A KDamper oscillator is proven to be a more effective alternative to conventional Tuned Mass Damper (TMD) approaches and Quazi Zero Stiffness (QZS) or negative stiffness isolators. In this paper, an extended version of the KDamper (EKD) concept is employed to control the dynamic responses of an undamped (or low damper) SDoF system subjected to various dynamic loads. The KDamper consists of an additional mass, artificial dampers, and positive and negative stiffness elements. The additional implemented mass is one order of magnitude smaller as compared to most mass related vibration absorbers (TMDs, TMDIs, KDampers, etc.). The artificial dampers and the stiffness element values are selected following an engineering-criteria driven optimization procedure that accounts for geometric constraints and manufacturing limitations. The negative stiffness element is realized with an articulated mechanism that employs pre-stresses conventional stiffness elements (spiral springs) and generates controlled negative stiffness (NS). In order to exploit the advantages that the inherent nonlinear nature the NS offers, such as robustness, broadband response and energy sinks, the proposed dynamic vibration absorber is designed to present significant geometric nonlinearity, that varies from none (linear system) to extreme. Thus, different test cases are presented with respect to the desired nonlinearity of the generated NS, as well as to the type of the external load subjected to the structure. This way we can determine in which cases extreme geometric nonlinearity is beneficial to the dynamic behavior of the controlled structure.
{"title":"Vibration Absorption using KDamper-based Devices with Extreme Geometric Nonlinearity","authors":"K. Kapasakalis, E. Sapountzakis","doi":"10.46300/9104.2022.16.3","DOIUrl":"https://doi.org/10.46300/9104.2022.16.3","url":null,"abstract":"A KDamper oscillator is proven to be a more effective alternative to conventional Tuned Mass Damper (TMD) approaches and Quazi Zero Stiffness (QZS) or negative stiffness isolators. In this paper, an extended version of the KDamper (EKD) concept is employed to control the dynamic responses of an undamped (or low damper) SDoF system subjected to various dynamic loads. The KDamper consists of an additional mass, artificial dampers, and positive and negative stiffness elements. The additional implemented mass is one order of magnitude smaller as compared to most mass related vibration absorbers (TMDs, TMDIs, KDampers, etc.). The artificial dampers and the stiffness element values are selected following an engineering-criteria driven optimization procedure that accounts for geometric constraints and manufacturing limitations. The negative stiffness element is realized with an articulated mechanism that employs pre-stresses conventional stiffness elements (spiral springs) and generates controlled negative stiffness (NS). In order to exploit the advantages that the inherent nonlinear nature the NS offers, such as robustness, broadband response and energy sinks, the proposed dynamic vibration absorber is designed to present significant geometric nonlinearity, that varies from none (linear system) to extreme. Thus, different test cases are presented with respect to the desired nonlinearity of the generated NS, as well as to the type of the external load subjected to the structure. This way we can determine in which cases extreme geometric nonlinearity is beneficial to the dynamic behavior of the controlled structure.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44333651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Winston Netto, Eloy Pena Asensio, S. M. Sundaram, C. Srinivasan
All practical and real-time systems are non-linear and dynamic in nature. In the majority of studies associated with systems, it is assumed that the system is linear and the dynamics of the system is remaining constant. Though these assumptions help in easier mathematical formulations of the systems, it also imposes a lot of restrictions on understanding the system completely and its behavior in depth. In this study, the focus is on capturing the varying dynamics of Mass - Spring – Damper system using a frequency domain-based system identification approach. The system identification technique is based on an adaptive filter which is implemented through MATLAB software.
{"title":"LMS Filter Based Frequency Domain System Identification of Mass – Spring – Damper System with Varying Dynamics","authors":"Winston Netto, Eloy Pena Asensio, S. M. Sundaram, C. Srinivasan","doi":"10.46300/9104.2022.16.1","DOIUrl":"https://doi.org/10.46300/9104.2022.16.1","url":null,"abstract":"All practical and real-time systems are non-linear and dynamic in nature. In the majority of studies associated with systems, it is assumed that the system is linear and the dynamics of the system is remaining constant. Though these assumptions help in easier mathematical formulations of the systems, it also imposes a lot of restrictions on understanding the system completely and its behavior in depth. In this study, the focus is on capturing the varying dynamics of Mass - Spring – Damper system using a frequency domain-based system identification approach. The system identification technique is based on an adaptive filter which is implemented through MATLAB software.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45534351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-31DOI: 10.46300/9104.2021.15.31
S. Mohamaddan, Aliff Rahman, M. Shanat, Siti Zawiah Md Dawal, A. Hanafusa
Chair comes in different sizes and shapes depending on the functions as well as the users involved. However, the designers seldom consider the ergonomics aspect in chair design. This research has been conducted as a case study to compare and select the best design parameters within two chairs known as Chair A and B using human modelling software called AnyBody. Different parameter was manipulated in the simulation which is backrest angles for Chair A and seat heights for Chair B. A total of ten chairs with different parameters (five from Chair A and five from Chair B) were conducted in the simulation. Results were generated through inverse dynamics analysis in the form of muscle activities envelopes and reaction force on vertebrae L4 to L5. The result shows that 80° backrest was the best ergonomics design for Chair A while 0.30 m seat height was the best ergonomics design for Chair B. The simulation conducted is important as an early ergonomics intervention before the real chair fabrication is conducted.
{"title":"Ergonomics Simulation and Analysis of Specially Designed Chair","authors":"S. Mohamaddan, Aliff Rahman, M. Shanat, Siti Zawiah Md Dawal, A. Hanafusa","doi":"10.46300/9104.2021.15.31","DOIUrl":"https://doi.org/10.46300/9104.2021.15.31","url":null,"abstract":"Chair comes in different sizes and shapes depending on the functions as well as the users involved. However, the designers seldom consider the ergonomics aspect in chair design. This research has been conducted as a case study to compare and select the best design parameters within two chairs known as Chair A and B using human modelling software called AnyBody. Different parameter was manipulated in the simulation which is backrest angles for Chair A and seat heights for Chair B. A total of ten chairs with different parameters (five from Chair A and five from Chair B) were conducted in the simulation. Results were generated through inverse dynamics analysis in the form of muscle activities envelopes and reaction force on vertebrae L4 to L5. The result shows that 80° backrest was the best ergonomics design for Chair A while 0.30 m seat height was the best ergonomics design for Chair B. The simulation conducted is important as an early ergonomics intervention before the real chair fabrication is conducted.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41649148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-31DOI: 10.46300/9104.2021.15.32
M. Kunelbayev, Abdildayeva Assel, Taganova Guldana
This article explores the use of machine learning algorithms to identify anomalies in the solar heating system. A solar heating system that has been developed consists of several parts to simplify the description and modeling process. The authors propose a new architecture for neural networks based on ordinary differential equations. The idea is to apply the new architecture for practical problems of accident prediction (the problem of extrapolation of time series) and classification (classification of accidents based on historical data). The developed machine learning algorithms, artificial intelligence techniques, the theory of differential equations - these directions allow us to build a model for predicting the system's accident rate. The theory of database management (non-relational databases) - these systems allow you to establish the optimal storage of large time series.
{"title":"Using Machine Learning Algorithms to Detect Anomalies in the Solar Heating System","authors":"M. Kunelbayev, Abdildayeva Assel, Taganova Guldana","doi":"10.46300/9104.2021.15.32","DOIUrl":"https://doi.org/10.46300/9104.2021.15.32","url":null,"abstract":"This article explores the use of machine learning algorithms to identify anomalies in the solar heating system. A solar heating system that has been developed consists of several parts to simplify the description and modeling process. The authors propose a new architecture for neural networks based on ordinary differential equations. The idea is to apply the new architecture for practical problems of accident prediction (the problem of extrapolation of time series) and classification (classification of accidents based on historical data). The developed machine learning algorithms, artificial intelligence techniques, the theory of differential equations - these directions allow us to build a model for predicting the system's accident rate. The theory of database management (non-relational databases) - these systems allow you to establish the optimal storage of large time series.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47389492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-28DOI: 10.46300/9104.2021.15.29
E. T. Tamayo, José W. Morales, Mauro D. Albarracín, Héctor L. Laurencio, Israel P. Pachacama, Brayan I. Guacapiña, Wilson M. Román
The parameters behavior that characterize the process was carried out through an experimental investigation to obtain the cooling temperature, heat transfer coefficients and the heat flow in mineral coolers. The values of water temperature, water flow and mineral temperature were recorded at the inlet and outlet of the cylindrical cooler. Experiments were carried out with five values of the mass flow, keeping the cylinder revolutions constant. The calculation procedure for the system was obtained, in the mineral coolers the heat transfer by conduction, convection and evaporation predominates as a function of the cooling zone. A reduction in temperature is shown with increasing length, the lowest temperature values were obtained for a mass flow of 8 kg/s. The mineral outlet temperature should not exceed 200 oC, therefore it is recommended to work with the mass flow less than 10 kg/s that guarantees the cooling process.
{"title":"Cooling Temperature and Heat Transfer Coefficients in Cylindrical Heat Exchangers","authors":"E. T. Tamayo, José W. Morales, Mauro D. Albarracín, Héctor L. Laurencio, Israel P. Pachacama, Brayan I. Guacapiña, Wilson M. Román","doi":"10.46300/9104.2021.15.29","DOIUrl":"https://doi.org/10.46300/9104.2021.15.29","url":null,"abstract":"The parameters behavior that characterize the process was carried out through an experimental investigation to obtain the cooling temperature, heat transfer coefficients and the heat flow in mineral coolers. The values of water temperature, water flow and mineral temperature were recorded at the inlet and outlet of the cylindrical cooler. Experiments were carried out with five values of the mass flow, keeping the cylinder revolutions constant. The calculation procedure for the system was obtained, in the mineral coolers the heat transfer by conduction, convection and evaporation predominates as a function of the cooling zone. A reduction in temperature is shown with increasing length, the lowest temperature values were obtained for a mass flow of 8 kg/s. The mineral outlet temperature should not exceed 200 oC, therefore it is recommended to work with the mass flow less than 10 kg/s that guarantees the cooling process.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47049843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-06DOI: 10.46300/9104.2021.15.28
N. Banichuk, A. Barsuk, S. Ivanova, T. Tuovinen
The paper considers the problems and the methods of spectral analysis of elastic structural systems. The presented consideration focuses on the translation-invariant spectral formulations. Some periodic representations and the spectral decomposition are derived. In the context of general analysis of translation-invariant systems, the particular problems of structural vibration and stability are solved in analytical form.
{"title":"Spectral Analysis of Translation-Invariant Mechanical Systems with Application to Structural Vibrations and Stability","authors":"N. Banichuk, A. Barsuk, S. Ivanova, T. Tuovinen","doi":"10.46300/9104.2021.15.28","DOIUrl":"https://doi.org/10.46300/9104.2021.15.28","url":null,"abstract":"The paper considers the problems and the methods of spectral analysis of elastic structural systems. The presented consideration focuses on the translation-invariant spectral formulations. Some periodic representations and the spectral decomposition are derived. In the context of general analysis of translation-invariant systems, the particular problems of structural vibration and stability are solved in analytical form.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48014912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-20DOI: 10.46300/9104.2021.15.27
T. Chakkour
Many fascinating astrophysical phenomena can be simulated insufficiently by standard numerical schemes for the compressible hydrodynamics equations. In the present work, a high performant 2D hydrodynamical code has been developed. The model is designed for the planetary formation that consists of momentum, continuity and energy equations. Since the two-phase model seems to be hardly executed, we will show in a simplified form, the implementation of this model in one-phase. It is applied to the Solar System that such stars can form planets. The finite volume method (FVM) is used in this model. We aim to develop a first-order well-balanced scheme for the Euler equations in the the radial direction, combined with second-order centered ux following the radial direction. This conception is devoted to balance the uxes, and guarantee hydrostatic equilibrium preserving. Then the model is used on simplified examples in order to show its ca- pability to maintain steady-state solutions with a good precision. Additionally, we demonstrate the performance of the numerical code through simulations. In particularly, the time evolution of gas orbited around the star, and some proper- ties of the Rossby wave instability are analyzed. The resulting scheme shows consequently that this model is robust and simple enough to be easily implemented.
{"title":"Application of Two-dimensional Finite Volume Method to Protoplanetary Disks","authors":"T. Chakkour","doi":"10.46300/9104.2021.15.27","DOIUrl":"https://doi.org/10.46300/9104.2021.15.27","url":null,"abstract":"Many fascinating astrophysical phenomena can be simulated insufficiently by standard numerical schemes for the compressible hydrodynamics equations. In the present work, a high performant 2D hydrodynamical code has been developed. The model is designed for the planetary formation that consists of momentum, continuity and energy equations. Since the two-phase model seems to be hardly executed, we will show in a simplified form, the implementation of this model in one-phase. It is applied to the Solar System that such stars can form planets. The finite volume method (FVM) is used in this model. We aim to develop a first-order well-balanced scheme for the Euler equations in the the radial direction, combined with second-order centered ux following the radial direction. This conception is devoted to balance the uxes, and guarantee hydrostatic equilibrium preserving. Then the model is used on simplified examples in order to show its ca- pability to maintain steady-state solutions with a good precision. Additionally, we demonstrate the performance of the numerical code through simulations. In particularly, the time evolution of gas orbited around the star, and some proper- ties of the Rossby wave instability are analyzed. The resulting scheme shows consequently that this model is robust and simple enough to be easily implemented.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44379030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-14DOI: 10.46300/9104.2021.15.26
S. Dol, Niraj Baxi, M. A. Said
By introducing a multiphase twin screw pump as an artificial lifting device inside the well tubing (downhole) for wet gas compression application; i.e. gas volume fraction (GVF) higher than 95%, the unproductive or commercially unattractive gas wells can be revived and made commercially productive once again. Above strategy provides energy industry with an invaluable option to significantly reduce greenhouse gas emissions by reviving gas production from already existing infrastructure thereby reducing new exploratory and development efforts. At the same time above strategy enables energy industry to meet society’s demand for affordable energy throughout the critical energy transition from predominantly fossil fuels based resources to hybrid energy system of renewables and gas. This paper summarizes the research activities related to the applications involving multiphase twin screw pump for gas volume fraction (GVF) higher than 95% and outlines the opportunity that this new frontier of multiphase fluid research provides. By developing an understanding and quantifying the factors that influence volumetric efficiency of the multiphase twin screw pump, the novel concept of productivity improvement by a downhole wet gas compression using above technology can be made practicable and commercially more attractive than other production improvement strategies available today. Review and evaluation of the results of mathematical and experimental models for multiphase twin screw pump for applications with GVF of more than 95% has provided valuable insights in to multiphase physics in the gap leakage domains of pump and this increases confidence that novel theoretical concept of downhole wet gas compression using multiphase twin screw pump that is described in this paper, is practically achievable through further research and improvements.
{"title":"A Review on the Application of Multiphase Twin Screw Pump as a Downhole Wet Gas Compressor to Improve Gas Wells Recovery Factor","authors":"S. Dol, Niraj Baxi, M. A. Said","doi":"10.46300/9104.2021.15.26","DOIUrl":"https://doi.org/10.46300/9104.2021.15.26","url":null,"abstract":"By introducing a multiphase twin screw pump as an artificial lifting device inside the well tubing (downhole) for wet gas compression application; i.e. gas volume fraction (GVF) higher than 95%, the unproductive or commercially unattractive gas wells can be revived and made commercially productive once again. Above strategy provides energy industry with an invaluable option to significantly reduce greenhouse gas emissions by reviving gas production from already existing infrastructure thereby reducing new exploratory and development efforts. At the same time above strategy enables energy industry to meet society’s demand for affordable energy throughout the critical energy transition from predominantly fossil fuels based resources to hybrid energy system of renewables and gas. This paper summarizes the research activities related to the applications involving multiphase twin screw pump for gas volume fraction (GVF) higher than 95% and outlines the opportunity that this new frontier of multiphase fluid research provides. By developing an understanding and quantifying the factors that influence volumetric efficiency of the multiphase twin screw pump, the novel concept of productivity improvement by a downhole wet gas compression using above technology can be made practicable and commercially more attractive than other production improvement strategies available today. Review and evaluation of the results of mathematical and experimental models for multiphase twin screw pump for applications with GVF of more than 95% has provided valuable insights in to multiphase physics in the gap leakage domains of pump and this increases confidence that novel theoretical concept of downhole wet gas compression using multiphase twin screw pump that is described in this paper, is practically achievable through further research and improvements.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43630654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-04DOI: 10.46300/9104.2021.15.25
Navya Thirumaleshwar Hegde, A. Vaz, C. G. Nayak
Unmanned Aerial Vehicles (UAVs) guidance, control and navigation have directed the attention of many researchers in both aerospace engineering as well as control theory. Due to the unique rotor structure of Tiltrotor hybrid UAVs, they exhibit special application value. Quad Tiltrotor UAVs set up a distinctive platform that satisfies the needs of the varying mission requirements by combining the conventional features of high-speed cruise capabilities of an aircraft and hovering capabilities of a helicopter and by tilting its four rotors. The aim of this research article is to control the attitude and altitude of the UAV in the presence of uncertainty using two different control techniques. This paper addresses the comparative analysis of the robust H-infinity controller with classical PID control designs for the transition manoeuvre of a hybrid UAV: the VTOL Tiltrotor UAV. The proposed controllers achieve hover to cruise mode transition and vice-versa. The main idea behind the design of controller is to model and analyze the UAV’s position and attitude dynamics. The desired flight trajectory and the transition manoeuvre is achieved by controlling the tilt angle in 15° intervals from 90° to 0° and vice-versa. Performance index subjected to IAE is estimated and compared for both the controllers in the presence of noise, disturbances and uncertainties. The results of simulation illustrate that the robust H-infinity controller achieves better transition, good adaptability, robust performance and robust stability for the whole flight envelope when compared with the PID controller.
{"title":"Closed Loop Performance Analysis of Classical PID and Robust H-infinity Controller for VTOL Unmanned Quad Tiltrotor Aerial Vehicle","authors":"Navya Thirumaleshwar Hegde, A. Vaz, C. G. Nayak","doi":"10.46300/9104.2021.15.25","DOIUrl":"https://doi.org/10.46300/9104.2021.15.25","url":null,"abstract":"Unmanned Aerial Vehicles (UAVs) guidance, control and navigation have directed the attention of many researchers in both aerospace engineering as well as control theory. Due to the unique rotor structure of Tiltrotor hybrid UAVs, they exhibit special application value. Quad Tiltrotor UAVs set up a distinctive platform that satisfies the needs of the varying mission requirements by combining the conventional features of high-speed cruise capabilities of an aircraft and hovering capabilities of a helicopter and by tilting its four rotors. The aim of this research article is to control the attitude and altitude of the UAV in the presence of uncertainty using two different control techniques. This paper addresses the comparative analysis of the robust H-infinity controller with classical PID control designs for the transition manoeuvre of a hybrid UAV: the VTOL Tiltrotor UAV. The proposed controllers achieve hover to cruise mode transition and vice-versa. The main idea behind the design of controller is to model and analyze the UAV’s position and attitude dynamics. The desired flight trajectory and the transition manoeuvre is achieved by controlling the tilt angle in 15° intervals from 90° to 0° and vice-versa. Performance index subjected to IAE is estimated and compared for both the controllers in the presence of noise, disturbances and uncertainties. The results of simulation illustrate that the robust H-infinity controller achieves better transition, good adaptability, robust performance and robust stability for the whole flight envelope when compared with the PID controller.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47802034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-13DOI: 10.46300/9104.2021.15.24
A. Y. Ershova, Minggong Sha
In this work, we studied the properties of a specially synthesized organometallic coordination polymer - a porous coordination polymer with biocompatible structural elements based on oxoclusters of iron muconate (III). The samples were investigated by scanning electron microscopy, thermogravimetric analysis combined with differential scanning calorimetry, and the study of low-temperature nitrogen adsorption of a sample obtained by a modified solvothermal technique. It is shown that most of the pores of the sample have an average radius of 18,8 Å ~ 1,88 nm. Also, as a result of the study, it is necessary to conclude that the synthesized material has a developed surface area - it is 512,1 m2/g and the pore volume is ~ 0,48 cm3/g. It should be concluded that such materials are promising as components for a new generation of various kinds of functional materials with improved or unique characteristics. It is obvious that further research in this area is important from both fundamental and applied points of view.
在这项工作中，我们研究了一种特殊合成的有机金属配位聚合物-一种基于铁酸盐氧簇(III)的具有生物相容性结构元素的多孔配位聚合物。通过扫描电子显微镜，热重分析结合差示扫描量热法研究了样品的性质，并研究了通过改进的溶剂热技术获得的样品的低温氮吸附。结果表明，样品中大部分孔隙的平均半径为18.8 Å ~ 1.88 nm。同时，根据研究结果，有必要得出结论，合成材料具有发达的表面积-其为512,1 m2/g，孔隙体积为~ 0,48 cm3/g。因此，这些材料有望成为具有改进或独特特性的新一代各种功能材料的组成部分。显然，从基础和应用的角度来看，这一领域的进一步研究都很重要。
{"title":"Investigation of Physical Properties of Fe(III) Containing Metal-Organic Polymers","authors":"A. Y. Ershova, Minggong Sha","doi":"10.46300/9104.2021.15.24","DOIUrl":"https://doi.org/10.46300/9104.2021.15.24","url":null,"abstract":"In this work, we studied the properties of a specially synthesized organometallic coordination polymer - a porous coordination polymer with biocompatible structural elements based on oxoclusters of iron muconate (III). The samples were investigated by scanning electron microscopy, thermogravimetric analysis combined with differential scanning calorimetry, and the study of low-temperature nitrogen adsorption of a sample obtained by a modified solvothermal technique. It is shown that most of the pores of the sample have an average radius of 18,8 Å ~ 1,88 nm. Also, as a result of the study, it is necessary to conclude that the synthesized material has a developed surface area - it is 512,1 m2/g and the pore volume is ~ 0,48 cm3/g. It should be concluded that such materials are promising as components for a new generation of various kinds of functional materials with improved or unique characteristics. It is obvious that further research in this area is important from both fundamental and applied points of view.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70491906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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