scholarly journals Using of Recycled Materials to Protect the Working and Natural Environment by Reducing Noise and Vibration

2020 ◽  
Vol 70 (2) ◽  
pp. 197-211
Author(s):  
Žiaran Stanislav ◽  
Šooš Ľubomír ◽  
Chlebo Ondrej
Keyword(s):  
Frequency Spectrum ◽  
Natural Environment ◽  
Mechanical Systems ◽  
Experimental Results ◽  
Theoretical Knowledge ◽  
Sound Waves ◽  
Viscoelastic Materials ◽  
Recycled Materials ◽  
Noise And Vibration ◽  
Materials Used

AbstractThe aim of the article is to define the conditions for the use of recycled resilient materials in the reduction of noise and vibration as an integral part of the mounting and installation of mechanical systems in the work and natural environment. Based on the frequency spectrum, the vibro-isolation efficiency of the vibro-isolators and the viscoelastic materials used is analysed. The solution of this problem is based on the theoretical knowledge and methodology of the transmission of vibration-sound waves. The measurements of the vibration at the sources and along the path of transmission were performed for different recycled materials to compare experimental results with theory.

Analysis and Optimization of Conformal Patch Excited Wideband DRA of Several Shapes

Frequenz ◽  
2018 ◽  
Vol 72 (5-6) ◽  
pp. 197-208 ◽  
Author(s):  
Pramod Kumar ◽  
Santanu Dwari ◽  
Shailendra Singh ◽  
Ashok Kumar ◽  
N. K. Agrawal ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Frequency Spectrum ◽  
High Frequency ◽  
Unit Volume ◽  
Experimental Results ◽  
Impedance Bandwidth ◽  
High Frequency Structure Simulator ◽  
Triangular Shape ◽  
Operating Band ◽  
Peak Gain

AbstractIn this paper various shapes of DR antennas excited by common feed have been proposed and successfully implemented for wideband applications. Proposed structures are Hemispherical, Arrow-shaped and Triangular DRA, while common excited feed is inverted trapezoidal conformal patch. These shapes of DR offer significant optimization in several parameters such as impedance bandwidth, peak gain and bandwidth per unit volume of the antenna. By using inverted trapezoidal patch feed mechanism an impedance bandwidth (VSWR<2) of about 63 % for hemispherical shape, 66 % for arrow shape, and 72 % for triangular shape DRA has been achieved with maximum bandwidth per unit volume. Proposed wideband DRAs i. e. triangular, hemispherical, and arrow shapes of DR antennas cover almost complete C-band (4 GHz–8 GHz) frequency spectrum of microwave. The average peak gain within the operating band for hemispherical, arrow, and triangular shape DRA are about 5, 5.4, and 5.5 dB respectively. A comparative analysis of proposed structures for various antenna parameters has been analyzed by HFSS (High-Frequency Structure Simulator) and validated by experimental results.

Acoustic manipulation of fractal metamaterials with negative properties and near-zero densities

2021 ◽  
Author(s):  
Guanghua Wu ◽  
Yibo Ke ◽  
Lin Zhang ◽  
Meng Tao
Keyword(s):  
High Potential ◽  
Experimental Results ◽  
Acoustic Properties ◽  
Sound Insulation ◽  
Sound Waves ◽  
Acoustic Metamaterials ◽  
Acoustic Device

Abstract Acoustic metamaterials have high potential in diverse applications, including acoustic cloaking, sound tunneling, wavefront reshaping, and sound insulation. In the present study, new metamaterials consisting of spatial coiled units are designed and fabricated to manipulate sound waves in the range 0-1600 Hz. The effective acoustic properties and band diagrams are studied. The simulation and experimental results demonstrate that the metamaterials provide an effective and feasible approach to design acoustic device such as sound cloaking and insulators.

Rethinking Waste Through Design

2021 ◽  
pp. 449-459
Author(s):  
Caroline O'Donnell ◽  
Dillon Pranger
Keyword(s):  
Case Studies ◽  
Construction Industry ◽  
Recycled Materials ◽  
Sustainable Practices ◽  
The Us ◽  
Materials Used ◽  
Made In

This chapter will study the proliferation of architectural follies that use recycled or recyclable materials in a move to promote better practices in waste and recycling. Given the slow uptake of this impetus in the architectural world proper, the text will investigate the obstacles in engaging in materially sustainable practices in the construction industry as well as case studies for rethinking currently problematic materials. However, while some improvements have been made in the construction industry's use of recycled materials, the industry often dismisses the afterlife of materials used throughout the process. What are the motivations of the industry and how can we incentivize circular thinking in an industry that produces hundreds of millions of tons of waste per year in the US?

Minimum Span Frequency Assignment Based on a Multiagent Evolutionary Algorithm

2011 ◽  
Vol 2 (3) ◽  
pp. 29-42
Author(s):  
Jing Liu ◽  
Jinshu Li ◽  
Weicai Zhong ◽  
Li Zhang ◽  
Ruochen Liu
Keyword(s):  
Evolutionary Algorithms ◽  
Evolutionary Algorithm ◽  
Frequency Spectrum ◽  
Multiagent Systems ◽  
Experimental Results ◽  
Frequency Assignment ◽  
Assignment Problems ◽  
The Cost ◽  
Very High

In frequency assignment problems (FAPs), separation of the frequencies assigned to the transmitters is necessary to avoid the interference. However, unnecessary separation causes an excess requirement of spectrum, the cost of which may be very high. Since FAPs are closely related to T-coloring problems (TCP), multiagent systems and evolutionary algorithms are combined to form a new algorithm for minimum span FAPs on the basis of the model of TCP, which is named as Multiagent Evolutionary Algorithm for Minimum Span FAPs (MAEA-MSFAPs). The objective of MAEA-MSFAPs is to minimize the frequency spectrum required for a given level of reception quality over the network. In MAEA-MSFAPs, all agents live in a latticelike environment. Making use of the designed behaviors, MAEA-MSFAPs realizes the ability of agents to sense and act on the environment in which they live. During the process of interacting with the environment and other agents, each agent increases the energy as much as possible so that MAEA-MSFAPs can find the optima. Experimental results on TCP with different sizes and Philadelphia benchmark for FAPs show that MAEA-MSFAPs have a good performance and outperform the compared methods.

scholarly journals Validation of Nanoparticle Response to the Sound Pressure Effect during the Drug-Delivery Process

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 186 ◽  
Author(s):  
Mohamed Abbas ◽  
Mohammed Alqahtani ◽  
Ali Algahtani ◽  
Amir Kessentini ◽  
Hassen Loukil ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Sound Pressure ◽  
Pressure Effect ◽  
Experimental Results ◽  
Sound Waves ◽  
Subcutaneous Injections ◽  
Acrylic Plastic ◽  
Sound Pressure Levels ◽  
The Impact ◽  
Interaction Behaviors

Intravenous delivery is the fastest conventional method of delivering drugs to their targets in seconds, whereas intramuscular and subcutaneous injections provide a slower continuous delivery of drugs. In recent years, nanoparticle-based drug-delivery systems have gained considerable attention. During the progression of nanoparticles into the blood, the sound waves generated by the particles create acoustic pressure that affects the movement of nanoparticles. To overcome this issue, the impact of sound pressure levels on the development of nanoparticles was studied herein. In addition, a composite nanostructure was developed using different types of nanoscale substances to overcome the effect of sound pressure levels in the drug-delivery process. The results demonstrate the efficacy of the proposed nanostructure based on a group of different nanoparticles. This study suggests five materials, namely, polyimide, acrylic plastic, Aluminum 3003-H18, Magnesium AZ31B, and polysilicon for the design of the proposed structure. The best results were obtained in the case of the movement of these molecules at lower frequencies. The performance of acrylic plastic is better than other materials; the sound pressure levels reached minimum values at frequencies of 1, 10, 20, and 60 nHz. Furthermore, an experimental setup was designed to validate the proposed idea using advanced biomedical imaging technologies. The experimental results demonstrate the possibilities of detecting, tracking, and evaluating the movement behaviors of nanoparticles. The experimental results also demonstrate that the lowest sound pressure levels were observed at lower frequency levels, thus proving the validity of the proposed computational model assumptions. The outcome of this study will pave the way to understand the interaction behaviors of nanoparticles with the surrounding biological environments, including the sound pressure effect, which could lead to the useof such an effect in facilitating directional and tactic movements of the micro- and nano-motors.

Identification of Critical Net Positive Suction Head From Noise and Vibration in a Radial Flow Pump for Different Leading Edge Profiles of the Vane

2013 ◽  
Vol 135 (12) ◽  
Author(s):  
S. Christopher ◽  
S. Kumaraswamy
Keyword(s):  
Radial Flow ◽  
Leading Edge ◽  
Open Circuit ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Flow Rates ◽  
Noise And Vibration ◽  
Operating Condition ◽  
Radial Flow Pump ◽  
Flow Pump

Experimental investigations concerning cavitation in radial flow pump for three different leading edge profiles of the vane were carried out in an open circuit system. The operating condition of the radial flow pump under cavitating case was understood by measurement of noise and vibration along with the pump parameters for various speeds and flow rates. The outcome of the experimental results revealed that the noise and vibration were better predictors of inception and development of cavitation. Further observation inferred from critical net positive suction head (NPSH) curve of 3% head drop and critical NPSH value of noise and vibration are presented.

Design and Analysis of Micro Plastic Heat Exchanger

2012 ◽  
Vol 562-564 ◽  
pp. 1776-1779
Author(s):  
Yue Han ◽  
Heng Zhi Cai ◽  
Ya Jun Zhang ◽  
Da Ming Wu ◽  
Xin Liang Wang
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Chemical Engineering ◽  
Mechanical Systems ◽  
Experimental Results ◽  
Micro Electro Mechanical Systems ◽  
Micro Heat Exchanger ◽  
Simulation And Experiment ◽  
Energy Engineering

The heat exchanger is widely used in energy engineering, chemical engineering etc. And with development of the MEMS (Micro Electro Mechanical Systems), many researchers are interested in the micro heat exchanger. In this paper, the micro plastic heat exchangers are manufactured by modified PPS. A heat exchanger with polypropylene (PP) is also made for comparison. Simulation and experiment are carried out to determine the thermal performance of the micro plastic heat exchangers. The experimental results are compared with that of simulation. The results show the performance of the micro plastic heat exchanger is very close to that of metal heat exchanger with the same dimension.

A New Advanced Topology of Stacked Multicell Inverter

2014 ◽  
Vol 15 (4) ◽  
pp. 327-333 ◽  
Author(s):  
Mohamad R. Banaei ◽  
M. R. Jannati Oskuee ◽  
F. Mohajel Kazemi
Keyword(s):  
Frequency Spectrum ◽  
Output Voltage ◽  
Low Frequency ◽  
Experimental Results ◽  
The Novel ◽  
Stored Energy ◽  
Well Performance ◽  
Flying Capacitors ◽  
Voltage Frequency ◽  
Simulation Results

Abstract In this paper, a new advanced topology of stacked multicell inverter is proposed which is generally suitable for high number of steps associated with a low number of switches. Compared with traditional flying capacitor multicell and stacked multicell (SM) inverters, doubling the number of output voltage levels and the RMS value, ameliorating the output voltage frequency spectrum, decreasing the number and rating of components, stored energy and rating of flying capacitors are available with the proposed inverter. These improvements are achieved by adding only four low-frequency switches to the traditional SM inverter’s structure. The suggested topology is simulated using MATLAB/SIMULINK software, and simulation results are presented to indicate well-performance of the novel converter. In addition, the experimental results of proposed topology prototype have been presented to validate its practicability.

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