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This work aims to explain the effect of common salt on absorbance spectra and solubility of textile direct dyes, which is important in analysing and reusing wastewater of dyeing process.

Several textile dyes such as Direct red 243, Direct yellow 86 and Direct blue 201 solutions with and without NaCl salt were used to study the effect of common salt on solubility of textile direct dyes. Several methods such as derivative spectrophotometry, principal component analysis and colorimetric techniques were used to analyse the absorbance spectra of dye solution.

The obtained results indicate that the effect of common salt on absorbance spectra and solubility of textile direct dye depends on the chemical structure of dyes. The NaCl salt significantly affects the solubility of Direct red 243 (red dye) and Direct yellow 86 (yellow dye) which have Azo compounds containing four SO₃ functional groups. But the NaCl salt does not change the solubility of Direct blue 201 (Blue dye) which has Azo compound containing two SO₃ functional groups. Also, the NaCl salt decreases the accuracy of dye concentration prediction.

During reusing wastewater of dyeing process, the amount of dyes has been evaluated via absorbance spectra of dye solution.

This work explains the effect of common salt on solubility of textile direct dyes and the accuracy of dyes concentration prediction.

The aim of the paper was to study the effects of mordanting methods on the absorption behaviour of cochineal natural dye on polyamide fibres.

Iron sulphate and aluminium potassium sulphate salts were used as mordanting agents, and bottom mordanting, meta-mordanting and after mordanting methods were applied in the dyeing of polyamide samples with the cochineal natural dye. Colourimetric evaluations were carried out, and the principal component analysis was used to investigate the spectrophotometric properties of the dyed samples. Fastness properties of the dyed samples were also assessed.

The obtained results indicate that the method of mordanting has a great effect on the obtained shades, absorption behaviour and fastness properties. Based on the results, it was concluded that polyamide fabrics could be successfully dyed with cochineal and combination of dyeing with different mordanting methods, and different mordanting agents would develop the range of obtainable shades.

The textile and apparel industries have been widely criticised for their role in polluting the environment. So, the use of synthetic dyes has been limited and the use of natural dyes has increased. The literature survey indicates that there have been relatively few works investigating the dyeing of polyamide with cochineal natural dye. This research studies the effects of mordanting methods and mordant types on colourimetric and fastness properties of cochineal-dyed polyamide samples.

This paper aims to focus on the absorption behaviour of single and binary mixtures of natural dyes on wool. Natural dyes are multi-components with different structures and properties.

In this research, the absorption behaviour of single and binary mixtures of natural dyes was investigated on wool fibre. Study was conducted via some natural dyes, including pomegranate peel as a yellow natural dye with tannin, weld as a yellow natural dye without tannin and madder as a red natural dye without tannin. Applied mordant was alum, which was used in the pre-mordant method. Different shades were obtained by varying dye concentration in the binary mixture. The effect of tannin on absorption behaviour of binary mixture of natural dyes was investigated by spectral reflectance and colour parameters of dyed samples measurements.

Obtained results indicate that tannin affects the absorption behaviour of natural dyes in binary mixtures.

Because natural dyes are multi-components with different structure and properties, the study of compatibility and absorption behaviour of natural dyes in binary mixture on wool is important in applied researches.

The study of compatibility and absorption behaviour of binary mixture of natural dyes on wool is novel.

This work aims to study the effect of mordanting method as pre-mordanting (on-chrome), meta-mordanting (meta-chrome) and post-mordanting (after-chrome) on wool dyeing with madder natural dye without tannin and pomegranates peel, as a natural dye contains tannin.

The woolen yarn was dyed with madder and pomegranate peel natural dyes by three methods as pre-mordant, meta-mordant and pos-mordant. The color parameters and reflectance spectra of dyed samples were analyzed by using derivative spectroscopy and the principal component analysis (PCA) techniques.

The obtained results indicate that the color difference between the samples dyed with madder by pre-mordanting, and the samples dyed by other methods is more than the color difference between the samples dyed by meta-mordanting and post-mordanting. However, the color difference between samples dyed with pomegranate peel by pre-mordanting and meta-mordanting methods is less compared to other pairs. Also, analysis of reflectance spectra and color depth (K/S) values indicate that the color depth of dyed sample with madder by pre-mordanting method is more than other dyeing methods. But, the color depth of sample dyed with pomegranate peel by post-mordanting method is less compared to other methods. The analysis of first-, second-, third- and fourth-order derivatives of reflectance spectra and the study of the first, second, third and fourth PCs of reflectance spectra indicate that the reflectance of dyed samples with madder and pomegranates peel depends on the mordanting method.

Evaluation of the effect of mordanting method on color and reflectance of wool dyed with madder and pomegranates peel natural dyes using derivative spectroscopy and the PCA techniques

Reverse osmosis (RO) has become an important method of desalination to meet the ever-growing water needs around the world. Its integration with renewable energy source (RES) reduces the environmental impact of gas emissions and cost of conventional fossil energy sources. The optimal sizing of energy sources to power RO desalination system is intended mainly to minimize the annualized cost of the system and by extension minimize freshwater cost while maximizing production.

In this study, a mathematical optimization approach is used to determine the optimal energy mix, which includes grid power, diesel generator and a photovoltaic (PV) module to supply an RO desalination unit. Three cases of optimal sizing approach were compared. Case 1 is a system with only grid power and diesel generator as energy sources; Case 2 has PV incorporated in the energy supply mix while Case 3 has the three energy sources and a Time of Use (TOU) demand response program on the demand side.

The results of implementing the optimization models show that Case 3 turnout the highest freshwater production (1,521 m³/day) at a unit cost of 1.36$/m³ when compared to Case 1 with daily freshwater production of 1,250 m³/day at a unit cost of 1.68$/m³ and Case 2 having a daily freshwater production of 1,501 m³/day at a unit cost of 1.33$/m³.

The integration of RES to power desalination system with application of TOU demand response is the significance of this study.

The present study aims to focus on the feasibility of using an aqueous extract from the fruit shell of Camellia oleifera Abel as a source of natural colourant in printing-paste preparation for pigment printing of cotton fabric. The effects of pre- and post-mordanting with three common metallic mordants, that is AlK(SO₄)₂, CuSO₄ and FeSO₄ on colour yield and colour fastness properties are also investigated.

The printing paste was prepared by mixing the concentrated Camellia oleifera Abel fruit shell extract solution with commercially available synthetic thickener and binder. The fabric sample was printed with the prepared printing paste using a flat-screen printing technique. To determine the effects of pre- and post-mordanting, AlK(SO₄)₂, CuSO₄ and FeSO₄ mordant aqueous solutions with various concentrations were applied using the pad-dry technique. Comparisons between printing with and without mordants were evaluated in terms of colour strength (K/S values) and colour fastness to washing, light, crocking and perspiration.

Without the mordants, the printed fabric had a yellowish brown shade with acceptable colour fastness properties, that is fair to good wash fastness, moderate light fastness, good to very good crocking fastness and fair to good perspiration fastness. The use of mordants, especially CuSO₄ and FeSO₄, not only enhanced colour strength but also imparted different colours to the fabric. Compared to the unmordanted fabrics, colour fastness properties were mostly comparable or improved in the mordanted fabrics depending on the type and concentration of mordants.

Although in the case of CuSO₄ the light fastness was increased to a good to very good level, it is recommended that the final print be produced with a concentration of less than 0.125 gL⁻¹ to yield the print with the residual amount of Cu metal under the limit, that is less than 50 ppm as regulated by the Oeko-Tex^® standard.

The obtained prints from Camellia oleifera Abel fruit shell extract provided shades with satisfactory colour fastness to washing, light, crocking and perspiration. The extract from Camellia oleifera Abel fruit shell has the potential to be used as an alternative to synthetic dye in the textile industry.

The use of Camellia oleifera Abel fruit shells, which are considered as abundant byproducts of tea seed oil production, as natural colouring agents for pigment printing of cotton fabric has been reported for the first time. It will minimise the environmental impact of this waste and create more valuable textile products.

Finding blue colorants from natural sources is extremely difficult and, usually, the anthocyanin compounds are used for producing the blue color. This study aims to apply the Red Cabbage as a natural colorant to obtain different colors on wool yarn, as well as specify the optimum dyeing condition by response surface methodology for obtaining a blue color.

The effect of dyeing process parameters such as mordant concentration, dyeing time, pH of dyeing bath and dyeing temperature examined in the color characteristics of the dyed wool samples.

The obtained results indicated that the diverse colors achieve by varying the dyeing process parameters, which is in the range of 26° up to 271°. The non-mordanted dyed wool samples showed a red and red brownish color (Hue angle = 26° up to 70°), and the mordanted dyed wool samples showed a blue and blue-greenish color (Hue angle = 230° up to 271°). The obtained blue color with the optimized dyeing condition presented a considerable good wash and lightfastness.

This study provides a promising application of Red Cabbage as a natural colorant for obtaining different colors by varying the dyeing process parameters such as pH and stannous ion concentrations. The stannous ions yielded a co-pigmentation and presented a blue color on wool fibers, which is extremely difficult to obtain with natural colorant.

Currently, more renewable energy resources with advanced technology levels are incorporated in the electric power networks. Under this circumstance, the attainment of optimal economic dispatch is very much essential by the power system as the system requires more power generation cost and also has a great demand for electrical energy. Therefore, one of the primary difficulties in the power system is lowering the cost of power generation, which includes both economic and environmental costs. This study/paper aims to introduce a meta-heuristic algorithm, which offers an solution to the combined economic and emission dispatch (CEED).

A novel algorithm termed Levy-based glowworm swarm optimization (LGSO) is proposed in this work, and it provides an excellent solution to the combined economic and emission dispatch (CEED) difficulties by specifying the generation of the optimal renewable energy systems (RES). Moreover, in hybrid renewable energy systems, the proposed scheme is extended by connecting the wind turbine because the thermal power plant could not control the aforementioned costs. In terms of economic cost, emission cost and transmission loss, the suggested CEED model outperforms other conventional schemes genetic algorithm, Grey wolf optimization, whale optimization algorithm (WOA), dragonfly algorithm (DA) and glowworm swarm optimization (GSO) and demonstrates its efficiency.

According to the results, the suggested model for Iteration 20 was outperformed GSO, DA and WOA by 23.46%, 97.33% and 93.33%, respectively. For Iteration 40, the proposed LGSO was 60%, 99.73% and 97.06% better than GSO, DA and WOA methods, respectively. The proposed model for Iteration 60 was 71.50% better than GSO, 96.56% better than DA and 95.25% better than WOA. As a result, the proposed LGSO was shown to be superior to other existing techniques with respect to the least cost and loss.

This research introduces the latest optimization algorithm known as LGSO to provide an excellent solution to the CEED difficulties by specifying the generation of the optimal RES. To the best of the authors’ knowledge, this is the first work that utilizes LGSO-based optimization for providing an excellent solution to the CEED difficulties by specifying the generation of the optimal RES.

The widespread application of traditional grey model (GM) in different academic fields such as electrical engineering, education, mechanical engineering and agriculture provided the authors with an incentive to conduct the present empirical research in an accounting field, in particular, auditing practice. In this regard, the purpose of this paper is to employ the nonlinear type of the original GM to forecast the drastically changed data on audit reports, primarily due to the fact that the linear nature of GM is unable to forecast nonlinear data precisely. In essence, this paper adds value to the strand of audit report literature by examining the impact of different financial ratios on auditors’ opinion and then forecasting audit reports by employing GMs.

The grey forecasting model is known as a system containing uncertain information presented by grey numbers, equations and matrices. The grey forecasting model is employed by using a differential equation in an uncertain system with limited data set which is suitable for smoothing discrete data. In addition, the analyses are conducted by applying a sample of top 50 listed companies on the Tehran Stock Exchange during 2011-2016.

The findings suggest that audit reports are most influenced by the current ratio and conversely, least influenced by the ratio of working capital turnover. Moreover, the authors argue that the Nash nonlinear grey Bernoulli model is more precise than the nonlinear grey Bernoulli model and GM in forecasting audit reports.

The current study may give more strength to stakeholders in order to analyse and forecast audit report.

The purpose of this paper is to reveal the potential use of faba bean husk as natural dye, to create a color gamut and to observe the effect of different mordants. Dyeing properties of polyamide/elastane fabric using faba been husk were investigated. The effect of alum [KAl(SO₄)₂], iron II sulfate Fe(SO₄)7H₂O, tin II chloride (SnCI₂2H₂O), copper II sulfate (CuSO₄), citric acid (C₆H₈O₇), tartaric acid (C₄H₆O₆), oxalic acid (H₂C₂O₄), ammonium sulfate [(NH₄)₂SO₄], sodium acetate (C₂H₃NaO₂), combination of alum-iron, iron-tin and alum-tin were evaluated in terms of color yield, color coordinates and wash fastness.

Mainly, dyeings were conducted in accordance with a simultaneous mordanting method. However, pre-mordanted dyeings were also implemented with selected concentration (0.8 g/L) of metallic mordants to enrich color gamut. Control sample (without mordant) was used as a reference for examining the effect of different mordants. Dyed samples were compared mutually in the light of visual evaluation and color measurements and alternatives to metallic mordants were also assessed.

Significant differences occurred in color coordinates of dyed samples. The biggest color difference and completely different color shades were achieved with tin II chloride. The type of acid did not create visible color differences. As alternatives to metallic mordants; all of them may be used instead of alum (0.8 g/L). Tartaric acid and oxalic acid, instead of iron II sulfate (0.2 g/L), and ammonium sulfate (0.2 g/L) and sodium acetate (0.8 g/L), instead of alum (0.8 g/L), can be used. Sodium acetate cannot be replaced with iron. A combination of alum-iron and iron-tin can be the alternative to 0.2 and 0.8 g/L copper, respectively. All the samples provided good wash fastness (4/5) values.

Valorization of industrial, agricultural and domestic wastes as novel natural dye sources is an ecological and sustainable approach. Moreover, the use of man-made fibers in natural dyeing is an issue that needs to be developed and expanded. Few literatures have been found concerning the use of husks of faba bean as a natural colorant. In this initial study, husks of faba been as a vegetable waste were utilized in natural dyeing of polyamide/elastane fabric. It is suggested that this waste can be turned into an economic value through its valorization in natural dyeing.