scholarly journals Kinetics and Mechanism of Bulk Polymerization of Vinyl Chloride in a Polymerization Reactor

2015 ◽  
Vol 12 (2) ◽  
pp. 41
Author(s):  
A. S. Ibrahim ◽  
Y. A. Ali ◽  
H. M. Saad ◽  
I. H. Amur
Keyword(s):  
Mathematical Model ◽  
Vinyl Chloride ◽  
Chemical Properties ◽  
Bulk Polymerization ◽  
Liquid Phases ◽  
Proposed Model ◽  
Three Phase ◽  
Plant Data ◽  
Solid Phases ◽  
Physical And Chemical

Polyvinyl chloride (PVC) is the third most commonly produced polymer and is important because of its mechanical characteristics. The most common method of PVC manufacturing is the process of suspension. Although, there are several benefits associated with suspension, this study will focus on the bulk polymerization of vinyl chloride; highlight the physical and chemical properties of PVC, which can be changed through an estimation of the optimum ratio that exists between the hydrophilic and hydrophobic parts of the polymer’s surface, and propose a new mathematical model which will be helpful for the conversion of PVC into a useful form. The result will be the proposal of a new dynamic mathematical model for the three-phase structure model. All particles have been taken into account in the proposed model, which helped contribute to the reaction in gel, solid, and liquid phases, emphasizing the use of mercury (Hg) as a catalyst. The proposed mathematical model considers the heat and mass transfer between the liquid, gel, and solid phases with chemical reactions that occur between the liquid and solid phases, and between the gel and solid phases. The effect of the catalyst and volumetric flow rates of vinyl chloride monomer (VCM) on the system have been evaluated through the proposed mathematical model. Furthermore, the study’s experimental data have been compared with the findings of the suggested model in the context of concentration and temperature reaction. Obtained results show good agreement between the proposed mathematical model and the actual plant data.  

scholarly journals Palladium and Copper: Advantageous Nanocatalysts for Multi-Step Transformations

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1891
Author(s):  
Antonio Reina ◽  
Trung Dang-Bao ◽  
Itzel Guerrero-Ríos ◽  
Montserrat Gómez
Keyword(s):  
Chemical Properties ◽  
Added Value ◽  
Solid Supports ◽  
Nanosized Materials ◽  
Nano Structures ◽  
Liquid Phases ◽  
Wide Range ◽  
Synthetic Methodologies ◽  
Physical And Chemical ◽  
A Current

Metal nanoparticles have been deeply studied in the last few decades due to their attractive physical and chemical properties, finding a wide range of applications in several fields. Among them, well-defined nano-structures can combine the main advantages of heterogeneous and homogenous catalysts. Especially, catalyzed multi-step processes for the production of added-value chemicals represent straightforward synthetic methodologies, including tandem and sequential reactions that avoid the purification of intermediate compounds. In particular, palladium- and copper-based nanocatalysts are often applied, becoming a current strategy in the sustainable synthesis of fine chemicals. The rational tailoring of nanosized materials involving both those immobilized on solid supports and liquid phases and their applications in organic synthesis are herein reviewed.

Analyzing the Impact of Using Biodiesel in the Parameters of a 30 kW Micro-Turbine Control Model

2006 ◽  
Author(s):  
Manuel A. Rendo´n ◽  
Marco A. R. Do Nascimento ◽  
Pedro P. C. Mendes
Keyword(s):  
Electrical Power ◽  
Chemical Properties ◽  
Control Model ◽  
Model Parameters ◽  
Proposed Model ◽  
Complete Study ◽  
Micro Turbine ◽  
Turbine Speed ◽  
Physical And Chemical ◽  
The Impact

This work presents the modifications in a 30 kW gas micro-turbine speed control model, when it was supplied with castor bean biodiesel in several proportions. The concern about using biodiesel as an alternative fuel is increasing in the Brazilian distributed generation market. For this analytics, a complete study was developed considering the effects of using this new fuel. Characteristics like chemical composition, physical and chemical properties of the different mixtures were analyzed, especially focusing on the kinematic viscosity of the fuel. The tests results performed with the micro-turbine, originally projected for diesel, are shown. Mixtures of 5, 10, 15, 20, 25, 30, 50 e 100% of biodesel were used, and several variables were measured in the whole range of power. The influence of the biodiesel characteristics in the model parameters are commented in the conclusions. The possible application of the proposed model in studies of electrical power network is suggested in the end of the article.

scholarly journals Meta-learning Prediction of Physical and Chemical Properties of Magnetized Water and Fertilizer Based on LSTM

2021 ◽  
Author(s):  
Jing Nie ◽  
Nianyi Wang ◽  
Jingbin Li ◽  
Kang Wang ◽  
Hongkun Wang
Keyword(s):  
Optimization Model ◽  
Chemical Properties ◽  
Percentage Error ◽  
Physical And Chemical Properties ◽  
Magnetized Water ◽  
Proposed Model ◽  
Meta Learning ◽  
Update Rules ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract BackgroundDue to the high cost of data collection and labeling for magnetization detection of medium, the sample size is limited, it is not suitable to use deep learning method to predict its change trend. The prediction of physical and chemical properties of magnetized water and fertilizer(PCPMWF) by meta-learning can help to explore the effects of magnetized water and fertilizer irrigation on crops. MethodIn this article, we propose a meta-learning optimization model based on the meta-learner LSTM in the field of regression prediction of PCPMWF. In meta-learning, LSTM is used to replace MAML's gradient descent optimizer for regression tasks, enables the meta-learner to learn the update rules of the LSTM, and apply it to update the parameters of the model. The proposed method is compared with the experimental results of MAML and LSTM to verify the feasibility and correctness.ResultsThe average absolute percentage error of the meta-learning optimization model of meta-learner LSTM is reduced by 0.37% compared with the MAML model, and by 4.16% compared with the LSTM model.ConclusionsIn the case of few sample, the proposed model is superior to the traditional LSTM model and the basic MAML model.

Modeling of the Catalytic Distillation Process for the Synthesis of Ethyl Cellosolve Using A Three-Phase Nonequilibrium Model

2002 ◽  
Vol 1 (1) ◽  
Author(s):  
Yuxiang Zheng ◽  
Flora T. T. Ng ◽  
Garry L. Rempel
Keyword(s):  
Theoretical Plate ◽  
Solid Catalyst ◽  
Catalytic Distillation ◽  
Nonequilibrium Model ◽  
Liquid Phases ◽  
Three Phase ◽  
Model Predictions ◽  
Plant Data ◽  
Model Equations ◽  
Good Agreement

The catalytic distillation (CD) process for the synthesis of ethyl cellosolve from ethanol and ethylene oxide on molecular sieve catalyst NKC-01 in a 200 mm CD pilot column was simulated using the three-phase nonequilibrium model which was developed in our laboratory. The main feature of this model is that the actual rates for transport and reaction are used and the stage efficiency or HETP (height equivalent to a theoretical plate) is not required. The effect of multicomponent mass and heat transfer between vapor and liquid phases as well as between liquid and solid (catalyst) phases was taken into account according to the Maxwell-Stefan equations. The Newton-Raphson method was used to solve the model equations. The simulation profiles of the temperature and composition along the column are in good agreement with the pilot CD plant data obtained for the synthesis of ethyl cellosolve. Good agreement between model predictions and experimental data is also obtained for the yield and selectivity of the ethyl cellosolve. This model could be extended to simulate other CD processes and commercial scale CD plants.

CIS AND TRANS 1-ACETOXY-1,3-BUTADIENE: PHYSICAL AND CHEMICAL PROPERTIES, INFRARED AND ULTRAVIOLET SPECTRA

1960 ◽  
Vol 38 (7) ◽  
pp. 1070-1075 ◽  
Author(s):  
K. K. Georgieff ◽  
A. Dupré
Keyword(s):  
Acetic Anhydride ◽  
Infrared Spectra ◽  
Sodium Acetate ◽  
Chemical Properties ◽  
Bulk Polymerization ◽  
Physical And Chemical Properties ◽  
Ultraviolet Spectra ◽  
Cis And Trans ◽  
Physical And Chemical ◽  
And Chemical Properties

1-Acetoxy-1,3-butadiene was prepared by the reaction of crotonaldehyde with acetic anhydride in the presence of potassium or sodium acetate. The product was found to consist of two forms which, from their physical properties and infrared spectra, appear to be cis and trans. Mass and ultraviolet spectra, and methods of analysis are also reported. The cis form was found to be a substantially stronger inhibitor than the trans in the bulk polymerization of vinyl acetate using benzoyl peroxide as catalyst.

MATHEMATICAL MODEL OF ELECTROSPARK FORMATION OF WEAR-RESISTANT COATINGS ON PROCESSED SURFACES

2021 ◽  
Vol 3 (144) ◽  
pp. 108-115
Author(s):  
Said N. Sharifullin ◽  
◽  
Ayzat S. Akhmetzyanov ◽  
Tat’yana V. Toporkova
Keyword(s):  
Mathematical Model ◽  
Surface Layer ◽  
Chemical Properties ◽  
Research Purpose ◽  
Wear Resistant ◽  
Wear Resistant Coatings ◽  
Working Bodies ◽  
Percent Cobalt ◽  
Physical And Chemical ◽  
Agricultural Machines

The article considers a new direction in optimizing the process of plasma hardening of the surfaces of cutting elements of agricultural machines based on the use of electric spark discharge energy. (Research purpose) The research purpose is in optimizing the technological process of hardening the surfaces of cutting elements of agricultural machines by the method of electric spark alloying of carbide material elements. (Materials and methods) A device under RF patent No. 2655420, developed by the scientific supervisor of the subject S. N. Sharifullin, was used for electric spark alloying. A tungsten-cobalt rod with a diameter of 4 millimeters, consisting of 94 percent tungsten and 6 percent cobalt, was used as the electrode material for this case. The processed sample of 65G steel, which is the main material of the working bodies of tillage equipment. The physical and chemical properties of the samples were studied with a scanning electron microscope EVO 50 XVP from Zeiss. (Results and discussion) After the electric spark treatment of the alloyed elements, there were about ten, while their spectra also appear at different irradiation energies. The alloyed elements in the surface layer are not only separate, but also in the form of compounds with other elements. Such alloying elements as carbon, cobalt and tungsten appeared in a noticeable amount in the surface layer. Electric spark treatment allows increasing the microhardness of the surfaces of cutting elements of tillage equipment up to three times. (Conclusions) When developing a mathematical model of the electric spark formation of wear-resistant coatings on the treated surfaces, it is necessary to use the energy conservation equations of the electron gas, the Maxwell equations, the continuity and momentum equations. The complex solution of these equations makes it possible to obtain the required output parameters depending on the input ones.

scholarly journals Decay of the melt stream during dispersion in granulation devices

2019 ◽  
Vol 73 (5) ◽  
pp. 295-310
Author(s):  
Vsevolod Sklabinskiy ◽  
Artem Artyukhov ◽  
Mykola Kononenko ◽  
Jan Krmela
Keyword(s):  
Mathematical Model ◽  
Chemical Properties ◽  
Radial Component ◽  
Theoretical Description ◽  
Nitrogen Fertilizers ◽  
Scale Production ◽  
Improve Design ◽  
Practice Methods ◽  
Physical And Chemical

The aim of the article is a theoretical description and experimental study of the melt jet expiration process from a perforated shell of a vibrating granulator. Mathematical modeling of hydrodynamic flows was carried out based on the points of classical fluid and gas mechanics and technical hydromechanics. Reliability of the obtained experimental results is based on the application of time-tested in practice methods. Hydrodynamic properties of the liquid jet outflow were obtained. The presented mathematical model allows calculation of the radial component of the jet outflow velocity, as well as determination of the influences of physical and chemical properties of the liquid and the outflow hole diameter on the jet length and flow velocity along the axis to its disintegration into separated drops. The developed mathematical model extended with the theoretical description of the melt dispersion process from rotating perforated shells allowed us to improve design of the granulator to stabilize hydrodynamic parameters of the melt movement. The nitrogen fertilizers melt disperser was investigated regarding industrial-scale production and operating parameters of the process of jet decay into drops, drop size and monodispersity level were optimized.

scholarly journals The thermal conductivity of solid and liquid sulphur

1929 ◽  
Vol 122 (790) ◽  
pp. 633-646 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Change Point ◽  
Temperature Drop ◽  
Chemical Properties ◽  
Liquid Phases ◽  
Liquid Sulphur ◽  
History Of ◽  
The Subject ◽  
Crystalline Aggregates ◽  
Physical And Chemical

By reason of the multiplicity of its solid and liquid phases, the physical and chemical properties of sulphur have been the subject of many investigations in the past. The technique of measuring thermal conductivities using a temperature drop across the specimen of only a few degrees has reached a precision which affords an additional means of exploring change-point regions. An investigation has therefore been undertaken of the thermal conductivity of solid and liquid sulphur over a range of temperature from 20° C. to 210° C., a region which embraces the transition point from rhombic (α) to monoclinic (β) sulphur (95° C.), the “natural” melting point of monoclinic sulphur (115° C.), and the well-known change-point of liquid sulphur (160° C.) with its conspicuous alterations in physical properties (fig. 1). In the case of solid sulphur, measurements have been made of the thermal conductivity of the rhombic and monoclinic varieties each in the form of crystalline aggregates. The influence of the previous thermal history of a sample of sulphur on the velocity of the reversible rhombic-monoclinic transformation has been demonstrated by thermal conductivity measurements. In addition, measurements have been made on the “plastic” variety of sulphur obtained by the sudden chilling of molten sulphur near its boiling point, the progressive change in thermal conductivity being followed during the slow transition at room temperature from the unstable plastic to the stable rhombic form. It has also been shown by conductivity experiments how the rapidity of this transformation is influenced by the temperature.

scholarly journals Proposed Model for Shale Compaction Kinetics

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 137
Author(s):  
James Edward Smith ◽  
Edward Millard Smith-Rowland
Keyword(s):  
Fluid Pressure ◽  
Chemical Properties ◽  
Geothermal Gradient ◽  
Petroleum Exploration ◽  
Pressure Solution ◽  
Fine Grained ◽  
Depth Data ◽  
Proposed Model ◽  
Fractional Reduction ◽  
Physical And Chemical

Shales are the most abundant class of sedimentary rocks, distinguished by being very fine-grained, clayey, and compressible. Their physical and chemical properties are important in widely different enterprises such as civil engineering, ceramics, and petroleum exploration. One characteristic, which is studied here, is a systematic reduction of porosity with depth of burial. This is due increases in grain-to-grain stress and temperature. Vertical stress in sediments is given by the overburden less the pore fluid pressure, σ, divided by the fraction of the horizontal area which is the supporting matrix, (1−φ), where φ is the porosity. It is proposed that the fractional reduction of this ratio, Λ, with time is given by the product of φ4m/3, (1−φ)4n/3, and one or more Arrhenius functions Aexp(−E/RT) with m and n close to 1. This proposal is tested for shale sections in six wells from around the world for which porosity-depth data are available. Good agreement is obtained above 30–40 °C and fractional porosities less than 0.5. Single activation energies for each well are obtained in the range 15–33 kJ/mole, close to the approximate pressure solution of quartz, 24 kJ/mol. Values of m and n are in the range 1 to 0.8, indicating nearly fractal water-wet pore-to-matrix interfaces at pressure solution locations. Results are independent of over- or under-pressure of pore water. This model attempts to explain shale compaction quantitatively. For the petoleum industry, given porosity-depth data for uneroded sections and accurate activation energy, E, paleo-geothermal-gradient can be inferred and from that organic maturity, indicating better drilling prospects.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

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