On-Line Calorimetry in the Ethylene Coordination Polymerization

2014 ◽  
Vol 1613 ◽  
pp. 103-108
Author(s):  
José R. Infante-Martínez ◽  
Enrique Saldívar-Guerra ◽  
Odilia Pérez-Camacho ◽  
Víctor Comparán-Padilla ◽  
Maricela García-Zamora

ABSTRACTThe kinetic performance of metallocene type catalysts as well as their instantaneous activity is determined on line by two independent methods in the semi-batch polymerization of ethylene via metallocenes. On the basis of first-principles, both methods are described and guidelines for their implementation at a laboratory scale reactor are offered. Polymerization tests were conducted with two heterogenized metallocene catalysts showing that the direct method (based on ethylene flow measurement) and also the calorimetric method (based on energy balances) reported equivalent high quality information. The calorimetric method here developed can be readily used by the chemical practitioner as the notions and tools required for its implantation are easily grasped. It is noted that the calorimetric method has the advantage of requiring a low cost instrumentation (only thermocouples) whereas the direct method needs a relatively more sophisticated equipment (mass flow meter).

2020 ◽  
Vol 18 (1) ◽  
pp. 303-313 ◽  
Author(s):  
Aamir Rasheed ◽  
Tahseen Ghous ◽  
Sumaira Mumtaz ◽  
Muhammad Nadeem Zafar ◽  
Kalsoom Akhter ◽  
...  

AbstractIn the present work, a novel continuous flow system (CFS) is developed for the preconcentration and determination of Cr (VI) using Pseudomonas aeruginosa static biomass immobilized onto an effective and low-cost solid support of powdered eggshells. A mini glass column packed with the immobilized biosorbent is incorporated in a CFS for the preconcentration and determination of Cr (VI) from aqueous solutions. The method is based on preconcentration, washing and elution steps followed by colorimetric detection with 1,5-diphenyl carbazide in sulphuric acid. The effects of several variables such as pH, retention time, flow rate, eluent concentration and loaded volume are studied. Under optimal conditions, the CFS method has a linear range between 10 and 100 μg L-1 and a detection limit of 6.25 μg L-1 for the determination of Cr (VI). The sampling frequency is 10 samples per hour with a preconcentration time of 5 mins. Furthermore, after washing with a 0.1 M buffer (pH 3.0), the activity of the biosorbent is regenerated and remained comparable for more than 200 cycles. Scanning electron microscopy reveals a successful immobilization of biomass on eggshells powder and precipitation of Cr (VI) on the bacterial cell surface. The proposed method proves highly sensitive and could be suitable for the determination of Cr (VI) at an ultra-trace level.


2013 ◽  
Vol 834-836 ◽  
pp. 930-934
Author(s):  
Shou Liang Yang ◽  
Bao Liang Yang

The paper proposes a new design of high-accuracy On-line Metal Thickness Measuring Instrument, which was based on EP2C20 series FPGA chip, through adding NiosII soft processor and other interfaces to FPGA, equipped with high precision data collection system and TFT LCD module and so on. The key hardware blocks schematics and components of the RC Oscillation Circuit,eddy current sensor Circuit,rectifier and filter Circuit,A/D converting circuit,FPGA Circuit are described,software flow charts and sample codes are given. According to practice, The measurement range of this system is 1~100 mm and the resolving power is 0.1 μm. degree of linearity is 1%, The system has many features including small volume of hardware, low cost, high detecting precision, convenient operating, high intelligent and so on, leading to broad and bright future. Key words: NiosII processor; eddy current sensor; metal thickness


2011 ◽  
Vol 186 ◽  
pp. 11-15
Author(s):  
Li Cao ◽  
Wen Chen ◽  
Jun Xiao

Video processing technology is regarded as a low-cost detection technology in complex environment. Because the placement layer is thin and the surface is complex that causes high detection error and high cost in laser measurement. Two problems must be solved before using it in large-scale composite structures automatic placement. One is to obtain the high-quality and stable image, and the other is to improve efficiency of image processing. In this paper, a method obtaining the high quality placement gap images was studied. It made use of the optical characteristics of composite material’s surface texture. And some parameters were determined by experiments. To reduce the calculation cost of image processing, a placement gap measurement method based on line scanning was also proposed here. The method was effective in our detection experiments on an actual workpiece.


2015 ◽  
Vol 785 ◽  
pp. 106-110
Author(s):  
M.N.M. Hussain ◽  
Ahmad Maliki Omar ◽  
Intan Rahayu Ibrahim ◽  
Kamarulazhar Daud

An identification system of multiple-input single-output (MISO) model is developed in controlling dsPIC microcontroller of positive output buck-boost (POBB) converters for module mismatch condition of photovoltaic (PV) system. In particular, the possibility of the scheme is to resolve the mismatch losses from the PV module either during shading or mismatch module occurrences. The MPPT algorithm is simplified by identification approach of indirect incorporated with a simple incremental direct method to form a combined direct and indirect (CoDId) algorithms. Irregular consumption of solar irradiation on a PV module shall step-up or step down the voltage regarding to the desired DC output voltage of POBB converter. This optimized algorithm will ensure that the PV module to kept at maximum power point (MPP), preventing power loss during module mismatch incident in PV module especially during partial shading condition. The simulation and laboratory results for PV module of polycrystalline Mitsubishi PV-AE125MF5N indicate that the proposed model and development of PV system architecture performs well, while the efficiency up to 97.7% at critical of low solar irradiance level. The controlling signal is based on low-cost embedded microcontroller of dsPIC30F Digital Signal Control (DSC).


2019 ◽  
Vol 8 (2S11) ◽  
pp. 2515-2521

Most customarily used motor in the industries are induction motor due to its low cost, robustness and less maintenance. The change in the existing framework is necessary in order to make the motor more efficient one. This paper cast enlightenment about the PLC based 3 phase multi-starter control induction motor with energy efficient single control system. In order to start the engine's operation by its own power, starters are used. Various starters are available to initiate the 3-phase induction motor namely Direct On-line, Star-delta, autotransformer and rotor impedance. The employment of this PLC based techniques helps to increase the energy efficiency of the motor .The employability of PLC in this system is to help in the growth of automation. The hardware and software results of the multi starter control using single control systems are analysed


Robotica ◽  
1996 ◽  
Vol 14 (5) ◽  
pp. 575-582
Author(s):  
Jiming Liu

SUMMARYLearning in the age of information superhighway necessitates a properly-developed efficient vehicle that is not only powerful in directing users to the needed information or to situate in a reality through virtual settings, but also controllable at the various comfortable paces. The goal of this project is to explore a new on-line medium for users to navigate at their own pace in the structured cyberspace—knowledge space composed of concepts, systems design, application-oriented case studies, up-to-date industrial news (trends and product review), and on-line robotic systems, and to use it as a robotics work-bench for conducting controllable experiments/simulations. Through such an electronic learning medium, users will be able to acquire a global outlook as well as an integrated understanding of modern robotics in a manner that is low-cost, time-and-place-free, and student-centered.


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