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Article
Publication date: 2 April 2019

Nda Muhammad, Mohd Shalahuddin Adnan, Mohd Azlan Mohd Yosuff and Kabiru Abdullahi Ahmad

Sediment measurement is usually accessible on a periodic or distinct basis. The measurement of sediment (suspended and bedload), especially in the field, is vital in…

Abstract

Purpose

Sediment measurement is usually accessible on a periodic or distinct basis. The measurement of sediment (suspended and bedload), especially in the field, is vital in keeping essential data of sediment transport and deposition. Various techniques for measuring sediment have been used over time each with its merits and demerits. The techniques discussed in this paper for suspended sediment include bottle, acoustic, pump, laser diffraction, nuclear and optical. Other techniques for bedload measurement are; River bedload trap (RBT), CSU/FU bedload trap, Helley–Smith, Polish Hydrological Services (PIHM) device, pit and trough, vortex tube, radioactive traces and bedload–surrogate technologies. However, the choice of technique depends on multiple factors ranging from budget constraint, availability of equipment, manpower and data requirement. The purpose of this paper is to present valuable information on selected techniques used in sediment measurement, to aid researchers/practitioners in the choice of sediment measurement technique.

Design/methodology/approach

This paper presents a general review of selected field techniques used in sediment measurement (suspended and bedload). Each techniques mode of operation, merits and demerits are discussed.

Findings

This paper highlights that each technique has its peculiar merits and demerits. However, two techniques are generally preferred over others; the bottle sampling and the Helley–Smith sampler for measuring suspended and bedload sediment. This is because the applicability of these techniques is quite widespread and time-tested.

Originality/value

This review paper provides an in-depth description and comparison of selected existing field sediment measurement techniques. The objective is to ease decision-making about the choice of technique, as well as to identify the suitability and applicability of the chosen technique.

Details

World Journal of Engineering, vol. 16 no. 1
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 5 June 2017

Burcu Sancar Besen and Onur Balci

The purpose of this paper is to investigate the effects of silicone-based softeners, which were developed with different particle sizes (nano, micro, and macro) and…

Abstract

Purpose

The purpose of this paper is to investigate the effects of silicone-based softeners, which were developed with different particle sizes (nano, micro, and macro) and chemical structures, on the performance of 100 percent cotton fabrics knitted with different type of yarn (ring, open-end, and compact).

Design/methodology/approach

In the study, the silicone emulsions having expected particle sizes were produced at laboratory conditions. The produced silicone emulsions were applied to knitted fabrics with both padding and exhaust methods at different concentrations. Some characterization tests (particle size and zeta potential) were applied to the silicone emulsions before the applications. After the applications, CIELab values, whiteness and color fastness, hyrophility, abrasion, pilling, bursting strength, and stiffness performances of the samples were tested. The changes of the investigated properties were also examined via ANOVA.

Findings

According to the results, it was found that the silicone applications caused the CIELab values, whiteness degree, hyrophility, pilling, bursting strength and stiffness performance of the fabrics to change depending on the particle sizes of the emulsions, the yarn type of the fabrics, the application type, and the concentration of the silicone emulsions. When the ANOVA results were examined, it was seen that the types of the yarn and the silicone emulsions were the most effective working parameters on the results.

Research limitations/implications

Because no additives were added to the produced silicone emulsions, in the future research, they can be developed with the use of some additives. Thus, it can resolve some of the disadvantages of the silicone emulsions on the textiles.

Practical implications

While applying the silicone softeners to the knitted fabrics, the type of the yarn and the particle sizes of the emulsions must be determined according to each other, in order to obtain enough handle performance without causing negative change on the other important properties of the knitted fabrics.

Originality/value

When the studies regarding silicone softeners were investigated, it was found that there were no studies about the effect of the silicone softeners having different particle sizes on the physical and chemical structures of the knitted fabrics depending on the type of yarn and some working parameters such as concentration and type of the application.

Details

International Journal of Clothing Science and Technology, vol. 29 no. 3
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 1 August 2002

P.T. Vianco and J.A. Rejent

A methodology was developed to establish baseline metrics for assessing the isothermal aging of 63Sn‐37Pb (or 60Sn‐40Pb) solder joints in circuit board assemblies. Those…

Abstract

A methodology was developed to establish baseline metrics for assessing the isothermal aging of 63Sn‐37Pb (or 60Sn‐40Pb) solder joints in circuit board assemblies. Those metrics were the intermetallic compound layer thickness at the Sn‐Pb solder/Cu interface and the Pb‐rich phase particle size distribution in the solder. The baseline, or as‐fabricated, values for these metrics were 0.71±0.27 μm and 3.2±6.5×10−6 mm2, respectively. The rate kinetics were determined for growth of the intermetallic compound layer and coarsening of the Pb‐rich phase particles by isothermal aging experiments. The/were: (1) intermetallic compound layer thickness (μm)=0.714+ 3.265×103t0.58 exp(−52200/RT); and (2) Pb‐rich phase particle size (mm2)=3.2×10−6+1.47× 10−3t0.32 exp(−31000/RT).

Details

Soldering & Surface Mount Technology, vol. 14 no. 2
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 21 August 2009

John F. Peters, Raju Kala and Robert S. Maier

A critical step toward an efficient contact detection algorithm is to localize the contact search to the immediate neighborhood of each particle. In particular, cell‐based…

Abstract

Purpose

A critical step toward an efficient contact detection algorithm is to localize the contact search to the immediate neighborhood of each particle. In particular, cell‐based algorithms are simple and require O(N) computations but become inefficient when the particles are not roughly the same diameter. The purpose of this paper is to describe a hierarchical search method with the simplicity and efficiency of the neighbor search algorithm but which is insensitive to size gradation.

Design/methodology/approach

In this method, particles are allocated to cells based on their location and size within a nested hierarchical cell space. Contact searches are limited to neighboring particles of equal size within their own hierarchy and occasionally with particles of larger size when no contacts are found within their own hierarchy.

Findings

The method is shown to be effective for the most severe case of highly segregated particle distributions in which a large particle is surrounded by particles of much smaller size.

Originality/value

This paper is of value in concentrating on particular issues in implementing the hierarchical contact detection algorithm in a parallel computing environment using message‐passing interface.

Details

Engineering Computations, vol. 26 no. 6
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 26 April 2011

A.B. Spierings, N. Herres and G. Levy

A recent study confirmed that the particle size distribution of a metallic powder material has a major influence on the density of a part produced by selective laser…

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4601

Abstract

Purpose

A recent study confirmed that the particle size distribution of a metallic powder material has a major influence on the density of a part produced by selective laser melting (SLM). Although it is possible to get high density values with different powder types, the processing parameters have to be adjusted accordingly, affecting the process productivity. However, the particle size distribution does not only affect the density but also the surface quality and the mechanical properties of the parts. The purpose of this paper is to investigate the effect of three different powder granulations on the resulting part density, surface quality and mechanical properties of the materials produced.

Design/methodology/approach

The scan surface quality and mechanical properties of three different particle size distributions and two layer thicknesses of 30 and 45 μm were compared. The scan velocities for the different powder types have been adjusted in order to guarantee a part density≥99.5 per cent.

Findings

By using an optimised powder material, a low surface roughness can be obtained. A subsequent blasting process can further improve the surface roughness for all powder materials used in this study, although this does not change the ranking of the powders with respect to the resulting surface quality. Furthermore, optimised powder granulations lead generally to improved mechanical properties.

Practical implications

The results of this study indicate that the particle size distribution influences the quality of AM metallic parts, produced by SLM. Therefore, it is recommended that any standardisation initiative like ASTM F42 should develop guidelines for powder materials for AM processes. Furthermore, during production, the granulation changes due to spatters. Appropriate quality systems have to be developed.

Originality/value

The paper clearly shows that the particle size distribution plays an important role regarding density, surface quality and resulting mechanical properties.

Details

Rapid Prototyping Journal, vol. 17 no. 3
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 10 August 2018

Richard D. Sudduth

The importance of maximizing the particle packing fraction in a suspension by maximizing average particle size ratio of D5/D1 has been adequately shown to be important as…

Abstract

Purpose

The importance of maximizing the particle packing fraction in a suspension by maximizing average particle size ratio of D5/D1 has been adequately shown to be important as previously reported in the literature. This study aims to extend that analysis to include the best formulation approach to maximize the packing fraction with a minimum number of monodisperse particle sizes.

Design/methodology/approach

An existing model previously developed by this author was modified theoretically to optimize the ratio used between consecutive monodisperse particle sizes. This process was found to apply to a broad range of particle configurations and applications. In addition, five different approaches for maximizing average particle size ratio D̅5/D̅1 were addressed for blending several different particle size distributions. Maximizing average particle size ratio D̅5/D̅1 has been found to result in an optimization of the packing fraction. Several new concepts were also introduced in the process of maximizing the packing fraction for these different approaches.

Findings

The critical part of the analysis to maximize the packing fraction with a minimum number of particles was the theoretical optimization of the ratio used between consecutive monodisperse particle sizes. This analysis was also found to be effectively independent of the maximum starting particle size. This study also clarified the recent incorrect claim in the literature that Furnas in 1931 was the first to generate the maximum theoretical packing fraction possible for n different particles that was actually originally developed in conjunction with the Sudduth generalized viscosity equation. In addition, the Furnas generated equation was also shown to give significantly different results from the Sudduth generated equation.

Research limitations/implications

Experimental data involving monodisperse particles of different blends with a minimum number of particle sizes that are truly monodisperse are often extremely difficult to obtain. However, the theoretical general concepts can still be applicable.

Practical implications

The expanded model presented in this article provides practical guidelines for blending pigments using a minimum number of monodisperse particle sizes that can yield much higher ratios of the particle size averages D̅5/D̅1 and thus potentially achieve significantly improved properties such as viscosity.

Originality/value

The model presented in this article provides the first apparent guidelines to control the blending of pigments in coatings by the optimization of the ratio used between consecutive monodisperse particle sizes. This analysis was also found to be effectively independent of the maximum starting particle size.

Details

Pigment & Resin Technology, vol. 48 no. 1
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 21 August 2009

Paul W. Cleary

The purpose of this paper is to show how particle scale simulation of industrial particle flows using DEM (discrete element method) offers the opportunity for better…

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2586

Abstract

Purpose

The purpose of this paper is to show how particle scale simulation of industrial particle flows using DEM (discrete element method) offers the opportunity for better understanding of the flow dynamics leading to improvements in equipment design and operation.

Design/methodology/approach

The paper explores the breadth of industrial applications that are now possible with a series of case studies.

Findings

The paper finds that the inclusion of cohesion, coupling to other physics such fluids, and its use in bubbly and reacting flows are becoming increasingly viable. Challenges remain in developing models that balance the depth of the physics with the computational expense that is affordable and in the development of measurement and characterization processes to provide this expanding array of input data required. Steadily increasing computer power has seen model sizes grow from thousands of particles to many millions over the last decade, which steadily increases the range of applications that can be modelled and the complexity of the physics that can be well represented.

Originality/value

The paper shows how better understanding of the flow dynamics leading to improvements in equipment design and operation can potentially lead to large increases in equipment and process efficiency, throughput and/or product quality. Industrial applications can be characterised as large, involving complex particulate behaviour in typically complex geometries. The critical importance of particle shape on the behaviour of granular systems is demonstrated. Shape needs to be adequately represented in order to obtain quantitative predictive accuracy for these systems.

Details

Engineering Computations, vol. 26 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

Content available
Article
Publication date: 1 October 2000

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648

Abstract

Details

Pigment & Resin Technology, vol. 29 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 February 2001

Sven Berg

The wear of a machine element, whether it is due to fatigue or abrasive wear, will add contaminants in the form of particulates to the system. If a machine element is…

Abstract

The wear of a machine element, whether it is due to fatigue or abrasive wear, will add contaminants in the form of particulates to the system. If a machine element is starting to wear out it will produce a large amount of particles and it will finally break down. Since this can be very costly, one can establish the need to monitor the system so that one can foresee failure. There are many different ways to monitor a system, e.g. measurements of the temperature, pressure, vibrations and the degree of contamination. The purpose of contamination control is to extend the life of a component and thereby save money. When monitoring a system it is very important that the monitoring control instrument should give the right output. One important factor in achieving this is the withdrawal of a representative oil sample. In this paper an investigation of where and how to take a representative sample is performed using Stokes’ law and the migration of spheres in a channel. A generalised sedimentation chart for different oils and particles is introduced. Sampling routines for proper sample withdrawal are also presented.

Details

Industrial Lubrication and Tribology, vol. 53 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 21 March 2016

Chao Wang, Heyang Yu, Ni Zhan, Xubing Kang and Jingyu Zhang

The purpose of this paper is to develop a new vibration probe sensor for measurement of particle mass flow rate in gas–solid two phase flow.

Abstract

Purpose

The purpose of this paper is to develop a new vibration probe sensor for measurement of particle mass flow rate in gas–solid two phase flow.

Design/methodology/approach

A new vibration probe sensor based on polyvinylidene fluoride (PVDF) piezoelectric film is designed. The particle impact model according to Hertz contacting theory is presented. The average amplitude, standard deviation and spectral peak at the natural frequency of the probe (21.2 kHz) of the signals acquired through experiments are chosen as characteristic quantities for further analysis.

Findings

Through experimental study of relation between three characteristic quantities and the mass flow rate and air flow velocity, a good regularity is found in the average amplitude and the spectral peaks at natural frequency of the probe. According to the particle impact model, the structure of quantitative model is built and parameters of two models are calculated from experimental data. Additionally, tests are made to estimate mass flow rate. The average errors are 5.85 and 4.26 per cent, while the maximum errors are 10.81 and 8.65 per cent. The spectral peak at natural frequency of the probe is more applicable for mass flow rate measurement.

Practical implications

The sensor designed and the quantitative models established may be used in dilute phase pneumatic conveying lines of coal-fired power plants, cement manufacturing facilities and so on.

Originality/value

First, the new sensor is designed and the quantitative models are established. Second, the spectral peak at natural frequency of the probe is found that can be used for measurement of mass flow rate.

Details

Sensor Review, vol. 36 no. 2
Type: Research Article
ISSN: 0260-2288

Keywords

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