Search results for: mode coupling

Authors: Mohan T. Harish, Masson Lauriane, Sreevalsa Kolathayar

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Environmental issues raise alarm in the constructional field which implies a need for exploring new construction materials derived from the waste and residual products. This paper presents a detailed review of the alternatives approaches employed in the construction field using plastic waste in mixture with mixed with fillers. A detailed analysis of the plastic waste used in concrete, with soil, sand, clay and natural residues like sawdust, rice husk etc are presented. The different process carried forward was also discussed along with the scrutiny of the change in mechanical properties. The effect of coupling agents in the proposed mixture has been appraised in detail which gives implications for its future application in the field of plastic waste with viable materials in composite construction blocks.

Keywords: plastic waste, composite materials, construction block, concrete, natural residue, coupling agent

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Authors: E. Bounadja, M. O. Mahmoudi, A. Djahbar, Z. Boudjema

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This paper presents a control approach of the doubly fed induction generator (DFIG) in conjunction with a direct AC-AC matrix converter used in generating mode. This device is intended to be implemented in a variable speed wind energy conversion system connected to the grid. Firstly, we developed a model of matrix converter, controlled by the Venturini modulation technique. In order to control the power exchanged between the stator of the DFIG and the grid, a control law is synthesized using a high order sliding mode controller. The use of this method provides very satisfactory performance for the DFIG control. The overall strategy has been validated on a 2-MW wind turbine driven a DFIG using the Matlab/Simulink.

Keywords: doubly fed induction generator (DFIG), matrix converter, high-order sliding mode controller, wind energy

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Authors: Danhua Xu, Zhenlan Qian, Zhu Wang, Jiayan Fu, Ling Wang

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A new business mode called rural complex is proposed by the China’s government to promote the development the economy in the rural area. However, for the sake of current national conditions including the great number of labor farmers owning the small scale farmlands and the uncertain enthusiasm from the enterprises, it is challenging to develop the big scale rural complex. To react to the dilemmas, this paper puts forward the micro-rural complex to boost the small scale farms by co-participation from a bottom-up mode. By analyzing the potential opportunities to find the suitable mode, exploring the interdisciplinary and interdepartmental co-participation way beyond architecture design and spatial planning between different actors, the paper tries to find a complete process towards the sustainable micro-rural complex and conducts an ongoing practice to optimize it, to bring new insights and reference to the rural development. According to the transformation of the economy, the micro-rural complex will develop into two phases, both of which can be discussed in three parts, the economic mode, the spatial support, and the Cooperating mechanism. The first stage is the agriculture co-participation based on the rise of Community supported agriculture (CSA) in which the consumers buy the products planted in an organic way from the farmers directly with a higher price to support the small-scale agriculture and overcome the food safety issues. The following stage sets up the agritourism catering the citizens with the restaurants, inns and other tourist service facilities to be planned and designed. In the whole process, the interdisciplinary co-participation will play an important role to provide the guidelines and consultation from the agronomists, architects and rural planners to the farmers. This mode has been applied to an on-going farm project, from which to explore the mode in a more practical way. In conclusion, the micro-rural complex aims at creating a balanced urban-rural relationship by co-participation taking advantage of the different actors. The spatial development is considered from the economic mode and social organization. The integration of the mode based on the small-scale agriculture will contribute to a sustainable growth and realize the long run development in the rural area.

Keywords: micro-rural complex, co-participation, sustainable development, China

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Authors: Mohsin Ejaz, Shiao-Wei Kuo

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The growing production and exploitation of fossil fuels have placed human society in serious environmental issues. As a result, it's critical to design efficient and eco-friendly energy production and storage techniques. Porous organic polymers (POPs) are multi-dimensional porous network materials developed through the formation of covalent bonds between different organic building blocks that possess distinct geometries and topologies. POPs have tunable porosities and high surface area making them a good candidate for an effective electrode material in energy storage applications. Herein, we prepared a fully benzoxazine-based porous organic polymers (TPA–DHTP–BZ POP) through sonogashira coupling of dihydroxyterephthalaldehyde (DHPT) and triphenylamine (TPA) containing benzoxazine (BZ) monomers. Firstly, both BZ monomers (TPA-BZ-Br and DHTP-BZ-Ea) were synthesized by three steps, including Schiff base, reduction, and mannich condensation reaction. Finally, the TPA–DHTP–BZ POP was prepared through the sonogashira coupling reaction of brominated monomer (TPA-BZ-Br) and ethynyl monomer (DHTP-BZ-Ea). Fourier transform infrared (FTIR) and solid-state nuclear magnetic resonance (NMR) spectroscopy confirmed the successful synthesis of monomers as well as POP. The porosity of TPA–DHTP–BZ POP was investigated by the N₂ absorption technique and showed a Brunauer–Emmett–Teller (BET) surface area of 196 m² g−¹, pore size 2.13 nm and pore volume of 0.54 cm³ g−¹, respectively. The TPA–DHTP–BZ POP experienced thermal ring-opening polymerization, resulting in poly (TPA–DHTP–BZ) POP having strong inter and intramolecular hydrogen bonds formed by phenolic groups and Mannich bridges, thereby enhancing CO₂ capture and supercapacitive performance. The poly(TPA–DHTP–BZ) POP demonstrated a remarkable CO₂ capture of 3.28 mmol g−¹ and a specific capacitance of 67 F g−¹ at 0.5 A g−¹. Thus, poly(TPA–DHTP–BZ) POP could potentially be used for energy storage and CO₂ capture applications.

Keywords: porous organic polymer, benzoxazine, sonogashira coupling, CO₂, supercapacitor

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Authors: Chandra Gupt Porwal, Preeti C. Porwal

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Transient data reveals much about the machine's condition that steady-state data cannot. New technologies make this information much more available for evaluating the mechanical integrity of a machine train. Recent surveys at various stations indicate that simplicity is preferred over completeness in machine audits throughout the power generation industry. This is most clearly shown by the number of rotating machinery predictive maintenance programs in which only steady-state vibration amplitude is trended while important transient vibration data is not even acquired. Efforts have been made to explain what transient data is, its importance, the types of plots used for its display, and its effective utilization for analysis. In order to demonstrate the value of measuring transient data and its practical application in rotating machinery for resolving complex and persistent issues with turbine generators, the author presents a few case studies that highlight the presence of rotor instabilities due to the shaft moving towards the bearing centre in a 100 MM LMZ unit located in the Northern Capital Region (NCR), heavy misalignment noticed—especially after 2993 rpm—caused by loose coupling bolts, which prevented the machine from being synchronized for more than four months in a 250 MW KWU unit in the Western Region (WR), and heavy preload noticed at Intermediate pressure turbine (IPT) bearing near HP- IP coupling, caused by high points on coupling faces at a 500 MW KWU unit in the Northern region (NR), experienced at Indian power plants.

Keywords: transient data, steady-state-data, intermediate -pressure-turbine, high-points

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Authors: Md. Asaduzzaman

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A Silicon-on-insulator (SOI) perfectly vertical fibre-to-chip grating coupler is proposed and designed based on engineered subwavelength structures. The high directionality of the coupler is achieved by implementing step gratings to realize asymmetric diffraction and by applying effective index variation with auxiliary ultra-subwavelength gratings. The proposed structure is numerically analysed by using two-dimensional Finite Difference Time Domain (2D FDTD) method and achieves 96% (-0.2 dB) coupling efficiency and 39 nm 1-dB bandwidth. This highly efficient GC is necessary for applications where coupling efficiency between the optical fibre and nanophotonics waveguide is critically important, for instance, experiments of the quantum photonics integrated circuits. Such efficient and broadband perfectly vertical grating couplers are also significantly advantageous in highly dense photonic packaging.

Keywords: diffraction grating, FDTD, grating couplers, nanophotonic

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Authors: Fatemeh Babaeian, Nemai Chandra Karmakar

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Chipless RFID system is a wireless system for tracking and identification which use passive tags for encoding data. The advantage of using chipless RFID tag is having a planar tag which is printable on different low-cost materials like paper and plastic. The printed tag can be attached to different items in the labelling level. Since the price of chipless RFID tag can be as low as a fraction of a cent, this technology has the potential to compete with the conventional optical barcode labels. However, due to the passive structure of the tag, data processing of the reflection signal is a crucial challenge. The captured reflected signal from a tag attached to an item consists of different components which are the reflection from the reader antenna, the reflection from the item, the tag structural mode RCS component and the antenna mode RCS of the tag. All these components are summed up in both time and frequency domains. The effect of reflection from the item and the structural mode RCS component can distort/saturate the frequency domain signal and cause difficulties in extracting the desired component which is the antenna mode RCS. Therefore, it is required to study the reflection of the tag in both time and frequency domains to have a better understanding of the nature of the captured chipless RFID signal. The other benefits of this study can be to find an optimised encoding technique in tag design level and to find the best processing algorithm the chipless RFID signal in decoding level. In this paper, the reflection from a typical backscattered chipless RFID tag with six resonances is analysed, and different components of the signal are separated in both time and frequency domains. Moreover, the time domain signal corresponding to each resonator of the tag is studied. The data for this processing was captured from simulation in CST Microwave Studio 2017. The outcome of this study is understanding different components of a measured signal in a chipless RFID system and a discovering a research gap which is a need to find an optimum detection algorithm for tag ID extraction.

Keywords: antenna mode RCS, chipless RFID tag, resonance, structural mode RCS

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Authors: Jiahe Ru, Yan Pang, Zhaomiao Liu

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Necking processes of the Janus droplet generation in the cross-junction microchannels are experimentally and theoretically investigated. The two dispersed phases that are simultaneously shear by continuous phases are liquid paraffin wax and 100cs silicone oil, in which 80% glycerin aqueous solution is used as continuous phases. According to the variation of minimum neck width and thinning rate, the necking process is divided into two stages, including the two-dimensional extrusion and the three-dimensional extrusion. In the two-dimensional extrusion stage, the evolutions of the tip extension length for the two discrete phases begin with the same trend, and then the length of liquid paraffin is larger than silicone oil. The upper and lower neck interface profiles in Janus necking process are asymmetrical when the tip extension velocity of paraffin oil is greater than that of silicone oil. In the three-dimensional extrusion stage, the neck of the liquid paraffin lags behind that of the silicone oil because of the higher surface tension, and finally, the necking fracture position gradually synchronizes. When the Janus droplets pinch off, the interfacial tension becomes positive to drive the neck thinning. The interface coupling of the three phases can cause asymmetric necking of the neck interface, which affects the necking time and, ultimately, the droplet volume. This paper mainly investigates the thinning dynamics of the liquid-liquid interface in confined microchannels. The revealed results could help to enhance the physical understanding of the droplet generation phenomenon.

Keywords: neck interface, interface coupling, janus droplets, multiphase flow

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Authors: Rihab Hamdi, Amel Hadri Hamida, Ouafae Bennis, Fatima Babaa, Sakina Zerouali

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This paper features a sliding mode controller (SMC) for closed-loop voltage control of DC-DC three-cells buck converter connected in parallel, operating in continuous conduction mode (CCM), based on pulse-width modulation (PWM). To maintain the switching frequency, the approach is to incorporate a pulse-width modulation that utilizes an equivalent control, inferred by applying the SM control method, to produce a control sign to be contrasted and the fixed-frequency within the modulator. Detailed stability and transient performance analysis have been conducted using Lyapunov stability criteria to restrict the switching frequency variation facing wide variations in output load, input changes, and set-point changes. The results obtained confirm the effectiveness of the proposed control scheme in achieving an enhanced output transient performance while faithfully realizing its control objective in the event of abrupt and uncertain parameter variations. Simulations studies in MATLAB/Simulink environment are performed to confirm the idea.

Keywords: DC-DC converter, pulse width modulation, power electronics, sliding mode control

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Authors: Montree Bunruanses, Preecha Yupapin

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In this work, the quantum material called Amrita (elixir) is made from top-down gold into nanometer particles by fusing 99% gold with a laser and mixing it with drinking water using the atmospheric water (AWG) production system, which is made of water with air. The high energy laser power destroyed the four natural force bindings from gravity-weak-electromagnetic and strong coupling forces, where finally it was the purified Bose-Einstein condensate (BEC) states. With this method, gold atoms in the form of spherical single crystals with a diameter of 30-50 nanometers are obtained and used. They were modulated (activated) with a frequency generator into various matrix structures mixed with AWG water to be used in the upstream conversion (quantum reversible) process, which can be applied on humans both internally or externally by drinking or applying on the treated surfaces. Doing both space (body) and time (mind) will go back to the origin and start again from the coupling of space-time on both sides of time at fusion (strong coupling force) and push out (Big Bang) at the equilibrium point (singularity) occurs as strings and DNA with neutrinos as coupling energy. There is no distortion (purification), which is the point where time and space have not yet been determined, and there is infinite energy. Therefore, the upstream conversion is performed. It is reforming DNA to make it be purified. The use of Amrita is a method used for people who cannot meditate (quantum meditation). Various cases were applied, where the results show that the Amrita can make the body and the mind return to their pure origins and begin the downstream process with the Big Bang movement, quantum communication in all dimensions, DNA reformation, frequency filtering, crystal body forming, broadband quantum communication networks, black hole forming, quantum consciousness, body and mind healing, etc.

Keywords: quantum materials, quantum meditation, quantum reversible, Bose-Einstein condensate

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Authors: Bader Alruwaili, Surajit Ray

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Finite mixtures are a flexible and powerful tool that can be used for univariate and multivariate distributions, and a wide range of research analysis has been conducted based on the multivariate normal mixture and multivariate of a t-mixture. Determining the number of modes is an important activity that, in turn, allows one to determine the number of homogeneous groups in a population. Our work currently being carried out relates to the study of the modality of the skew normal distribution in the univariate and multivariate cases. For the skew normal distribution, the aims are associated with studying the modality of the skew normal distribution and providing the ridgeline, the ridgeline elevation function, the $\Pi$ function, and the curvature function, and this will be conducive to an exploration of the number and location of mode when mixing the two components of skew normal distribution. The subsequent objective is to apply these results to the application of real world data sets, such as flow cytometry data.

Keywords: mode, modality, multivariate skew normal, finite mixture, number of mode

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Authors: Hui Long, Chun Yin Tang, Ping Kwong Cheng, Xin Yu Wang, Wayesh Qarony, Yuen Hong Tsang

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Two dimensional (2D) materials have recently attained substantial research interest since the discovery of graphene. However, the zero-bandgap feature of the graphene limits its nonlinear optical applications, e.g., saturable absorption for these applications require strong light-matter interaction. Nevertheless, the excellent optoelectronic properties, such as broad tunable bandgap energy and high carrier mobility of Group 10 transition metal dichalcogenides 2D materials, e.g., PtS2 introduce new degree of freedoms in the optoelectronic applications. This work reports our recent research findings regarding the saturable absorption property of PtS2 layered 2D material and its possibility to be used as saturable absorber (SA) for ultrafast mode locking fiber laser. The demonstration of mode locking operation by using the fabricated PtS2 as SA will be discussed. The PtS2/PVA SA used in this experiment is made up of some few layered PtS2 nanosheets fabricated via a simple ultrasonic liquid exfoliation. The operational wavelength located at ~1 micron is demonstrated from Yb-doped mode locking fiber laser ring cavity by using the PtS2 SA. The fabricated PtS2 saturable absorber offers strong nonlinear properties, and it is capable of producing regular mode locking laser pulses with pulse to pulse duration matched with the round-trip cavity time. The results confirm successful mode locking operation achieved by the fabricated PtS2 material. This work opens some new opportunities for these PtS2 materials for the ultrafast laser generation. Acknowledgments: This work is financially supported by Shenzhen Science and Technology Innovation Commission (JCYJ20170303160136888) and the Research Grants Council of Hong Kong, China (GRF 152109/16E, PolyU code: B-Q52T).

Keywords: platinum disulfide, PtS2, saturable absorption, saturable absorber, mode locking laser

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Authors: Sang-Wook Lee, So-Yeon Jeon, Min-Gi Cho, Dae-Young Shin, Sung-Ho Hwang

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Hydraulic system of excavator gets working energy from hydraulic pump which is connected to output shaft of engine. Recently, main control valve (MCV) which is composed of several independent metering valve (IMV) has been introduced for better energy efficiency of the hydraulic system so that fuel efficiency of the excavator can be improved. Excavator with IMV has 5 operating modes depending on the quantity of regeneration flow. In this system, the hydraulic pump is controlled to supply demanded flow which is needed to operate each mode. Because the regenerated flow supply energy to actuators, the hydraulic pump consumes less energy to make same motion than one that does not regenerate flow. The horse power control is applied to the hydraulic pump of excavator for maintaining engine start under a heavy load and this control makes the flow of hydraulic pump reduced. When excavator is in complex operation such as loading or unloading soil, the hydraulic pump discharges small quantity of working fluid in high pressure. At this operation, the engine of excavator does not run at optimal operating line (OOL). The engine needs to be operated on OOL to improve fuel efficiency and by controlling hydraulic pump the engine can drive on OOL. By continuous mode changing of IMV, the hydraulic pump is controlled to make engine runs on OOL. The simulation result of this study shows that fuel efficiency of excavator with IMV can be improved by considering engine OOL and continuous mode changing algorithm.

Keywords: continuous mode changing, engine fuel consumption, excavator, fuel efficiency, IMV

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Authors: Hu-Jiang Shi, Li-Juan Zhu

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The implication of 5-hydroxytryptamine 2C receptor (5-HT2CR) in affective behaviors is a topic of debate, and the underlying mechanisms remain largely unclear. Here, we elucidate that the interaction between hippocampal neuronal nitric oxide synthase (nNOS) and carboxy-terminal PDZ ligand of nNOS (CAPON) contributes to the disruption of hippocampal excitation-inhibition (E/I) balance, which is responsible for the anxiety- and depressive-like behaviors caused by chronic stress-related 5-HT2CR signaling deficiency. In detail, activation or inhibition of 5-HT2CR by CP809101 or SB242084 modulates nNOS-CAPON interaction by influencing intracellular Ca²⁺ release. Notably, the dissociation of nNOS-CAPON abolishes SB242084-induced anxiety- and depressive-like behaviors, as well as the reduction in extracellular signal-regulated kinase (ERK)/cAMP-response element binding protein (CREB)/synapsin signaling and SNARE complex assembly. Furthermore, nNOS-CAPON blockers restore the impairments caused by SB242084, including the reduction in SNARE assembly-mediated γ-aminobutyric acid (GABA) vesicle release and a consequent shift of the E/I balance toward excitation in CA3 pyramidal neurons. Conclusively, our findings disclose the regulatory role of 5-HT2CR in anxiety- and depressive-like behaviors and highlight the hippocampal nNOS-CAPON coupling-triggered E/I imbalance as a pivotal cellular event underpinning the behavioral consequences of 5-HT2CR inhibition.

Keywords: 5-HT2CR, anxiety, depression, nNOS-CAPON coupling, excitation-inhibition balance, neurotransmitter release

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Authors: Byung Ho Jung, Ji Eun Shin, Dong Hoon Lim

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Rhipe that integrates R and Hadoop environment made it possible to process and analyze massive amounts of data using a distributed processing environment. In this paper, we implemented multiple regression analysis using Rhipe with various data sizes of actual data. Experimental results for comparing the performance of our Rhipe with stats and biglm packages available on bigmemory, showed that our Rhipe was more fast than other packages owing to paralleling processing with increasing the number of map tasks as the size of data increases. We also compared the computing speeds of pseudo-distributed and fully-distributed modes for configuring Hadoop cluster. The results showed that fully-distributed mode was faster than pseudo-distributed mode, and computing speeds of fully-distributed mode were faster as the number of data nodes increases.

Keywords: big data, Hadoop, Parallel regression analysis, R, Rhipe

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Authors: Iftikhar Ahmad, A. Benallegue, A. El Hadri

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In this paper, we have proposed an observer for the reconstruction and a control law for the rejection application of unknown bounded external disturbance in a dynamical system. The strategy of both the observer and the controller is designed like a second order sliding mode with a proportional-integral (PI) term. Lyapunov theory is used to prove the exponential convergence and stability. Simulations results are given to show the performance of this method.

Keywords: non-linear systems, sliding mode observer, disturbance rejection, nonlinear control

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Authors: Maamar Latroch, Mohamed Bourahla

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Forward topology used in switch mode power supply (SMPS) is one of the most famous configuration feeding DC systems such as telecommunication systems and other specific applications where the galvanic isolation is required. This configuration benefits of the high frequency feature of the transformer to provide a small size and light weight of the over all system. However, the stresses existing on the power switch during an ON/OFF commutation limit the transmitted power to the DC load. This paper investigates the main causes of the stresses in voltage existing during a commutation cycle and suggest a low cost solution that eliminates the overvoltage. As a result, this configuration will yield the possibility of the use of this configuration in higher power applications. Simulation results will show the efficiency of the presented method.

Keywords: switch mode power supply, forward topology, resonance topology, high frequency commutation

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Authors: V. T. Ngo, D. M. Xie

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Frequently, in the design of machines, some of parameters that directly affect the rotor dynamics of the machines are not accurately known. In particular, bearing stiffness support is one such parameter. One of the most basic principles to grasp in rotor dynamics is the influence of the bearing stiffness on the critical speeds and mode shapes associated with a rotor-bearing system. Taking a rig shafting as an example, this paper studies the lateral vibration of the rotor with multi-degree-of-freedom by using Finite Element Method (FEM). The FEM model is created and the eigenvalues and eigenvectors are calculated and analyzed to find natural frequencies, critical speeds, mode shapes. Then critical speeds and mode shapes are analyzed by set bearing stiffness changes. The model permitted to identify the critical speeds and bearings that have an important influence on the vibration behavior.

Keywords: lateral vibration, finite element method, rig shafting, critical speed

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Authors: Lopamudra Bakshi Basu

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Transport is one of the most important characteristic features of Indian cities. The physical and societal requirements determine the selection of a particular transport system along with the uniqueness of road networks. Kolkata has a mixed traffic of which Paratransit system plays a crucial role. It is an indispensable transport system in Kolkata mainly because of its size and service flexibility which has led to a unique network character. The paratransit system, mainly the autorickshaws, is the most favoured mode of transport in the city. Its fast movement and comfortability make it a vital transport system of the city. Since the inception of the autorickshaws in Kolkata in 1981, this mode has gained popularity and presently serves nearly 80 to 90 percent of the total passenger trips. This employment generating mode of transport has increased its number rapidly affecting the city’s traffic. Minimal check on their growth by the authority has led to traffic snarls along many streets of Kolkata. Indiscipline behavior, violation of traffic rules and rash driving make situations even worse. The rise in the number and increasing popularity of the autorickshaws make it an interesting study area. Autorickshaws as a paratransit mode play its role as a leader or a follower. However, it is informal in its planning and operations, which makes it a problem area for the city. The entire research work deals with the growth and expansion of the number of vehicles and the routes within the city. The development of transport system has been interesting in the city, which has been studied. The growth of the paratransit modes in the city has been rapid. The network pattern of the paratransit mode within Kolkata has been analysed.

Keywords: growth, informal, network characteristics, paratransit, service flexibility

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Authors: Nor Mazlin Zahari, Lian Gan, Xuerui Mao

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The power production in wind farms and the mechanical loads on the turbines are strongly impacted by the wake of the wind turbine. Thus, there is a need for understanding and modelling the turbine wake dynamic in the wind farm and the layout optimization. Having a good wake model is important in predicting plant performance and understanding fatigue loads. In this paper, the Dynamic Mode Decomposition (DMD) was applied to the simulation data generated by a Direct Numerical Simulation (DNS) of flow around a turbine, perturbed by upstream inflow noise. This technique is useful in analyzing the wake flow, to predict its future states and to reflect flow dynamics associated with the coherent structures behind wind turbine wake flow. DMD was employed to describe the dynamic of the flow around turbine from the DNS data. Since the DNS data comes with the unstructured meshes and non-uniform grid, the interpolation of each occurring within each element in the data to obtain an evenly spaced mesh was performed before the DMD was applied. DMD analyses were able to tell us characteristics of the travelling waves behind the turbine, e.g. the dominant helical flow structures and the corresponding frequencies. As the result, the dominant frequency will be detected, and the associated spatial structure will be identified. The dynamic mode which represented the coherent structure will be presented.

Keywords: coherent structure, Direct Numerical Simulation (DNS), dominant frequency, Dynamic Mode Decomposition (DMD)

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Authors: M. Najafi

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In the present paper, a large turbo-generator shaft train including a heavy-duty gas turbine engine, a coupling, and a generator is established. The method of analysis is based on finite element simplified model for lateral and torsional vibration calculation. The basic elements of rotor are the shafts and the disks which are represented as circular cross section flexible beams and rigid body elements, respectively. For more accurate results, the gyroscopic effect and bearing dynamics coefficients and function of rotation are taken into account, and for the influence of shear effect, rotor has been modeled in the form of Timoshenko beam. Lateral critical speeds, critical speed map, damped mode shapes, Campbell diagram, zones of instability, amplitudes, phase angles response due to synchronous forces of excitation and amplification factor are calculated. Also, in the present paper, the effect of imbalanced rotor and effects of changing in internal force and temperature are studied.

Keywords: rotor dynamic analysis, finite element method, shaft train, Campbell diagram

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Authors: Ahmed Alkarimi, Kevin Welham

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Organic mixed mode monolithic columns were fabricated from; glycidyl methacrylate-co-ethylene dimethacrylate-co-stearyl methacrylate, using glycidyl methacrylate and stearyl methacrylate as co monomers representing 30% and 70% respectively of the liquid volume with ethylene dimethacrylate crosslinker and 2,2-dimethoxy-2-phenylacetophenone as the free radical initiator. The monomers were mixed with a binary porogenic solvent, comprising propan-1-ol, and methanol (0.825 mL each). The monolith was formed by photo polymerization (365 nm) inside a borosilicate glass tube (1.5 mm ID and 3 mm OD x 50 mm length). The monolith was observed to have formed correctly by optical examination and generated reasonable backpressure, approximately 650 psi at a flow rate of 0.2 mL min⁻¹ 50:50 acetonitrile: water. The morphological properties of the monolithic columns were investigated using scanning electron microscopy images, and Brunauer-Emmett-Teller analysis, the results showed that the monolith was formed properly with 19.98 ± 0.01 mm² surface area, 0.0205 ± 0.01 cm³ g⁻¹ pore volume and 6.93 ± 0.01 nm average pore size. The polymer monolith formed was further investigated using proton nuclear magnetic resonance, and Fourier transform infrared spectroscopy. The monolithic columns were investigated using high-performance liquid chromatography to test their ability to separate different samples with a range of properties. The columns displayed both hydrophobic/hydrophilic and hydrophobic/ion exchange interactions with the compounds tested indicating that true mixed mode separations. The mixed mode monolithic columns exhibited significant separation of proteins.

Keywords: LC separation, proteins separation, monolithic column, mixed mode

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Authors: Phannarithisen Ong

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Children's independent mobility for school trips promotes physical and mental well-being, reduces parental chauffeuring and traffic congestion, and boosts children's public confidence. However, in Thailand, despite a decade of rail mass transit development in Bangkok City, cars still queue to drop students at schools near transit stations. This worsens congestion, urging better independent mobility among children in mass transit regions. The high reliance on the private vehicle will influence the private mode in the children's adulthood. This research emphasizes mass transit use among high school students near transit systems. Through a questionnaire survey, quantitative and qualitative methods reveal key factors impacting school trip mode choice. Preliminary findings highlight children's independence as crucial. The socioeconomic, demographic, trip, and transportation traits explain private car use, even schools near mass transit stations. The outcomes of this study will shed light on urban strategic policies for improvement, advocacy, and encouragement of students using mass transit for school trips, which will help normalize the use of mass transit for such trips.

Keywords: children's independence mobility, mode choice, school trips, TOD, extraneous variable, children's independency

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Authors: S. Sivakumar, Ashwin Bala, S. Prithviraj, K. Panthala Rajakumaran, R. Pradeep, J. Udhayakumar

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Studies reveal that acetylene gas derived from hydrolysis of calcium carbide has similar properties to that of diesel. However, the self-ignition temperature of acetylene gas is higher than that of diesel. Early investigations reveal that acetylene gas could be used as alternative fuel mode. In the present work, acetylene gas of 31/min were inducted and diesel was injected into the combustion chamber of a single cylinder air cooled diesel engine. It was observed that the higher calorific value of acetylene gas improves the brake thermal efficiency at full load conditions. The CO and HC emissions were higher at part load conditions as compared to conventional diesel. The Nox emission level was higher and smoke emission was lower during dual fuel mode under all operating conditions. It is concluded that dual fuel mode of acetylene gas and diesel improves the brake thermal efficiency and reduces smoke in diesel engine.

Keywords: acetylene gas, diesel engine, Nox emission, CO emission, HC emission

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Authors: Carlos Oliveira Santiago Filho, Ciro Egoavil, Eduardo Oliveira, Jéferson Galdino, Moises Galileu, Tiago Oliveira Correa

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Transfer of Electrical Energy through resonant inductive magnetic coupling is demonstrated experimentally in a system containing coil primary for transmission and secondary reception. The topology used in the prototype of the Class-E amplifier, has been identified as optimal for power transfer applications. Characteristic of the inductor and the load are defined by the requirements of the resonant inductive system. The frequency limitation the of circuit restricts unloaded “Q-Factor”, quality factor of the coils and thus the link efficiency. With a suitable circuit, copper coil unloaded Q-Factors of over 1,000 can be achieved in the low Mhz region, enabling a cost-effective high Q coil assembly. The circuit is capable system capable of transmitting energy with direct current to load efficiency above 60% at 2 Mhz.

Keywords: magnetic induction, transfer of electrical energy, magnetic coupling, Q-Factor

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Authors: Kevin Anderson, Sukhwinder Singh Sandhu, Nouh Anies, Shilpa Ravichandra, Steven Dobbs, Donald Edberg

Abstract:

This paper presents the results of a Finite Element based vibration analysis of a solar powered Unmanned Aerial Vehicle (UAV). The purpose of this paper was to quantify the free vibration, forced vibration response due to differing point inputs in order to mimic the vibration induced by actuators (magnet in coil generators) used to aid in the flight of the UAV. A Fluid-Structure Interaction (FSI) study was performed in order to ascertain pertinent deigns stresses and deflections as well as aerodynamic parameters of the UAV airfoil. The 10 ft span airfoil is modeled using Mylar as the primary material. Results show that the free mode in bending is 4.8 Hz while the first forced bending mode is in the range of 16.2 to 16.7 Hz depending on the location of excitation. The free torsional bending mode is 28.3 Hz, and the first forced torsional mode is in the range of 26.4 to 27.8 Hz, depending on the location of excitation. The FSI results predict the coefficients of aerodynamic drag and lift of 0.0052 and 0.077, respectively, which matches hand-calculations used to validate the Finite Element based results. FSI based maximum von Mises stresses and deflections were found to be 0.282 MPa and 3.4 mm, respectively. Dynamic pressures on the airfoil range of 1.04 to 1.23 kPa corresponding to velocity magnitudes in the range of 22 to 66 m/s.

Keywords: ANSYS, finite element, FSI, UAV, vibrations

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Authors: J. Y. Sun, H. Z. Shen

Abstract:

We study the photon blockade at exceptional points for a non-Hermitian optomechanical system coupled to the driven whispering-gallery-mode microresonator with two nanoparticles under the weak optomechanical coupling approximation, where exceptional points emerge periodically by controlling the relative angle of the nanoparticles. We find that conventional photon blockade occurs at exceptional points for the eigenenergy resonance of the single-excitation subspace driven by a laser field and discuss the physical origin of conventional photon blockade. Under the weak driving condition, we analyze the influences of the different parameters on conventional photon blockade. We investigate conventional photon blockade at nonexceptional points, which exists at two optimal detunings due to the eigenstates in the single-excitation subspace splitting from one (coalescence) at exceptional points to two at nonexceptional points. Unconventional photon blockade can occur at nonexceptional points, while it does not exist at exceptional points since the destructive quantum interference cannot occur due to the two different quantum pathways to the two-photon state not being formed. The realization of photon blockade in our proposal provides a viable and flexible way for the preparation of single-photon sources in the non-Hermitian optomechanical system.

Keywords: optomechanical systems, photon blockade, non-hermitian, exceptional points

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Authors: Ashish Bohre, Blaž Likozar, Saikat Dutta, Dionisios G. Vlachos, Basudeb Saha

Abstract:

Graphene oxide, decorated with surface oxygen functionalities, has emerged as a sustainable alternative to precious metal catalysts for many reactions. Herein, we report for the first time that graphene oxide becomes super active for C-C coupling upon incorporation of multilayer crystalline features, highly oxidized surface, Brønsted acidic functionalities and defect sites on the surface and edges via modified oxidation. The resulting improved graphene oxide (IGO) demonstrates superior activity to commonly used framework zeolites for upgrading of low carbon biomass furanics to long carbon chain aviation fuel precursors. A maximum 95% yield of C15 fuel precursor with high selectivity is obtained at low temperature (60 C) and neat conditions via hydroxyalkylation/alkylation (HAA) of 2-methylfuran (2-MF) and furfural. The coupling of 2-MF with carbonyl molecules ranging from C3 to C6 produced the precursors of carbon numbers 12 to 21. The catalyst becomes inactive in the 4th cycle due to the loss of oxygen functionalities, defect sites and multilayer features; however, regains comparable activity upon regeneration. Extensive microscopic and spectroscopic characterization of the fresh and reused IGO is presented to elucidate high activity of IGO and to establish a correlation between activity and surface and structural properties. Kinetic Monte Carlo (KMC) and density functional theory (DFT) calculations are presented to further illustrate the surface features and the reaction mechanism.

Keywords: methacrylic acid, itaconic acid, biomass, monomer, solid base catalyst

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Authors: Tayebeh Saghapour, Sara Moridpour, Russell George Thompson

Abstract:

One of the common aims of transport policy makers is to switch people’s travel to active transport. For this purpose, a variety of transport goals and investments should be programmed to increase the propensity towards active transport mode choice. This paper aims to investigate whether built environment features in neighbourhoods could enhance the odds of active transportation. The present study introduces an index measuring public transport accessibility (PTAI), and a walkability index along with socioeconomic variables to investigate mode choice behaviour. Using travel behaviour data, an ordered logit regression model is applied to examine the impacts of explanatory variables on walking trips. The findings indicated that high rates of active travel are consistently associated with higher levels of walking and public transport accessibility.

Keywords: active transport, public transport accessibility, walkability, ordered logit model

Procedia PDF Downloads 309

Authors: Jia-Shiun Chen, Hsiu-Ying Hwang

Abstract:

Hybrid electric vehicles can reduce pollution and improve fuel economy. Power-split hybrid electric vehicles (HEVs) provide two power paths between the internal combustion engine (ICE) and energy storage system (ESS) through the gears of an electrically variable transmission (EVT). EVT allows ICE to operate independently from vehicle speed all the time. Therefore, the ICE can operate in the efficient region of its characteristic brake specific fuel consumption (BSFC) map. The two-mode powertrain can operate in input-split or compound-split EVT modes and in four different fixed gear configurations. Power-split architecture is advantageous because it combines conventional series and parallel power paths. This research focuses on input-split and compound-split modes in the two-mode power-split powertrain. Fuzzy Logic Control (FLC) for an internal combustion engine (ICE) and PI control for electric machines (EMs) are derived for the urban driving cycle simulation. These control algorithms reduce vehicle fuel consumption and improve ICE efficiency while maintaining the state of charge (SOC) of the energy storage system in an efficient range.

Keywords: hybrid electric vehicle, fuel economy, two-mode hybrid, fuzzy control

Procedia PDF Downloads 351