Journal articles on the topic 'Kinetic researches'
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Kasymova, M. K., А. B. Bayeshov, G. N. Zhylysbayeva, A. K. Mamyrbekova, and O. N. Chechina. "KINETIC RESEARCHES AND ELECTROCHEMICAL BEHAVIOUR OF LEAD AT POLARIZATION ALTERNATING CURRENT." BULLETIN 6, no. 376 (December 15, 2018): 139–46. http://dx.doi.org/10.32014/2018.2518-1467.37.
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Barysheva, Olga, Renat Sadykov, Yuri Khabibullin, and Elizaveta Zheltukhina. "Forecasting of an output of eco toxicants at thermal decomposition of chemical fuel." E3S Web of Conferences 140 (2019): 08002. http://dx.doi.org/10.1051/e3sconf/201914008002.
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Combustion of high-energy chemical fuels containing chlorine in the element structure can lead to formation in the particles of smoke of super eco toxicants—the polychlorinated dioxins and furans. The numerical experiment conducted was based on solution of the equations of chemical kinetics. The computational and theoretical researches directed to the solution of a problem of determination of parameters of combustion products of chemical fuels taking into account formation of harbingers of the polychlorinated dioxins were executed. The main data on the accepted method of determination of disequilibrium structures of products of burning the chlorine-containing chemical fuels were represented. Based on the analysis of references about mechanisms and speeds of chemical reactions of transformations of chlorine-containing connections, the kinetic model of formation of predecessors of dioxins is constructed. The carried-out calculations showed (assuming chemical balance) that process of formation of dioxins is significantly disequilibrious. The results of kinetic researches on emission of harbingers of dioxins showed the nature of the influence of different components of combustion products of chemical fuels on time for the different levels of temperatures.
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Zerajic, Stanko, and Jelenka Savkovic-Stevanovic. "The kinetic models of the bioprocess with free and immobilized cells." Chemical Industry and Chemical Engineering Quarterly 13, no. 4 (2007): 216–26. http://dx.doi.org/10.2298/ciceq0704216z.
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The kinetic models are fundamental knowledge of biochemical and microbial processes. The aim of the work is the kinetic model research based on biochemical and microbial mechanisms of the cell growth, the substrate consumption and the product formation. The engineering goal is to obtain ethanol as a fuel from renewable resources by a biosynthesis process. The engineering goal requires the inclusion of the inhibitory effect of a high substrate and ethanol concentration in the kinetic models. The interactions of the ethanol synthesis with the growth biomass mechanism were researched. The models of the ethanol forming mechanisms were incorporated in the complex structure of the kinetic models. The researches of the kinetic models were realized by computer simulation and experimental verification at the ethanol biosynthesis process from glucose with free and immobilized cells Saccharomyces cerevisiae. The model parameters and the limits were estimated by experimental validation. The base of the verified deterministic and semi-empiric kinetic models was created. The model base may be onward used for the process simulation models generating.
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Mamed-zade, A. M. "Effect of electro-kinetic processes on filtration of fluids and gas in porous medium." Azerbaijan Oil Industry, no. 2 (February 15, 2021): 16–21. http://dx.doi.org/10.37474/0365-8554/2021-2-16-21.
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The paper reviews the fluid and gas flow in the porous medium considering electro-kinetic phenomena – electro-phoresis and electro-osmosis, as well as the charges associated with them. These phenomena are due to the double electric layer on the border of division of disperse system phases. Electro-kinetic phenomena are follows: electro-phoresis, electro-osmosis, flow potential (Quincke effect) and sedimentation potential (Dorn effect). The formulas for the motion of fluid and gas in porous medium considering the properties of porous medium and saturating them fluids, as well as the interaction between them, which is described with electro-kinematic phenomena, have been obtained. Obtained formulas have been evaluated via the results of laboratory researches.
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Bogățeanu, Răzvan, Claudiu Bîșu, Constantin Dogariu, Sorin Mihai Croitoru, and Dana Tilină. "Researches on mechanical vibrations used in assistive devices manufacturing." MATEC Web of Conferences 290 (2019): 01001. http://dx.doi.org/10.1051/matecconf/201929001001.
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Deformable structures vibrate (oscillatory motion) under the action of impulses or variable forces. Vibration of a mechanical structure results from the transformation of potential energy into kinetic energy and could be used in the construction of assistive devices. The vibratory devices for posttraumatic rehabilitation of upper limbs can stimulate muscular, circulatory and neurological systems. The paper presents the necessary elements for the personalization of rehabilitation devices like orthoses and some theoretical and experimental results related to this subject. For the persons with disabilities, the integration of enabling technologies and attributes embracing mobility, sensors and actuators provides the possibility of achieving independence in their social life. The paper underlines the importance of the systematic application of technologies, engineering methodologies or other scientific principles used in order to overpass the barriers confronted by people with disabilities.
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Huang, Shuheng, Linxin Chen, Hu Mei, Duo Zhang, Tingting Shi, Zuyin Kuang, Yu Heng, Lei Xu, and Xianchao Pan. "In Silico Prediction of the Dissociation Rate Constants of Small Chemical Ligands by 3D-Grid-Based VolSurf Method." International Journal of Molecular Sciences 21, no. 7 (April 2, 2020): 2456. http://dx.doi.org/10.3390/ijms21072456.
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Accumulated evidence suggests that binding kinetic properties—especially dissociation rate constant or drug-target residence time—are crucial factors affecting drug potency. However, quantitative prediction of kinetic properties has always been a challenging task in drug discovery. In this study, the VolSurf method was successfully applied to quantitatively predict the koff values of the small ligands of heat shock protein 90α (HSP90α), adenosine receptor (AR) and p38 mitogen-activated protein kinase (p38 MAPK). The results showed that few VolSurf descriptors can efficiently capture the key ligand surface properties related to dissociation rate; the resulting models demonstrated to be extremely simple, robust and predictive in comparison with available prediction methods. Therefore, it can be concluded that the VolSurf-based prediction method can be widely applied in the ligand-receptor binding kinetics and de novo drug design researches.
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Yemelyanova, V. S., T. V. Shakieva, Zh K. Kairbekov, E. M. Shakiev, and B. B. Baizhomartov. "Low-Temperature Catalytic Clearing of Gases of Thermal Power Station from Harmful Impurity in the Presence of the Cobalt Complexes Fixed on a Polymeric Matrix." Advanced Materials Research 807-809 (September 2013): 1586–92. http://dx.doi.org/10.4028/www.scientific.net/amr.807-809.1586.
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The results of optimization of catalysts for gases clearing from sulfur dioxide using processes of oxidation are presented in this work. The researches carried out with the help of modern methods: kinetic, IR-, UV-spectrophotometric, viscometry, LG-chromatography, redox-potentiometric. It is shown, that developed complexes of transitive metals immobilized on a polymeric matrix are highly effective and stable catalysts for the sulphur dioxide oxidation processes. By the example of cobalt compounds the reactions kinetic investigated in details, the kinetic equation is received, allowing to optimize process of gases clearing from sulfur dioxide, kinetic and thermodynamic parameters of process are calculated.
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Погожих, Микола Іванович, Андрій Олегович Пак, Микола Анатолійович Чеканов, Єгор Олексійович Іштван, and Ігор Миколайович Павлюк. "Researches of system water of food raw materials by thermodynamic and molecular-kinetic methods." Eastern-European Journal of Enterprise Technologies 5, no. 11(71) (October 17, 2014): 42. http://dx.doi.org/10.15587/1729-4061.2014.27790.
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Tsimbalista, O. R. "KINESICS IN PARALINGUISTIC ASPECTS." PRECARPATHIAN BULLETIN OF THE SHEVCHENKO SCIENTIFIC SOCIETY Word, no. 3(55) (April 12, 2019): 89–95. http://dx.doi.org/10.31471/2304-7402-2019-3(55)-89-95.
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The article deals with the thorough description of main directions of modern kinesic research in the paralinguistic aspect. Particular attention is paid to the term "paralinguistics", which studies communicatively meaningful nonverbal components and "kinesics," in which they consider the language of the body in a broad sense. It is defined which terms are used to denote non-verbal units. It is established that gestures can be considered as an auxiliary functional component. Gestures are necessary in cases where it is impossible to verbalize (for example, because of the language barrier and hearing problems). In addition, gestures are often used when verbal statements are considered socially inappropriate.It was analyzed which 6 main functions perform gestures. It was found out that the noncommunicational human systems of the person are subordinate, secondary systems. It is noted that non-verbal components are inherent in their regularities in the formation of the expression and transmission of information. The main directions of modern kinetic researches are indicated. Three large kinetic groups are considered: prequenics, microkinesics, macroconesisics. Nonverbal components are inherent in their regularities in the formation of the expression and transmission of information, which are now becoming the subject of research on the theory of communication.Principal methodological issues that cover the study of all types of kinesics (from gestures to pantomime), phonation (from speech to vocal art), proxemic (posture, position of communications), as well as communication with the participation of so-called situational text will create the opportunity to prevent communicative failures in the process of communication of representatives of different ethnic cultures.
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Belok, Fatima, Mostafa Rabea, Mohamed Hanafi, and Ibtihal El Bastawissi. "Facades for Achieving Visual Comfort: High Performance Computing." International Journal of Environmental Science & Sustainable Development 4, no. 1 (March 30, 2019): 1. http://dx.doi.org/10.21625/essd.v4i1.486.
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Within the last few decades, many digital technologies have been integrated to the field of architecture. This in turn has developed a number of architectural trends based on these revolutionary changes. Kinetic skin is one of these trends that is directly related to visual performance and comfort, an important aspect. The feeling of comfort is related to the sense organs network; i.e. the eyes, ears, nose, tactile sensors, heat sensors and brain. Visual sensation is the most dominant one in human perception since the eye contains two thirds of the nerve fibers within human central nervous system.The use of kinetic facades for achieving visual comfort in spaces has been recently the subject of many researches, where various aspects have been explored. However, this paper will attempt to review these researches while identifying gaps and potential for future research.
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CENGIZ, S., L. CAVAS, and K. YURDAKOC. "Alpha-amylase inhibition kinetics by caulerpenyne." Mediterranean Marine Science 11, no. 1 (March 30, 2010): 93. http://dx.doi.org/10.12681/mms.93.
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Many algae have important secretions which are generally used for defensive purposes. These secretions take attentions of a lot of researchers who are wondering if these metabolites can be used for medical researches or not. Among these metabolites, caulerpenyne (CYN) which is the main metabolite of Caulerpa species, have had an important place in Caulerpa researches since the results related to its determined properties such as cytotoxic, antiviral, antiproliferative and apoptotic effects have been proven by many scientific reports. In the present study, the inhibitory effect of CYN isolated from C. prolifera on alpha-amylase was investigated. The inhibition experiments were done with CYN by spectrophotometric determination method. In order to evaluate the type of inhibition Lineweaver–Burk plot was produced. The results obtained from enzyme kinetic studies exhibited an un-competitive type of inhibition, which is characterized by the difference of Vmax and KM from those of the free enzyme, of alpha-amylase in the presence of CYN. The present study showed that Caulerpa species can be a potential target for producing diabetic drugs in the light of the results obtained for CYN.
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Ang, Chun Kit, Ammar A. Al-Talib, Sook Meng Tai, and Wei Hong Lim. "Development of a footstep power generator in converting kinetic energy to electricity." E3S Web of Conferences 80 (2019): 02001. http://dx.doi.org/10.1051/e3sconf/20198002001.
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Kinetic energy is considered as one of the renewable energies. Substantial amounts of researches were conducted to investigate the feasibility of converting the kinetic energy into electricity. Nevertheless, most of these previous works emphasized on the selection of suitable materials and the design of power generator which tends to be complicated. In this paper, a simple and yet low cost mechanism has been proposed to enhance the performance and efficiency of energy conversion from kinetic energy to electricity energy by placing a mechanical footstep power generator on the hind foot region. A total of 45 individuals were invited to participate in the experiments and the experiment results are then compared with the theoretical results.
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ZHANG, YUE, and JINCAN CHEN. "STATISTICAL INTERPRETATION ON THE BROWNIAN STEPS OF KINESIN AND ITS PERFORMANCE CHARACTERISTICS." Modern Physics Letters B 23, no. 14 (June 10, 2009): 1753–61. http://dx.doi.org/10.1142/s0217984909019910.
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Kinesin is a stepping motor that moves along microtubules in discrete steps of 8 nm and there may exist three events in kinesin movement, i.e. the forward step, the backward step and the detachment. On the basis of the data obtained in the advanced experiments and the assumption that the rates of the three stochastic reaction events are Boltzmann type, the mechanical kinetic and thermodynamic properties of the kinesin motor are investigated through a statistical method. The mean dwell time, velocity, run length, power and efficiency of the motor are calculated theoretically. The effects of the temperature and load on the performance of the motor are discussed. It is found that the temperature dependent relations of both the mean run length and the efficiency ηM are not simply linear. The results are in good agreement with those obtained in previous experimental researches.
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Huang, Zihao, Junan Li, and Jiakun Lian. "Wearable Sensors for Detecting and Measuring Kinetic Characteristics." Journal of Physics: Conference Series 2174, no. 1 (January 1, 2022): 012007. http://dx.doi.org/10.1088/1742-6596/2174/1/012007.
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Abstract Wearable devices play an important role in our daily life. We can use it in the sports area and the medical area. This review uses many articles to introduce how to use different sensors to analyze human kinetic characteristics. This review is divided into three parts. In the first sections, we will introduce the working principle and its calculation method of the different sensors such as IMUs sensors, pressure transducers, etc. The second part will show you some research about using wearable sensors to calculate the joint data and link the data with human movement. These researches can help us stay far away from joint diseases. In conclusion, we give some suggestions about the improvement of wearable devices.
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Petrov, L., and Y. Petryk. "THEORETICAL RESEARCHES OF A CAR WHEEL WITH A TRACTION COMPENSATOR." Odes’kyi Politechnichnyi Universytet Pratsi 1, no. 63 (2021): 27–37. http://dx.doi.org/10.15276/opu.1.63.2021.03.
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he rolling process of the wheel drive is accompanied by the loading of the wheel drive by the force of gravity, which leads to compression and stretching of the tire during its deformation. The article deals with the study of the mechanical system “automobile wheel-spring compensator of traction force”, using the theorem on the change of kinetic energy of this system, the general equation of dynamics, as well as the Lagrange equation of the second kind. The purpose of the study is to improve the design and technological scheme of rolling the wheel drive, converting the energy of the wheel drive into the rotational motion of the wheel-elastic traction compensator, which is an auxiliary factor to this technology. The scientific and practical significance of the work lies in the fact that for the first time a technology was proposed in which the share of rotational motion energy of a mechanical system “automobile wheel-spring traction compensator” was introduced during rotation of a wheel drive, which significantly increases traction. The research methodology was to establish a mathematical relationship between the force created by the “car wheel-spring traction compensator” and the additional path that the wheel travels. The result is the developed geometry of the wheel drive in the damping cycle “automotive wheel-spring traction compensator” failure of the bearing surface. The value of the study, the results of this work will contribute to the automotive industry. A model for increasing the traction capabilities of the vehicle is proposed.
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Zheldakov, Dmitry, Radik Mustafin, Vladimir Kozlov, Askar Gaysin, Dmitriy Sinitsin, and Bulat Bulatov. "Durability Control of Brickwork's Material Including Operation Parameters of the Building Enclosure." Mathematical Modelling of Engineering Problems 8, no. 6 (December 22, 2021): 871–80. http://dx.doi.org/10.18280/mmep.080605.
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This paper aims to develop a method to determine material durability based on physicochemical laws that describe chemical corrosion in building enclosures. The subject of this research is studying the chemical corrosion in the material in building constructions. The object of this research is the material of building ceramics. Methods that the authors used for reaching this goal include developing a multi-staged process of material degradation of building ceramics, conduction of thermodynamic calculations, and conducting laboratory research on process kinetics. The results of kinetic researches are generalized based on a developed mathematical model. This comprehensive approach to solving the goal task allowed obtaining the following results: research methods of chemical processes in brick material and its plaster on humidification were developed. A mathematical model for evaluating material degradation in time with the changing climatic influence on enclosure was developed.
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DAVIDENKO, Anna Yu, Valery P. POPOV, and Dmitry V. POPOV. "KINETIC CHARACTERISTICS OF FRACTURE PROCESSES AS CRITERIA OF CONCRETE DURABILITY." Urban construction and architecture 9, no. 3 (September 15, 2019): 99–105. http://dx.doi.org/10.17673/vestnik.2019.03.13.
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The results of the study of the processes of destruction of concrete by different types of external influences obtained by the Samara school of architecture and construction Academy are considered. The process of destruction of concrete with the release of the main stages formed by the volume of the released energy of cracking is analyzed. According to researches one of groups of parameters of concrete destruction - kinetic characteristics-is offered as criteria of durability of this material. The proposed group includes such indicators as the intensity of cracking and the tendency of concrete to crack. In this case, the possibility of using the proposed characteristics is justified.
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NOORI, K., P. KHORSHID, and M. AFSARI. "Derivation of radial electric fields using kinetic theory in tokamak." Journal of Plasma Physics 79, no. 5 (January 16, 2013): 513–17. http://dx.doi.org/10.1017/s0022377812001171.
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AbstractIn the current study, radial electric field with fluid equations has been calculated. The calculation started with kinetic theory, Boltzmann and momentum balance equations were derived, the negligible terms compared with others were eliminated, and the radial electric field expression in steady state was derived. As mentioned in previous researches, this expression includes all types of particles such as electrons, ions, and neutrals. The consequence of this solution reveals that three major driving forces contribute in radial electric field: radial pressure gradient, poloidal rotation, and toroidal rotation; rotational terms mean Lorentz force. Therefore, radial electric field and plasma rotation are connected through the radial momentum balance.
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Negrean, Iuliu, Claudiu Schonstein, Kalman Kacso, Calin Negrean, and Adina Duca. "Formulations about Dynamics of Mobile Robots." Solid State Phenomena 166-167 (September 2010): 309–14. http://dx.doi.org/10.4028/www.scientific.net/ssp.166-167.309.
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In this paper the dynamics equations for a mobile robot, named PatrolBot, will be developed, using new concepts in advanced mechanics, based on important scientific researches of the main author, concerning the kinetic energy. In keeping the fact that the mathematical models of the mobile platforms are different besides the other robots types, due to nonholonomic constraints, these dynamic control functions, will be computed, according to these restrictions for robot motion.
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Batrinescu, Gheorghe, Dana Garganciuc, Ovidiu Popa, and Mihaela Olteanu. "Kinetic Study of Maltodextrine Saccharification Process using Amyloglucosidase Covalently Immobilised." Revista de Chimie 59, no. 1 (February 9, 2008): 30–32. http://dx.doi.org/10.37358/rc.08.1.1700.
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The membranes with immobilized enzymes have a double role, as a separation barrier and a biocatalyst. The membranes immobilize the enzymes in insoluble state by direct binding (e.g. covalent binding) or in soluble state, by adsorption at the separation surface, depending on the polymer nature and the membrane structure. The researches purpose was to emphasize the biocatalytic activity of a membrane-immobilized enzyme system. This paper relates the original results from the kinetic study of maltodextrine saccharification process. The dextrines are obtained by enzymatic hydrolise of starch with a-amilase.The process took place into an enzymatic membrane bioreactor equipped with an active membrane from brominated polyphenileneoxide with 28% bromination degree, having amyloglucosidase covalently immobilized. In this bioreactor carries on the conversion of dextrines to maltose and glucose, under the biocatalytic action of amyloglucosidase.
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Negrean, Iuliu, Ioan Vuscan, Claudiu Schonstein, Kalman Kacso, Adina Duca, and Calin Negrean. "Dynamics of Hybrid Robot Structures Using Variational Principles." Solid State Phenomena 166-167 (September 2010): 303–8. http://dx.doi.org/10.4028/www.scientific.net/ssp.166-167.303.
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The purpose of this paper is to determine the dynamic equations for a hybrid robot structure which consists of a mobile robot named PatrolBot and a 2TR robot serial structure. The motion equations will be determined on the basis of the new concepts in advanced mechanics, such as Matrix Exponentials Algorithm and Variation Principles in Analytical Mechanics, concerning the kinetic and acceleration energy part of important scientific researches deployed by the main author.
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Manafov, M. R., G. S. Aliyev, A. I. Rustamova, and V. I. Kerimli. "ANALYSIS OF THE CURRENT STATE OF RESEARCHES OF THE DEPOSITION OF ASPHALT-RESINOUS SUBSTANCES, PARAFFIN, AND MODELING METHODS. REVIEW PART II: WAX DEPOSITION." Azerbaijan Chemical Journal, no. 2 (June 29, 2021): 13–23. http://dx.doi.org/10.32737/0005-2531-2021-2-13-23.
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The mechanism of paraffin formation in transport pipes is briefly discussed. A kinetic model of the formation and wax deposition from oil is proposed. Comparison of the model with the available experimental data gave satisfactory results. The review considers software tools for modeling the wax deposition process. It is noted that the simulation results are not always applicable to real field cases. For a more reliable interpretation, the scaling effect must be taken into account. In the work various technologies for wax removal are considered
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Liu, Xi Wen, and Chao Ying Liu. "Finite Element Analysis of Circular Piezoelectric Resonator with Box Fixation." Applied Mechanics and Materials 713-715 (January 2015): 594–97. http://dx.doi.org/10.4028/www.scientific.net/amm.713-715.594.
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The ANSYS finite element analysis model for circular piezoelectric resonator is built in this paper, and experiments are carried out for verifying the validity of the finite element model. The influence of the piezoelectric resonator's fixation ways on the natural frequencies and vibration displacement is discussed, lower natural frequencies and higher efficiency of converting electric energy to kinetic energy will be gotten in the box fixation way. The researches on this paper provide a theoretical basis and effective ways for piezoelectric resonator design and optimization.
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Nasibullina, O. A., and Rif G. Rizvanov. "The Study of the Destruction of Pipelines, Subject to Stress Corrosion Cracking." Materials Science Forum 992 (May 2020): 695–99. http://dx.doi.org/10.4028/www.scientific.net/msf.992.695.
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Stress corrosion cracking (SCC) is one of the reasons of failure of main gas pipelines. SCC appears in the form of the single and multiple cracks arising on an outer surface of a pipe. In work different types of the analysis of destruction of the pipeline having multiple cracks are presented. For the purpose of studying of a number of features of SCC by authors various researches were conducted: electrochemical researches, potentiodynamic measurements at various temperatures. With the help of potentiometric studiesit is shown that at low temperatures process of formation of a passive film is at a loss, however, with temperature increase processes of oxidation of metals proceed much quicker, at the same time decrease of their thermodynamic opportunity is observed. The nature of temperature effect is defined on oxidation rate of metals by temperature dependence of a kinetic constant of chemical reaction that is expressed by the Arrhenius equation.
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Kadhim, H. S., G. A. Quadir, A. K. Farhan, U. Ryspek, and K. A. Ismail. "Numerical Simulation for the Aerodynamics of Vertical Axis Wind Turbine with Two Different Rotors Having Movable Vanes." Applied Mechanics and Materials 786 (August 2015): 205–9. http://dx.doi.org/10.4028/www.scientific.net/amm.786.205.
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Wind energy has seen a rapid growth worldwide. Wind turbines are typical devices that convert the kinetic energy of wind into electricity. Researches in the past have proved that Vertical Axis Wind Turbines (VAWTs) are more suitable for urban areas than Horizontal Axis Wind Turbines (HAWTs). In the present design of the VAWT, the power prodused depends on the drag force generated by the individual blades and interactions between them in a rotating configuration. Numerical simulation for the aerodynamics of VAWT with tow different rotors (Three and Foure blades ) having movable vanes are curred out. The For numerical simulation, commercially available computational fluid dynamic (CFD) softwares GAMBIT and FLUENT are used. In this work the Shear Stress Transport (SST) k-ω turbulence model was used which is better than the other turbulence models available as suggested by some researchers. The predicted results show agreement with those reported in the literature for VAWT having different blades designs.
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Zhi, Jing Zhang, Cheng Zu Ren, and Jing Chuan Dong. "Study on Post-Processing of Five-Axis Cnc Machining." Applied Mechanics and Materials 141 (November 2011): 524–28. http://dx.doi.org/10.4028/www.scientific.net/amm.141.524.
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According to the feature of five-axis CNC machine tools’structure, do researches on post-process technique. By means of analysis of the kinetic model of five-axis CNC machine tools, Position and orientation of the tool in the workpiece coordinate system transforms to that of the machine coordinate system. Besides, Because of the rotation，Five-axises maching will produce the non-linear error．This article provides an easy algorithm to find the maximum non-linear error. Finally, an impeller, for example, simulates in the computer and machine by a 5-axis machine tool.
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Li, Dongmei, Chaofan Weng, Yi Ruan, Kan Li, Guoan Cai, Chenyao Song, and Qiang Lin. "An Optical Chiral Sensor Based on Weak Measurement for the Real-Time Monitoring of Sucrose Hydrolysis." Sensors 21, no. 3 (February 2, 2021): 1003. http://dx.doi.org/10.3390/s21031003.
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A chiral sensor with optical rotation detection based on weak measurement for the kinetic study of sucrose hydrolysis is presented. Based on the polarization modulation to the pre-selection state, the optical rotation of chiral sample was accurately determined through the central wavelength shift of the output spectrum. With this approach, the concentration response curves of sucrose and its hydrolysis products, i.e., fructose and glucose, were experimentally obtained for the hydrolysis analysis. By collecting the output spectrum with a frequency of 100 Hz and fitting the central wavelength shift synchronously during the measurement, the sucrose hydrolysis process was monitored in real time. Different hydrolysis conditions with varied concentration of invertase enzyme and citrate were implemented in this work. As a consequence, the real-time hydrolysis curves of the hydrolysis process with distinct velocities was achieved and analyzed. Such a kinetic monitoring about sucrose hydrolysis with optical rotation detection technology played a critical role in the researches involving sucrose, and also revealed the great potential of weak measurement in intersections, such as food safety inspection and chemical analysis.
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Likhanov, V. A., and O. P. Lopatin. "Modeling of nitrogen oxides emission in the cylinder of tractor gas-diesel engine." Traktory i sel hozmashiny 83, no. 7 (July 15, 2016): 3–8. http://dx.doi.org/10.17816/0321-4443-66171.
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The article is devoted to the modeling of process of nitrogen oxides formation in the cylinder of diesel engine operating on compressed natural gas. The combustion of methane-air mixture, ignited by atomized pilot oil that is injected through multijet nozzle, in the cylinder of gas-diesel engine increases the rate of turbulent fluctuations, which leads to intensification of heat and mass exchange in the plume, and significantly increases the rate of formation and decomposition of nitrogen oxides. The calculation of expected emissions of nitrogen oxides in the cylinder of diesel engine and their content in the exhaust gases is carried out. It is done on the basis of the results of kinetic systems modeling for calculation of the kinetics of nitrogen oxides formation during combustion of natural gas and diesel fuel, taking into account the influence of turbocharging, intermediate cooling of charged air and exhaust gas recirculation. In the mathematical modeling of nitrogen oxide formation in the cylinder of diesel engine, the combustion process is divided into two zones, namely the zone of fresh mixture and the zone of combustion products. First zone is a mixture of fresh air with recycled gases (if there is a process of recycling) and residual gases. Before combustion starts, this zone occupies the whole cylinder. During combustion, the volume of zone of combustion products increases. Theoretical researches are carried out on the basis of developed mathematical model for calculation of nitrogen oxides in the cylinders of 4Ch 11.0/12.5 and 4ChN 11.0/12.5 diesel engines. The high precision of theoretical calculations of volumetric content and mass concentration of nitrogen oxides is confirmed, compared to the results of experimental researches (the difference does not exceed 5%).
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Setiadi, Tjandra, Indrie Ratnasari, and Trimaharika Widarena. "Permodelan reaktor sharon dengan umpan urea-amonia." Jurnal Teknik Kimia Indonesia 6, no. 2 (October 2, 2018): 617. http://dx.doi.org/10.5614/jtki.2007.6.2.4.
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SHARON (Single reactor High activity Ammonia Removal Over Nitrite)-Anammox (Anaerobic Ammonium Oxidation) has never been used for treating wastewater with high urea content. Three prior researches have been done to examine the performance of SHARON process with urea-ammonia feed but the results are still unable to explain its performance. To explain these results, a model of SHARON process is needed to be built. Based on material balances of SHARON process in a stirred tank reactor, a model was built. The model is nonlinear differential equation system and was solved using Least Square Method with the help of MATLAB. The simulation result shows that nitrate was always occurred in the effluent of the SHARON process. Based on this research, equimolar nitrite to ammonia ratio can be obtained only if the feed is equimolar in urea and bicarbonate composition. Optimized kinetic parameter obtained are μmaxamm = 1,16E-05 s-1, μmaxnit = 3,998E-05 s-1, KNH3amm = 3,346E-02 mol mL-3, Kl,HNO2amm = 1,45E-02 mol mL-3, Kl,HNO2amm = 6,14E-03 mol mL-3. This result show that there are inhibition in oxidizing ammonium in the reactor and inhibition on growth of the nitrite oxidizer. Keywords : modelling, SHARON, urea-ammonia, kinetic parameter Abstrak Proses SHARON (Single reactor High activity Ammonia Removal Over Nitrite)-Anammox (Anaerobic Ammonium Oxidation) belum pernah digunakan untuk mengolah air limbah dengan konsentrasi urea tinggi. Data-data yang diperoleh dari percobaan pendahuluan belum dapat menjelaskan unjuk kerja reaktor SHARON dengan umpan berupa urea-amonia. Oleh karena itu, perlu disusun pemodelan matematika untuk menentukkan parameter kinetika pertumbuhan mikroba dan parameter stoikiometrik reaksi yang terjadi pada reaktor SHARON. Penyusunan model dilakukan berdasarkan neraca massa reaktor tangka reaktor kontinyu berpengaduk. Model yang dihasilkan berupa system model menunjukkan bahwa konsentrasi nitrat sama dengan nol pada keluaran reaktor SHARON dengan umpan urea-amonia tidak dapat dicapai. Untuk mendapatkan nisbah nitrit terhadap nitrat yang ekuimolar, diperlukan umpan dengan komposisi urea dan bikarbonat yang ekuimolar. Parameter kinetic yang diperoleh dari hasil optimasi model adalah μmaxamm = 1,16E-05 s-1, μmaxnit = 3,998E-05 s-1, KNH3amm = 3,346E-02 mol mL-3, Kl,HNO2amm = 1,45E-02 mol mL-3, Kl,HNO2amm = 6,14E-03 mol mL-3. Kata Kunci : pemodelan, SHARON, urea-amonia, parameter kinetik
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Azevedo, C. A., C. T. Falcón, and D. C. Estumano. "APPLICATION OF BAYESIAN TECHNIQUE FOR PARAMETER ESTIMATION IN A FERMENTATIVE PROCESS." Revista de Engenharia Térmica 19, no. 1 (September 9, 2020): 105. http://dx.doi.org/10.5380/reterm.v19i1.76441.
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In the current world scenario, there has been noted an increase of researches on biofuel production, more specifically bioethanol, produced from biomass, in order to obtain more information to analyze, understand and optimize this fermentative process. The modelling process, which include the determination of a kinetic model and its respective parameters, is a fundamental step in defining operating strategies and understand how the experimental conditions can affect the optimal system operating conditions. The present work employs a bayesian technique to estimate the parameters of a classical kinectic model used by Silva and collaborators (2016), because, unlike the classical techniques, it is possible to take into account the uncertainty of the measurements and the prior knowledge of the parameters can be accounted for in probabilistic terms. In this context, by using simulated measurements, for the parameters estimation it is propose a sensitivity analysis of the parameters model to define the most relevant ones to be estimate and the use of the Monte Carlo Markov Chain method through the Metropolis-Hastings algorithm, evaluating the influence of four types of priori probability distribution of data set: uniform, gaussian, log-normal and Rayleigh. The obtained results showed that the sensibility analysis is an important step on parameter estimation and algorithm used was satisfactory in estimating the parameters of the kinectic model used, demonstrating the possibility of using it as a tool for time and cost reduction in experimental tests.
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Morita, Yoshiko. "Researches for long time on the Autonomous Kinetic Rehabilitation Centering the Motivative Exercise (Takizawa Method) to Restructure the Rehabilitation Medicine ." BIOPHILIA 2014, no. 2 (2014): 53. http://dx.doi.org/10.14813/ibra.2014.53.
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Seki, Kazuaki, S. Harada, and Toru Ujihara. "Bulk 3C-SiC Crystal by Top Seeded Solution Growth Method." Materials Science Forum 740-742 (January 2013): 311–14. http://dx.doi.org/10.4028/www.scientific.net/msf.740-742.311.
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In this paper, we review our researches on the high-quality 3C-SiC bulk crystal growth. The polytype control and the suppression of defects are essential in the growth 3C-SiC on hexagonal SiC seed crystals. The growth polytype of SiC is usually controlled by the inheritance of the seed crystal. In contrast, we established kinetic polytype control in which the preferential growth of 3C-SiC can be achieved by the difference in the growth rates depending on supersaturation for the polytypes. In the growth of 3C-SiC, double positioning boundaries (DPBs) are often formed by the existence of twinned domain. The elimination of DPBs can be achieved utilizing the anisotropy of the step advance velocity.
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Shen, Zhao Wei, Cun Hong Pan, Sui Gao Ye, Hai Yan Lu, and Li Hui Wang. "The Economic Loss Estimate of Dam Break Based on 2D Dam Break-Wave Numerical Simulation." Applied Mechanics and Materials 405-408 (September 2013): 2457–62. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.2457.
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A 2D numerical model based on Boltzmann equation and an unstructured FVM grid with a kinetic flux vector splitting (KFVS) scheme was developed to simulate dam break-wave. As an example, propagation of the dam-break wave of one reservoir dam at Yuhang District of Hangzhou in Hangzhou was simulated by this model. Using regional economy, population, and geography data of 2008, the economic loss caused by dam failure was evaluated. The result shows that total economic loss is about 20% of the GDP in Yuhang, which is close to the conclusion of some existing researches. It is foreseeable that this method would to be used more widely in Zhejiang for dam safety management.
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Degtyar, Liudmila, Irina Zhukova, and Anastasia Kuts. "Electrodeposition kinetics and surface morphology of Ni-B-UDD composite coating." E3S Web of Conferences 273 (2021): 04015. http://dx.doi.org/10.1051/e3sconf/202127304015.
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The article presents the results of kinetic investigates of electrodeposition of a composite electrochemical coating based on a nickel-boron alloy. Current efficiency, polarization potentiodynamic researches had shown the joint participation in the electrodeposition process of finely dispersed compounds of nickel hydroxides, poorly soluble nickel and boron compounds present in the electrolyte or formed during electrolysis, and ultradispersed diamond introduced into the electrolyte. Comparison of 2D and 3D scans of the surfaces of the formed coatings confirmed the leveling effect of additives, as well as sparingly soluble nickel and boron compounds on the structure of coatings. The proposed composite electrochemical coatings can be used instead of chrome coatings when restoring parts and units of agricultural machinery.
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Qu, Jin Yu, and Li Yan Liang. "Modeling and Simulation for Super Capacitor Braking Energy Recovery Process of Micro EV." Advanced Materials Research 383-390 (November 2011): 7390–95. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.7390.
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Super-capacitor is suitable as braking energy storage device for electric vehicle because of its high charge and discharge rate, long life, simple structure and reliable performance advantages. When driving motor of the electric vehicles runs on regenerative electric power state, it can not only provide braking force, but also charge to the energy storage device to recover the kinetic energy, thus endurance mileage of electric vehicle can be extended considerably. In this paper, braking energy recovery model was built by using the Matlab/Simulink software, and whole vehicle model based on automobile theory, the motor efficiency model and super-capacitor model were mainly included. Meanwhile some researches were made on the simulation, and the impact of the super-capacitor on the braking energy recovery was analyzed.
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Ogilvie, Gordon I. "James Clerk Maxwell and the dynamics of astrophysical discs." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 366, no. 1871 (January 24, 2008): 1707–15. http://dx.doi.org/10.1098/rsta.2007.2180.
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Maxwell's investigations into the stability of Saturn's rings provide one of the earliest analyses of the dynamics of astrophysical discs. Current research in planetary rings extends Maxwell's kinetic theory to treat dense granular gases of particles undergoing moderately frequent inelastic collisions. Rather than disrupting the rings, local instabilities may be responsible for generating their irregular radial structure. Accretion discs around black holes or compact stars consist of a plasma permeated by a tangled magnetic field and may be compared with laboratory fluids through an analogy that connects Maxwell's researches in electromagnetism and viscoelasticity. A common theme in this work is the appearance of a complex fluid with a dynamical constitutive equation relating the stress in the medium to the history of its deformation.
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Narvariya, Pushpendra, and Joseph Singh. "Anthropometric Prediction of Ball Velocity Among Medium Pace Bowlers in Cricket." International Journal for Research in Applied Sciences and Biotechnology 9, no. 2 (March 12, 2022): 51–55. http://dx.doi.org/10.31033/ijrasb.9.2.6.
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The aim of this study was to predict the ball velocity on the basis of anthropometric variables of male division level cricket bowlers. Materials and methods: A total of 08 medium pace bowlers (mean ± standard deviation; age= 20.2±2.09 years; height= 172±3.65cms.) who participated in recent Gwalior division cricket competition were selected for the study. For anthropometric variables following measurements were conducted: standing height, upper arm length, lower arm length, palm length, upper leg length, lower leg length. Ball velocity was measured with a doppler radar gun. The stepwise multiple regression was conducted to predict the ball velocity of medium pace bowlers based on selected anthropometric variables. Results: The results suggest that lower arm length and ball velocity had a significant relationship (r = 0.780; p 0.001). In addition, a prediction model (Ball velocity = 76.601+1.507 [lower arm length]) with an R2 value of 0.608 was developed, with lower arm length being the only predictor. Conclusion: This also signifies that there may be other factors that contributes to the ball velocity such as strength of shoulders, run-up speed, kinematic variables, or kinetic variables. Therefore, future researches should focus on all those parameters that were not included in this study.
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H. Habeeb, K., and A. S. Jabir. "The Effect of Sulfur Sources, Levels and Time of Addition on Kinetics of Sulfur." Al-Qadisiyah Journal For Agriculture Sciences (QJAS) (P-ISSN: 2077-5822 , E-ISSN: 2617-1479) 7, no. 2 (April 14, 2018): 146–53. http://dx.doi.org/10.33794/qjas.vol7.iss2.36.
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A field experiment has been conducted atSuwera Researches Station in Wasit Governorate in spring season 2015 in clay loam in order to study the effect of sulfur sources R1 agriculture sulfur (90% sulfur) R2-foam sulfur (75% sulfur) at the levels of 0, 2500, 5000 kg,s,ha-1. represented the levels of S0, S1, S2 and time of addition T (30 days before sowing T0), 15 days before sowing (T1) and during sawing (T2) on the availability and release of sulfur in soil extracted by (5*10-4 M) citric acid during the period of plant growth (30, 60, 90, 120 days after sowing) by using kinetics concepts to determine the best kinetics equation that describes well the mechanic of sulfur release in soil which represents the amounts of sulfur availability for the plant.
Results show significant effect on sources, levels and addition time of sulfur availability and release abstracted by citric acid (5*104 M) during plant growth periods. Agriculture sulfur source is the highest level at the addition level S2 (5000 kg S. H-1) at addition time T2. The highest values are achieved at 30 days after sawing, at 376, 382 and 375 mg So=4.kg-1 soil respectively. Also, the triple interaction treatment R1S2T2has achieves the highest values of released sulfur abstracted by citric acid at the same time, at 520 mg So=4.kg-1.soil.
Results show that all kinetics equations of sulfur which is abstracted by citric acids (5*104 M) in soil growth plant periods. Also, all the kinetic are equations clarifying well the mechanism of releasing sulfur from soil and fertilizers and the first order equation is the highest amongst all equations. The values of coefficient of sulfur release speed (ks) between 0.001 – 0.004 Cmolc. Kg-1 day-1
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Pandey, Shraddha, Shashi K. Misra, and Nisha Sharma. "Development of Usnic Acid Embedded Eudragit Microspheres for Alleviation of Nosocomial Infections." Anti-Infective Agents 18, no. 1 (February 4, 2020): 79–87. http://dx.doi.org/10.2174/2211352517666190126161205.
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Background: Usnic Acid has been progressively reported in the literature as one of the chiefly significant lichen metabolites exemplified by an ample diversity of applications such as antimicrobial, antifungal, antiviral, antiprotozoal agents, etc. Herein, we shed a light on nosocomial infections and formulated topical microspheres loaded with Usnic acid for improved antimicrobial activity. Recent patents and novel researches were referred to pursue the present work. Methods: Usnic acid embedded Eudragit microspheres were designed applying solvent evaporation method, investigated for topography and drug-polymer compatibility studies. Dialysis bag method was utilized for studying drug release kinetics. In vitro antibacterial assay was carried out against the virulent bacterial strain of Staphylococcus aureus using the disc diffusion method. Results: Topography studies revealed the formation of regular, micro-sized, smooth surface microspheres. Well defined and specific structural peaks were obtained from FTIR and TGA studies, revealing drugpolymer compatibility. The dissolution profile suggested Korsmeyer Peppas kinetic and Fickian kind of diffusion from microspheres. The pre-eminent activity of formulated microspheres was visualized from the disc diffusion study against Staphylococcus aureus. Conclusion: The strong biological activity of Usnic acid –loaded Eudragit RS and Eudragit RL microspheres provides a promising application for corresponding material as a bactericidal agent for the alleviation of nosocomial infection. Findings paid attention to the potential of usnic acid microspheres for effective treatment of dermal and nosocomial infections caused by S. aureus.
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Asfaha, Yemane G., Feleke Zewge, Teketel Yohannes, and Shimelis Kebede. "Investigation of cotton textile industry wastewater treatment with electrocoagulation process: performance, mineralization, and kinetic study." Water Science and Technology 85, no. 5 (February 16, 2022): 1549–67. http://dx.doi.org/10.2166/wst.2022.061.
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Abstract In this study, the performance of the electrocoagulation (EC) process was evaluated for its capability to remove color, total organic carbon (TOC), chemical oxygen demand (COD) using aluminium electrodes. Response surface methodology based on Box-Behnken design was used to optimize different operating conditions of the processes. The interaction effects of four independent variables such as dye concentration, applied current density, electrolysis time, and pH on the percentage of COD, TOC, and color removal were investigated by the EC process. ANOVA analysis was made to examine the significance of input parameters and their interaction effect on responses. At the optimum operating conditions, 89% of color, 47% of TOC, and 76% of COD removal rate were achieved using the EC process. Different research works have been reported on the treatment of textile wastewater by the EC process. However, these researches vary regarding working conditions such as dye type, concentration, current density, pH, electrolysis time, and electrode type. Also, most literature focuses mainly on the performance of the technology. However, it is also important to investigate the economic aspect, removal mechanism, and mineralization study. Thus, economic analyses, mineralization, kinetic, sludge characterization studies of the technology were performed.
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Khomichak, Liubomyr, Inha Kuznietsova, Svetlana Vysotska, and Sergiy Tkachenko. "Research of drying kinetics of prepared wheat flour." FOOD RESOURCES 9, no. 16 (June 25, 2021): 212–20. http://dx.doi.org/10.31073/foodresources2021-16-20.
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Introduction. Processing of grain raw material with influence on starch or albumens by application of heat treatment creates the variety of functional properties of a product and is perspective in the modern terms vital functions of man. Research methods and methods. The flour obtained from wheat of the Ascanian wheat and from wheat of the soft varieties: Sophia ("sweet wheat"), Blond (soft) and Chornobrova (enriched with micro- and macronutrients) were used in the study. Thermal modification of flour samples was carried out in a convective manner. The control sample for determining the quality indicators is obtained in industrial conditions, extruded wheat flour produced by LLC "AS groups, LTD". Research results. The obtained kinetic dependence shows the gradual loss of moisture standards with different speed which accordingly influences on duration of drying. The moisture content of the drying agent most affects the intensity at the initial stage of the constant drying rate. With an increase in the moisture content of the coolant, the period of constant drying increases and the amount of evaporated moisture increases during this period. With the subsequent removal of moisture from raw materials, the degree of influence of this parameter on the intensity decreases. The nature of the drying curves is the same and the recommended process for obtaining modified flour is the process duration of 300 minutes or 5 hours. It was determined microscopically, that the samples of dried wheat flour have a purpose and are partially destroyed by starch granules and amorphization of biocomposite materials. Based on the data on the kinetics of drying flour samples, the kinetic coefficients and values of the critical moisture content for drying wheat flour were calculated, which is 1.18-1.30 %. It was determined that for the sensorial indicators the obtained samples have indicators characteristic of the varietal characteristics of wheat, from which the flour was taken. In terms of physical and chemical parameters, the modified wheat flour samples are not inferior to the well-known industrial sample of extruded flour. Conclusions. Use of flour, obtained from the wheat with different correlation of amilose and amylopectin, positively influences on a technological process and allows to extend the assortment of modified starch products, and accordingly, food products. Kinetics of the convective drying standards of the flour is investigated. Researches showed that a it is physically modified flour obtained from the different sorts of the soft wheat is not inferior in quality to the extruded wheat flour.
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Voynalovich, O. V., and S. M. Holopura. "Justification of risk-based approach of operation of mobile agricultural equipment on example of details of separate units of tractors." Naukovij žurnal «Tehnìka ta energetika» 11, no. 3 (November 18, 2020): 173–79. http://dx.doi.org/10.31548/machenergy2020.03.173.
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It is shown that in order to justify the extension of the service life of the machine beyond the resource set by the developers, it is necessary to focus on the allowable risks of accidents that can lead to accidents. After all, today for mobile agricultural machinery, the operation of which is associated with high-risk work, the concept of acceptable (acceptable) risk is not used, which does not allow to assess the danger of being on fields, farms and roads without machinery, with exhaustion of installed resources. The purpose of researches is to justify the permissible risk of exploitation of mobile agricultural machinery, in array of details and elements of constructions which have accumulated defects (damage). This paper analyzes the kinetics of accumulation of operational defects in the array of parts of individual components (systems) of tractors. MTZ-80 tractors (82) were chosen as the object of research, as one of the most common in Ukraine. To detect cracks, a developed eddy current flaw detector was used, the sensitivity of which allowed to find cracks several millimeters or larger in length without preparing the surface of the controlled parts. It is shown that the kinetic dependences of the accumulation of operational defects in the parts of tractor units in the analyzed range of service life are monotonically increasing, which can be described by exponential functions with a sufficiently high reliability. It is noted that the obtained dependences are similar to the kinetic dependences of the accumulation of static and dynamic (fatigue) damage obtained as a result of laboratory tests of samples of construction materials, which allows to use approaches to the criteria of the limit state of laboratory samples due to the power load to establish the boundary life of mobile agricultural machinery. However, the kinetics of the intensity of the occurrence of operational cracks in the array of tractor parts is not monotonous and has a maximum in the range of about 11-13 years of operation. This service life can be used as a criterion to stop the operation of the tractor, to carry out defectoscopy of parts and to replace defective parts. With such a long service life of the tractor, there is the greatest probability of sudden destruction of the tractor components and the creation of emergencies.
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Zahedi, Ehsan, Mahsa Babaie, and Hooman Bahmanpour. "Adsorption properties of boroxol ring doped zigzag boron nitride nanotube toward NO molecule using DFT." International Journal of Modern Physics B 30, no. 17 (June 30, 2016): 1650101. http://dx.doi.org/10.1142/s0217979216501010.
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In previous researches it is demonstrated that reactivity and sensitivity of boron nitride nanotubes (BNNTs) toward gas molecules can be modified by impurity. In this work, oxygen defect for three nitrogen sites was used to study the adsorption of NO molecule through the surface of boroxol ring of oxygen doped BNNT (7,0) with different adsorption patterns, including side-on and end-on. All calculations are performed using the DFT-B3LYP/6-31G[Formula: see text] level of theory, and their electronic energies are corrected by gCP and D3 correction terms. High binding energies indicate that NO molecule undergoes chemical adsorption with large charge transfer from the tube which can significantly change electronic properties of the tube. Density of state (DOS) and partial DOS (PDOS) analyses revealed that adsorption of NO molecule on the boroxol ring position is covalent in nature with significant effect on the electronic properties of tube. The Laplacian of electron density, Lagrangian kinetic energy density, Hamiltonian kinetic energy density and potential energy density at bond critical points between the tube and NO indicate that the interaction between the tube and NO molecule is covalent in nature. Topological analysis of the electron localization function shows that electrons in the new formed bonds are approximately localized, meaning that the nature of adsorption process is chemical covalent. The studied nanotube is a suitable candidate to filter and eliminate NO gas molecule.
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Fatmawati, Akbarningrum, Ari Anggoro, Kamila Adila Muslim, Arief Widjaja, Tantular Nurtono, and Hanny Frans Sangian. "Mathematical Modelling of Alkaline and Ionic Liquid Pretreated Coconut Husk Enzymatic Hydrolysis." Bulletin of Chemical Reaction Engineering & Catalysis 16, no. 2 (April 28, 2021): 331–41. http://dx.doi.org/10.9767/bcrec.16.2.10306.331-341.
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The problem of crude oil reserve shortage and air quality decline currently have led researches on renewable fuel such as bioethanol and biohydrogen. The attempt to provide such biofuel involves the utilization of enormously available wasted materials, lignocellulose. Coconut husk is one of such materials available in Indonesia. The previous work had reported the quantity of total reducing sugar produced after the enzymatic hydrolysis of pretreated coconut husk. The pretreatment methods used were dilute sodium hydroxide solution (1 and 4% w/v), 1,3-methylmethylimidazolium dimethyl phosphate ionic liquid and the combination of both methods. This work focused on constructing the mathematical model which describes the kinetic of those enzymatic hydrolysis reactions. Mathematical model expressions help describing as well as predicting the process behavior, which is commonly needed in the process design and control. The development of mathematical model in this work was done based on the total reducing sugar concentration resulted in batch hydrolysis reaction. The kinetic parameters including initial available substrate (S0), maximum reaction rate (rmax), and half-maximum rate constant (KM). According to the values of half-maximum rate constant (KM), the enzymatic hydrolysis performance of coconut husk treated using ionic liquid is better than that treated using dilute alkaline solution as the former had shown lower KM value and hence higher enzyme affinity to the substrate. The best hydrolysis result was performed using combination of 1% dilute sodium hydroxide solution and ionic liquid with kinetic model parameter of 0.5524 g/L.h of rmax, 0.0409 g/L of KM, and 4.1919 g/L of S0. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
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Алексеева, А., A. Alekseeva, С. Степанова, and S. Stepanova. "Kinetics of Oil Sorption by Material Based on Leaf Litter." Safety in Technosphere 7, no. 2 (January 23, 2019): 10–14. http://dx.doi.org/10.12737/article_5c35c2da1217b1.03580813.
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Studies of leaf litter as a sorption material with respect to oil at various temperatures have been carried out. It has been revealed that with process temperature increasing, the samples sorption capacity decreases. The oil sorption mechanism has been studied. It has been shown that the active sorption time was in the interval from 60 to 600 seconds. It has been proved that at the time of oil and sorption material contact for more than 600 seconds, the desorption process began. Kinetic dependencies of oil absorption by the proposed sorption material have been constructed and analyzed. The reaction order determination by a graphic method has showed that obtained functions with a high degree of correlation can be attributed to first-order heterogeneous reactions. Have been calculated thermodynamic parameters confirming the absence of a chemical reaction between oil and leaf litter. The carried out researches determine the most acceptable parameters of oil sorption by material based on leaf litter.
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Palma, Vincenzo, Concetta Ruocco, Marta Cortese, Simona Renda, Eugenio Meloni, Giovanni Festa, and Marco Martino. "Platinum Based Catalysts in the Water Gas Shift Reaction: Recent Advances." Metals 10, no. 7 (June 29, 2020): 866. http://dx.doi.org/10.3390/met10070866.
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The water gas shift (WGS) is an equilibrium exothermic reaction, whose corresponding industrial process is normally carried out in two adiabatic stages, to overcome the thermodynamic and kinetic limitations. The high temperature stage makes use of iron/chromium-based catalysts, while the low temperature stage employs copper/zinc-based catalysts. Nevertheless, both these systems have several problems, mainly dealing with safety issues and process efficiency. Accordingly, in the last decade abundant researches have been focused on the study of alternative catalytic systems. The best performances have been obtained with noble metal-based catalysts, among which, platinum-based formulations showed a good compromise between performance and ease of preparation. These catalytic systems are extremely attractive, as they have numerous advantages, including the feasibility of intermediate temperature (250–400 °C) applications, the absence of pyrophoricity, and the high activity even at low loadings. The particle size plays a crucial role in determining their catalytic activity, enhancing the performance of the nanometric catalytic systems: the best activity and stability was reported for particle sizes < 1.7 nm. Moreover the optimal Pt loading seems to be located near 1 wt%, as well as the optimal Pt coverage was identified in 0.25 ML. Kinetics and mechanisms studies highlighted the low energy activation of Pt/Mo2C-based catalytic systems (Ea of 38 kJ·mol−1), the associative mechanism is the most encountered on the investigated studies. This review focuses on a selection of recent published articles, related to the preparation and use of unstructured platinum-based catalysts in water gas shift reaction, and is organized in five main sections: comparative studies, kinetics, reaction mechanisms, sour WGS and electrochemical promotion. Each section is divided in paragraphs, at the end of the section a summary and a summary table are provided.
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Limouei, Soroush Sadeghnejad, Mojtaba Sadighi, and Abdolreza Ohadi. "Free Vibration Analysis of Composite Sandwich Plate with Viscoelastic Core." Key Engineering Materials 471-472 (February 2011): 658–63. http://dx.doi.org/10.4028/www.scientific.net/kem.471-472.658.
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New Reddy-type elements based on Reddy’s higher-order theory are used in the analysis of composite sandwich plates with viscoelastic core, which is achieved by considering independent transverse displacements on two faces and linear variations through depth of plate core. In addition, Young modulus, rotational inertia, and kinetic energy of core are considered and core is assumed as 3D elastic structure with the properties of an orthotropic viscoelastic material. To improve the Reddy’s higher-order theory, a rectangular element with four nodes, which each node has seven degrees of freedom, is proposed. Hamilton’s principle has been used to obtain the equations of motion. A finite element code for structural response analysis of the free vibration is developed. The obtained results are compared with existence researches. The influence of material properties, lamination schemes, and fiber angle on natural frequencies of composite plates are investigated.
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Li, Di-Hua, Yan Wang, Yuan-Shan Lv, Jun-Hong Liu, Lei Yang, Shu-Kun Zhang, and Yu-Zhen Zhuo. "Preparative Purification of Liriodendrin fromSargentodoxa cuneataby Macroporous Resin." BioMed Research International 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/861256.
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The preparative purification of liriodendrin fromSargentodoxa cuneatausing macroporous resin combined with crystallization process was evaluated. The properties of adsorption/desorption of liriodendrin on eight macroporous resins were investigated systematically. X-5 resin was selected as the most suitable medium for liriodendrin purification. The adsorption of liriodendrin on X-5 resin fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model. Dynamic adsorption/desorption tests were performed using a glass column packed with X-5 resin to optimize the separation process of liriodendrin. After one treatment with X-5 resin, the content of liriodendrin in the product was increased 48.73-fold, from 0.85% to 41.42%, with a recovery yield of 88.9%. 97.48% liriodendrin was obtained by further crystallization and determined by HPLC. The purified product possessed strong antioxidant activity. In conclusion, purification of liriodendrin might expend its further pharmacological researches and further applications in pharmacy.
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Rusnak, S. M., A. V. Matviy, V. V. Kopach, O. V. Kopach, L. P. Shcherbak, and P. M. Fochuk. "Kinetic parameters of Cd0.85-xMnxZn0.15Te (x = 0.05-0.20) alloys melting and crystallization processes." Chernivtsi University Scientific Herald. Chemistry, no. 819 (2019): 83–88. http://dx.doi.org/10.31861/chem-2019-819-10.
Full textAbstract:
The kinetic parameters of melting and crystallization of Cd0.85-xMnxZn0.15Te (x = 0.05-0.20) alloys were investigated by the differential thermal analysis (DTA) method at different heating/cooling rates. Cd0.85-xMnxZn0.15Te alloys were synthesized from elementary materials in a vertical furnace with a high-gradient temperature that prevented the sublimation of the components. The DTA was carried out in an automatic system. The heating and cooling rates were 5 and 10°С/min, and the dwell time was 10, 30 and 60 minutes. The DTA were processed in two different ways. Using the first treatment method we found that the melt of the Cd0.80Mn0.05Zn0.15Te alloy crystallize with the supercooling, and it occurs at melt superheating higher than 12 °С. But the melt’s “negative” supercooling effect is present for alloy when the melt are superheated to 12 °C compared to the melting temperature of the alloy, which is evidence of two-phase alloy (solid phase - melt) at these temperatures. Also we determined that as the holding temperature increases the crystallization temperature decreases and the crystallization rate increases. We investigated that the area of the crystallization effect increases with increasing holding temperature. Concerning on the second treatment method we found the dependence of the solid-state volume fraction (φsolid state) versus the intermediate dwell temperature of the alloy during the heating process for Cd0.80Mn0.05Zn0.15Te. It shows that increasing of the melt-dwell temperature led to the melts full homogenization only near 1117 °C. Thus according to our previous researches we can say that the Cd1-x-уMnxZnyTe alloy’s melting temperature increases with ZnTe concentration increasing: ~1100-1102°С for Cd0.95-xMnxZn0.05Te alloys (x=0.05-0.30), ~1102-1104°С for Cd0.90-xMnxZn0.10Te alloys (x=0.05-0.30) and ~1116-1119°С for Cd0.80Mn0.05Zn0.15Te alloys.
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Wang, Weijun, Jing’an Feng, Wenkang Wan, Peng Zhang, and Songlin Yang. "Modeling and Analysis of the Kinetic Influence of Liquid Sloshing Characteristics on High-Clearance Sprayers." Discrete Dynamics in Nature and Society 2021 (November 12, 2021): 1–15. http://dx.doi.org/10.1155/2021/9926962.
Full textAbstract:
To research the influence of liquid sloshing on the driving stability of high-clearance sprayers, this paper builds an equivalent liquid sloshing mechanical model and obtains the stochastic acceleration excitation of the rectangular spray tank using the Adams kinetic model, thus obtaining the relationship between the impact force, moment, and the stochastic acceleration using Fluent numerical simulation analysis. This paper makes further calculations with MATLAB/Simulink system models, and the result from comparing these two calculations shows that the equivalent strategy proposed in this paper has a better consistency. Based on the consideration of the acting forces of the additional moment due to lateral movement of the center of mass of the liquid and the dynamic pressure due to liquid sloshing in the tank, this paper builds a mathematical model of the sprayer and researches the influence of the filling ratio and vehicle velocity on the vehicle stability through stochastic acceleration excitation. The results show that, in the case of different speeds, the liquid sloshing has a small influence on the overall roll angle; in the case of different filling ratios, the liquid sloshing has a big influence on the overall roll angle, the slip angle of the center of mass, and the yaw angular velocity; the filling ratio k = 0.85 and the speed u = 1 m/s−2 m/s are safe operation parameters of the sprayer. This research provides reference solutions for the stability control and optimization problems of the high-clearance sprayer and semitrailer.