Here’s an article that may be of the members’ interest. Chemical and Engineering News published a cover story about the latest development in Yucca Mountain repository for nuclear waste. It has a comprehensive review for the history and experts’ opinions on this issue, but not much new information. For the full text, check out the link: The Forever Waste .

For those who are following the element 122 discussions, a fellow DNCT member wrote an excellent review on the validity of their data. To learn more or join the discussion, check out Addressing Marinov’s Element 122 Claim.

Noel

[1] Photo of Yucca Mountain from Wikipedia

PDF Article Link

According to the LA Times report[1], these greens are washed in potent chlorine bath, often up to three times, before they are bagged and shipped to the retailer. This standard procedure has a reported 90% effectiveness in killing the microorganisms that may cause harmful effects to the human body.

I don’t know about you, but I would rather not take that 10% chance to get sick. In the single breakout of E. Coli due to cross contamination with the cattle back in 2006, 200 people became ill and three lost their lives. That’s the 10% chance that nobody should have to take.

This past month at the ACS National Meeting in New Orleans, researchers from the USDA presented their findings and results of radiation treatment of fresh produces. Irradiation of high energy beams of photons or electrons, said the scientist, can disrupt the DNA of these pathogens. While the chlorine rinse offers a 90% effectiveness in killing bacterias on the surface of the leaves, it is not able to penetrate beneath the surface. Irradiation method has a reported >99.9% effectiveness in wiping out pathogens such as E. coli, salmonella and listeria, and the high energy beams allows penetrating power that works inside and outside the leaves.

Some members of the scientific community are calling irradiation one of the “few intervention steps that indeed can penetrate the leaf surface and kill microorganisms.”

Irradiation for enhancement of food safety is permitted for some hamburger meat, poultry and spices, but not for fruits and vegetables. However, there has not been any health problems associated with eating irradiated food. So why is FDA steering away from adopting an improved method that could potentially save lives?

Consumer experts and food safety researchers offer some of their speculations:

1. Irradiation may damage the apparence of the product, which may not be as appealing to the customers
2. Nobody would buy lettuce from a bag with a radiation sticker
3. The treatment could shorten shelf lives of the products
4. Technically, irradiated produces cannot be certified organic

Though reasonable, it is hard to believe that the above mentioned points would stop either FDA or independent research institutes from further investigating in a method that could possibly be so much more potent in eradicating pathogens than the existing practice. Perhaps these novel ideas would not suffer as much if we could deliver more transparent and correct ideas regarding the applications of radiation.

Using innovative ideas to improve the quality of our everyday lives, isn’t that what science is all about?

Noel

[1] USDA scientists say irradiation could be key to food safety

A complete listing of available channels is available at:

http://aimtvgroup.com/altv/wheretowatch/

So far we have seen several new members sign up and have already gained another author. So sign up, and take part in the latest tool for the DNCT.

Also, the talk Noel and I gave about online social networking tools (this blog specifically) in a CHED symposium can be found here:

Incorporating Online Social Networking tools to Facilitate Participation and Discussion in Nuclear Chemistry.

However, here’s some info on sessions you really should attend:

1.) Monday, April 7 2008, at 4:35 PM Hilton New Orleans Riverside — Oak Alley, Oral #768
Incorporating social networking tools to facilitate participation and discussion in nuclear chemistry
M. N. Ali, Noel N Chang, Mitch A. Garcia, Heino Nitsche

That will be the semi-grand unveiling of this blog. Be sure to attend to learn more about how to get involved in the blog, and hear about future development plans.

2.) Monday, April 7 2008, at 8:35 AM Hilton New Orleans Riverside — Oak Alley, Oral #184
Development of chemical forums, blogs, wikis, RSS feeds, crowdsourcing, and social bookmarking websites for chemistry
Mitch A. Garcia, M. N. Ali, Noel N Chang, Heino Nitsche

Attend this session to learn more about how to use new internet technologies for research and teaching purposes.

For the DNCT sessions, here is how the timing has worked out.

See complete list of sessions

Legend A = AM; P = PM; D = AM/PM;

Don’t forget that the NUCL business meeting from 5 - 6pm Monday evening at 211 — E. Morial Convention Center.

We all expect that a persons diet greatly affects the concentration of certain commonly found isotopes. 13C, 15N, 34S, 40K are all present in our bodies, though in such small quantities that they don’t appear to have a significant effect on our health. Ideally you could measure the concentration of these isotopes, or their relative isotopic ratio, and learn the dietary habits of an individual. By taking into account small differences caused by fractionation events during metabolism and the larger differences in 15N values, the isotopic ratios of 13C, 15N, and 34S provide limited geographic based information about the origins of a food source.

Cerling and Ehleringe, however, chose to look at a more unlikely source for traceable isotopes that turns out to be more useful and easily detectable.

Hydrogen (²H) and oxygen (¹⁸O) isotope ratios of organic matter are more useful, because ²H and ¹⁸O values of precipitation and tap waters vary along geographic gradients (10, 11). Although differences in the ²H and ¹⁸O values of scalp hair have been noted in humans (12), less is known about diet–organism patterns of ²H and ¹⁸O values. Four potential sources can be important: dietary organic molecules, dietary waters, drinking waters, and atmospheric diatomic oxygen.

The ²H and ¹⁸O values of keratin in human hair should be influenced by a number of factors during synthesis within the hair follicle, including all dietary and atmospheric sources of H and O. Bear in mind, however, that their discussion was limited to the ²H that was not subject to postsynthesis isotopic exchange. Cerling and Ehleringe hypothesized that variations in the nonexchangeable ²H and ¹⁸O values in human keratin could provide insights into water and human diet across geographical regions if the hydrogen and/or oxygen isotopes from these sources were recorded in human hair.

After developing a model to account for the difference in the isotopic ratios between drinking water, body water and the actual scalp hair, Cerling and Ehleringer tested the model by attempting to predict the geographic region of origin of individuals based on the isotope composition. They obtained ²H and ¹⁸O values in hair sampled from 65 cities in 18 states. Their model which was a function of drinking water, bulk diet, and protein isotope ratios, explained more then 85% of the observed variation and strongly reproduced the relationship of the isotopic composition of hair samples to that of local drinking water.

Plots of the relationships between mean H isotope ratios (Upper) and mean O isotope ratios (Lower) of human scalp hair and tap water for samples randomly acquired in cities representing 18 states across the United States. The lines through the data in each plot represent model-predicted values based on local tap water and a continental supermarket diet.

The really interesting part, though, is this:

Based on the geographical distributions of the isotope ratios of tap waters and the assumption of a “continental supermarket” dietary input, we constructed maps of the expected average H and O isotope ratios in human hair across the contiguous 48 states. Applications of this model and these observations are extensive and include detection of dietary information, reconstruction of historic movements of individuals, and provision of region-of-origin information for unidentified human remains.

So now using a sample of a persons hair, not only can we find out exactly who they are (DNA) we can find out where they are from…as long as they are drinking local tap water.

International Atomic Energy Agency (IAEA) is the only international organization established to regulate and monitor nuclear installation. With 144 member states and the active threat of terrorism, the IAEA suffers from a significant increase in workload with insufficient funding.

In 2002, the Nuclear Security Fund was created in the wake of the 9/11 attack. This plausible effort was deemed ineffective since the fund relies on voluntary funding from its member states, according to an article in Nature. With an inadequate annual budget of 15 million Euro (22.5 million USD), this security fund fails to perform its intended function.

Furthermore, the technology used in detecting nuclear threat needs a complete overhaul. While a vast variety of novel technology are available to detect even a trace amount of hazardous materials, IAEA still utilizes analytical instruments that are “often three decades old and have no available spare parts.” This is not to mention the problem with backlogging samples and even difficulty with obtaining a sample from a potential target. With a mere annual budget of 280 million Euro (406 million USD), the agency does not even have adequate funding to purchase the satellite image needed to search for suspicious targets.

Finally, it is necessary for nuclear operators around the world to form a better network of communication and information sharing. An organized discussion would be effective in developing safe and secure practice. The US Nuclear Threat Initiative is an example of such forum.

Many initiatives and changes are needed to improve and reform the IAEA. None of them comes cheap considering the cutting-edge technology and degree of specificity of this field. However, nuclear security is just as important, if not more applicable, than the next source of security threat. A properly funded regulation agency would be the first step towards building a safer and more open community globally.

For more information, see Nuclear security undervalued, Nature

The soon to be available Large Hadron Collider (LHC, pictured above) of CERN utilizes several superconducting magnets (kept at just 1.9 K) to guide charged particles to a desired projectile. Scheduled to be in operation by May of this year, it is the largest and highest energy particle accelerator in the world.[1] Using the LHC, a special run is scheduled for April 2008 in attempt to recreate the Big Bang.

By colliding charged particles at high velocity, researchers hope to reproduce the first billionth second after the Big Bang. By successfully doing so, this exercise would further validate the theory–some claim as the origin of life–since the Nobel win of Professor George Smoot in 2007.

However, the public hype of the launch of LHC isn’t all for the recreation of the mysterious Big Bang. Much of its attention is the possibility of creating a time machine as a side product of this exercise. As mathematicians Irina Aref’eva and Igor Volovich of Moscow’s Steklov Mathematical Institute pointed out, Einstein’s theory of general relativity suggests that particle collisions at such high energy level would distort the space-time fabric surrounding it. This distortion can create a wormhole, or “time tunnel,” allowing time traveling.[2] A related interview with Irina Aref’eva is available on YouTube.

Such claim sounds little more than a scene out of some scifi movie; and many in the scientific community agrees. Most remains skeptical of the production and application of the man-made wormhole. Surely, arguments like the lack of “time travelers” from the future still echo every time machine idea is brought up. Since what will happen inside the particle accelerator is still largely unknown, its secondary consequences also remain unpredictable.

Noel

[1] Large Hadron Collider, Wikipedia

[2] The world’s first time machine? Tunnel to the past could open door to future within three months, say Russians

In these papers, Bethe proposed two possible fusion reaction mechanisms that enables stellar energy production. They are as follows:

p + p –> ²H

²H + p –> ³He

This helium-3 nucleus further reacts, resulting in helium-4. A second reaction chain was named the C-N-O cycle. This mechanism uses a small amount of carbon, interacting with nitrogen and oxygen intermediates to produce He nuclei from ejected protons as an end product.

While later experiments confirmed the validity of both of his mechanism proposals, he was incorrect in predicting the reaction prevalent in solar energy production. Bethe concluded that C-N-O cycle is the dominant mechanism by the estimated temperature on the sun at that time, which was an over approximation. Both of Bethe’s proposed mechanisms are accepted in the current astrophysics community, with proton-proton fusion as the main source of solar energy.

This pair of articles marked the beginning of many stellar physics discoveries to come. More detail on Bethe’s theory is available in the new APS online archive!

For more information: Landmarks: What Makes the Star Shine?

Noel