stream flow out from a device to exergy provided to the device. In the second way the heat exchanger is treated as an entropy generator and the exergy efficiency is defined using the ratio of generated entropy to exergy provided to the exchanger by hot stream. For heat exchangers this efficiency can be also defined as a ratio of an increase of exergy in heated stream to a decrease of exergy in heating stream. In this paper the process of fine solid particles heating in fluidized bed with a bubble phase is considered. The hydrodynamics of fluidization is described by Kunii' and Levenspiel's two-phase model. The influence of fluidized bed hydrodynamics and heating kinetics as well pressure drop of process gas on exergy-based efficiency is investigated. The calculations for both definitions of exergy-based efficiency were performed. The results show that values of both exergy-based efficiencies strongly depend on process hydrodynamics and kinetics as well pressure drop. For both considered definitions of exergy-based efficiency these dependences are different especially related to limiting values.
Studies presented in this paper are connected with the cost optimization of fluidized drying processes in continuous flowing dryer. The minimized function (performance index) describes total process costs expressed in...
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ISBN:
(纸本)9788392238140
Studies presented in this paper are connected with the cost optimization of fluidized drying processes in continuous flowing dryer. The minimized function (performance index) describes total process costs expressed in exergy unit. The performance index includes operating and investment costs. Two forms of performance index are taken into account. These forms result from two various descriptions of investment costs. Operating cost has the same description for both forms of performance index. The investment cost depends on the apparatus characteristic size, for fluidized dryer it is usually a dryer volume. The functions describing relationship between apparatus size and investment outlay can take a various forms. Moreover due to market fluctuations values of some coefficients, appearing in these functions, oscillate. It is important that accepted form of the function which describes dependence between apparatus price and its characteristic size, can strongly influence on optimal solutions. In these studies the influence of accepted function on obtained optimization results are investigated. The two forms of this function are considered. In the first case the apparatus price is linear function of its characteristic size, whereas in the second case the apparatus price is power function of the size. For the function describing apparatus price versus its characteristic size, influence of function forms as well various values of coefficients appearing in this function was analyzed in this paper.
Neural network-based soft sensors are developed for quality estimation of kerosene, a refinery crude distillation unit side product. Based on temperature and flow measurements two soft sensors serve as the estimators ...
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Neural network-based soft sensors are developed for quality estimation of kerosene, a refinery crude distillation unit side product. Based on temperature and flow measurements two soft sensors serve as the estimators for the kerosene distillation end point (95%) and freezing point. The neural networks are trained by the adaptive gradient method using cascade learning. Research results show possibilities of applying soft sensors for refinery product quality estimation and inferential control as an alternative for process analyzers and laboratory assays.
作者：
Hirmajer, T.Fikar, M.Balsa-Canto, E.Banga, J.R.Institute of Information Engineering
Automation and Mathematics Department of Information Engineering and Process Control Faculty of Chemical and Food Technology STU Radlinského 9 812 37 Bratislava Slovakia
Spanish Council for Scientific Research C Eduardo Cabello 6 36208 Vigo Spain
This paper explores the possibilities of using the combination of the state of the art nonlinear programming problem solver IPOPT and the initial value problem solver CVODES (incorporated in SUNDIALS) for the solution...
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ISBN:
(纸本)9780889867116
This paper explores the possibilities of using the combination of the state of the art nonlinear programming problem solver IPOPT and the initial value problem solver CVODES (incorporated in SUNDIALS) for the solution of dynamic optimization problems, also regarded as open loop optimal control problems (OCP). Recent works confirm the potential of IPOPT in solving large scale optimization problems and particularly in solving optimal control problems in the framework of the complete parameterization approach [12]. Here the OCP problems are solved using the control vector parameterization scheme and the advantages and disadvantages of the combination CVP + IPOPT + CVODES are evaluated through several examples.
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