M. Abdel Rehim, H.M. Fahmy, Z.E. Mohamed, M.H. Abo‐Shosha and N.A. Ibrahim
The purpose of this paper is to show how to remove some dyestuffs, as pollutants, from their aqueous solutions.
Abstract
Purpose
The purpose of this paper is to show how to remove some dyestuffs, as pollutants, from their aqueous solutions.
Design/methodology/approach
To achieve the goal, a water soluble hyperbranched poly (ester‐amide) (HBP) was synthesised using the melt polycondensation method by the reaction of maleic anhydride (MA) and diisopropanol amine (DIPA) at 140°C at a molar ratio of 1:1.3 MA: DIPA, respectively. This HBP was incorporated in the preparation of an effective microcrystalline cellulose (MCC)/dimethyloldihydroxyethylene urea (DMDHEU)/HBP adduct by crosslinking HBP with DMDHEU in presence of MCC. Furthermore, the prepared adduct was characterised by investigation its infra red and then utilised in the removal of three anionic dyestuffs from aqueous solutions, namely Irgalan Blau 3GL (an acid dye), SIRIUS Blau S‐BRR (a direct dye) and Levafix Brill Orange P‐GR (a hydrolysed reactive dye).
Findings
The results obtained revealed that the optimum conditions for preparing MCC/DMDHEU/HBP adduct are [HBP], 90 g/l; [DMDHEU], 200 g/l; LR, 1/3.3; [NC4LH], 20 g/l; a time of 30 min and a temperature of 160°C. Moreover, the results also showed that the extent of removal of such dyestuffs from their aqueous solutions by the prepared adduct follows the order: reactive dye>acid dye>direct dye, it is more pronounced at lower than at higher pH values and the removal of each dye by that adduct follows a first‐order reaction.
Research limitations/implications
Other substrates such as chitosan can be used to prepare more effective adducts.
Practical implications
Hyperbranched polymers can be used effectively to prepare ion exchangers capable of removing the pollutants of dyestuffs from their aqueous solutions.
Originality/value
The aforementioned prepared HBP is a novel hyperbranched polymer and could be applied in the removal of many other pollutants.
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N. A. Ibrahim, Z. M. El-Sayed, H. M. Fahmy, A. G. Hassabo and M. H. Abo-Shosha
The inclusion of softeners (20 g/l), namely, Siligen VN (silicon based), Basosoft SWK (cationic), or Leomin NI (nonionic), in a dimethyloldihydroxy ethylene urea (DMDHEU, 50 g/l…
Abstract
The inclusion of softeners (20 g/l), namely, Siligen VN (silicon based), Basosoft SWK (cationic), or Leomin NI (nonionic), in a dimethyloldihydroxy ethylene urea (DMDHEU, 50 g/l) finishing formulation of 65/35 cotton/polyester blended fabric, enhances the resiliency of the fabric, which is expressed as the dry wrinkle recovery angle (WRA). The fabric acquires the ability to keep a rose oil fragrance upon storage up to 3 months. Improving the WRA and acquiring the ability to keep the fragrance can be descendingly arranged as follows: Siligen VN>Basosoft SWK>Leomin NI. Increasing the Siligen VN concentration (0-30 g/l) in the finishing formulation is accompanied by a small increase in the WRA, and a noticeable enhancement in the ability to keep the rose oil fragrance upon storage. By increasing the rose oil concentration (100-300 g/l) in a perfumed bath of cross-linked/Siligen VN, the softened fabric is accompanied by a slight drop in the WRA, and a decreasing ability to keep the fragrance up to 3 months.
However, the extent of the fragrance is higher at higher rose oil concentrations, regardless of the storage time. The ability of the fabric to keep the fragrance can be attributed to solubilization and/or encapsulation of the perfume in the oleophilic segments of the softener, and its slow release with time, so that the smell can be sensed. This ability decreases after increasing the storage time up to 3 months, and depending on the type of perfume oil used, is descendingly arranged as follows: jasmine oil > rose oil > sandal oil.
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Public debt management is now an integral part of overall macroeconomic management in many developing and emerging market economies. Preventing unsustainable debt accumulation and…
Abstract
Purpose
Public debt management is now an integral part of overall macroeconomic management in many developing and emerging market economies. Preventing unsustainable debt accumulation and maintaining healthy fiscal profile begins with understanding its key drivers both in the short and in the long run. The purpose of this paper is to analyze public debt and current account dynamics in Ethiopia.
Design/methodology/approach
This study applies structural vector auto-regressive (SVAR) model on annual time series data to study general government debt and current account dynamics in Ethiopia for the period 1980–2018.
Findings
Both the impulse response and forecast error variance decomposition results confirm that fiscal balance exerts the strongest influence on both government debt and current account balance in the short run. In addition, own shock as well as shocks stemming from gross fixed capital formation and growth have significant effects on general government debt. The findings were robust to alternative data transformation, differing Choleski ordering of the model variables, and inclusion of exogenous deterministic terms that capture changes in the political landscape.
Practical implications
The most important implication is that since fiscal balance is the strongest determinant of both public debt and current account balance, public investment efficiency is relevant here than anywhere else in the national economy. A recent study by Barhoumi et al. (2018) found that the sub-Saharan region lags behind its peers in terms of public sector investment efficiency with inefficiency gap of as large as 54% depending on the indicator variable for public investment output. Improving public investment spending efficiency would reduce government debt by enhancing productivity and growth – which has significant negative effect on public debt.
Originality/value
First, the few studies conducted on Ethiopia are dominated by single equation specifications and do not account for the possibility of endogenous feedback effects among the model variables. Second, still equally important is the role of rising gross fixed capital formation in Ethiopia, which increased from about 13% (relative to GDP) in the 1980s to about 35% in the 2010s. Ignoring this variable amounts to a major model misspecification when analyzing short-run macro dynamics in low-income economies. Finally, the paper complements existing limited studies on Ethiopia by comparing the strength of shock propagation mechanisms using alternative data transformation techniques.
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Zakiul Fuady Muhammad Daud and Raihanah Azahari
The purpose of this paper is to identify the conditions of the wajibah (obligatory) will under compilation of Islamic law (KHI) and the application and rationale of wajibah wills…
Abstract
Purpose
The purpose of this paper is to identify the conditions of the wajibah (obligatory) will under compilation of Islamic law (KHI) and the application and rationale of wajibah wills in religious justice. The wajibah will is a form of judicial wealth transition that can deliver an inheritance to an heir who is not otherwise eligible for it. It is implemented in some Islamic countries, including Indonesia, based on the KHI.
Design/methodology/approach
This is a descriptive qualitative study that uses documentation as a data-collection method. This study applies the content-analysis method to the data collected.
Findings
The results of study indicate that, under KHI, a wajibah will only be given to adopted children. Nevertheless, in the practice of religious justice, the wajibah will is also granted to heirs of faiths other than Islam and to illegitimate children. The rationale for the wajibah will involves historical factors and public considerations.
Originality/value
This paper provides information on the practice of the wajibah will in Indonesia in view of the plurality of the Indonesian people. Thus, the wajibah will is an appropriate instrument to attain justness in the well-being of the community. This paper also attempts to give a critical review of the practice based on five necessities.
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This study aims to the synthesis of some novel 4-arylazo-3-hydroxythiophene analogues containing sulphapyridine and sulphathiazole dyestuffs and studying their application in…
Abstract
Purpose
This study aims to the synthesis of some novel 4-arylazo-3-hydroxythiophene analogues containing sulphapyridine and sulphathiazole dyestuffs and studying their application in dyeing polyester fabrics and rendering their antibacterial efficacy.
Design/methodology/approach
Simultaneous dyeing and antibacterial finishing for polyester fabric using a new antibacterial disperse dye having a modified chemical structure to thiophene dyes were studied. Construction of the thiophene dyes was carried out by diazo-coupling of diazotized sulphonamide-containing heterocyclic rings sulphapyridine and sulphathiazole with ethyl α-phenylthiocarbamoyl-acetoacetate followed by cyclizing the produced 2-arylazo-thioacetanilide with various α-halogenated reagents. All newly synthesized compounds were characterized by elemental analysis and extensive study of their spectral data (IR and 1H-NMR). The dyeing characteristics of these thiophene dyestuffs were evaluated at optimum conditions. Antibacterial activities of the obtained thiophene dyes were studied against some Gram-positive and Gram-negative bacteria.
Findings
The synthesized thiophene-containing sulphonamides dyes were applied on polyester fabric. The modified dyes exhibited a good fastness properties and antibacterial efficacy against some Gram-positive and Gram-negative bacteria. Synthesized dyes showed higher antibacterial potency than the reference standard drug.
Research limitations/implications
Synthesis of these disperse azo dyes for textile dyeing had never been reported previously.
Practical implications
The dyestuffs derived from thiophene are reasonable azo disperse dyestuffs giving good all-round fastness properties on polyester fabrics.
Originality/value
Thiophene dyes are used for dyeing polyester fabrics with brilliant colour and good fastness properties. The presence of sulphonamides moieties increase their fastness properties and elevate their antibacterial properties. Moreover, they can be used as antimicrobial finish due to their bactericidal properties on dyed textiles. This work afforded a new thiophene colorant that can be used in many different uses like polyester packing, thread Surgery, blends and other uses in medical textile.
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The purpose of the paper is to propose a new method for checking the positivity and asymptotic stability of descriptor continuous‐time and discrete‐time linear systems.
Abstract
Purpose
The purpose of the paper is to propose a new method for checking the positivity and asymptotic stability of descriptor continuous‐time and discrete‐time linear systems.
Design/methodology/approach
The proposed method is based on the elementary operations applied to descriptor linear systems with regular pencils.
Findings
The descriptor systems with regular pencils are transformed to equivalent standard systems which are used for checking of the asymptotic stability of descriptor systems.
Originality/value
The paper proposes a new method for investigation of the positivity and asymptotic stability of descriptor continuous‐time and discrete‐time linear systems.
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Ruchi Mishra, Ashok K. Pundir and L. Ganapathy
The purpose of this paper is to propose a novel integrated approach using analytical hierarchy process (AHP) and technique for order of preference by similarity to ideal solution…
Abstract
Purpose
The purpose of this paper is to propose a novel integrated approach using analytical hierarchy process (AHP) and technique for order of preference by similarity to ideal solution (TOPSIS) methods for evaluation and prioritization of appropriate manufacturing flexibility type required in the face of multiple environmental uncertainties.
Design/methodology/approach
Using a case study of an Indian fashion apparel firm, the study demonstrates the application of the proposed integrated framework for evaluation and prioritization of manufacturing flexibility. The study uses AHP method to determine importance weight of environmental uncertainty criteria and subcriteria and then employs TOPSIS method to determine the final ranking of manufacturing flexibility types required to cope up with these uncertainties.
Findings
The findings of the case suggest that the proposed integrated approach is feasible and practically implementable for manufacturing flexibility assessment.
Research limitations/implications
AHP has been extensively studied and used, but the major limitation of this proposed approach is the involvement of large number of pairwise comparisons leading to difficulty in maintaining consistency in pairwise comparisons.
Practical implications
The proposed approach can work as a benchmarking tool to practitioners in evaluating and prioritizing manufacturing flexibility alternatives and to suggest strategic allocation of resource by prioritizing different manufacturing flexibilities types.
Originality/value
Unlike conventional approaches, the study provides meaningful knowledge to decision makers by demonstrating a simple, flexible, and efficient method to evaluate and rank the appropriate manufacturing flexibility types.
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Heba Abdelrazik Mohamed and Mona Hassan Abdel Rehim
– The purpose of this paper was to protect carbon steel from corrosion with self–aggregated, eco-friendly, water-soluble hyperbranched polyamide-ester (Hb-PAE).
Abstract
Purpose
The purpose of this paper was to protect carbon steel from corrosion with self–aggregated, eco-friendly, water-soluble hyperbranched polyamide-ester (Hb-PAE).
Design/methodology/approach
Hb-PAE was synthesized through bulk polycondensation reaction between maleic anhydride and di-isopropanol amine. Complete structural analysis for the obtained polymer was performed using Fourier Transfer Infra-Red Spectroscopy, 1H NMR, Thermal gravimetric analysis (TGA) and differential scanning calorimetry, and the molar mass was measured using gel permeation chromatography/refractive index. For this study, the surface activity of Hb-PAE with hydroxyl end groups was investigated. Surface tension of 1.0 × 10−6 to 0.1M of both Hb-PAE/H2O and Hb-PAE/1N HCl systems was measured, and the critical aggregation concentration (CAC) in both systems was determined. Hb-PAE was examined as a corrosion inhibitor for plain carbon steel in both neutral (distilled water) and acidic (1N HCl) media. The corrosion of the steel was studied quantitatively by measuring its weight loss in both media in the absence and presence of Hb-PAE. The surface morphology of the exposed steel test samples was examined using scanning electron microscopy.
Findings
It was found that Hb-PAE inhibited corrosion of steel around the CAC, and its corrosion inhibition efficiency was increased by increasing its concentration.
Originality/value
The research can provide a reference for the relationship between the aggregation concentration of the prepared Hb-PAE with its corrosion inhibition efficiency on plain carbon steel. Hb-PAE as a corrosion inhibitor is environmentally acceptable, economical and readily available.
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Hatem E. Gaffer and Ismail I. Althagafi
The purpose of this paper is to synthesize some new azobenzene dyestuffs clubbed with thiazolidinone moiety and their solicitation in dyeing polyester fabrics representing their…
Abstract
Purpose
The purpose of this paper is to synthesize some new azobenzene dyestuffs clubbed with thiazolidinone moiety and their solicitation in dyeing polyester fabrics representing their antibacterial evaluation.
Design/methodology/approach
Herein, the authors report the synthesis of new thiazolidinone moiety after the coupling of diazotized 4-aminoacetophenone with resorcinol. The newly synthesized dyes were characterized by IR, elemental analysis, mass spectroscopy and proton nuclear magnetic resonance (1H NMR) spectral studies. The characteristics of dyeing of these dyestuffs were evaluated at optimum conditions. Concurrent with dyeing of polyester fabric for synthesized dyes with their antibacterial activity was estimated. Antimicrobial activity of the dyed fabrics at different concentrations was evaluated against gram-positive and gram-negative bacteria.
Findings
Synthesized azobenzene dyestuffs clubbed with thiazolidinone dyes were applied on polyester fabrics. It was remarked that the modified dyes exhibited better colourfastness properties. Furthermore, the synthesized dyes revealed antimicrobial activity against gram-positive and gram-negative bacteria.
Research limitations/implications
The synthesized azobenzene dyes for polyester dyeing were not bore earlier.
Practical implications
The azobenzene dyes were accountable for giving improved colourfastness properties on polyester fabrics.
Social implications
The synthesized azobenzene derivatives are sensibly expensive and applicable dyes accompanied with good antimicrobial and anticancer activities.
Originality/value
A common process could be affording textiles of colour and antibacterial assets. The newly synthesized dyes containing thiazolidinone moieties with azobenzene coupler showed interesting disperse colourant for polyester with good antibacterial activity.
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Kh M. Mostafa and A.A. El-Sanabary
This study aims to use multi-functional viscose fabric that was facilely developed with with respect to ease and care characteristics, reinforcement effect and antibacterial…
Abstract
Purpose
This study aims to use multi-functional viscose fabric that was facilely developed with with respect to ease and care characteristics, reinforcement effect and antibacterial activity by using novel echo friendly antibacterial finish based on citric acid/sodium hypophosphite and the authors’ previously tailor-made poly meth acrylic acid (MAA)-chitosan graft copolymer via alternative microwave curing approach instead of traditional high-temperature cure one.
Design/methodology/approach
Viscose fabric was paddled twice in the cross-linking formulations containing different concentrations of citric acid, poly (MAA)-chitosan graft copolymer and sodium hypophosphite to 90 % wet pick up and dried at 100°C for 3 min in an electric oven. Then, the treated fabrics were placed on the disk spinner of the microwave oven and cured at different power (100–800 Watt) for various durations (60–180 s). The fabric was then water-rinsed and dried at ambient condition before use.
Findings
Results revealed that the above echo friendly method for finished viscose fabrics was found to achieve relatively high dry wrinkle recovery angle and maintain the loss in tensile strength within the acceptable range, as well as antibacterial activity against Escherichia coli and Staphylococcus aureus as a gram-negative and gram-positive bacteria, respectively; in addition to durability up to ten washing cycles. Furthermore, scanning electron microscope images, nitrogen content and add on % of the finished fabric confirmed the penetration of grafted chitosan inside the fabric structure. The tentative mechanism for these reactions is advocated.
Originality/value
The novelty addressed here is undertaken with the advantages of using citric acid as a nonformaldehyde, safe and cheap poly carboxylic acid as a crosslinking agent and sodium hypophosphite as a potential catalyst, in addition to the authors’ noncitable multifunctional echo friendly tailor-made poly (MAA)-chitosan graft copolymer for imparting reinforcement and antibacterial characteristics to viscose fabric that uses the pad-dry/cure microwave fixation for progressively persuaded heat within the fabric during curing.
Research limitations/implications
This was done to see the impact of microwave as green and efficient tool with respect to reduction in organic solvents, chemicals and exposer time as well as fixation temperature on the finishing reaction in comparison with traditional pad-dry-cure method.
Practical implications
Poly (MAA)-chitosan graft copolymer as amphoteric biopolymer was expected to impart multifunctional properties to viscose fabrics especially with comparable dry wrinkle recovery angle and minimize the loss in tensile strength in addition to antibacterial properties in comparison with untreated one.