The role of ascorbate in antioxidant protection of biomembranes: Interaction with vitamin E and coenzyme Q

One of the vital roles of ascorbic acid (vitamin C) is to act as an antioxidant to protect cellular components from free radical damage. Ascorbic acid has been shown to scavenge free radicals directly in the aqueous phases of cells and the circulatory system. Ascorbic acid has also been proven to protect membrane and other hydrophobic compartments from such damage by regenerating the antioxidant form of vitamin E. In addition, reduced coenzyme Q, also a resident of hydrophobic compartments, interacts with vitamin E to regenerate its antioxidant form. The mechanism of vitamin C antioxidant function, the myriad of pathologies resulting from its clinical deficiency, and the many health benefits it provides, are reviewed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44796/1/10863_2004_Article_BF00762775.pd

Experiments and entropy generation minimization analysis of a cross-flow heat exchanger

This paper presents a cross-flow plate type heat exchanger which has been studied and manufactured in the laboratory conditions because of its effective use in waste heat recovery systems. This new heat exchanger is tested with an applicable experimental set up, considering temperatures, velocity of the air and the pressure losses occurring in the system. These variables have measured and the efficiency of the system has determined. The irreversibility of the heat exchanger has been taken into consideration while the design of the heat exchanger is being performed so that the minimum entropy generation number has analysed with respect to second law of thermodynamics in the cross-flow heat exchanger. The minimum entropy generation number depends on parameters called optimum flow path length, dimensionless mass velocity and dimensionless heat transfer area. Variations of the entropy generation number with these parameters are analysed and introduced with their graphics and comments. © 1997 Elsevier Science Ltd

An investigation on colour analysis and fastness properties of the denim fabric dyed with a different method

Denim is a fabric which is produced by weaving dyed warp and weft yarns. The most important feature of denim fabric is the colour which is created by indigo dyeing. The mere reason for this special look is magical ''Indigo'' which the warp yarns are dyed with. In this study, an innovative dyeing method was applied by adding an extra step to indigo-sulphur dyeing. The main target was achieving the unique colour transitions and appearances. At the scheduled research, colour analysis and fastness properties were evaluated

Comfort and performance properties of raised and laminated denim fabrics

In this study, denim fabrics manufactured using standard processes were selected as reference fabric and subjected to mechanical and chemical finishing treatment. The effects of the two finishing treatments on the comfort and performance properties of the fabric were investigated. The test samples were the reference fabric, raised fabric and laminated fabric. The comfort tests were for fabric thickness, air permeability and water vapor permeability. The performance tests were for tensile strength, fabric stiffness, tearing strength and fastness. Colour and microscopic image analyses of the samples were also made and evaluated. Raising and lamination improved the thermal resistance properties, whereas raising increased air permeability. Evaluating the performance, fastness and colour properties of the raised and laminated fabric samples did not reveal any significantly negative outcomes. Raising can be recommended for use on the condition that seasonal variations be considered, since it creates comfortable denim fabrics with improved thermal resistance and air permeability. © 2016, Institute of Biopolymers and Chemical Fibres. All rights reserved

Irreversibility analysis of cross flow heat exchangers

In this paper, a cross flow plate type heat exchanger, operating with unmixed fluids, was analyzed with balanced cross flow. For this aim, a cross flow plate type heat exchanger was developed and manufactured in the laboratory. The heat exchanger was tested with an applicable experimental set up, and temperatures, velocity of the air and the pressure losses occurring in the system were measured so that the effectiveness of the heat exchanger has been determined. The minimum entropy generation number has been taken into consideration with respect to the second law of thermodynamics for the heat exchanger in this analysis. The minimum entropy generation number depends on parameters such as optimum flow path length, dimensionless mass velocity, dimensionless heat transfer area and dimensionless heat transfer volume. The variations between the entropy generation number and these parameters were analyzed for the manufactured heat exchanger and introduced with their graphics

An experimental application on denim garment to give thermal regulation property

In this context, the influence of ‘phase change material (PCM) finishing on denim jeans’ on thermal regulation and other selected properties was investigated. Denim garments were treated with microcapsulated PCM in various concentrations given in bath and by dipping, followed by the curing process. Differential scanning calorimeter tests were applied to denim fabrics. Morphology of microcapsules was characterized by scanning electron microscopy analyses and color analyses of the garments were done and evaluated. © 2016 The Textile Institute

Investigation of some comfort properties of fabrics laminated with different types of membranes

The aim of this study is to determine and evaluate some comfort properties of laminated fabrics obtained with different membranes. In the study, 100% PES woven fabric was laminated using membrane materials as PU (polyurethane), PES (poliester) and PTFE (polytetrafluoroethylene). Water repellent finishing process was applied to these fabrics and some comfort tests of the fabric were carried out in two groups. These groups are; Group 1, subjected to lamination after the application of water repellent finishing process; group 2, subjected to water repellent finishing process after lamination process. The comfort tests included water repellent, air permeability, water impermeability, and water vapor transmission tests. The obtained results from experimental studies were compared with graphics and thus interpreted. In conclusion, it could be recommended to apply water repellent processes after lamination, in contrast to traditional method using water repellent process prior to lamination

Second-law and experimental analysis of a cross-flow heat exchanger

This article presents a cross-flow plate-type heat exchanger that has been studied and manufactured in laboratory conditions because of its effective use in waste heat recovery systems. This new heat exchanger was tested with an applicable experimental setup, considering temperatures, velocity of the air, and the pressure losses occurring in the system. These variables were measured and the efficiency of the system was determined. The irreversibility of the heat exchanger was taken into consideration, while the design of the heat exchanger was such that the minimum entropy generation number was analyzed with respect to the second law of thermodynamics in the cross-flow heat exchanger. The minimum entropy generation number depends on the parameters called the optimum flow path length and dimensionless mass velocity. Variations of the entropy generation number with these parameters are analyzed. © 1999 Taylor & Francis Group, LLC