Natural inorganic cation exchange materials, such as clays and zeolites, have been extensively studied and used in the removal of radioactive ions from water via ion exchange and are subsequently disposed of in a safe way. However, synthetic inorganic cation exchange materials – such as synthetic micas, g-zirconium phosphate, niobate molecular sieves, and titanate – have been found to be far superior to natural materials in terms of selectivity for the removal of radioactive cations from water. Radioactive cations are preferentially exchanged with sodium ions or protons in the synthetic material. More importantly, a structural collapse of the exchange materials occurs after the ion exchange proceeds to a certain extent, thereby forming a stable solid with the radioactive cations being permanently trapped inside. Hence, the immobilized radioactive cations can be disposed safely.

“Based on our earlier work, we have now demonstrated a potentially cost-effective method to remediate cesium and iodine ions from contaminated water by using the unique chemistry of titanate nanotubes and nanofibers to chemisorb these ions,” HuaiYong Zhu, a professor of chemistry at the Queensland University of Technology, tells Nanowerk.

The team, which reported their findings in the September 20, 2011 online edition of Angewandte Chemie International Edition (“Capture of Radioactive Cesium and Iodide Ions from Water by Using Titanate Nanofibers and Nanotubes”), also found that the new sorbents can not only take up these ions but efficiently trap them for safe disposal because of their unique structural and chemical features.

“The sorbents take up cesium ions via an exchange with sodium ions in the nanostructures; the rapid uptake of cesium ions eventually triggers a phase transition of the titanate and traps the cesium ions inside permanently for safe disposal,” explains Zhu. “This is because the fibers and tubes consist of negatively charged thin layers – as thin as two oxygen atoms – and phase transition of the layers with low rigidity can be readily induced.”

In order to capture and immobilize iodine ions from water, the researchers anchored silver oxide nanocrystals on the external surfaces of titanate nanotubes and nanofibers by chemical bonds owing to their crystallographic similarity. These composites can efficiently capture iodine ions forming silver iodine precipitate on the titanates.

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Ultraviolet radiation can be divided into three regions: UVA (320–400 nm), UVB(290–320 nm) and UVC (200–290 nm). Although UVC is the most damaging UV radiation, it is filtered out by the ozone layer in the stratosphere before reaching the earth’s surface. The radiation in the UVB region (partially filtered by ozone) can penetrate both the stratum corneum and the epidermis of human skin. It has
sufficient energy to cause damage, such as sunburn, to human skin. This is particularly true for fair-skinned individuals. The UVA radiation, which is unfiltered by ozone, has deeper penetration of human skin to the dermis; it, thereby, stimulates the formation of melanin and produces a tan, which acts as the first line of defense for the protection from sunburn. UVA radiation, therefore, is also called the “tanning region.” Although having considerably lower energy than UVB, UVA photons can cause delayed damages to the skin.

The fundamental function of a sunscreen is to serve as a filter that can prevent the penetration of ultraviolet radiation. The substances most commonly used in commercial sunscreen preparations include p-aminobenzoic acids (PABA), cinnamates, oxybenzone, salicylates, and metal oxides, such as TiO2 and ZnO. In addition to their ability to scatter sunlight, inorganic particles, such as TiO2, do
absorb strongly in the UVA and UVB regions.

Rutile and Anatase TiO2

In addition to its amorphous state, two of the most common crystalline forms of TiO2 are rutile and anatase. The two crystalline forms share many similarities, such as their physical appearance, refractive index, density, low toxicity, and high stability in the presence of strong acids and bases. As a physical blocker for sunlight, bot
crystalline forms would serve the purpose well. Their photochemical properties, however, are very different. TiO2 is a semiconductor. When a semiconductor particle absorbs light, it promotes an electron from its valence band to its conduction band, leading to a charge separation. In rutile TiO2, the charge separation is quickly diminished through a charge recombination within the particle and the energy is released as heat. This translates to a low photoactivity and an effective conversion of UV light into heat. As a result, any photoinduced reactions that can pose damage to the skin are avoided. The low photoactivity and its desirable UV absorption spectrum, which cover the entire erythemal curve make rutile TiO2 an ideal choice as UV blocker for sunscreen preparations.

For amorphous and anatase TiO2, the lifetime of the charge separation is much longer than that on a rutile particle. The electron and electron hole, therefore, have greater opportunity to undergo redox reactions on the surface; therefore, anatase has been extensively used for applications involving such electron transfer processes as
photocatalysis for environmental waste treatment and photovoltaic design for solar energy storage. Extensive reviews on these interesting topics are available. Due to their photoactivity, amorphous and anatase TiO2 are not suitable for sunscreen applications.

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The TiO2 nanoparticles induced single- and double-strand DNA breaks and also caused chromosomal damage as well as inflammation, all of which increase the risk for cancer. The UCLA study is the first to show that the nanoparticles had such an effect, said Robert Schiestl, a professor of pathology, radiation oncology and environmental health sciences, a Jonsson Cancer Center scientist and the study’s senior author.

Once in the system, the TiO2 nanoparticles accumulate in different organs because the body has no way to eliminate them. And because they are so small, they can go everywhere in the body, even through cells, and may interfere with sub-cellular mechanisms.

The study appeared the week of November 16 2009 in the journal Cancer Research.

In the past, these TiO2 nanoparticles have been considered non-toxic in that they do not incite a chemical reaction. Instead, it is surface interactions that the nanoparticles have within their environment- in this case inside a mouse — that is causing the genetic damage, Schiestl said. They wander throughout the body causing oxidative stress, which can lead to cell death.

It is a novel mechanism of toxicity, a physicochemical reaction, these particles cause in comparison to regular chemical toxins, which are the usual subjects of toxicological research, Schiestl said.

“The novel principle is that titanium by itself is chemically inert. However, when the particles become progressively smaller, their surface, in turn, becomes progressively bigger and in the interaction of this surface with the environment oxidative stress is induced,” he said. “This is the first comprehensive study of titanium dioxide nanoparticle-induced genotoxicity, possibly caused by a secondary mechanism associated with inflammation and/or oxidative stress. Given the growing use of these nanoparticles, these findings raise concern about potential health hazards associated with exposure.”

The manufacture of TiO2 nanoparticles is a huge industry, Schiestl said, with production at about two million tons per year. In addition to paint, cosmetics, sunscreen and vitamins, the nanoparticles can be found in toothpaste, food colorants, nutritional supplements and hundreds of other personal care products.

“It could be that a certain portion of spontaneous cancers are due to this exposure,” Schiestl said. “And some people could be more sensitive to nanoparticles exposure than others. “I believe the toxicity of these nanoparticles has not been studied enough.”

Schiestl said the nanoparticles cannot go through skin, so he recommends using a lotion sunscreen. Spray-on sunscreens could potentially be inhaled and the nanoparticles can become lodged in the lungs.

The mice were exposed to the TiO2 nanoparticles in their drinking water and began showing genetic damage on the fifth day. The human equivalent is about 1.6 years of exposure to the nanoparticles in a manufacturing environment. However, Schiestl said, it’s not clear if regular, everyday exposure in humans increases exponentially as continued contact with the nanoparticles occurs over time.

“These data suggest that we should be concerned about a potential risk of cancer or genetic disorders especially for people occupationally exposed to high concentrations of titanium dioxide nanoparticles, and that it might be prudent to limit their ingestion through non-essential drug additives, food colors, etc.,” the study states.

Next, Schiestl and his team will study exposure to the nanoparticles in mice that are deficient in DNA repair, to perhaps help find a way to predict which people might be particularly sensitive to them.

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Cancerous and non-cancerous cells are incubated with silver nanoparticle biotags, and then analyzed by shining the red laser on them. The biotags are shown on the cells' surface. Those glowing red in the middle are the cancer biomarkers, and those glowing green are standard biomarkers that bind to many cell types. A high ratio of red to green is found on the cancer cells.

While the new technology is years away from use in a clinical setting, the researchers are nonetheless confident that it will be useful in developing a microdevice that will help in understanding when prostate cancer will metastasize, or spread to other parts of the body.

“There have been studies to find the relationship between the number of cancer cells in the blood, and the outcome of the disease,” said first author Alessia Pallaoro, postdoctoral fellow in UCSB’s Department of Chemistry and Biochemistry. “The higher the number of cancer cells there are in the patient’s blood, the worse the prognosis.

“The cancer cells that are found in the blood are thought to be the initiators of metastasis,” Pallaoro added. “It would be really important to be able to find them and recognize them within blood or other bodily fluids. This could be helpful for diagnosis and follow-ups during treatment.”

The team developed a novel technique to discriminate between cancerous and non-cancerous cells using a type of laser spectroscopy called surface enhanced Raman spectroscopy (SERS) and silver nanoparticles, which are biotags.

The team is working to translate the technology into a diagnostic microdevice for studying cancer cells in the blood. Cells would be mixed with nanoparticles and passed through a laser, then discriminated by the ratio of two signals.

The two types of biotags used in this research have a particular affinity that is dictated by the peptide they carry on their surface. One type attaches to a cell receptor called neuropilin-1, a recently described biomarker found on the surface membrane of certain cancer cells. The other biotag binds many cell types (both cancerous and non-cancerous) and serves as a standard measure as the cells are analyzed.
In this study, the team mixed the two biotags and added them to the healthy and tumor cell cultures. The average SERS signal over a given cell image yielded a ratio of the two signals consistent with the cells’ known identity.

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World Energy Consumption, 1990- 2035 (quadrillion Btu), source: eia.gov

Although the world continues to recover from the 2008-2009 global recession, the recovery is uneven. In advanced economies, recovery has been slow in comparison with recoveries from past recessions. Unemployment is still high among the advanced economies, and real estate markets and household income growth remain weak. Debt levels in a number of small economies of the European Union—Greece, Ireland, and Portugal—required European Union intervention to avert defaults. Concerns about fiscal sustainability and financial turbulence suggest that economic recovery in the OECD countries will not be accompanied by the higher growth rates associated with past recoveries. In contrast, growth remains high in many emerging economies, in part driven by strong capital inflows and high commodity prices; however, inflation pressures remain a particular concern, along with the need to rebalance external trade in key developing economies.

Beyond the pace and timing of the world’s economic recovery, other events have compounded the uncertainty associated with this year’s energy outlook. Oil prices rose in 2010 as a result of growing demand associated with signs of economic recovery and a lack of a sufficient supply response. Prices were driven even higher at the end of 2010 and into 2011 as social and political unrest unfolded in several Middle Eastern and African economies. Oil prices increased from about $82 per barrel3 at the end of November 2010 to more than $112 per barrel in day trading on April 8, 2011. The impacts of quickly rising prices and possible regional supply disruptions add substantial uncertainty to the near-term outlook. In 2011, the price of light sweet crude oil in the United States (in real 2009 dollars) is expected to average $100 per barrel, and with prices expected to continue increasing in the long term, the price reaches $108 per barrel in 2020 and $125 per barrel in 2035 in the IEO2011 Reference case.

The aftermath of the devastating earthquake and tsunami that struck northeastern Japan on March 11, 2011—which resulted in extensive loss of life and infrastructure damage, including severe damage to several nuclear reactors at Fukushima Daiichi—provides another major source of uncertainty in IEO2011. The near-term outlook for Japan’s economy is lower than the already sluggish growth that was projected before the events, but the impact on the rest of Asia and on world economic health as a whole probably will be relatively small, given that Japan has not been a major factor in regional economic growth in recent years. However, the event may have more profound implications for the future of world nuclear power. The IEO2011 projections do not reflect the possible ramifications of Fukushima for the long-term global development of nuclear power or the policies that some countries have already adopted in its aftermath with respect to the continued operation of existing nuclear plants. more

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In a press conference organised in Kathmandu Sunday, SEF founder Chanda Rana said the recent survey carried out by the Zoological Society of London found that 50 percent of the rhino have already been affected by the Mikania.

“During my filming I found one third of prime rhino habitat in the CNP were already engulfed by the infestation of the wild weed,” said Rana who has recently produced a documentary called ‘Mile a Minute, a serious threat to CNP’, as an initiation to raise awareness regarding the impact of the wild climber.

Rana also informed that SEF will organise a national workshop in the second week of November at CNP which will have the participation of all the stakeholders on Mikinia infestation.

The SEF has also planned to arrange visit of Prime Minister Baburam Bhattarai to some areas of the national park where infestation of Mikinia Micrantha is most severe. nepalnews.com

What is Mikania micrantha ?

Mikania micrantha is a perennial creeping climber known for its vigorous and rampant growth. It is branchy, slender-stemmed perennial vine. The leaves are arranged in opposite pairs along the stems and are heart-shaped or triangular with an acute tip and a broad base. Leaves may be 4-13cm long. The flowers, each 3-5mm long, are arranged in dense terminal or axillary corymbs. Individual florets are white to greenish-white. The seed is black, linear-oblong, five-angled and about 2mm long. Each seed has a terminal pappus of white bristles that facilitates dispersal by wind or on the hair of animals.

Botanical name: Mikania micrantha (L.) Kunth
Nepali: Lahare Banmara
Common names: American rope (English), Chinese creeper (English)

Mikania micrantha is plant killing weeds and which is mostly affects young regeneration and creates unfavorable condition for regeneration. It is newly seen in Nepal and it is not in people’s notice. Several countries and territories are trying to manage the major weeds of the region but result seen is not effective. It can be reduced or eradicated through creating shade which is not suitable for Mikania micrantha. Several community forests are also affected by this weeds which can be eradicated through user participation. It is important to control or destroy in very beginning before dispersal of seeds. If it is spread widely will reduce the productivity, destroy regeneration and degrade the forest condition. Once it proliferated throughout the forest then will become costly to control by any means. Control burning is also one way to contain chances of wider spreading. more

A carcinogen is a substance that causes a cellular malfunction, causing the cell to become cancerous and thus potentially lethal to the surrounding tissue and ultimately the body as these rapidly growing mutated cells take over. With the surge in cancer rates among all segments of the population, many people are attempting to reduce or eliminate their exposure to carcinogens. Titanium dioxide is regarded as an inert, non-toxic substance by many regulatory bodies such as the MSDS (Material Safety Data Sheets) and others charged with the responsibility of safeguarding the health of occupational workers and public health. the MSDS states that titanium dioxide can cause some lung fibrosis at fifty times the nuisance dust, defined by the US Department of Labor as 15 mg/m cubed (OSHA) or 10 mg/m cubed (ACGIH Threshold Limit Value). the ACGIH states that titanium dioxide is not classifiable as a human carcinogen. Symptoms of chronic overexposure to titanium dioxide in an industrial setting, according to the MSDS, include a slight increase in lung tumour incidence in lab rats. it also states when titanium dioxide was fed to rats/mice in a carcinogen bioassay, it was not carcinogenic. the NIOSH declares that at 5000 mg/m cubed there was slight lung fibrosis, concluding that this substance was carcinogenic in rats.

The NIOSH declaration of carcinogenicity in rats is based on a study by Lee, Trochimowicz & Reinhardt, Pulmonary Response of Rats Exposed to Titanium Dioxide by Inhalation for two Years (1985). the authors of this study found that rats chronically exposed to excessive dust loading of 250 mg/m cubed and impaired clearance mechanisms within the rat, for six hours per day, five days per week for two years, developed slight lung tumours. they also noted that the biological relevance of this data to lung tumours in humans is negligible. it is important to note that rats are known to be an extremely sensitive species for developing tumours in the lungs when overloaded with poorly soluble, low toxicity dust particles. Rat lungs process particles very differently compared to larger mammals such as dogs, primates or humans (Warheit, 2004). this sensitivity in the lungs has not been observed in other rodent species such as mice or hamsters (Warheit, 2004), therefore using the rat model to determine carcinogenicity of titanium dioxide in humans can be misleading, as extrapolation of species-specific data to humans is erroneous.

Many organizations and businesses have perpetuated this assessment of the carcinogenicity of titanium dioxide (ewg.org). however, several studies and study reviews have been used to compile the safety disclaimers for the regulations on the permitted use of titanium dioxide. One such study review took place in Rome, 1969 between the World Health Organization and the Food & Agriculture Organization of the United Nations. Cross species analyses were performed and reviewed for possible toxicity of titanium dioxide. the conference concluded that among the following species: rats, dogs, guinea pigs, rabbits, cats and human males, ingestion of titanium dioxide at varying diet percentages and over long periods of time did not cause absorption of this mineral. Titanium dioxide particulates were not detected in the blood, liver, kidney or urine and no adverse effects were noted from its ingestion. the U.S. Food & Drug Administration (2002) allows for its ingestion, external application including the eye area, and considers it a safe substance for public health. other epidemiological studies showed that workers exposed to titanium dioxide exhibited no statistically significant relationship between such exposure with lung cancer and respiratory disease, although some cases of pulmonary fibrosis did occur. these studies were conducted in industrial settings where the increased exposure puts these individuals more at risk than the average person.

Titanium dioxide is listed as a safe pigment, with no known adverse effects. it is not listed as a carcinogen, mutagen, teratogen, comedogen, toxin or as a trigger for contact dermatitis in any other safety regulatory publications beside the NIOSH (Antczak, 2001; Physical & Theoretical Chemical Laboratory, Oxford University respectively).

One form of mineral or mineral extract, including titanium dioxide, that we should be concerned about is ultrafine or nano particles. As technology has advanced, so has its ability to take normal sized particles of minerals and reduce them to sizes never before imagined. While many are praising this new technology, others are warning of its inherent dangers to our bodies. a study by Churg et. al. at the University of British Columbia in their paper Induction of Fibrogenic Mediators by Fine and Ultrafine Titanium Dioxide in Rat Tracheal Explants (1999) found that ultrafine particles of the anatase form of titanium dioxide, which are less than 0.1 microns, are pathogenic or disease causing.

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Deputy Bangkok Governor Mr. Theerachon Manomaipiboon presided over the launching of ‘Bangkok Car Free Day 2011’ today to raise the awareness of the global warming and encourage people to leave their cars at home and instead travel by public transportation or ride a bicycle on Sunday.

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A team led by Hansan Liu, Gilbert Brown and Parans Paranthaman of the Department of Energy lab’s Chemical Sciences Division found that titanium dioxide creates a highly desirable material that increases surface area and features a fast charge-discharge capability for lithium ion batteries. Compared to conventional technologies, the differences in charge time and capacity are striking.

“We can charge our battery to 50 percent of full capacity in six minutes while the traditional graphite-based lithium ion battery would be just 10 percent charged at the same current,” Liu said.

Compared to commercial lithium titanate material, the ORNL compound also boasts a higher capacity – 256 vs. 165 milliampere hour per gram – and a sloping discharge voltage that is good for controlling state of charge. This characteristic combined with the fact oxide materials are extremely safe and long-lasting alternatives to commercial graphite make it well-suited for hybrid electric vehicles and other high-power applications.

The results, recently published in Advanced Materials, could also have special significance for applications in stationary energy storage systems for solar and wind power, and for smart grids. The titanium dioxide with a bronze polymorph also has the advantage of being potentially inexpensive, according to Liu.

At the heart of the breakthrough is the novel architecture of titanium dioxide, named mesoporous TiO2-B microspheres, which features channels and pores that allow for unimpeded flow of ions with a capacitor-like mechanism. Consequently, a lithium ion battery that substitutes TiO2-B for the graphite electrode charges and discharges quickly.

“Theoretical studies have uncovered that this pseudocapacitive behavior originates from the unique sites and energetics of lithium absorption and diffusion in TiO2-B structure,” the authors write in their paper, titled “Mesoporous TiO2-B Microspheres with Superior Rate Performance for Lithium Ion Batteries.”

Paranthaman noted that the microsphere shape of the material allows for traditional electrode fabrication and creates compact electrode layers. He also observed, however, that the production process of this material is complex and involves many steps, so more research remains to determine whether it is scalable.

Other authors of the paper are Zhonghe Bi, Xiao-Guang Sun, Raymond Unocic and Sheng Dai. The research was supported by DOE’s Office of Science, ORNL’s Laboratory Directed Research and Development program, and ORNL’s SHaRE User Facility, which is sponsored by Basic Energy Sciences.

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Given recent reports that show London’s air to be among the filthiest in Europe, a clothing solution could be just up London’s street. Especially if that street is Oxford Street or any other area with a high number of pedestrians.

“A significant reduction in the level of air borne pollutants in a large city such as London could be achieved if, for every metre of pavement width, 30 people wearing Catalytic Clothes walked past each minute,” say developers Catalytic Clothing.

The jeans, or any other clothing fitted with the new technology, “harness the power of a photocatalyst to break down air borne pollutants,” by using light as an energy source.

“When the light shines on the photocatalyst, the electrons in the material are rearranged and they become more reactive,” adds the Catalytic Clothing website.

Further reactions then “cause pollutants to break down into non-harmful chemicals”.

Any material can become a pollution eater with the addition of a sort-of conditioner containing the photocatalysts, but different materials need different catalyst set-ups.

For the purposes of demonstration, jeans fit the bill since, “there are more pairs of jeans in existence than there are people on the earth,” as the Catalytic Clothing people put it.

The nanotech denim – developed by a team at Sheffield University and another at the London College of Fashion – has been formed into a display called The Field of Jeans for the London Design Festival, which runs from 17-25 September.

catalytic clothing faq