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Messages - Khandoker Samaher Salem

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136
Informative post. We have to be concerned about it.

137
NIce post. Hopefully it will help all of us.

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Yes, incorporation of CNTs is one of the ways to prepare Smart fabrics which is designed to get electricity, besides other types of nanotubes and nano particles can be used also.

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Smart fabrics and interactive textiles (SFIT) are defined as textiles that are able to sense stimuli from the environment and react or adapt to them in a predetermined way. For example, smart textiles/garments can incorporate sensors/actuators, processing and communications for use in applications such as health monitoring, consumer products and in the automotive sector. Smart fabrics and interactive textiles represent the next generation of fabrics and the potential opportunities for exploiting them are enormous. During recent involvement with the textiles community and talking in particular to developers of smart fabrics and intelligent clothing, it has become clear that a major obstacle towards integrating electronic functionality into fabrics is the portable power supply required. For example, whilst conductive tracks can be printed onto, or conductive yarns woven into, a fabric, the power supply for any integrated device is presently a standard battery. This requires conventional connection and must be repeatedly replaced and removed during washing. No matter how integrated the functionality of the fabric becomes, at present there is no alternative to powering the system using discrete batteries.

Energy harvesting (also known as energy scavenging) is concerned with the conversion of ambient energy present in the environment into electricity. Energy Harvesting is now a significant research topic with conferences such as PowerMEMS, IEEE MEMS, Transducers, DTIP and Eurosensors featuring at least one session on the subject. Energy harvesters do not have the energy density (energy stored for a given volume) of a battery but offer the attraction of an integrated power supply that will last the lifetime of the application and will not require recharging or replacement. This project will focus on harvesting energy from two sources: kinetic and thermal energy all of which have been identified as promising approaches for powering mobile electronics.

- Kinetic Energy Harvesting - For example, there is a large amount of kinetic energy available from human motion. Human motion characterised by large amplitude, low frequency movements that can also exert large forces. It has been estimated that 67W of energy are available in each step .

- Thermal Energy Harvesting - Harvesting of energy from heat sources (such as the human body) can be achieved by the conversion of thermal gradients to electrical energy using the Seebeck effect. There has been interest in the generation of power from body heat as a means to power wearable devices. For example Seiko have produced a wrist watch powered by body heat. Reported results for power densities achieved from micro-fabricated devices are 0.14 microW/mm^2 from a 700 mm^2 device for a temperature difference of 5 K, which is typically achievable for wearable applications.

The proposal involves using rapid printing processes and active printed inks to achieve energy harvesting fabrics. This will result in a low cost, easy to design, flexible and rapid way to realise energy harvesting textiles/garments. Both inkjet and screen printed are fully accepted processes widely used in the textile industry for depositing patterns. The proposed screen and inkjet printing processes have many benefits including low-cost, repeatability, flexibility, suitability for small/medium series and mass production, short development time, compatibility with a wide range of textiles and the capability of depositing a wide range of materials. The inks and associated printing parameters will be researched to enable the bespoke design and layout of the energy harvesting films in the application being addressed. The research will provide a toolbox of materials and processes suitable for a range of different fabrics that enable a user to develop the energy harvesting fabric best suited to their requirements.

References

Research Group: Electronics and Electrical Engineering
Themes: Energy Harvesting, Novel Sensors
University of Southampton

140
Science and Information / Re: Reduction of end Breakage in spinning
« on: July 23, 2013, 12:50:16 PM »
Good one. Can you please give more info about it.

141
Is it applicable for day to day usable fabric in terms of economic view.

142
Nutrition and Food Engineering / Uncovering the secrets of tea
« on: November 17, 2012, 12:02:06 PM »
Everyone knows that a cup of tea is good for you, but the exact reasons for this are not clear. To discover the fundamentals of tea’s health benefits, scientists in Germany have investigated the interactions of compounds from tea with cells on a molecular level.

Both green and black tea contain  around 30,000 polyphenolic compounds, some of which have been shown to have numerous health benefits, including reducing cardiovascular disease, osteoporosis and inflammation. Despite their positive effects, which have been seen in epidemiological findings and clinical trials, their exact biochemical mechanism is still not clear. Polyphenols can act as antioxidants, and for a long time this was thought to be the reason for their health benefits. However, recent studies have shown that this only plays a small part in their effectiveness.

To uncover how tea polyphenols affect cells, Nikolai Kuhnert from Jacobs University Bremen, and colleagues, set out to investigate the interactions of tea polyphenols at a molecular level. Working from a previous report that showed that tea polyphenols accumulated in the nuclei of plant cells, they used mass spectrometry and circular dichroism spectroscopy to measure the interactions between individual polyphenol molecules and biomolecules from the nucleus – histone proteins, double-stranded DNA and quadruplex DNA.

The scientists found that the polyphenols bound to the proteins and the DNA, but also that two major polyphenols showed selectivity for binding to quadruplex DNA over double-stranded DNA. Quadruplex DNA makes up the telomeres at the ends of chromosomes, which protect the chromosome from deterioration (for example, through ageing). ‘One can speculate that any compound able to bind to the quadruplex stabilises it and prolongs the life-span of an organism,’ says Kuhnert. ‘Additionally, the telomere plays an important role in cancer therapy.’

Susanne Henning from the Centre for Human Nutrition, University of California Los Angeles, US, comments: ‘It appears to be highly sophisticated chemistry. However, as the authors point out, this is only an in vitro study. There are limiting factors for the tea polyphenols being taken up and highly metabolised and excreted rapidly in the urine.’ Kuhnert agrees: ‘For this work, it needs to be urgently established whether any phenolics accumulate in the cell nucleus of human cells under dietary settings.’

The team hopes that this work will spark new avenues of research in tea polyphenols and are planning to continue their work on the characterisation of processed foods, identifying compounds with interesting biological activities. They are particularly interested in black tea, caramel and roasted coffee, and are just beginning to investigate cocoa, which is even more complex than tea.

References


G Mikutis et al, Food Funct., 2012, DOI: 10.1039/c2fo30159h

Source:Internet



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Interesting Maths / Re: Tower of Hanoi
« on: November 15, 2012, 05:37:39 PM »
Interesting !!!

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