Development of mathematical model to predict vertical wicking behaviour. Part I : flow through yarn

Theoretical models have been proposed in this article (Parts I and II) to predict the vertical wicking behaviour of yarns and fabrics based on different fibre, yarn and fabric parameters. The first part of this article deals with the modelling of flow through yarn during vertical wicking, whereas the second part deals with the modelling of vertical wicking through the fabric. The yarn model has been developed based on the Laplace equation and the Hagen– Poiseuille’s equation on fluid flow; pore geometry has been determined as per the yarn structure. Factors such as fibre contact angle, number of filaments in a yarn, fibre denier, fibre cross-sectional shape, yarn denier and twist level in the yarn have been taken into account for development of the model. Lambertw, a mathematical function, has been incorporated, which helps to predict vertical wicking height at any given time, considering the gravitational effects. Experimental verification of the model has been carried out using polyester yarns. The model was found to predict the wicking height with time through the yarns with reasonable accuracy. Based on the proposed yarn model, a mathematical model has been developed to predict the vertical wicking through plain woven fabric in the second part of this article

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Kinetics and mechanism of oxidation of aliphatic aldehydes by N-bromobenzamide

112-115The oxidation of six aliphatic aldehydes by N-bromobenzamide (NBB) in 1:1 (v/v) acetic acid-water leads to the formation of the corresponding carboxylic acids. The reaction is first order with respect to both NBB and aldehyde and is catalysed by hydrogen ions. The observed hydrogen ion dependence indicates that both NBB and its protonated form are reactive oxidizing species. The oxidation of MeCDO exhibits a substantial kinetic isotope effect. With an increase in the proportion of acetic acid in the solvent mixture of acetic acid and water, the rate decreases. Addition of benzamide has no effect on the rate. The reaction fails to induce the polymerization of acrylonitrile. The role of aldehyde hydrate in the oxidation process is discussed. The rates correlate well with Taft's o* substituent constants, with negative reaction constant. A mechanism involving transfer of a hydride ion to the oxidant in the rate determining step has been proposed

Mathematical model to predict vertical wicking behaviour” : Part II - Flow through woven fabric

The aim of the paper is to develop a mathematical model to predict vertical wicking behaviour of woven fabric. The first part of this series (Part I) has dealt with the mathematical model for predicting vertical wicking through yarn. In this part a model has been proposed to predict vertical wicking of the woven fabric, based on the developed yarn model. In order to model the flow through woven fabric along with the vertical flow through liquid carrying threads, the horizontal flow through transverse threads has also been taken into account. A simplified fabric geometrical concept (inclined tube geometry) and Peirce geometry for plain woven fabric have been used to define the fabric structure. Warp and weft linear density, fabric sett and yarn crimp have been considered in the fabric modelling. The theoretical wicking values of the yarn and fabric made from that yarn have been compared. Experimental verification of the model has been carried out using polyester and polypropylene fabrics. The model is found to predict the wicking height with time through the yarns and fabrics with reasonable accurac

Studies on moisture transmission properties of PV-blended fabrics

Moisture transmission properties are most important for fabric comfort.We have studied the moisture transmission properties of the plain-woven fabric produced with polyester–viscose-(PV) blended yarns. PV-blended yarns of varying blend proportion, yarn count and twist levels have been used for fabric manufacture. A three-variable Box and Behnken factorial design technique has been used to study the interaction effects of the above variables on the aforesaid characteristics of fabrics. The interactive effect of these three variables on the air permeability, water vapour permeability, in-plane wicking and vertical wicking of PV-blended fabrics has been studied and the response surface equations for all the properties have been derived; also, the design variables have been optimized for all the moisture transmission-related properties. Most of the moisture transmission characteristics were found to be affected significantly by blend proportion, count and twist levels at 95% level of significance with the present variables

Modeling and simulation of moisture transmission through fibrous structures – Part I: Water vapuor transmission

The moisture transmission behaviour of clothing plays an important role in determining its thermo-physiological comfort. The determination of the factors involved in moisture transmission of clothing and its prediction have become a main concern for researchers for many years. An attempt has been made to review the research studies on modelling and simulation of moisture transmission through fibrous assemblies. The review work has been divided in two parts. The first part deals with moisture vapour transmission and the second with liquid water transmission through fibrous materials. The various processes involved in water vapour transmission through fibrous materials are diffusion, absorption – desorption, convection, evaporation and condensation. The models on water vapour transmission through fibrous materials are based on the mass balance equation. Some of the studies involving theoretical work on vapour transmission have been conducted on individual processes. Others consider the inter-related effects involved. Moisture vapour transmission through textile materials is coupled with heat transfer phenomena, due to its hygroscopic nature. The atmospheric conditions, the structure of the fibrous materials and the hygroscopic nature of the fibres significantly influence the processes. Amongst the available models on vapour transmission, the model developed by Li and Zhu predicts simultaneous sheat and moisture transfer considering moisture sorption, condensation and capillary liquid diffusion in porous textiles and this model is best suited for determining textile clothing comfort.(undefined

[Accepted, unedited version] Network analysis for identifying potential anti-virulence targets from whole transcriptome of Pseudomonas aeruginosa and Staphylococcus aureus exposed to certain anti-pathogenic polyherbal formulations

Introduction: Antimicrobial Resistance (AMR) is a serious global threat. Identification of novel antibacterial targets is urgently warranted to help the antimicrobial drug discovery programmes. This study attempted identification of potential targets in two important pathogens Pseudomonas aeruginosa and Staphylococcus aureus. Methods: Transcriptome of Pseudomonas aeruginosa and Staphylococcus aureus exposed to two different quorum-modulatory polyherbal formulations were subjected to network analysis to identify the most highly networked differentially expressed genes (hubs) as potential anti-virulence targets. Results: Genes associated with denitrification and sulfur metabolism emerged as the most important targets in P. aeruginosa. Increased build-up of nitrite (NO2) in P. aeruginosa culture exposed to the polyherbal formulation Panchvalkal was confirmed through in vitro assay too. Generation of nitrosative stress and inducing sulfur starvation seemed to be effective anti-pathogenic strategies against this notorious gram-negative pathogen. Important targets identified in S. aureus were the transcriptional regulator sarA, immunoglobulin-binding protein Sbi, serine protease SplA, the saeR/S response regulator system, and gamma-haemolysin components hlgB and hlgC. Conclusion: Further validation of the potential targets identified in this study is warranted through appropriate in vitro and in vivo assays in model hosts. Such validated targets can prove vital to many antibacterial drug discovery programmes globally