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1 – 10 of over 1000
Article
Publication date: 26 June 2019

Paula Nogueira Curi, Francielly Corrêa Albergaria, Rafael Pio, Maria Cecília Evangelista Vasconcelos Schiassi, Bruna de Sousa Tavares and Vanessa Rios de Souza

The purpose of this paper is to characterise eight different fig cultivars with respect to antioxidant activity and bioactive compound content and to assess the influence of these…

Abstract

Purpose

The purpose of this paper is to characterise eight different fig cultivars with respect to antioxidant activity and bioactive compound content and to assess the influence of these cultivars on the physicochemical characteristics, rheological properties and sensory acceptance of the obtained jelly to identify cultivars with increased potential for processing when grown in subtropical regions.

Design/methodology/approach

The analyses of fig fruits and fig jellies were performed in triplicate. To characterise the fig cultivars, analyses of antioxidant activity, phenolic compound content and ascorbic acid concentration were performed on fresh fruits. For the jellies, the total titratable acidity, pH, soluble solids, colour, texture profile and sensory attributes were analysed.

Findings

With respect to antioxidant activity and bioactive compounds, the Roxo de Valinhos displayed the highest antioxidant activity according to the ABTS method, ß-carotene and DPPH; the Três num Prato, Lemon and Brunswick cultivars presented the highest ascorbic acid values; and the Três num Prato cultivar also had the highest total phenolic content. Generally, the various fig cultivars yielded jellies with different physical and chemical characteristics and different rheological properties. This variation did not significantly affect acceptability. This study demonstrates that all of the evaluated cultivars have high potential for processing.

Originality/value

This study evaluated the processing potential of Roxo de Valinhos and other fig cultivars in the form of jelly, which in view of the food risk concerns of the dried fig, seems to be an interesting alternative for consumption of processed fig.

Details

British Food Journal, vol. 121 no. 8
Type: Research Article
ISSN: 0007-070X

Keywords

Abstract

Purpose

The purpose of this paper is to optimize a mixed juice made from Brazilian Cerrado fruits (cagaita, mangaba and marolo).

Design/methodology/approach

The juices were evaluated by rheological, physical, physicochemical, nutritional and sensory acceptance analyses. The mixture design is a widely used tool for product optimization, allowing the determination of factors, combinations and levels that provide best responses.

Findings

The results show that using mangaba pulp negatively contributed to juice acceptance, but resulted in the highest ascorbic acid content. The treatments produced using cagaita and marolo pulps presented a greater acceptance by consumers, and contributed to higher antioxidant activity and phenolic compounds content. The juice prepared with a mixture of equivalent quantities of the three fruits had the highest β-carotene and lycopene contents.

Practical implications

This research has shown that different fruit combinations can improve sensory and nutritional characteristics, adding value to the final product.

Social implications

The processing of mixed juices could increase population access to the nutrients present in Brazilian Cerrado fruits, given that they are seasonal and perishable fruits.

Originality/value

In recent years, there has been an increase in the development of new food products based on Cerrado native fruits, however information on the chemical and nutritional characteristics, rheological behavior, and sensory attributes of the derivative products are still limited, resulting in a lack of scientific investments in this area. In addition, it is necessary to optimize the developed products to offer the consumer a unique product, combining the characteristics of two or more fruits, which adds value to the final product.

Details

British Food Journal, vol. 120 no. 10
Type: Research Article
ISSN: 0007-070X

Keywords

Article
Publication date: 12 April 2013

Sheweta Barak, Deepak Mudgil and Bhupendar Singh Khatkar

The purpose of the paper is to study the effect of the gliadin and glutenin fractions of gluten on the cookie quality.

1019

Abstract

Purpose

The purpose of the paper is to study the effect of the gliadin and glutenin fractions of gluten on the cookie quality.

Design/methodology/approach

Ten different wheat varieties were analyzed for the flour physicochemical characteristics, gluten composition and rheological properties. The different flours were baked into cookies. The cookies were analyzed for spread ratio and texture. Relationships of various flour parameters, gluten composition and cookie characteristics were determined.

Findings

Gluten subfractions, damaged starch, protein, AWRC values were significantly correlated to the cookie spread and texture. Damaged starch (r=−0.638), protein (r=−0.508) and AWRC (r=−0.844) had a negative relationship with the cookie spread. The flours with higher SDS sedimentation value also produced cookies with lower spread ratio and harder texture. The study clearly demonstrated a positive correlation between Gli:Glu ratio (r=0.765) and spread ratio and a negative correlation (r=−0.528) with hardness of the cookies measured in terms of breaking force. Flours with lower dough development time and dough stability performed better as cookie flours.

Originality/value

The gliadins and Gli/Glu ratio had a significant effect on the cookie spread and texture and the prediction equation developed during the study could accurately predict the cookie spread from the Gli/Glu ratio and AWRC values.

Details

British Food Journal, vol. 115 no. 4
Type: Research Article
ISSN: 0007-070X

Keywords

Article
Publication date: 4 August 2020

Salwa H. El-Sabbagh, Nivin M. Ahmed, Doaa Samir Mahmoud and Wael S. Mohamed

The purpose of this paper is to evaluate the efficiency of commercial silica, silica fume-waste (SF) and modified silica fume-waste (mSF) as reinforcing filler in…

Abstract

Purpose

The purpose of this paper is to evaluate the efficiency of commercial silica, silica fume-waste (SF) and modified silica fume-waste (mSF) as reinforcing filler in acrylonitrile-butadiene rubber (NBR) and ethylene propylene diene monomer (EPDM) through the mixing process of rubber. The composites were prepared using different loadings of silica fume and commercial silica in EPDM and NBR composites. Structural characterization of silica and SF was done using X-ray fluorescence and scanning electron microscopy (SEM). The surface of silica fume waste was modified using poly methyl methacrylate/butyl acrylate through emulsion polymerization to increase the interaction between silica and rubber, then consequently better dispersion in rubber matrix was obtained. The mSF waste was characterized using FT-IR spectra and transmission electron microscopy.

Design/methodology/approach

The investigated rubber mixes and vulcanizates were evaluated by measuring the curing characteristics, mechanical testing, thermogravimetric analysis and morphological studies (SEM). The mechanical properties of composites including tensile strength, elongation at break and modulus were estimated and analyzed.

Findings

The results revealed that the composites (NBR and EPDM) containing mSF as filler exhibited better rheological and mechanical properties compared to unmodified silica waste and commercial silica. The SEM analysis indicated that the mSF was homogeneously dispersed through the surface of NBR and EPDM composites. Also, results showed that (NBR and EPDM) composites exhibited remarkable improvements in tensile strength, elongation at break and hardness in the presence of mSF; they also showed an increase in the thermal stability. This means that the treatment of surface SF can improve its dispersion in rubber.

Research limitations/implications

Silica cannot be applied in rubber matrix without surface modification because of their incompatibility; their dispersion is not good without surface modification.

Practical implications

The modified silica surface is considered as effective reinforcing filler which can replace other fillers because of its lower surface energy and enhanced intercalating behavior in rubber.

Social implications

This study is just a start in establishing rubber projects with wide applications in the industry and providing a cheap local product while preserving the quality and that is the use of factory waste, which helps in protecting the environment from pollution.

Originality/value

mSF is cheap with relatively high purity, which make rubber/mSF composites appear as new grade of material that can be used in different media rather than rubber.

Details

Pigment & Resin Technology, vol. 50 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 5 April 2021

Hoda Sabry Othman, Maher A. El-Hashash, S.H. El-Sabbagh, A.A. Ward and Galal A.M. Nawwar

Calcium and Zinc lignates were proven to be good antioxidants for rubber composites. The purpose of this paper is to evaluate the copper lignate antioxidant activity along with…

Abstract

Purpose

Calcium and Zinc lignates were proven to be good antioxidants for rubber composites. The purpose of this paper is to evaluate the copper lignate antioxidant activity along with evaluating its electrical conductivity in rubber composites.

Design/methodology/approach

The antioxidant activity of the Cu-LSF complex was compared with that of standard commercial antioxidant additives as a green alternative. The rheological characteristics, thermal aging and mechanical and electrical properties were evaluated for the NBR vulcanizates containing the different antioxidants in the presence or absence of coupling agents.

Findings

Results revealed that the Cu-LSF complex (5 phr) can function as a compatibilizing, antioxidant and electrical conductivity agent.

Originality/value

The new copper complex prepared from paper-pulping black liquor of wastes could be used as a green antioxidant and electrical conductivity agent in rubber composites.

Article
Publication date: 5 May 2015

Salwa H El-Sabbagh, Doaa S. Mahmoud, M. F. Zawrah, Nivin M. Ahmed and Magdy W. Sabaa

The purpose of this paper is to evaluate the efficiency of organobentonite (OB) as reinforcing filler in acrylonitrile-butadiene rubber (NBR). The composites were prepared using…

Abstract

Purpose

The purpose of this paper is to evaluate the efficiency of organobentonite (OB) as reinforcing filler in acrylonitrile-butadiene rubber (NBR). The composites were prepared using different loadings of OB and studying in details their properties. A series of OB was modified using surfactant N-cetyl-N, N, N-trimethyl ammonium bromide (CTAB) with concentrations 0.5, 1 and 2 cation exchange capacity (CEC) of bentonite.

Design/methodology/approach

The different bentonites were characterized using different analytical and spectro-photometric techniques, such as infra red, X-ray diffraction, thermogravimetric analysis and scanning electron microscopy, while rubber vulcanizate rheological, morphological, swelling and thermal properties were examined using different standard instrumental testing and methods.

Findings

The study revealed that the modification of bentonite using CTAB showed significant enhancement on NBR properties, and the optimum filler loading was 12 phr for both 0.5CEC OB and 2CEC OB. These modified bentonites improved reinforcing properties to NBR vulcanizates. Also, results showed that composites exhibited remarkable improvements in tensile strength, elongation at break and hardness in the presence of modified bentonite and also an increase in thermal stability.

Research limitations/implications

Na-B cannot be applied in rubber matrix without modification because it is incompatible with it.

Practical implications

The modified bentonite is considered as efficient reinforcing filler which can replace other fillers because it has lower surface energy and improved intercalating behaviour in rubber matrix.

Originality/value

These papered bentonites are cheap with relatively high purity, which make rubber/clay composites emerge as new class of material and can be used in different fields other than rubber.

Article
Publication date: 22 October 2019

Kanwar Pal Singh, Arvind Kumar and Deo Raj Kaushal

This paper aims to the transportation of high concentration slurry through pipelines that will require thorough understanding of physical and rheological properties of slurry, as…

Abstract

Purpose

This paper aims to the transportation of high concentration slurry through pipelines that will require thorough understanding of physical and rheological properties of slurry, as well as its hydraulic flow behavior. In spite of several contributions by the previous researchers, there is still a need to enrich the current understanding of hydraulic conveying through pipeline at various flow parameters. The pilot plant loop tests, particularly at high concentrations, are tedious, time-consuming and complex in nature. Therefore, in the current research the prediction methodology for slurry pipeline design based on rheological model of the slurry is used for calculation of pressure drop and other design parameters.

Design/methodology/approach

It has been established that slurry rheology plays important role in the prediction of pressure drop for laminar and turbulent flow of commercial slurries through pipeline. In the current research fly ash slurry at high concentration is chosen for rheological analysis. The effect of particle size and solid concentration is experimentally tested over the rheological behavior of slurry and based on the rheological data a correlation is developed for calculation of pressure drop in slurry pipeline.

Findings

The present study strongly supports the analytical approach of pressure drop prediction based on the rheological parameters obtained from the bench scale tests. The rheological properties are strongly influenced by particle size distribution (PSD), shear rate and solid mass concentration of the slurry samples. Pressure drop along the pipeline is highly influenced by flow velocity and solid concentration. The presence of coarser particles in the slurry samples also leads to high pressure drop along the pipeline. As the concentration of solid increase the shear stress and shear viscosity increase cause higher pressure drop.

Research limitations/implications

The transportation of slurry in the pipeline is very complex as there are lot of factors that affect the flow behavior of slurry in pipelines. From the vast study of literature it is found that flow behavior of slurry changes with the change in parameters such as solids concentration, flow velocity, PSD, chemical additives and so on. Therefore, the accurate prediction of hydraulic parameter is very difficult. Different slurry samples behave differently depending upon their physical and rheological characteristics. So it is required to study each slurry samples individually that is time-consuming and costly.

Practical implications

Nowadays in the world, long distance slurry pipelines are used for the transportation of highly concentration slurries. Many researchers have carried out an experiment in the design aspects of hydraulic transportation system. Rheological characteristics of slurry also play crucial role in determining important parameters of hydraulic conveying such as head loss in commercial slurry pipeline. The current research is useful for the prediction of pressure drop based on rheological behavior of fly ash slurry at various solid concentrations. The current research is helpful for finding the effect of solid concentration and flow velocity on the flow behavior of slurry.

Social implications

Slurry pipeline transportation has advantages over rail and road transportation because of low energy consumption, economical, less maintenance and eco-friendly nature. Presently majority of the thermal power plants in India and other parts of the world dispose of coal ash at low concentration (20 per cent by weight) to ash ponds using the slurry pipeline. Transporting solids in slurry pipelines at higher concentrations will require a thorough knowledge of pressure drop. In the current research a rheological model is proposed for prediction of pressure drop in the slurry pipeline, which is useful for optimization of flow parameters.

Originality/value

All the experimental work is done on fly ash slurry samples collect from the Jharli thermal power plant from Haryana State of India. Bench scale tests are performed in the water resource laboratory of IIT Delhi for physical and rheological analysis of slurry. It has been shown in the results that up to solid concentration of 50 per cent by mass all the samples behave as non-Newtonian and follows a Herschel–Bulkley model with shear thickening behavior. In the present research all the result outcomes are unique and original and does not copied from anywhere.

Details

World Journal of Engineering, vol. 16 no. 6
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 13 September 2022

Chaitanya D.V.S.K. and Naga Satish Kumar Ch.

This study aims on a broad review of Concrete's Rheological Properties. The Concrete is a commonly used engineering material because of its exquisite mechanical interpretation…

Abstract

Purpose

This study aims on a broad review of Concrete's Rheological Properties. The Concrete is a commonly used engineering material because of its exquisite mechanical interpretation, but the addition of constituent amounts has significant effects on the concrete’s fresh properties. The workability of the concrete mixture is a short-term property, but it is anticipated to affect the concrete’s long-term property.

Design/methodology/approach

In this review, the concrete and workability definition; concrete’s rheology models like Bingham model, thixotropy model, H-B model and modified Bingham model; obtained rheological parameters of concrete; the effect of constituent’s rheological properties, which includes cement and aggregates; and the concrete’s rheological properties such as consistency, mobility, compatibility, workability and stability were studied in detail.

Findings

Also, this review study has detailed the constituents and concrete’s rheological properties effects. Moreover, it exhibits the relationship between yield stress and plastic viscosity in concrete’s rheological behavior. Hence, several methods have been reviewed, and performance has been noted. In that, the abrasion resistance concrete has attained the maximum compressive strength of 73.6 Mpa; the thixotropy approach has gained the lowest plastic viscosity at 22 Pa.s; and the model coaxial cylinder has recorded the lowest stress rate at 8 Pa.

Originality/value

This paper especially describes the possible strategies to constrain improper prediction of concrete’s rheological properties that make the workability and rheological behavior prediction simpler and more accurate. From this, future guidelines can afford for prediction of concrete rheological behavior by implementing novel enhancing numerical techniques and exploring the finest process to evaluate the workability.

Details

World Journal of Engineering, vol. 21 no. 1
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 29 November 2021

Guangyuan Wu, Haitao Zhang, Junfeng Sun and Tengjiang Yu

In order to evaluate the rheological properties of asphalt more comprehensively and effectively, and to explore and discuss the practicability of relevant models in the evaluation…

Abstract

Purpose

In order to evaluate the rheological properties of asphalt more comprehensively and effectively, and to explore and discuss the practicability of relevant models in the evaluation of the rheological properties of asphalt.

Design/methodology/approach

Based on the rheological and viscoelastic theories, temperature scanning, frequency scanning and multiple stress creep recovery (MSCR) tests of different modified asphalt were carried out by dynamic shear rheometer (DSR) to obtain relevant viscoelastic parameters and evaluate the high temperature properties of different modified asphalt. Based on the time-temperature equivalence principle, the main curve was constructed to study the viscoelastic properties of asphalt in a wider frequency domain. The main curve was fitted with the CAM model, and the rheological properties of different modified asphalt were evaluated through the analysis of model parameters. The creep stiffness and creep velocity of different modified asphalt were obtained through the rheological test of bending beam (BBR), and the low-temperature performance of different modified asphalt was analyzed by using Burgers model to fit the creep compliance.

Findings

The results show that the high temperature rheological properties of several modified asphalt studied in the test are ranked from best to worst as follows: PE modified asphalt > SBS modified asphalt > SBR modified asphalt. Short-term aging can improve the high temperature performance of asphalt, and different types of modifiers can promote or inhibit this improvement effect. Based on BBR test and Burgers model fitting analysis, SBR modified asphalt has the best low temperature performance, followed by SBS modified asphalt, while PE modified asphalt has poor low temperature performance, so it is not suitable to be used as road material in low temperature area.

Originality/value

Combined with effective evaluation methods, the rheological properties of asphalt at different temperatures and angles were systematically evaluated, and the evolution of rheological properties of asphalt characterized by model parameters was further analyzed by advanced model simulation.

Details

Journal of Engineering, Design and Technology , vol. 21 no. 5
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 13 November 2017

Fei Yan, Ziyu Wang, Yuchen Du, Shijie Su, Yan Zheng and Qinfeng Li

This paper aims to investigate the flow characteristics of lubricating grease in extremely cold weather in which it is difficult to convey the grease due to a huge pressure drop.

Abstract

Purpose

This paper aims to investigate the flow characteristics of lubricating grease in extremely cold weather in which it is difficult to convey the grease due to a huge pressure drop.

Design/methodology/approach

The rheological behavior of grease at various temperatures is studied by a rotary rheometer to determine the constitutive equation of lubricating grease. Based on the Herschel–Bulkley (H–B) model, the flow pattern of grease is then simulated by computational fluid dynamics and compared with the test results.

Findings

The yield stress increased dramatically when the shear rate was less than 1s−1 in the rheological experiments of continuous shear mode, and the phenomenon was more significant with the decrease in temperature. The rheological data obtained from the continuous shear mode agrees with the H–B equation after the shear thinned. In extremely cold conditions, there is a large yield stress in the lubricating grease; the numerical results show that the viscosity of lubricating grease increased with an increase in temperature, and the viscosity and velocity of lubricating grease showed uneven distribution leading to difficulty of lubricating grease delivery.

Originality/value

This paper focuses on the flow characteristics of lubricating grease in extremely cold area conditions which is studied rarely. In addition, the continuous shear model and oscillatory model are combined to establish the constitutive equations. Experiment and numerical simulation method are all used by establishing the H–B models.

Details

Industrial Lubrication and Tribology, vol. 69 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

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