Comparison Of Design Parameters Research Articles

Comparative analysis of dielectric substrate materials (FR-4 & RT/Duriod 5880) for antenna array (8*1) designing

In this communication a comparative study of two materials for designing antenna array (8*1) system, simulated by CST Microwave Studio for 5G mobile (base station) applications, is carried out. Array is constructed by FR-4 (low cost substrate material) and Rogers RT/ Duriod 5880 (high efficiency substrate material).Ground and conductor patch are made by PEC (perfect electric conductor).Comparison of design parameters has been done and results of simulated arrays for two materials are determined. A Wilkinson power divider network also has been designed by PEC material for feeding. Simulated array gain 10.31dBi for FR4 (8*1) substrate material and 15.59 dBi for Roger substrate in 5G range (3.4–3.6 GHz) mobile base station applications. Efficiency of Rogers substrate is 98.14% for 8*1 array. An antenna array (4*1) is fabricated over a double sided copper laminated FR-4 epoxy glass material and the result of S 11 is verified by vector network analyzer (VNA).

Learning by Doing: Integrating Shape Grammar as a Visual Coding Tool in Architectural Curricula

Computational design and shape grammars hold a growing appeal in the architectural curricula. This paper aims to assess shape grammars as a visual teaching method that integrates manual exploration based on “learning by doing” in early education curricula without digital software. As a primary outcome of a visual design course at the British university in Egypt, four self-structured pavilions are fabricated by first-year architecture students. Experimentation occurs through a process of visual computing which develops a deeper understanding of material qualities. A comparison of design parameters is conducted through hands-on experiments that include design principles, unit transformations, connection types, assembly process, and functional aspects. The paper examines the skills that students acquired during the course. This study concludes that by applying shape grammars in design studios, students are adequately prepared at the foundational level for their transition towards learning computational design.

Effect of design parameters of dental implant on stress distribution: a finite element analysis

Nowadays, root osseointegrated dental implants are used widely in dentistry mainly for replacement of the single missing tooth. The success rate of osseointegrated dental implants depends on different factors such as bone conditions; surgery insertion technique, loading history, and biomechanical interaction between jawbone and implant surface. In recent years, many studies have investigated design factors using finite element analysis with a concentration on major parameters such as diameter, pitch, and implant outlines in the distribution of stress in the bone-implant interface. There is still a need to understand the relationship and interaction of design factors individually with stress distribution to optimize implant structure. Therefore, the present study introduced a new dental implant and investigated the effect of design parameters on stress distribution. The finite element modeling was developed to facilitate the study with a comparison of design parameters. Boundary and loading conditions were implemented to simulate the natural situation of occlusal forces. Based on results, V-shape threads with maximum apex angle caused a high rate of micro-motion and high possibility of bone fracture. Low Von-Mises stress was associated with low bone growth stimulation. Besides, small fin threads did not integrate with cancellous bone and consequently lower stress accommodation. V-5 fin had no extraordinary performance in cancellous bone. Small surface areas of fins did not integrate with the surrounding bone and high-stress concentration occurred at the tail. These fins are recommended as threads replacement. It was concluded that the implant structure had less influence on stress distribution under horizontal loading.

Ultrasound enhanced electrostatic batch assembly for MEMS

This paper describes ultrasound enhanced electrostatic batch assembly (U2EBA) as a low-cost, batch microassembly method to assemble 3D microsystems. U2EBA involves placing the die in an external DC electric field perpendicular to the substrate and actuating the die with an off-chip, bulk-piezoelectric ceramic. The foremost advantages of this method are the simplicity of the assembly setup, applicability to a broad range of surface micromachining processes, lack of any additional fabrication steps or unusual materials, and fully off-chip nature that requires no electrical or mechanical contact to the assembled microstructures. After an investigation of the forces involved in U2EBA, experiments aiming to quantify the anti-stiction effect of ultrasonic actuation are described. Yield rates reaching up to 100% are reported from 8×8 arrays of hinged mirror/paddle structures with dimensions of 97μm×180μm. Reasons of failure for the unassembled structures and the maximum limit for the electrostatic assembly forces are discussed. Experiments on different hinged microstructures allowed comparison of design parameters and revealed a 22% improvement in the assembly yield due to the addition of dimples over the paddle region of the microstructures.

A New Approach to Solving Reliability Optimization Design of Gear Box

Reliability optimization design of the gear box is proposed. It includes an objective function, 30 design variables and 52 constraints. It is important to note that material properties, geometry parameters and applied loads of the structure are assumed to be normal random variables. Reliability calculation adopts the HL-RF method. The comparison of design parameters demonstrates the proposed method.

Switched Reluctance Drive and inverter-fed Induction Machine - a comparison of design parameters and drive performance

Design parameters and measured drive performance of a commercially manufactured Switched Reluctance Drive and an inverter-fed Induction Machine are compared. Both drives are designed for the same rated torque and speed and for identical cooling conditions, namely totally enclosed, fan-cooled machines. Measurements and calculation show that the main outer dimensions of both motors are nearly equal for comparable thermal utilisation. The Switched Reluctance drive delivers a higher efficiency, but also a considerably higher noise level due to several sharp resonances.

Validation of single scatter model for backscatter density gauges

Gamma-backscatter gauges are used to obtain a nonintrusive measurement of the density of bulk materials from the surface. The backscatter process has been emulated by a single scatter model and a multi-scatter version using Monte-Carlo statistics. Although the single scatter model appears to give a satisfactory explanation of the backscatter process, a full-scale investigation of the validity of this model has not previously been possible. A mathematical model, which accurately represents the detector in its working environment, has been developed. The model makes a comparison possible through the accurate calculations of both maxima and normalised range or bandwidth of the detector characteristics. This allows a comparison of design parameters by different routes and forms the basis of a validation of the single scatter model.

Nitrogen Control: Design Considerations for Supported Growth Systems

In recent years, attention has been focused on developing technically reliable and eco nomically feasible processes for the biological removal of nitrogenous compounds from waste water. Process selection and design for bio logical nitrification and denitrification is diffi cult because many reactor types and configura tions have been investigated and reported feasible. All of the biological processes which have been considered to date for nitrification and/or denitrification can be classified as either suspended growth or supported growth sys tems. Sutton et al.,1 presented a review and com parison of design parameters for suspended growth systems for nitrogen control. Kinetic and operational data were reported for a tem perature range of 5? to 25 ?C under conditions that allowed direct comparison of different sys tems. This paper presents a similar review for supported growth biological reactors?the ro tating biological contactor (rbc) and the sub merged packed column (spc). It is conceivable that there could be basic environmental differences between organisms in suspended growth reactors and those which form a growth matrix on solid surfaces. Kinetic studies of suspended growth systems generally have assumed that all active organisms have equal contact opportunities with nutrients. With supported growth reactors, nutrient con centration gradients through the matrix could affect contact opportunities. Logically, diffu sion might be expected to play an important role in determining substrate removal rates.