Science blog

Last December ('05), physicists held the 23rd Solvay Conference in Brussels, Belgium. Amongst the many topics covered in the conference was the subject matter of string theory. This theory combines the apparently irreconcilable domains of quantum physics and relativity. David Gross a Nobel Laureate made some startling statements about the state of physics including: "We don't know what we are talking about" whilst referring to string theory as well as “The state of physics today is like it was when we were mystified by radioactivity.” The Nobel Laureate is a heavyweight in this field having earned a prize for work on the strong nuclear force and he indicated that what is happening today is very similar to what happened at the 1911 Solvay meeting. Back then, radioactivity had recently been discovered and mass energy conservation was under assault because of its discovery. Quantum theory would be needed to solve these problems. Gross further commented that in 1911 "They were missing something absolutely fundamental," as well as "we are missing perhaps something as profound as they were back then." Coming from a scientist with establishment credentials this is a damning statement about the state of current theoretical models and most notably string theory. This theoretical model is a means by which physicists replace the more commonly known particles of particle physics with one dimensional objects which are known as strings. These bizarre objects were first detected in 1968 through the insight and work of Gabriele Veneziano who was trying to comprehend the strong nuclear force. Whilst meditating on the strong nuclear force Veneziano detected a similarity between the Euler Beta Function, named for the famed mathematician Leonhard Euler, and the strong force. Applying the aforementioned Beta Function to the strong force he was able to validate a direct correlation between the two. Interestingly enough, no one knew why Euler's Beta worked so well in mapping the strong nuclear force data. A proposed solution to this dilemma would follow a few years later. Almost two years later (1970), the scientists Nambu, Nielsen and Susskind provided a mathematical description which described the physical phenomena of why Euler's Beta served as a graphical outline for the strong nuclear force. By modeling the strong nuclear forces as one dimensional strings they were able to show why it all seemed to work so well. However, several troubling inconsistencies were immediately seen on the horizon. The new theory had attached to it many implications that were in direct violation of empirical analyses. In other words, routine experimentation did not back up the new theory. Needless to say, physicists romantic fascination with string theory ended almost as fast as it had begun only to be resuscitated a few years later by another 'discovery.' The worker of the miraculous salvation of the sweet dreams of modern physicists was known as the graviton. This elementary particle allegedly communicates gravitational forces throughout the universe. The graviton is of course a 'hypothetical' particle that appears in what are known as quantum gravity systems. Unfortunately, the graviton has never ever been detected; it is as previously indicated a 'mythical' particle that fills the mind of the theorist with dreams of golden Nobel Prizes and perhaps his or her name on the periodic table of elements. But back to the historical record. In 1974, the scientists Schwarz, Scherk and Yoneya reexamined strings so that the textures or patterns of strings and their associated vibrational properties were connected to the aforementioned 'graviton.' As a result of these investigations was born what is now called 'bosonic string theory' which is the 'in vogue' version of this theory. Having both open and closed strings as well as many new important problems which gave rise to unforeseen instabilities. These problematical instabilities leading to many new difficulties which render the previous thinking as confused as we were when we started this discussion. Of course this all started from undetectable gravitons which arise from other theories equally untenable and inexplicable and so on. Thus was born string theory which was hoped would provide a complete picture of the basic fundamental principles of the universe. Scientists had believed that once the shortcomings of particle physics had been left behind by the adoption of the exotic string theory, that a grand unified theory of everything would be an easily ascertainable goal. However, what they could not anticipate is that the theory that they hoped would produce a theory of everything would leave them more confused and frustrated than they were before they departed from particle physics. The end result of string theory is that we know less and less and are becoming more and more confused. Of course, the argument could be made that further investigations will yield more relevant data whereby we will tweak the model to an eventual perfecting of our understanding of it. Or perhaps 'We don't know what we are talking about.'

Switchgrass has long been a staple crop of farmers. It is used as fodder for farm animals, fuel, and electrical needs, as a buffer strip and soil erosion control. However, when President Bush introduced The Biofuels Initiative during his 2006 state of the nation address, he moved this native prairie grass’ use as an energy crop to the forefront. The Biofuels Initiative is a critical part of the president’s advanced energy initiatives. It seeks to reduce the country’s dependence on foreign oil suppliers by more than 75% of oil imports by 2025. The aim is to accomplish this with the use of non-food based biomass, such as agricultural waste, trees, forest residues, and perennial grasses specifically switchgrass to produce energy fuels. When distilled switchgrass produces ethanol, an alcohol that fuels vehicles. Currently ethanol is blended at a ratio of 15 percent to 85 percent of gasoline and sold as E-85. Switchgrass or Tall Panic Grass is a short rhizomatous plant. It is highly adaptable for it can be planted in different parts of the country of varying climate conditions. It is also drought resistant. From planting to care and harvesting, it costs less energy to produce biofuel from switchgrass. Harvest semi-annually Switch is a perennial crop, which means it can be harvested twice a year for close to 10 years, before the crop has to be replanted. It also grows fast, absorbs the solar energy, and turns this energy into cellulose. Ethanol is extracted from the cellulose by means of distillation. High yield per acre Results from among 19 BFDP (Bioenergy Feedstock Development Program) research sites on both the Eastern and Central United States have shown that switchgrass can be harvested at 15 tons an acre. When distilled into ethanol, this yields 1,500 gallons of ethanol an acre. When averaged on a six-year basis, this means a yield of 115,000 of gallons of ethanol from each acre. Cost efficient Results from a study undertaken by the University of California Berkeley, has found out that it takes more energy to produce gasoline than it does to produce ethanol. Multiple uses Expected advances in gasification technologies will yield other useful fuels: diesel fuel, methane gas, and methanol. Environmentally Friendly Switchgrass poses no danger to the soil’s fertility as it even adds organic matter. Switchgrass has an intricate system of stems and roots. This system reaches into the deeper parts of the soil to hold on to it, stopping soil erosion. Switchgrass are reliable buffers. Farmers plant these grasses along wetlands and steambanks to filter out pesticides and to prevent these dangerous chemicals from entering the water supply. Switchgrass removes carbon dioxide (CO2) from the air and puts these back in the soil. Fossil fuels, on the other hand release huge amounts of CO2 into the atmosphere, increasing air pollution and worsening the greenhouse gas effects. Financially rewarding It costs less to grow switchgrass. When you add government tax incentives and grants raising switchgrass will be as profitable as extracting fossil fuels. These are the present disadvantages of using switchgrass as the main source of biofuels. The need to improve pretreatment technologies Current technologies are not efficient in extracting higher yields from switchgrass. R&D efforts should correct this. The need to allocate land for switchgrass Is there available agricultural land to plant switchgrass? A system must be set in place to ensure there is land for both switchgrass and food crops. The use of switchgrass as an energy crop is decidedly viable from the economic, production, and environmental aspects. However, the success of switchgrass as an energy crop will depend on these key factors: government policies and funding, R&D efforts, technological innovations and vehicle efficiency.

We talked to North America’s leading In Situ Leach (ISL) uranium mining engineers, and had them explain exactly how ISL worked. Most of the significant ISL operations in the United States were designed and/or constructed by these engineers. They explained how ISL mining is really just reversing the process of Mother Nature. ISL EXTRACTION AND PROCESSING During ISL mining, water is pumped to the surface from production wells that contain uranium in very low concentrations, on the order of parts per million concentrations. The next step in the ISL process is to extract the uranium dicarbonate. Extraction is done by chemically exchanging ions inside a processing facility. “The ion exchange process is very analogous to a home Culligan® water softener,” Anthony revealed. “It removes hardness or calcium from the water by replacing it with sodium, using ion exchange resins. If you go to Lowe’s or Home Depot, and buy a water softener, you basically have a home version of a uranium extraction plant.” The main difference is your water softener will have a cation exchanger. “For a uranium plant to function properly, you need to use an anion exchange resin, which is specifically designed to load uranium,” Anthony clarified. And what is this magical “ion exchange resin”? The resin is comprised of little polymer beads, which are charged particles having an affinity for uranium anions. “There are literally millions of these small resin beads in a vessel, which can adsorb low concentration of uranium in solution,” said Anthony. Adsorption is when something is attracted to something else or clings to it, like static electricity. Why do you have to process uranium like this? “In essence, the ion exchange process is a beneficiation (reduction) process that concentrates large volumes of low concentrate uranium solution into a much smaller volume containing a much higher concentration of uranium,” said Anthony. In other words, the beneficiation is just concentrating the uranium from the large volume of water in which it is mined into a more compact form. The preferred means is through an ion exchange. Anthony gave a real-life example of the beneficiation process, “Three million gallons of wellfield solution containing dilute concentrations of uranium, of 100 parts per million minus 0.10 grams/liter, is passed through a bed of ion exchange resin. This might take 24 hours to achieve if the solution is flowing at 2,500 gallons per minute. After this length of time, the resin becomes loaded with approximately 2,500 pounds of uranium.” STRIPPING THE URANIUM Stripping the uranium is called the elution process. This is done through a chemical exchange of positively and negatively charged ions. Resins are classified by the charge on the active sites. “The active sites on the resin are positively charged for anion resins and negatively charged for cation resins,” Norris enlightened us. “The resin’s ability to extract chemical ions from a solution is derived from what’s called an active site,” he continued. “In our case, chloride ions obtained from ordinary tale salt are used to stabilize or temporarily neutralize this positively charged active site.” The negatively charged chloride ion sticks to the positively charged site, held in place by what Norris called “electrostatic forces.” When the negatively charged ions, such as uranyl dicarbonate, are placed in contact with the solution, it will kick off the chloride and replace that with the uranyl dicarbonate. That was the chemistry lesson. Anthony summed it up in a nutshell, “They just displace it. There’s a greater affinity for the chloride ion to the resin than there is for the uranium. So, the uranium is stripped from the resin bed.” The processing facility chemically strips the loaded uranium from the resin by soaking the entire package of uranium-laden resin in a salt bath solution. “The volume of salt solution is on the order of 10,000 gallons resulting in a solution concentration of 30 grams/liter uranium,” Anthony said, describing the process of how the uranium becomes concentrated. “The stripped uranium solution concentration is magnified 300 times more than the wellfield solution,” he informed us. “The concentration level can now be economically processed for recovery: precipitation, dewatering, drying and drumming for a nuclear facility.” GETTING URANIUM INTO THE DRUM After the uranium has been removed from the solution, it is precipitated. At this point in the processing stage, you have yellowcake slurry. Up close, it looks like a sort of yellowish and wet, runny cement mixture. The dewatering process does just that, it removes the water from the yellowcake mixture. “I use a filter press, a device that is designed to separate solids from solutions,” explained Anthony. Filter presses are extensively used in various types of food, chemical and drug processing across the world. “The uranium solids, now looking more like yellowcake, are retained in the filter press, where they can be washed and later air dried, before drying them to a powder with a low temperature vacuum dryer,” said Anthony taking us step by step through this process. So what is the filter press and how do you end up with the finished yellowcake when you’re done? “It’s a series of plates and hollow frames, or it could be a series of recessed chambers,” Anthony answered. “Filter cloth is draped over the plates or chalked in the recessed chambers. The yellowcake slurry is pumped through the filter allowing the liquid phase to pass through the filter cloth, trapping the uranium oxide inside the device.” Anthony likes to pack the filter press up with as much yellowcake as it can hold. “It is then washed with clean water to displace the chloride ions to a low level,” Anthony explained. If you don’t remove the chloride concentrations to the acceptable level required by an uranium enrichment facility, a fine is assessed against that shipment. The final steps include conveying the yellowcake to the vacuum dryer. The uranium oxide’s color depends on how high or low a temperature is used to dry the “yellowcake.” Patrick Drummond, the Smith-Highland Ranch plant superintendent, showed us pure uranium oxide dried at high temperatures. It was nearly black. After the drying process is complete, the uranium is packaged up in DOE-approved 55 gallon drums and transported to an enrichment facility. It is then when the enriched uranium can finally be used to power a nuclear reactor and provide an inexpensive source of electricity.

There have been a lot of research studies on micro bubbles in recent years. Micro bubbles are miniature gas bubbles of less than 50 microns diameter in water. The micro bubbles, which mostly contain oxygen or air, can remain suspended in the water for an extended period. Gradually, the gas within the micro bubbles dissolves into the water and the bubbles disappear. These bubbles are generated by various types of aerators now available in the market. These micro bubbles, being of extremely small size, are characterized by having electrical charges. They attract suspended floating particles very effectively. This particular property has been used in sludge treatment by using the micro bubbles to capture and float organic matters, thus decreasing the time required for the sludge treatment. Micro bubbles have also been introduced by the Japanese to market safe and good tasting oysters. Micro bubbles of concentrated oxygen containing about 2% ozone can be used to inactivate norovirus in shellfish and oysters. This norovirus is one of the major pathogens causing food poisoning in winter. This is a much more cost effective method compared to cultivating the oysters in sterile seawater and using chlorine-based germicide. Another emergent usage of micro bubbles is in the areas of cancer treatment. Scientists are in the process of developing a method of diagnosing cancer lesions by injecting micro bubbles into the blood stream. During the ultrasonic scan for cancer lesions, the micro bubbles contract and expand rapidly due to the pressures produced by the ultrasonic beam. Groups of the micro bubbles at cancerous tumours will show up very visibly on ultrasonic scans to indicate the presence of cancerous cells. Due to their large surface area volume ratio, micro bubbles can penetrate deeply into a surface for effective cleaning. This cleaning effect of micro bubbles is used in cleaning the inside of vegetables such as cabbage and radish sprout, as well as maintenance of freshness with vegetables in one particular vegetable processing center in Japan. On a more personal level, the micro bubbles can penetrate deeply into skin for a good scrub without the need for any shampoo or soap. This skin treatment has been introduced within some spas in Japan as well as shops specializing in bathing pets. Needless to say, the baths are especially helpful for pets which have skin allergies to pet shampoos. Suwa companies are also developing a small handy micro bubble generator which can be used at home. With all the product development going on, very soon, you may be able to purchase a micro bubble generator at your electronics store and relax in a micro bubble bath at home.