Rectangular System Research Articles

Investigation of Diagrid Structures Over Gherkin Tower

21st.Century witnesses enormous technological development effecting Architecture also: New and improved building materials and construction techniques, highly innovative development of structural systems utilizing advanced computer software leads to significant novelties in built environment, worldwide. The ‘Diagrid Structure’, having a hyperboloid form, of which the first design and implementation was applied by V. Shukhov in, as early as, 1896. Both due to diagrid and to its doubly curved form, it proved to achieve greater lateral strength, rigidity and efficiency than rectangular frame system, decreasing the amount of the required material, besides offering the possibility of prefabrication and ease of assembly. Although the first diagrid structure was built in 1963- the IBM building in Pittsburgh- it did not utilize a doubly curved form. The system was not widely recognized until the Gherkin Tower designed by Sir N. Foster was completed in London, in 2003, displaying the twinning of architectural and structural design.

Successive and profitability of pruning in canopy management and high density planting in guava orchard under western Uttar Pradesh condition

The current study was conducted to examine the successive and profitability of pruning in canopy management and high density planting in Guava orchard under Western Uttar Pradesh condition. The experiment was carried out in the orchard established at Research Farm, Krishi Vigyan Kendra, Hastinapur, Sardar Vallabhbhai Patel, University of Agriculture & Technology, Meerut, during the year 2017-2018 were studied. Rectangular system of planting and layout is preferred as it facilitates orchard operations. Planting was done in the month of February- March and August-September. Observation revealed that the pruning and high density with plant spacing (3.0 X 3.0 M) increased the fruit yield significantly, Similarly, with increase in spacing wise pruning in canopy management and high density was need to increased. Plant growth in term of stock girth of P. guajava cv. Florda seedless (47.20 cm) and scion girth of P. guajava cv. Allahabad seedless (44.7 cm), tree spread (N - S) and canopy volume increased with the plant spacing (3.0 × 3.0 M), while tree height decreased. To increase in plant spacing, number of fruits per plant, yield per plant and fruit density was higher at 3.0 × 3.0 M and least in 6.0 × 6.0 M plant spacing. Pruning in canopy management and high planting density was found to be better owing to maximum absorption of solar radiation and optimum microclimate in the orchard leading to better yield in plants, higher fruit density and yield efficiency, However yield per hectare was maximum 3.0 X3.0 M spacing in during rainy season and in 6.0 × 3.0 M spacing during winter.

Numerical study of the surface and subsurface vortices suppression in a rectangular pump basin using anti‐vortex devices

AbstractThe present study reports the results of high‐resolution free surface Unsteady Reynolds Averaged Navier–Stokes (URANS) simulations of the three‐dimensional (3D) flow field in a rectangular pump intake system. The numerical simulations are composed of various scenarios without/with various anti‐vortex devices (AVDs) to suppress the surface and subsurface vortices around the pipe. For this purpose, after performing a comparison between the streamlines of a benchmark test case and the data available in the literature, the 3D vortical structures around the pipe and inside of the basin have been visualized using the Q‐criterion. In addition, the circulation and swirl angle indices inside the pipe are implemented for evaluating the performance of different types of AVDs. The results showed that the surface vortices cause low frequency oscillations in the pump inlet. In this case, the use of a curtain wall controls the surface vortices and eliminates low frequency and high amplitude oscillations in the pump inlet. Examining various cases with AVDs shows that none of the scenarios with AVDs could fully control the surface and submerged vortices. Due to this fact, a novel geometry for the pump basin is introduced which suppresses the entire free surface, submerged and floor vortices.

Modelling of Transport System Operational Reliability a Markov Approach

Abstract The workability of a transport system is associated with performance and operational reliability. Operational reliability provides a measure of the probability that a transport system will realize transport process as intended. Performance reliability is an adequacy measure of transport process realization under specific environmental and traffic conditions. Transport system can be modelled as repairable, multistate, non-homogenous rectangular or dendrite system. This article provides the Markov and semi Markov models for estimation of the operational and performance reliability of city transport system. The system is semi homogenous it means that serial subsystems have the same reliability function. The reliability of any serial subsystem is exponential. The distribution of the repair time is any probability distribution. In case where the probability distribution of the repair time is exponential, the Markov process is used to construct simulation model. The simulation model was applied at Microsoft Excel. Many stochastic models in engineering, logistic and even finance or insurance are setup in a spreadsheet for simulation. The semi Markov model of the multistate reliability of repaired system is applied to the street system. The embedded Markov chain was used to count stationary probabilities. The possibility of application of the results is illustrated by an example for the systems with rectangular or dendrite shaped accordingly, consist of three types of elements.

Suppression of Lateral Vibration in Rectangular Ultrasonic Plastic Soldering Tool Based on Phononic Crystal Structure

In this paper, the design of large-size rectangular ultrasonic plastic soldering system is studied by using the band gap theory of phononic crystal and coupled vibration theory of large-size rectangular tool. In practical engineering applications, lateral vibration of the large-size rectangular tool will seriously cause the displacement of the tool's radiation surface uneven. So the lateral vibration of the tool should be suppressed. As we all know, phononic crystal materials can suppress the vibration and they are composed of two or more different materials periodically (including matrix material and scattering material). This paper uses periodic slotted structure to suppress the lateral vibration of the large-size rectangular tool. The lateral vibration band gap of the large-size rectangular tool which has periodic slotted structure in this paper is simulated. In addition, the influence of the scatterer's size on the lateral vibration band gap is also obtained. At the same time, the magnitude and uniformity of the tool's radiation surface displacement before and after slotting is compared in experiments. The research shows that by reasonably designing the periodic structure and size of the phononic crystal, the lateral vibration of the large-size rectangular tool can be effectively suppressed, and the displacement of the tool's radiation surface can be more even.

Robust stabilization for rectangular descriptor fractional order interval systems with order 0 < α < 1

This paper considers the normalization and stabilization of rectangular descriptor fractional order interval systems with fractional order 0 < α < 1. Firstly, a rectangular descriptor fractional order interval system is transformed into an augmented square descriptor fractional order interval system by adopting the proportional and derivative type dynamic compensator. Secondly, by using the generalized rank of matrix, we can make the augmented square descriptor fractional order interval system normalized. Thirdly, a less conservative sufficient condition is expressed in terms of a set of bilinear matrix inequalities which can be efficiently solved by an iterative LMI algorithm. Finally, a numerical example is given to verify the effectiveness of the results in this paper.

Comparative Analysis of Rectangular and Circular Four-resonator Coil System for Wireless Power Transfer Using Magnetic Resonance Coupling Technique

Comparative Analysis of Rectangular and Circular Four-resonator Coil System for Wireless Power Transfer Using Magnetic Resonance Coupling Technique

Numerical analysis of microwave heating cavity: Combining electromagnetic energy, heat transfer and fluid dynamics for a NaY zeolite fixed-bed

Three-dimensional mathematical model was developed for a rectangular TE10n microwave heating cavity system, working at 2.45 GHz. Energy/heat, momentum equations were solved together with Maxwell’s electromagnetic field equations using Comsol Multiphysics® simulation environment. The dielectric properties, ε' and ε'', of NaY zeolite (Si/Al = 2.5) were evaluated as a function of temperature. Considering these values, the microwave heating of a porous fixed-bed made of dry NaY zeolite was simulated. Electric field distribution, axial and radial temperature profiles and temperature evolution with time were obtained. The zeolite fixed bed was heated up to 180 °C in 5 min, with 30 W power. The fixed-bed temperature evolution under non-steady state conditions showed the same trend as the one observed experimentally with only an average deviation of 10.3%. The model was used to predict microwave heating of other materials improving energy efficiency of the microwave cavity. Furthermore, the developed model was able to predict thermal runaway for zeolites.

Terahertz multi-plasmon induced reflection and transmission and sensor devices in a graphene-based coupled nanoribbons resonators

We demonstrate numerically multi-plasmon-induced reflection (PIR), multi-plasmon-induced transparency (PIT) and propose a highly sensitive refractive index nanosensor in a novel ultra-compact graphene-based nano-device, operating in the terahertz frequency range. The base structure of the system is composed out of a bus waveguide made out of graphene coupled to resonators inserted along or aside the waveguide where each resonator is constituted by a set of two coupled graphene nano-ribbons (CGNR). The latters behave as a molecule-like entity, whose surface plasmon eigen-modes originate from the splitting of the single ribbons modes. We show that the two CGNRs can also be regarded as an effective rectangular cavity-like system, so that the insertion of the latter along or aside the graphene bus waveguide (GBW) enables the design of tunable selective or rejective filters, respectively. By inserting two identical effective cavities in the structure, into a Λ-like state (in analogy with three level atomic systems), we show the possibility of realizing multiple plasmon induced reflection, and highlight its fast light-features. On the other hand, if the two identical cavities are set symmetrically on each side of the GBW with slightly detuned Fermi energy levels in a V-like configuration, multi-plasmon induced transparency can be obtained. In addition, a highly sensitive refractive index nanosensor is showcased. The latter consists in a GBW, side-coupled to an effective cavity-oscillator embedded with the analyte to be detected. The sensitivity of the sensor is numerically derived. Owing to its simple structure, the proposed sensor may offer the advantage of being easily fabricated. The showcased graphene-based devices proposed in this work should help the design of tunable and highly integrated optical devices such as nano-filters, optical switches and highly sensitive nanosensors.

Fundamental period of vibrations influencing characteristics of torsional irregularity in reinforced concrete buildings

This paper presents an analysis of irregular reinforced concrete buildings with respect to fundamental period of vibrations. During earthquake, reinforced concrete building with asymmetric building system experience extensive damage due to this torsional irregularity. Torsional irregularity of reinforced concrete buildings has been analysed with taking the strength and stiffness eccentricities as the main parameters of the rectangular in-plan building system. Displacement demand in reinforced concrete building has been determined in terms of fundamental period of vibrations and the behaviour of the building system was presented using the normalised displacement of buildings. The hypothetical model has been analysed has been set up using varies values of fundamental period of vibrations using Ruaumoko program and the lateral displacement of the building were extracted using Fortran program. The results indicated through the damage index showed that the fundamental period of vibration plays an important role in earthquake studies on reinforced concrete building since earthquake induced excessive displacement to the building system under the increment of the fundamental period of vibrations.

Buckling Analysis of Sandwich Plate Systems with Stiffening Ribs: Theoretical, Numerical, and Experimental Approaches

This paper discusses a global buckling analysis approach for sandwich plates with stiffening ribs. The approach is based on theoretical study and is implemented by the finite element method (FEM). The equilibrium equation corresponding to critical global buckling of the sandwich plate with stiffening ribs under simple supported boundary condition is established by the energy method. The critical buckling solutions for a typical rectangular sandwich plate system (SPS) with a single stiffening rib in the longitudinal direction are then investigated while varying the potential influencing factors. The shear rigidity within the inner core exerts little effect on global buckling and can be neglected. An FEM study on elastic buckling was then conducted via ANSYS software. The advantages of the SPS were highlighted via its elastic eigenvalue buckling numerical analysis with multiple stiffeners. The ultimate buckling loads were computed similarly for different influential factors. Finally, an SPS specimen was tested in a compression test. The results showed that when the rib spacing is large, the local buckling of the plates in the grillage is controllable and the SPS is more resistant to both local and global buckling. The results based on our theoretical method agreed well with those of the FEM and experimental results.

Development of [formula omitted]-inverse model by using generalized polynomial chaos

We present a hp-inverse model to estimate a smooth, non-negative source function from a limited number of observations for a two-dimensional linear source inversion problem. A standard least-square inverse model is formulated by using a set of Gaussian radial basis functions (GRBF) on a rectangular mesh system with a uniform grid space. Here, the choice of the mesh system is modeled as a random variable and the generalized polynomial chaos (gPC) expansion is used to represent the random mesh system. It is shown that the convolution of gPC and GRBF provides hierarchical basis functions for the linear source inverse model with the hp-refinement capability. We propose a mixed l1 and l2 regularization to exploit the hierarchical nature of the basis functions to find a sparse solution. The hp-inverse model has an advantage over the standard least-square inverse model when the number of data is limited. It is shown that the hp-inverse model provides a good estimate of the source function even when the number of unknown parameters (m) is much larger the number of data (n), e.g., m∕n>40.

Method of fabricating an array of diffractive optical elements by using a direct laser lithography

Recently, aspheric lenses have been developed to correct various aberrations and to produce optical elements with various functions. In particular, efforts have focused on fabrication miniaturized and compact elements that make the use of flat, diffractive optical elements such as zone plates to replace conventional lenses. Direct laser lithography is one of the typical methods used to manufacture such diffraction optical elements. By using a high magnification objective lens, it generates a laser beam with a spot size of less than 1 μm at the focal point. To produce a pattern, such as a diffraction grating, a chromium-coated surface is controllably exposed to this light. In this study, the process conditions for fabricating a zone plate using a direct laser lithography were studied by using an air-bearing type linear XY stage which can easily make various patterns including a zone plate array. The previous studies using a polar coordinate lithographic system have an advantage for fabricating the circular type zone plate because the system uses a rotational stage. It, however, is not proper to fabricate an array type diffractive optics element. In this study, we used a rectangular type lithographic system by using an XY stage and tested the fabrication issues such as a runout error. The optical performance of the zone plate array fabricated by the suggested method was also verified by experimental evaluation.

Three-step alternating and preconditioned scheme for rectangular matrices

In this article, a three-step alternating iterative scheme for rectangular system has been proposed. The convergence and comparison analysis of the proposed method has been discussed for the class of semi-monotone matrices and which confirms the faster convergence of our scheme. A preconditioned approach is also presented in this paper to relax the semi-monotonicity condition. The preconditioned approach is very promising and converges faster than some of existing schemes. We finally validated all the theoretical results by some numerical examples.

Delineation of Agricultural Drainage Pipe Patterns Using Ground Penetrating Radar Integrated with a Real-Time Kinematic Global Navigation Satellite System

Better methods are needed for mapping agricultural drainage pipe systems. Prior research on small test plots indicates that ground penetrating radar (GPR) is oftentimes capable of detecting buried drainage pipes; however, the feasibility of employing this geophysical technique in larger field areas has not been adequately evaluated. Ground penetrating radar integrated with a Real-Time Kinematic (RTK) Global Navigation Satellite System (GNSS) may be an effective and efficient means of mapping drain lines within agricultural fields. Therefore, GPR-RTK/GNSS was tested in three agricultural settings; with Site 1 and Site 2 located in Beltsville, MD, USA and Site 3 near Columbus, OH, USA. Soils at the three sites ranged from silty clay loam to loamy sand. A GPR unit with 250 MHz antennas was used to detect drainage pipes, and at Sites 1 and 2, a physical GNSS base station was utilized, while a virtual base station was employed at Site 3. The GPR-RTK/GNSS configurations used in this study delineated a complex rectangular drainage pipe system at Site 1, with one set of drainage pipes oriented southwest-northeast and a second oriented southeast-northwest. At Site 2, a herringbone drain line pattern was outlined, and at Site 3, random drain lines were found. When integrated with RTK/GNSS, spiral or serpentine GPR transects (or spiral/serpentine segments of a GPR transects) were utilized to provide insight on drain line directional trends. Consequently, given suitable field conditions, GPR integrated with RTK/GNSS can be a valuable tool for farmers and drainage contractors needing to map subsurface drainage systems.

Assessment of shunted piezoelectric devices for simultaneous noise and vibration reduction: comparison of passive, active and hybrid networks

Structural vibration and noise control of a cavity-backed three-layered smart piezo-coupled rectangular panel system under harmonic or transient loads is achieved by using purely active, passive, and hybrid active/passive piezoelectric shunt networks. Problem formulation is based on the classical lamination plate theory, Maxwell’s equation for piezoelectric materials, linear circuit theory, and wave equation for the enclosed acoustic domain. The orthogonal mode expansions along with the modal coupling theory are employed to obtain the coupled differential equations of the electro-mechanical-acoustic system, which are then put into the convenient state-space form, and subsequently solved numerically in both frequency and time domains. A triple-mode hybrid RLC shunt circuit, in series with an external active voltage source and connected to a single electroded piezoelectric segment, is tuned to the dominant resonance frequencies of the composite structure. The linear quadratic optimal control (LQR) theory is adopted for obtaining the active control gains. The frequency and time domain performances of the passive, active and hybrid multi-modal piezoelectric systems are calculated and discussed in terms of sensor output voltage, local sound pressure, and control effort. It is found that the hybrid control methodology with properly tuned circuit parameters can be an excellent candidate for simultaneous vibration and structure-borne noise control of the cavity-coupled smart panel with decreased control effort. Also, the active control strategy integrated in the hybrid control system is demonstrated to enhance the overall system damping characteristics and improve the control authority at frequencies where the passive shunt network performs weakly. Limiting cases are considered and correctness of the mathematical model is verified by using a commercial finite element software as well as by comparisons with the literature.

Evaluation of different maze systems for the determination of feed attractability for longarm river prawn Macrobrachium tenellum

Previous studies have shown that crustacean feed attractability has an enormous importance, because the consumption, quality and feed conversion rate can be improved, by reducing the time of residence pre-ingestion and the leaching of nutrients. For this reason, different protocols and methods has been developed to measure feed attractability. This study evaluated the use of maze type Y, and rectangular systems to determine the attractant power of a commercial feed on longarm river prawn Macrobrachium tenellum . The Y type maze system without barriers, and with three different types of barriers (with or without access to the area where a commercial feed) was evaluated. Ten prawns were placed in the acclimation chamber of the system at 28°C for 60 min before the start of the experiment. To start the test, commercial feed (20% of prawn biomass) was placed into the system feeding area, then the acclimation chamber was open to allow for the free prawn movement, evaluating the feed attractability by measuring the time for the first “hit”, total number of hits, and the number of prawns which entrances to the feeding area during 15 min. Similar tests were performed with a rectangular type maze system, comparing the atractability results obtained in both systems. The results presented here highlight the importance of the genus behavior and the selection of protocols and systems, as well as the materials used in its maze system construction, for attractability testing in M. tenellum .

A simple first-order shear deformation theory for vibro-acoustic analysis of the laminated rectangular fluid-structure coupling system

This paper presents a simple first-order shear deformation theory (SFSDT), which is used for the first time to analyze the vibro-acoustic characteristics of the laminated rectangular plate-cavity coupling system filled with air or water. The proposed theory contains only four unknowns and has greater application scope and higher computation accuracy compared with the classical plate theory (CPT). The admissible functions of displacements and sound pressure of the fluid-structure coupling system are expressed as superposition of the periodic functions based on the Fourier series method. Combined with the artificial virtual spring technology, the proposed theory could be used to analyze the composite coupling system under various combinations of classical boundary conditions or arbitrary elastic boundary conditions. Based on the free vibration analysis of the laminated rectangular plate in-vacuo, both the natural characteristics analysis and the forced response analysis under the excitation of a unit point force or a unit point sound source are carried out. The differences between the weak coupling system with air as medium and the strong coupling system with water as medium are discussed in detail and some new results and new conclusions have been given, which could be the benchmark for the future research.

State Observer-Based Backstepping Terminal Sliding Mode Control for Rectangular Robot Systems

This study focuses on the fast state estimation of unmeasured state variable and uncertainty by using super-twisting state observer and adaptive law, and the design of a backstepping-based terminal sliding mode controller for rectangular robot systems. Introducing a super-twisting state observer can estimate unmeasured velocity information more rapidly than a conventional high-gain state observer. A backstepping controller with super-twisting observer is combined with a terminal sliding mode control scheme, which demonstrates faster error convergence performance than conventional backstepping sliding mode control. This estimation law, combined with the robustness of the controller for unknown states and dynamics, results in outstanding control performance when compared to conventional model-based computed torque control methods. The stability of the proposed control system was verified by using the Lyapunov-candidate-function. Comparative simulation and experimental results for the two-axis rectangular robot system demonstrate the efficacy of the proposed control scheme.

Parameterization study on the moderately thick laminated rectangular plate-cavity coupling system with uniform or non-uniform boundary conditions

This paper investigates the vibro-acoustic characteristics of the moderately thick laminated rectangular plate-cavity coupling system by using a modified Fourier series method. In the established model, two boundary conditions of moderately thick laminated rectangular plate are set as uniform elastic supports and non-uniform elastic supports including multi-points elastic supports or partial elastic supports. Besides, the three-dimensional rectangular cavity with rigid walls or impedance walls is discussed in the studied model. The admissible function of the displacements and sound pressure of the coupling system is set as the superposition function combined with Fourier cosine series and Fourier sin series. The Lagrangian energy principle is used to express the coupling system. The vibro-acoustic coupling characteristics can be obtained based on Rayleigh-Ritz technique. It shows good convergence and agreement of the present method by being compared with the finite element method (FEM) and the related literatures. This paper focuses on the study of free and forced vibro-acoustic analysis for the moderately thick laminated rectangular plate-cavity coupling system. Moreover, some results are achieved by discussing the effects of various plate thicknesses, different types of elastic supports, lamination schemes and various impedance boundary conditions on the natural characteristics and responses of the coupling system.