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1 – 10 of 137Diana Stoyanova Germanova‐Krasteva, Galya Dimitrova Kandzhikova and Atanas Grigorov Bochev
The purpose of this paper is to investigate the influence of some structural characteristics of terry fabrics on the rate of sorption.
Abstract
Purpose
The purpose of this paper is to investigate the influence of some structural characteristics of terry fabrics on the rate of sorption.
Design/methodology/approach
Fabrics are produced by changing the weft density and the pile height. An experimental stand for dynamic measurement of water sorption is created. The quantities of water absorbed by the fabric over time are determined. The sorption rates are calculated and discussed.
Findings
The dynamics of the sorption process are assessed through the sorption curves presented. The sorption rates for the main sorption stages, as well the average rate for weft and warp direction, are calculated. Results are statistically worked out applying ANOVA. Appropriate conclusions about the influence of the investigated parameters on sorption process are made.
Originality/value
The originality/value of this paper is: determination of the rates of water sorption for the particular time intervals and the average rates for the entire test period; and assessment of the infuence of the loop height and weft density on the sorption rates.
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Ionut Nicolae, Dana Miu and Cristian Viespe
The detection of H2 concentrations in concentrations undetectable by the conventional detection method of surface acoustic wave (SAW) sensors based on frequency shift, by…
Abstract
Purpose
The detection of H2 concentrations in concentrations undetectable by the conventional detection method of surface acoustic wave (SAW) sensors based on frequency shift, by correlating analyte presence with Fourier spectra components.
Design/methodology/approach
Fast Fourier Transform (FFT) and autocorrelation analysis of phase noise in a SnO2-coated SAW sensor was performed. Fourier spectra were obtained by FFT from the SAW sensor resonance frequency instability, in the absence of analyte, and for H2 concentrations between 0.08 and 0.4 per cent.
Findings
All analyte concentrations are below the sensor limit of detection, which is 0.8 per cent for H2. Although these analyte concentrations caused no significant change in the resonance frequency of the SAW resonator, the FFT spectra presented several modifications, namely, the appearance of a new peak and the decrease of randomness. The authors consider that the effect is because of the chaotic behavior of the temporal dependence of the SAW resonance frequency. This explanation is substantiated by the decrease observed in the SAW oscillator autocorrelation function, which is an indication for a chaotic behavior.
Practical implications
As chaotic systems are extremely sensitive to perturbation, measurement methods based on chaos diagnosis could potentially greatly improve the SAW detection.
Originality/value
Fourier spectra components were correlated with analyte presence in concentrations undetectable by the conventional SAW detection method based on frequency shift.
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Salvinija Petrulyte, Asta Velickiene and Donatas Petrulis
– The purpose of this paper is to investigate the resistance to pile loop extraction of terry fabrics regarding the pile height and impact/finishing.
Abstract
Purpose
The purpose of this paper is to investigate the resistance to pile loop extraction of terry fabrics regarding the pile height and impact/finishing.
Design/methodology/approach
Fabrics are manufactured by changing the pile height and applying impact/finishing procedures. The resistance to pile loop extraction are determined. The factorial designs are made. For informative experiment the linear type of regression are analysed. Yarn pull-out behaviour in terry fabrics is discussed.
Findings
The dynamics of yarn pull-out process in terry fabrics is estimated through the force-pulling distance curves presented. The resistance to pile loop extraction is determined. All statistical analysis is performed. Appropriate conclusions about the influence of fabrics structure and impact/finishing on yarn pull-out process are made.
Originality/value
The study developed analysis and empiric mathematical equations suitable for evaluating and designing fabrics with the resistance to pile loop extraction ability required. Assessment of the influence of fabric's pile height and impact/finishing on the yarn pull-out is proposed.
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Chiara Bertolin and Filippo Berto
This article introduces the Special Issue on Sustainable Management of Heritage Buildings in long-term perspective.
Abstract
Purpose
This article introduces the Special Issue on Sustainable Management of Heritage Buildings in long-term perspective.
Design/methodology/approach
It starts by reviewing the gaps in knowledge and practice which led to the creation and implementation of the research project SyMBoL—Sustainable Management of Heritage Buildings in long-term perspective funded by the Norwegian Research Council over the 2018–2022 period. The SyMBoL project is the motivation at the base of this special issue.
Findings
The editorial paper briefly presents the main outcomes of SyMBoL. It then reviews the contributions to the Special Issue, focussing on the connection or differentiation with SyMBoL and on multidisciplinary findings that address some of the initial referred gaps.
Originality/value
The article shortly summarizes topics related to sustainable preservation of heritage buildings in time of reduced resources, energy crisis and impacts of natural hazards and global warming. Finally, it highlights future research directions targeted to overcome, or partially mitigate, the above-mentioned challenges, for example, taking advantage of no sestructive techniques interoperability, heritage building information modelling and digital twin models, and machine learning and risk assessment algorithms.
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G. Mishra, S.R. Mohapatra, P.R. Behera, B. Dash, U.K. Mohanty and B.C. Ray
The main objective of this experimental investigation is to assess the effect of thermal and cryogenic treatment on hygrothermally conditioned glass fibre reinforced epoxy matrix…
Abstract
Purpose
The main objective of this experimental investigation is to assess the effect of thermal and cryogenic treatment on hygrothermally conditioned glass fibre reinforced epoxy matrix composites, and the impact on its mechanical properties with change in percentage of individual constituents of the laminates.
Design/methodology/approach
The present investigation is an attempt at evaluating the performance of the laminates subjected to different thermal and cryogenic treatments for varying time with prior hygrothermal treatment. The variability of hygrothermal exposure is in the range of 4‐64 h. Glass fibre reinforced plastics laminates with different weight fractions 0.50‐0.60 of fibre reenforcements were used. The ILSS, which is a matrix dominated was studied by three‐point bend test using INSTRON 1195 material testing machine.
Findings
The post‐hygrothermal treatments (both thermal and cryogenic exposures) resulted in an increase in the rate of desorption of moisture. It is noted that the hygrothermal treatment prior to the exposure to thermal or cryogenic conditioning is the major attribute to the variations in the ILSS values. The extent of demoisturisation of the hygrothermally conditioned composites due to a thermal or a cryogenic exposure is observed to be inversely related to its ILSS, independent of the fibre‐weight fractions. Also the ILSS is inversely related to the fibre‐weight fraction irrespective of the post‐hydrothermal treatment.
Originality/value
The reported data are based on experimental investigations.
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Juan Carlos Lucas Aguirre, German Antonio Giraldo Giraldo and Misael Cortés Rodríguez
In order to understand interactions aw vs equilibrium moisture content (EMC) in fortified coconut powder, moisture sorption isotherms were constructed under different storage…
Abstract
Purpose
In order to understand interactions aw vs equilibrium moisture content (EMC) in fortified coconut powder, moisture sorption isotherms were constructed under different storage conditions in order to predict the changes in their physical, chemical and microbiological properties that occur during storage and processing, which are unique to each food.
Design/methodology/approach
For which the moisture sorption isotherms were determined at three different temperatures (15, 25 and 35 °C), in a range of water activity from 0.1 to 0.90. Nine models, namely, the GAB, BET, Oswin, Smith, Halsey, Henderson, Chung and Pfost, Peleg and Caurie equations, were fitted to the sorption data. Various statistical tests were adopted as criteria to evaluate the fit performance of the models.
Findings
Of the models tested, the Peleg model gave the best fit to experimental data (R2 = 0.997; RMSE = 0.276), across the full range of water activities and at different temperatures. Humidity of the monolayer (mo) was found between 2.54 and 2.34%, a fundamental parameter to define the storage and control conditions, given that it is considered the value at which the product is more stable. The net sorption isosteric heat (Qst) increased to maximum and then diminished with increased moisture content (Xw); maximum values were obtained in the Xw interval between 0.48 and 2.87% (db), being between 35.72 and 99.26 kJ/mol, where the maximum value indicates coverage of the strongest bond sites and higher adsorbate-adsorbent interaction.
Originality/value
These results provide reliable experimental data on water absorption isotherms of the CP + FAC important to determine optimal processing, storing and packaging conditions.
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Viju Subramoniapillai and Govindharajan Thilagavathi
In recent years, oil spill pollution has become one of the main problems of environmental pollution. Recovering oil by means of sorbent materials is a very promising approach and…
Abstract
Purpose
In recent years, oil spill pollution has become one of the main problems of environmental pollution. Recovering oil by means of sorbent materials is a very promising approach and has acquired more attention due to its high cleanup efficiency. Compared to synthetic fibrous sorbents, the use of natural fibers in oil spill cleanups offers several advantages including environmental friendliness, degradable features and cost-effectiveness. Therefore, studies on developing sorbents using natural fibers for oil spill cleanup applications have become a research hotspot.
Design/methodology/approach
This paper reviews the work conducted by several researchers in developing oil sorbents from fibers such as cattail, nettle, cotton, milkweed, kapok, populous seed fiber and Metaplexis japonica fiber. Some featured critical parameters influencing the oil sorption capacity of fibrous substrates are discussed. Oil sorption capacity and reusability performance of various fibers are also discussed. Recent developments in oil spill cleanups and test methods for oil sorbents are briefly covered.
Findings
The main parameters influencing the oil sorption capacity of sorbents are fiber morphological structure, fiber density (g/cc), wax (%), hollowness (%) and water contact angle. An extensive literature review showed that oil sorption capacity is highest for Metaplexis japonica fiber followed by populous seed fiber, kapok, milkweed, cotton, nettle and cattail fiber. After use, the sorbents can be buried under soil or they can also be burned so that they can be vanished from the surface without causing environmental-related issues.
Originality/value
This review paper aims to summarize research studies conducted related to various natural fibers for oil spill cleanups, fiber structural characteristics influencing oil sorption and recent developments in oil spill cleanups. This work will inspire future researchers with various knowledge backgrounds, particularly, from a sustainability perspective.
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Isabel Brás, Luis Teixeira Lemos, Arminda Alves and M. Fernando R. Pereira
Nowadays trace organic pollutants represent a major concern in water treatment systems. Activated carbon has been used for most applications aiming at the reduction of these kind…
Abstract
Nowadays trace organic pollutants represent a major concern in water treatment systems. Activated carbon has been used for most applications aiming at the reduction of these kind of compounds in aqueous effluents, but regeneration needs and high operation costs led to a renewed interest in the search for alternative sorbents. Pine bark is an excedentary raw material from sawmills in Portugal, and therefore a profitable natural resource that has already been successfully tested in the adsorption of organochlorines from contaminated water. This study aims at characterizing the pine bark surface structurally and chemically, to understand the nature of sorption occurring when a trace organic contaminant is present in aqueous effluents. Pentachlorophenol (PCP) was the trace contaminant used in the experiments. Scanning electron microscopy (SEM), mercury porosimetry, Fourier transform infrared spectroscopy (FTIR) and X‐ray photoelectron spectroscopy (XPS) were the techniques used, in addition to classical chemical analysis and solid phase micro extraction (SPME) prior to gas chromatography with mass spectrometry (GC‐MS) for PCP quantification. The pine bark proved to be a material of very low porosity, low specific surface area, strong carbon aromatic content probably relative to polyphenols and lignin composition. Sorption experiments showed a good correlation for the linear adsorption isotherm, as well as the desorption experiments. In the conditions tested, the average PCP removal after 24 h was above 98 per cent. This material proved to be an encouraging sorbent for cheap water remediation solutions.
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Haibao Lu, Aying Zhang, Yongtao Yao and Long Lin
– This paper aims to present a phenomenological model to investigate the underlying mechanism and predict the bio-inspired performance under different thermo-temporal conditions.
Abstract
Purpose
This paper aims to present a phenomenological model to investigate the underlying mechanism and predict the bio-inspired performance under different thermo-temporal conditions.
Design/methodology/approach
Flory-Rehner free-energy functions are applied to quantitatively identify the driving forces in the viscously bio-inspired response of a dynamic polymer network. Furthermore, the permeation transition equation is adopted to couple water gradient and water sorption/desorption into the free-energy function.
Findings
The results show that the influence of potential energy on deformation can be related to a stretching ratio that uniquely determines water sorption/desorption, locomotion frequency and contractile stress. Finally, by means of combining the free-energy function and Arrhenius equation, a phenomenological thermo-temporal model is developed and verified by the experimental results.
Research limitations/implications
This study focuses on exploring the theoretical mechanism and significantly enhances understanding of relevant experimental features reported previously.
Originality/value
The outcome of this study will provide a powerful phenomenological and quantitative tool for study on shape memory effect in bio-inspired polymers.
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Looks at the eighth published year of the ITCRR and the research, from far and near, involved in this. Muses on the fact that, though all the usual processes are to the fore, the…
Abstract
Looks at the eighth published year of the ITCRR and the research, from far and near, involved in this. Muses on the fact that, though all the usual processes are to the fore, the downside part of the industry is garment making which is the least developed side. Posits that the manufacture of clothing needs to become more technologically advanced as does retailing. Closes by emphasising support for the community in all its efforts.
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