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1 – 4 of 4Tuna Uysaler, Pelin Altay and Gülay Özcan
In the denim industry, enzyme washing and its combination with stone washing are generally used to get the desired worn-out look. However, these conventional methods include high…
Abstract
Purpose
In the denim industry, enzyme washing and its combination with stone washing are generally used to get the desired worn-out look. However, these conventional methods include high water, energy and time consumption. Nowadays, laser fading, which is a computer-controlled, dry, ecological finishing method, is preferred in the denim fading process. The purpose of this study is to observe the effects of chemical pretreatment applications on laser-faded denim fabric in terms of color and mechanical properties. To eliminate the enzyme washing process in denim fading and to minimize the disadvantages of laser fading, such as decreased mechanical properties and increased fabric yellowness, various chemical pretreatment applications were applied to the denim fabric before laser fading, followed by simple rinsing instead of enzyme washing.
Design/methodology/approach
Two different indigo-dyed, organic cotton denim fabrics with different unit weights were exposed to pretreatment processes and then laser treatment, followed by simple rinsing. Polysilicic acid, boric acid, borax and bicarbonate were used for pretreatment processes, and laser treatment was carried out under optimized laser parameters (40 dpi resolution and 300 µs pixel time). Tensile strength was tested, and color values (CIE L*, a*, b*, ΔE*, C* and h), color yield (K/S), yellowness and whiteness indexes were measured to identify the color differences.
Findings
Before laser fading, 30 g/L and 40 g/L polysilicic acid pretreatments for sulfur-indigo-dyed fabric and a mixture of 10 g/L boric acid and 10 g/L borax pretreatments for the fabric only indigo-dyed were recommended for the laser fading with sufficient mechanical properties and good color values.
Originality/value
With the chemical pretreatments defined in this study, it was possible to reduce yellowness and maintain the mechanical properties after laser fading, thus minimizing the disadvantages of laser treatment and also eliminating enzyme washing.
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Keywords
Pelin Altay, Selin Hanife Eryürük, Gülay Özcan, Didem Öztürk, Melda Naz Saral and Çağla Altınordu
Firefighters are exposed to high outdoor temperature and heat stress caused by metabolic activities during firefighting and should wear protective clothing to ensure their safety…
Abstract
Purpose
Firefighters are exposed to high outdoor temperature and heat stress caused by metabolic activities during firefighting and should wear protective clothing to ensure their safety and health. Traditional firefighter protective suits are bulky and heavy garments with reduced thermal comfort properties since the fabric thickness and moisture barrier layers prevent heat transfer of the garment and cause additional heat stress. The aim of this study is to reduce heat stress by creating a new fabric design with silica aerogel membrane as a moisture barrier for three-layer fabric system.
Design/methodology/approach
Polyacrylonitrile (PAN) nanofibers were produced with three different silica aerogel contents and used for three-layered clothing system as a moisture barrier for giving desired protectiveness and thermal comfort to firefighters. Different fabric combinations were designed using two types of outer shell fabrics, two types of moisture barrier fabrics, two types of thermal barrier fabrics and PAN/silica aerogel membranes.
Findings
The results show that a lighter fabric system with improved wearer’s mobility and thermal comfort properties (thermal resistance and moisture permeability) is achieved with the use of PAN/silica aerogel membrane as an intermediate layer compared to commercial thermal protective fabric systems.
Originality/value
Differently from traditional thermal protective clothing, which may not provide adequate protection in long-term heat conditions or when exposed to flash fire, a new thermal protective clothing has been developed to be used in extremely hot environments, providing desired technical and performance properties, ease to wear comfort.
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Asli Pelin Gurgun and Kerim Koc
As a remedy to usually voluminous, complicated and not easily readable construction contracts, smart contracts can be considered as an effective and alternative solution. However…
Abstract
Purpose
As a remedy to usually voluminous, complicated and not easily readable construction contracts, smart contracts can be considered as an effective and alternative solution. However, the construction industry is merely known as a frontrunner for fast adoption of recent technological advancements. Numerous administrative risks challenge construction companies to implement smart contracts. To highlight this issue, this study aims to assess the administrative risks of smart contract adoption in construction projects.
Design/methodology/approach
A literature survey is conducted to specify administrative risks of smart contracts followed by a pilot study to ensure that the framework is suitable to the research question. The criteria weights are calculated through the fuzzy analytical hierarchy process method, followed by a sensitivity analysis based on degree of fuzziness, which supports the robustness of the developed hierarchy and stability of the results. Then, a focus group discussion (FGD) is performed to discuss the mitigation strategies for the top-level risks in each risk category.
Findings
The final framework consists of 27 sub-criteria, which are categorized under five main criteria, namely, contractual, cultural, managerial, planning and relational. The findings show that (1) regulation change, (2) lack of a driving force, (3) works not accounted in planning, (4) shortcomings of current legal arrangements and (5) lack of dispute resolution mechanism are the top five risks challenging the adoption of smart contracts in construction projects. Risk mitigation strategies based on FGD show that improvements for the semi-automated smart contract drafting are considered more practicable compared to full automation.
Originality/value
The literature is limited in terms of the adoption of smart contracts, while the topic is receiving more attention recently. To support easy prevalence of smart contracts, this study attempts the most challenging aspects of smart contract adoption.
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Belkis Ustamehmetoğlu, Pelin Yazıcı and Nilgun Kızılcan
The purpose of this paper is to obtain a conductive polymer by using a fluorescence comonomer which is an insulator. In this study, methyl ethyl ketone formaldehyde resin (MEKFR…
Abstract
Purpose
The purpose of this paper is to obtain a conductive polymer by using a fluorescence comonomer which is an insulator. In this study, methyl ethyl ketone formaldehyde resin (MEKFR) modified with carbazole‐9‐carbonyl chloride (CzCl) was synthesised via hydroxyl groups of MEKFR. Electrochemical polymerisation of Cz‐MEKFR comonomer was carried out potentiostatically and a green, conductive polymer P(Cz‐MEKFR) was obtained. The advantages of obtaining alternative structure of P(Cz‐MEKFR) to the random copolymer were reported.
Design/methodology/approach
Cz‐MEKFR comonomer was synthesised by the esterification reaction of CzCl and hydroxyl groups of MEKFR. Then, for the electrochemical polymerisation, potentiodynamic electrodeposition of Cz‐MEKFR comonomer in dichloromethane on to Pt was carried out. Electrochemical activities of polymers were tested by electrochemical methods (i.e. polarization curves and cyclovoltammetry). UV‐visible, NMR, polarization curves, cyclovoltammetric, solid‐state conductivity measurements and in situ spectroelectrochemical methods were performed for the characterization of polymers.
Findings
Carbazole‐9‐carbonyl chloride(CzCl) modified MEKFR was synthesised. This new carbazole‐modified resin (Cz‐MEKFR comonomer) has fluorescence property. The ionization potentials (Ip), electron affinity (Ea), optical band gap (Eg), peak potentials (Ep) and doping degree (y) of the polymers were calculated. Results were compared with the PCz homopolymer and the copolymer obtained from the mixture of MEKFR with carbazole P(Cz‐co‐MEKFR).
Research limitations/implications
This study focuses on obtaining a conductive polymer by using a fluorescence comonomer which is an insulator. In order to remove pyridine from comonomer, successively washing with several portions of dilute aqueous H2SO4, water‐saturated aqueous sodium hydrogen carbonate, and hot water is necessary.
Practical implications
This work provides technical information for the synthesis of fluorescence comonomer and conducting an alternative polymer.
Originality/value
A new Cz‐CFR comonomer was synthesised. This comonomer has a higher Tm value than MEKFR alone and also has fluorescence property. The band gap of the copolymer is not remarkably lower than polycarbazole. The oxidation potential of P(Cz‐MEKFR) was found to be higher than the PCz homopolymer and the solubility of copolymer is 30 per cent higher than homopolymer.
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