Visualisation and Metering of Two Phase Counter-gravity Slurry Flow using ERT

Two-phase slurry flow is encountered in many industries such as petroleum, mining and related industries. The abrasiveness of slurry and interaction of solid particles with the carrier liquid make slurry flow measurement one of the most challenging applications in multi-phase flow metering. This paper presents a new method of solid-liquid flow metering, in which the Electrical Resistance Tomography (ERT) is used in combination with a commercial Electromagnetic Flow Meter (EMF) to measure the volumetric flow rate of each phase. A set of experiments were carried out using a mixture of sand particles and tap water as slurry. Two different sand types (coarse and medium), with a particle size range of 53-2330 μm, were pumped through a 50 mm inner-diameter pipeline. The range of throughput solids concentration used in the experiments was 5%-10% and operated the transport velocity was 2-5 m/s. The effect of solids concentration and solids velocity on the measurement scheme is discussed. The measurement results are compared to that of Coriolis mass flow meter and discharge flow measurement system (flow diversion system). The accuracy of the measurement results is assessed and the performance of the applicability of the proposed method is highlighted

Triangle of Safety Technique: A New Approach to Laparoscopic Cholecystectomy

Backgrounds and Study Aims. Common bile duct (CBD) injury is one of the most serious complications of laparoscopic cholecystectomy (LC). Misidentification of the CBD during dissection of the Calot's triangle can lead to such injuries. The aim of the authors in this study is to present a new safe triangle of dissection. Patients and Method. 501 patients under went LC in the following approach; The cystic artery is identified and mobilized from the gall bladder (GB) medial wall down towards the cystic duct which would simultaneously divide the medial GB peritoneal attachment. This is then followed by dividing the lateral peritoneal attachment. The GB will be unfolded and the borders of the triangle of safety (TST) are achieved: cystic artery medially, cystic duct laterally and the gallbladder wall superiorly. The floor of the triangle is then divided to delineate both cystic duct and artery in an area relatively far from CBD. Results. There were little significant immediate or delayed complications. The mean operating time was 68 minutes, nearly equivalent to the conventional method. Conclusions. Dissection at TST appears to be a safe procedure which clearly demonstrates the cystic duct and may help to reduce the CBD injuries

The social work profession in Palestine: challenges and strategies for future development

The research looks at the development of social work in Palestine amidst the crisis and political conflict ensuing from the colonial occupation of the Palestinian Occupied Territories and the continuing pressures this and neoliberal policies of donors has placed on social work education and practice. In providing a historical overview of Palestinian society and of indigenous forms of social work throughout its history, it explores the developments of more formal practices and how these have shaped social work education. Using individual interviews and focus groups, a qualitative methodology is used to explore the meanings participants make of their experiences within education and their understanding and interpretations of the policies and practices that have affected their experiences as educators, graduates and representatives of the social work profession. The findings suggest a need for an indigenous Palestinian social work model developed through an understanding of the crucial role that social work has served in addressing issues that arise from the political conflict. It recommends the development of a national framework for the profession that would provide a shared vision, purpose, standards, and values by which education and practices should be guided

Perovskite-Based Nanomaterials and Nanocomposites for Photocatalytic Decontamination of Water

The exploration of functional nanomaterials with superior catalytic activity for practical photocatalytic water decontamination is of significant importance. Perovskite-based nanomaterials, which demonstrate excellent photophysical and catalytic properties, are widely investigated as a class of adaptable materials for the photocatalytic degradation of environmental pollutants. This chapter introduces the recent progresses in using perovskite-based nanocomposites with particular emphasis on the applications for effective photocatalytic degradation of organic pollutants in wastewater. It starts by presenting the general principles and mechanisms governing photocatalytic degradation of organic pollutants in water by perovskite, along with the design criteria for perovskite-based nanocomposites. It then explains various strategies used to prepare perovskite-based nanocomposites with the aim of enhancing their photocatalytic activity. By the end of the chapter, the remaining challenges and perspectives for developing efficient perovskite-based photocatalysts with potential large-scale application are highlighted

Automated Horizontal Slurry Flow Regime Recognition Using Statistical Analysis of the ERT Signal

Flow regime recognition is not only useful for characterisation of the flow, but also for the purpose of modeling, system controls and optimization and correction of flow regime dependent flow meters. This paper proposes a new indirect method for on-line recognition of the active horizontal slurry flow regime using statistical signal analysis of measurements obtained with a high performance Electrical Resistance Tomography system (ERT). Significant features of the ERT signal are extracted from both time domain and frequency domain. A set of experiments were carried out using a pilot-scale slurry flow loop, through which a mixture of sand and tap water was pumped into a 50 mm inner-diameter test section. All common slurry flow regimes are considered in the recognition scheme, including the transitional regime boundaries covering the transport velocity range of 1.5-5 m/s. Two types of sand are used in the experiments, medium (75-900 μm) and coarse (150-2200 μm), each with different throughput volumetric concentration, 2% and 10%. 1.2 m transparent pipe section was included into the test section, so as to visually inspect the prevailing flow regime and capture photographic images of the flow. A code was developed not only to render the recognition of the active flow regime, but also to visualise the distribution of the solid particles across the pipe crosssection and display the mean solids volume fraction. The evaluation of the proposed recognition method suggests 90.32% successful rate

Electrical resistance tomography-based multi-modality sensor and drift flux model for measurement of oil–gas–water flow

From IOP Publishing via Jisc Publications RouterHistory: received 2022-01-08, revised 2022-05-14, oa-requested 2022-05-16, accepted 2022-05-30, epub 2022-06-14, open-access 2022-06-14, ppub 2022-09-01Publication status: PublishedFunder: University of Chester; doi: http://dx.doi.org/10.13039/100010333Abstract: This paper proposes a novel method to measure each constituent of an oil–gas–water mixture in a water continuous flow, typically encountered in many processes. It deploys a dual-plane electrical resistance tomography sensor for measuring dispersed phase volume fraction and velocity; a gradiomanometer flow density meter and a drift flux model to estimate slip velocities; with absolute pressure and temperature measurements. These data are fused to estimate constituent volume flow rates. Other commonly used operational parameters can be further derived: water cut or water liquid ratio (WLR) and gas volume fraction (GVF). Trials are described for flow rates of water 5–10 m3 h−1; oil 2–10 m3 h−1 and gas 1–15 m3 h−1. The comparative results are included with published data from the Schlumberger Gould Research flow facility. The paper proposes the use of the described configuration for measurement of volume flow rates in oil–gas–water flows with an absolute error of ±10% within GVF 9%–85% and WLR > 45%

Measurement of Interphase Forces based on Dual-modality ERT/DP Sensor in Horizontal Two-phase Flow Gas-water

In order to better understand the mechanisms of two-phase flow and the prevailing flow regimes in horizontal pipelines, the evaluation of interphase forces is paramount. This study develops a method to quantitatively estimate the interphase force in two-phase gas-water flow in horizontal pipeline. The electrical resistance tomography technology is used to measure the void fraction, while the differential pressure perpendicular to the horizontal pipe is measured in different flow patterns via a Differential Pressure sensor. The inner pipe diameter is 50 mm, the water flow range from 3.26 m3/h to 7.36 m3/h, the gas flowrate range from 1 to 60 l/min, which covered a range of flow patterns, the absolute pressure range from0.07 MPa to 0.12 MPa. The relationship between the differential pressure drop and interphase force is established, and the effects of these forces on the flow are analyzed. Experimental results indicate that the dual-modality measurement system was successfully provided a quantitative evaluation of inter-phase forces in two-phase horizontal gas-water flow

Mesoscale regulation of droplet templates to tailor microparticle structures and functions

The hierarchical design of mesoscale structures in droplet templates determines the structure and functionality of the resultant microparticles. In this review, we summarize recent progress on the control of microfluidic emulsion templates for the synthesis of polymeric microparticles with desired functionality and internal structure. We introduce strategies for controlling the morphology and interfacial stability of emulsion templates. These strategies are based on manipulation of the mesoscale structure of amphiphilic molecules and nanoparticles at emulsion-droplet interfaces. We also discuss strategies for controlling the mesoscale structure of microparticles, which involve manipulating the interfacial mass-transfer and chemical reactions during template synthesis. We provide insight on the use of these strategies for the rational design and fabrication of polymeric microparticles with predictable internal structures and functionality at the single-particle level

Smart hydrogels with wide visible color tunability

Pigmentary coloration can produce viewing angle-independent uniform colors via light absorption by chromophores. However, due to the limited diversity in the changes of the molecular configuration of chromophores to undergo color change, the existing materials cannot produce a wide range of visible colors with tunable color saturation and transmittance. Herein, we propose a novel strategy to create materials with a wide visible color range and highly tunable color saturation and transmittance. We fabricated a hydrogel with poly (acrylamide-co-dopamine acrylamide) networks swollen with Fe3+-containing glycerol/water in which the covalently crosslinked polyacrylamide backbone with pendant catechols can ensure that the hydrogel maintains a very stable shape. Hydrogels containing adjustable catechol-Fe3+ coordination bonds with flexible light-interacting configuration changes can display a wide range of visible colors based on the complementary color principle. The catechol-Fe3+ complexes can dynamically switch between noncoordinated and mono-, bis- and tris-coordinated states to harvest light energy from a specific wavelength across the whole visible spectrum. Therefore, these hydrogels can be yellow, green, blue, and red, covering the three primary colors. Moreover, color saturation and transmittance can be flexibly manipulated by simply adjusting the Fe3+ content in the hydrogel networks. The versatility of these smart hydrogels has been demonstrated through diverse applications, including optical filters for color regulation and colorimetric sensors for detecting UV light and chemical vapors. This proposed smart hydrogel provides a universal color-switchable platform for the development of multifunctional optical systems such as optical filters, sensors, and detectors

Smart Hydrogel Grating Immunosensors for Highly Selective and Sensitive Detection of Human-IgG

This document is the Accepted Manuscript version of a Published Work that appeared in final form in [Industrial & Engineering Chemistry Research], copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see [https://pubs.acs.org/doi/10.1021/acs.iecr.0c00780].A smart diffraction grating immunosensor based on antigen-responsive hydrogel with enhanced analyte-induced volume changes is developed for highly selective and sensitive detection of human immunoglobulin G (H-IgG). The hydrogel grating contains poly(N-isopropylacrylamide) (PNIPAM) backbones with dual-cross-linking based on the dynamic complexation between pendent goat-anti-human IgG (GAH-IgG) and pendent H-IgG, and the covalent bonding by 4-arm-polyethylene glycol-acrylamide. Upon recognizing free H-IgG in the environment, the pendent GAH-IgG in the hydrogel can form new GAH-IgG/H-IgG complexes with free H-IgG because the binding constant of GAH-IgG to the free H-IgG is much larger than that of GAH-IgG to the pendent H-IgG and thus result in the decomplexation of GAH-IgG/H-IgG complexes with the pendent H-IgG as well as the swelling of hydrogel. The thermo-responsive PNIPAM backbones enable enhancement of H-IgG-responsive volume change of the proposed hydrogel grating via temperature regulation. Moreover, the cross-linker 4-arm-polyethylene glycol-acrylamide provides excellent transparency for the PNIPAM backbones during the volume change, which ensures output of diffracted optical signals with high intensity. With the elaborately designed molecular structures, the hydrogel grating allows highly selective and sensitive detection of [H-IgG] with a detection limit as low as 1.3 × 10–8 M. This work provides a simple and flexible strategy for developing diffraction grating immunosensors based on stimuli-responsive hydrogels for efficient detection of biomarkers