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Carbon nanotube(Not to be confused with Carbon fiber.)
Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1,significantly larger than for any other material. These cylindrical carbon molecules have unusual properties, which are valuable for nanotechnology, electronics, optics and other fields of materials science and technology. In particular, owing to their extraordinary thermal conductivity and mechanical and electrical properties, carbon nanotubes find applications as additives to various structural materials. For instance, in (primarily carbon fiber) "baseball bats, car parts" and even "golf clubs" , where nanotubes form only a tiny portion of the material(s).
Nanotubes are members of the fullerene structural family, which also includes the spherical buckyballs, and the ends of a nanotube may be capped with a hemisphere of the buckyball structure. Their name is derived from their long, hollow structure with the walls formed by one-atom-thick sheets of carbon, called graphene. These sheets are rolled at specific and discrete ("chiral") angles, and the combination of the rolling angle and radius decides the nanotube properties; for example, whether the individual nanotube shell is a metal or semiconductor. Nanotubes are categorized as single-walled nanotubes (SWNTs) and multi-walled nanotubes (MWNTs). Individual nanotubes naturally align themselves into "ropes" held together by van der Waals forces, more specifically, pi-stacking.
Applied quantum chemistry, specifically, orbital hybridization best describes chemical bonding in nanotubes. The chemical bonding of nanotubes is composed entirely of sp2 bonds, similar to those of graphite. These bonds, which are stronger than the sp3 bonds found in alkanes, provide nanotubules with their unique strength.

Carbon nanotubes are the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively. This strength results from the covalent sp2 bonds formed between the individual carbon atoms. In 2000, a multi-walled carbon nanotube was tested to have a tensile strength of 63 gigapascals (GPa). (For illustration, this translates into the ability to endure tension of a weight equivalent to 6422 kg on a cable with cross-section of 1 mm2.) Further studies, conducted in 2008, revealed that individual CNT shells have strengths of up to ~100 GPa, which is in good agreement with quantum/atomistic models. Since carbon nanotubes have a low density for a solid of 1.3 to 1.4 g/cm3,its specific strength of up to 48,000 kN•m•kg−1 is the best of known materials, compared to high-carbon steel's 154 kN•m•kg−1.
Under excessive tensile strain, the tubes will undergo plastic deformation, which means the deformation is permanent. This deformation begins at strains of approximately 5% and can increase the maximum strain the tubes undergo before fracture by releasing strain energy.
Although the strength of individual CNT shells is extremely high, weak shear interactions between adjacent shells and tubes leads to significant reductions in the effective strength of multi-walled carbon nanotubes and carbon nanotube bundles down to only a few GPa’s.This limitation has been recently addressed by applying high-energy electron irradiation, which crosslinks inner shells and tubes, and effectively increases the strength of these materials to ~60 GPa for multi-walled carbon nanotubes and ~17 GPa for double-walled carbon nanotube bundles.
CNTs are not nearly as strong under compression. Because of their hollow structure and high aspect ratio, they tend to undergo buckling when placed under compressive, torsional, or bending stress.

Standard single-walled carbon nanotubes can withstand a pressure up to 24GPa without deformation. They then undergo a transformation to superhard phase nanotubes. Maximum pressures measured using current experimental techniques are around 55GPa. However, these new superhard phase nanotubes collapse at an even higher, albeit unknown, pressure.
The bulk modulus of superhard phase nanotubes is 462 to 546 GPa, even higher than that of diamond(420 GPa for single diamond crystal)

Kinetic properties
Multi-walled nanotubes are multiple concentric nanotubes precisely nested within one another. These exhibit a striking telescoping property whereby an inner nanotube core may slide, almost without friction, within its outer nanotube shell, thus creating an atomically perfect linear or rotational bearing. This is one of the first true examples of molecular nanotechnology, the precise positioning of atoms to create useful machines. Already, this property has been utilized to create the world's smallest rotational motor. Future applications such as a gigahertz mechanical oscillator are also envisaged.

Electrical properties

Band structures computed using tight binding approximation for (6,0) CNT (zigzag, metallic) (10,2) CNT (semiconducting) and (10,10) CNT (armchair, metallic).
Because of the symmetry and unique electronic structure of graphene, the structure of a nanotube strongly affects its electrical properties. For a given (n,m) nanotube, if n = m, the nanotube is metallic; if n − m is a multiple of 3, then the nanotube is semiconducting with a very small band gap, otherwise the nanotube is a moderate semiconductor. Thus all armchair (n = m) nanotubes are metallic, and nanotubes (6,4), (9,1), etc. are semiconducting.
However, this rule has exceptions, because curvature effects in small diameter carbon nanotubes can strongly influence electrical properties. Thus, a (5,0) SWCNT that should be semiconducting in fact is metallic according to the calculations. Likewise, vice versa-- zigzag and chiral SWCNTs with small diameters that should be metallic have finite gap (armchair nanotubes remain metallic).In theory, metallic nanotubes can carry an electric current density of 4 × 109 A/cm2, which is more than 1,000 times greater than those of metals such as copper, where for copper interconnects current densities are limited by electromigration.
Multiwalled carbon nanotubes with interconnected inner shells show superconductivity with a relatively high transition temperature Tc = 12 K. In contrast, the Tc value is an order of magnitude lower for ropes of single-walled carbon nanotubes or for MWNTs with usual, non-interconnected shells

Current applications
Current use and application of nanotubes has mostly been limited to the use of bulk nanotubes, which is a mass of rather unorganized fragments of nanotubes. Bulk nanotube materials may never achieve a tensile strength similar to that of individual tubes, but such composites may, nevertheless, yield strengths sufficient for many applications. Bulk carbon nanotubes have already been used as composite fibers in polymers to improve the mechanical, thermal and electrical properties of the bulk product.
•   Easton-Bell Sports, Inc. have been in partnership with Zyvex Performance Materials, using CNT technology in a number of their bicycle components—including flat and riser handlebars, cranks, forks, seatposts, stems and aero bars.
•   Zyvex Technologies has also built a 54' maritime vessel, the Piranha Unmanned Surface Vessel, as a technology demonstrator for what is possible using CNT technology. CNTs help improve the structural performance of the vessel, resulting in a lightweight 8,000 lb boat that can carry a payload of 15,000 lb over a range of 2,500 miles.
•   Amroy Europe Oy manufactures Hybtonite carbon nanoepoxy resins where carbon nanotubes have been chemically activated to bond to epoxy, resulting in a composite material that is 20% to 30% stronger than other composite materials. It has been used for wind turbines, marine paints and variety of sports gear such as skis, ice hockey sticks, baseball bats, hunting arrows, and surfboards.
Other current applications include:
•   tips for atomic force microscope probes
•   in tissue engineering, carbon nanotubes can act as scaffolding for bone growth

Potential applications
The strength and flexibility of carbon nanotubes makes them of potential use in controlling other nanoscale structures, which suggests they will have an important role in nanotechnology engineering. The highest tensile strength of an individual multi-walled carbon nanotube has been tested to be is 63 GPa Carbon nanotubes were found in Damascus steel from the 17th century, possibly helping to account for the legendary strength of the swords made of it

Because of the carbon nanotube's superior mechanical properties, many structures have been proposed ranging from everyday items like clothes and sports gear to combat jackets and space elevators. However, the space elevator will require further efforts in refining carbon nanotube technology, as the practical tensile strength of carbon nanotubes can still be greatly improved.
For perspective, outstanding breakthroughs have already been made. Pioneering work led by Ray H. Baughman at the NanoTech Institute has shown that single and multi-walled nanotubes can produce materials with toughness unmatched in the man-made and natural worlds.
Carbon nanotubes are also a promising material as building blocks in bio-mimetic hierarchical composite materials given their exceptional mechanical properties (~1TPa in modulus, and ~100 GPa in strength). Initial attempts to incorporate CNTs into hierarchical structures led to mechanical properties that were significantly lower than these achievable limits. Windle et al. have used an in situ chemical vapor deposition (CVD) spinning method to produce continuous CNT yarns from CVD grown CNT aerogels. With this technology, they fabricated CNT yarns with strengths as high as ~9 GPa at small gage lengths of ~1 mm, however, defects resulted in a reduction of specific strength to ~1 GPa at 20 mm gage length. Espinosa et al. developed high performance DWNT-polymer composite yarns by twisting and stretching ribbons of randomly oriented bundles of DWNTs thinly coated with polymeric organic compounds. These DWNT-polymer yarns exhibited unusually high energy to failure of ~100 J•g−1 (comparable to one of the toughest natural materials – spider silk), and strength as high as ~1.4 GPa. Effort is ongoing to produce CNT composites that incorporate tougher matrix materials, such as Kevlar, to further improve on the mechanical properties toward those of individual CNTs.
Because of the high mechanical strength of carbon nanotubes, research is being made into weaving them into clothes to create stab-proof and bulletproof clothing. The nanotubes would effectively stop the bullet from penetrating the body, although the bullet's kinetic energy would likely cause broken bones and internal bleeding.

In electrical circuits
As electrical cables and wires
As paper batteries
Solar cells
Hydrogen Storage
Radar Absorption

A 2006 editorial written by Marc Monthioux and Vladimir Kuznetsov in the journal Carbon described the interesting and often-misstated origin of the carbon nanotube. A large percentage of academic and popular literature attributes the discovery of hollow, nanometer-size tubes composed of graphitic carbon to Sumio Iijima of NEC in 1991.
In 1952 L. V. Radushkevich and V. M. Lukyanovich published clear images of 50 nanometer diameter tubes made of carbon in the Soviet Journal of Physical Chemistry. This discovery was largely unnoticed, as the article was published in the Russian language, and Western scientists' access to Soviet press was limited during the Cold War. It is likely that carbon nanotubes were produced before this date, but the invention of the transmission electron microscope (TEM) allowed direct visualization of these structures.
Carbon nanotubes have been produced and observed under a variety of conditions prior to 1991. A paper by Oberlin, Endo, and Koyama published in 1976 clearly showed hollow carbon fibers with nanometer-scale diameters using a vapor-growth technique.Additionally, the authors show a TEM image of a nanotube consisting of a single wall of graphene. Later, Endo has referred to this image as a single-walled nanotube.
In 1979, John Abrahamson presented evidence of carbon nanotubes at the 14th Biennial Conference of Carbon at Pennsylvania State University. The conference paper described carbon nanotubes as carbon fibers th
at were produced on carbon anodes during arc discharge. A characterization of these fibers was given as well as hypotheses for their growth in a nitrogen atmosphere at low pressures.
In 1981, a group of Soviet scientists published the results of chemical and structural characterization of carbon nanoparticles produced by a thermocatalytical disproportionation of carbon monoxide. Using TEM images and XRD patterns, the authors suggested that their “carbon multi-layer tubular crystals” were formed by rolling graphene layers into cylinders. They speculated that by rolling graphene layers into a cylinder, many different arrangements of graphene hexagonal nets are possible. They suggested two possibilities of such arrangements: circular arrangement (armchair nanotube) and a spiral, helical arrangement (chiral tube).
In 1987, Howard G. Tennett of Hyperion Catalysis was issued a U.S. patent for the production of "cylindrical discrete carbon fibrils" with a "constant diameter between about 3.5 and about 70 nanometers..., length 102 times the diameter, and an outer region of multiple essentially continuous layers of ordered carbon atoms and a distinct inner core...."
Iijima's discovery of multi-walled carbon nanotubes in the insoluble material of arc-burned graphite rods in 199and Mintmire, Dunlap, and White's independent prediction that if single-walled carbon nanotubes could be made, then they would exhibit remarkable conducting properties  helped create the initial buzz that is now associated with carbon nanotubes. Nanotube research accelerated greatly following the independent discoveries by Bethune at IBM and Iijima at NEC of single-walled carbon nanotubes and methods to specifically produce them by adding transition-metal catalysts to the carbon in an arc discharge. The arc discharge technique was well-known to produce the famed Buckminster fullerene on a preparative scale, and these results appeared to extend the run of accidental discoveries relating to fullerenes. The original observation of fullerenes in mass spectrometry was not anticipated, and the first mass-production technique by Krätschmer and Huffman was used for several years before realizing that it produced fullerenes.
The discovery of nanotubes remains a contentious issue. Many believe that Iijima's report in 1991 is of particular importance because it brought carbon nanotubes into the awareness of the scientific community as a whole

Textile science, events, trade and issues / wish uuuuuuuuuu
« on: January 01, 2012, 12:19:57 AM »
May the new year
Bring these wishes to all of you
Warmth of love, comfort of home
Joy for your children,
Company and support of family n friends
A caring heart that accepts
N treats all human beings equally
Enrichment of knowledge n
Richness of diversity
Courage to seek n speak the truth
Even if it means standing alone
Hopes n dreams of a just world n
The desire to make it happen
A light to guide your path
Helping hands to strengthen unity
Serenity n peace within your mind,
Heart n soul
Food for thought n soul
A hand to hold

2012 is Coming! Before 2011 Ends,

Let Me Thank all the Good People like U,
Who made '2011' so much Beautiful 4 Me.
I Pray U be Blessed with Faithful Years Ahead.

I wish You a

Fantastic JANUARY
Love able FEBRUARY
Marvelous MARCH
Fool less APRIL
Enjoyable MAY
Successful JUNE
Wonderful JULY
Independent AUGUST
Tastiest OCTOBER
Beautiful NOVEMBER

Have a VICTORIOUS '2012'

Textile science, events, trade and issues / Bamboo textiles
« on: December 30, 2011, 01:58:20 AM »
Bamboo textiles

Bamboo textiles are cloth, yarn, and clothing made out of bamboo fibres. While historically used only for structural elements, such as bustles and the ribs of corsets, in recent years a range of technologies have been developed allowing bamboo fibre to be used in a wide range of textile and fashion applications. Modern bamboo clothing is clothing made from either 100% bamboo yarn or a blend of bamboo and cotton yarn. The bamboo yarn can also be blended with other textile fibres such as hemp or even spandex.

Traditional uses
In China and Japan, thin strips of bamboo were woven together into hats and shoes. One particular design of bamboo hats was associated with rural life, being worn almost universally by farmers and fishermen in order to protect their heads from the sunAn 1881 bustle design.
In the West, bamboo, alongside other components such as whalebone and steel wire, was sometimes used as a structural component in corsets, bustles and other types of structural elements used in fashionable women's dresses.

Manufacture of bamboo viscose
Recent technologies have allowed cellulose processed from bamboo to be spun into viscose yarn.Modern bamboo yarn is therefore a regenerated cellulose fibre. One such technology was filed in 2003 as US patent 7313906 by inventors Xiangqi Zhou, Zheng Liu, Liming Liu, and Hao Geng developed one such method of turning bamboo into yarn, creating new uses for bamboo in clothing.

The steps in the manufacturing of bamboo viscose are as follows:
1) Bamboo leaves and the soft, inner pith from the hard bamboo trunk are extracted using a steaming process and then mechanically crushed
2) The crushed bamboo is soaked in sodium hydroxide to produce cellulose. A common misconception is that sodium hydroxide is a harmful chemical[citation needed]. If used in a responsible manner sodium hydroxide has little known effect on the environment and health of workers. It is routinely used in the processing of organic cotton into fibre and is approved by the Global Organic Textile Standards (GOTS) and the Soil Association.Sodium hydroxide does not remain as a residue on clothing as it easily washes away and can be neutralised to harmless and non-toxic sodium sulphate salt. A chemical used in this step that can cause nervous system damage with chronic exposure is carbon disulfide.If handled properly there are no negative side effects for humans and environment as sulphur containing by products can easily be transformed into sulphuric acid which is needed for the spinning process.
3) The bamboo cellulose is forced through spinneret nozzles (like a sieve) into a sulphuric acid bath that hardens the solution into viscose fibre threads and neutralizes the caustic sodium hydroxide to form Glauber's salt, sodium sulphate, which is used e.g. as a filler in lessive detergents. The process is the standard viscose process. This process is also used to manufacture fibres from wood pulp.
4) The fibre threads are spun into viscose yarn and rolled onto spools. According to textile classification so called bamboo is standard viscose, abbreviation CV. It has no advantages with respect to standard viscose made from wood pulp like e.g. beech or eucalyptus.
The processing of the cellulose pulp into fibre "can" be cleaner than the processing used for conventional viscose "if" a closed loop process captures and reclaims all the solvents used in the manufacturing, though this is "not" standard practice.New processes stress enviromental purity and is under constant observation to confirm non pollution. The resulting bamboo viscose fibre is very soft to the touch.

Source of raw material
Most of the bamboo used to make bamboo fibre and bamboo clothing is grown in China by Hebei Jigao Chemical Fiber Company.They hold the patent on the process for turning bamboo into fibre. This facility produces all of the bamboo viscose on the market. The bamboo is certified organic by OCIA (The Organic Crop Improvement Association). To strictly control the quality of raw material, Hebei Jigao Chemical Fiber Company has built its own bamboo plantation in Sichuan Province, China, and keeps strict control over it. The bamboo is grown in accordance to the international organic standard of OCIA/IFOAM and the USDA National Organic Program, so as to ensure each bamboo stalk is of 100% natural growth and without any chemical pesticides. The proof of the ecologically sound methods behind bamboo production is the fact that all of the fibre produced at the facility in China is Oeko-Tex 100 certified.This certifies that the finished fibre has been tested for any chemicals that may be harmful to a person’s health and has been found to contain no trace chemicals that pose any health threat whatsoever. This means that every company working with bamboo starts with the same raw material and that this material is not contaminated.

Textile science, events, trade and issues / Textile in Medical Science
« on: December 29, 2011, 12:12:11 AM »
         Textiles  in Medical Science

 Medical textiles are one of the most rapidly expanding sectors in the technical textile market, according to reports, and hosiery products with medical industry applications are among a long list of textile products being consumed in that market. An important field of application of textile in medicine has been developed such as wound care and preventing chronic wounds. Bandages and wound dressings are most commonly used because they are affordable and reusable. The medical textile should have bio-compatibility, flexibility and strength.

Combination of textile technology and medical sciences has resulted into a new field called medical textiles. New areas of application for medical textiles have been identified with the development of new fibers and manufacturing technologies for yarns and fabrics. Development in the field of textiles, either natural or manmade textiles, normally aimed at how they enhance the comfort to the users. Development of medical textiles can be considered as one such development, which is really meant for converting the painful days of patients into the comfortable days.
Medical and hygiene textiles products range from high volume disposable products for babies’ nappies, feminine hygiene and adult incontinence, to extremely specialised and high value textile products for use in blood filtration, surgical sutures, prostheses and, most recently, scaffolds supporting tissue growth.
    Bandages and dressing:
Bandages and dressings are both used in wound management. A bandage is a piece of cloth or other material used to bind or wrap a diseased or injured part of the body. Usually shaped as a strip or pad, bandages are either placed directly against the wound or used to bind a dressing to the wound. A dressing can consist of a wide range of materials, sometimes containing medication, placed directly against the wound.

    Artificial Kidney:
The kidney serve as filtering devices of the blood. The nephrons, the working units of kidney, filter waste materials out of the blood and produce urine to secrete toxins from body. The kidneys also maintain normal concentrations of body fluids, which play a key role in homeostasis. In the natural kidney, ultrafiltration of the blood occurs through the glomerular  capillaries leading to the removal of waste products and the purification of blood. In an artificial unit a membrane dependent ultrafiltration achieves essentially the same result. Hemodialysis is indispensable for people suffering from kidney disease.

     Mechanical lung:
Mechanical lungs use microporous membranes that provide high permeability for gases(both O2 and CO2) but low permeability for liquid flow and functions in the same manner as the natural lung allowing oxygen, displaces carbon dioxide, thus effecting purification. In this devices, oxygen flows around hollow fibres  at extremely low pressure. Blood flow inside of the fibre. The oxygen permeats the micropores of the fibre and comes in contact with the blood. The pressure gradient between the blood and oxygen is kept near zero to prevent mixing of oxygen and blood. Red blood cells capture oxygen by diffusion process.

     Artificial liver:
The artificial liver utilizes hollow fibres or membranes similar to those used for the artificial kidney to perform their  function . Oxygen cells are placed around the fibres and blood flows inside the fibre. Blood nutrients pass through the fibre wall to the oxygen cells and enzymes pass from the cells to the blood. The metabolism of the liver is very complicated which poses problems for the artificial liver. This can be solved by using a double lumen structure with a hollow fibre within a hollow fibre. Blood runs outside and in contact with liver cells and blood, and after purification it runs inside the fibre.

We see from our discussion technical textile use in medical science widely. And we see most of the artificial body parts made by technical textile.

Textile science, events, trade and issues / Problems og RMG in bangladesh
« on: December 28, 2011, 01:11:40 AM »
 ???************Problems Of Rmg Sector*********** ???

Problems Regarding With RMG
The garment industry of Bangladesh has been the key export division and a main source of foreign exchange for the last 25 years. National labor laws do not apply in the EPZs, leaving BEPZA in full control over work conditions, wages and benefits. Garment factories in Bangladesh provide employment to 40 percent of industrial workers. But without the proper laws the worker are demanding their various wants and as a result conflict is began with the industry.
Low working salary is another vital fact which makes the labor conflict. Worker made strike, layout to capture their demand. Some time bonus and the overtime salary are the important cause of crisis. Insufficient government policy about this sector is a great problem in Garments Company.
There are some other problems which are associated with this sector. Those are- lack of marketing tactics, absence of easily on-hand middle management, a small number of manufacturing methods, lack of training organizations for industrial workers, supervisors and managers,
autocratic approach of nearly all the investors, fewer process units for textiles and garments, sluggish backward or forward blending procedure, incompetent ports, entry/exit complicated and loading/unloading takes much time, time- consuming custom clearance etc.

autocratic approach of nearly all the investors, fewer process units for textiles and garments, sluggish backward or forward blending procedure, incom
Percentage (%)
Medium Low
Graph: Secondary problems of Garments Industries
Safety Problems
Safety need for the worker is mandatory petent ports, entry/exit complicated and loading/unloading takes much time, time- consuming custom clearance etc.
to maintain in all the organization. But without the facility of this necessary product a lot of accident is occur incurred every year in most of the company. Some important cause of the accident are given below-
● Routes are blocked by storage materials
● Machine layout is often staggered
● Lack of signage for escape route
● No provision for emergency lighting
● Doors, opening along escape routes, are not fire resistant.
● Doors are not self-closing and often do not open along...

The problems in the industry pre-date the riots which took place just over a month ago and which were attended by deaths, injuries and the destruction of property. Over the years, hazardous working conditions have resulted in the deaths of many workers through factory fires and collapses.The Spectrum Factory building collapse of April 2005 killed 64 people, injured over 70 and left hundreds jobless. In February 2006 a fire destroyed the four-story KTS Textile Industries in Bangladesh’s port city of Chittagong again killing scores of mostly young and female workers. Workers, who are mostly young women, also face an acutely difficult working environment – wages are low, hours are long, forced labour is practised, child labour exists, sexual harassment exists, freedom is curtailed, whether it be locked doors or rights of association, and there are a multititude of other practices which go against international labour standards and codes of conduct (= non-compliance).
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At the level of legislation and business dealings, lack of implementation of laws, restrictive laws and unfair buying practices by buyers compound the issue of non-compliance.

What is to be done?

What has emerged quite emphatically is that for the Bangladesh industry to survive it has to take on board the issue of “compliance” with internationally recognised social, labour and environmental standards. There are many initiatives underway – buyers have their corporate social responsibility initiatives, the government has set up task forces and fora, there are the Memoranda of Understanding with the trade unions and the manufacturers’ and exporters’ associations. There are many stakeholders, and dialogue is imperative and all important. There needs to be the capacity and will amongst all the stakeholders, and particularly the government, to take forward and develop “compliance” and create an industry with an enhanced global image and global...
 ;D :)

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