The Scientific Marksman
Table of Contents Innovation (4)
The Future of Prosthetic Limbs The Power of a Flower The Art of Human Telepathy The Growing Cloud The Study of the Hough Transform Through Computer Vision Cleaning the Spill The Genetic Battle of the Sexes A New New Frontier Star Lores
The Spine Preparation of Porous Nanostructures via the Epoxide Addition Method: A Study of pH and Gel Formation with Templating Solar Cells A Brief Look at Cancer
When Will I Ever Have to Know This? Inflammation from the Cellular to Organismal Level at UT Southwestern Cartoon Our Presidential Candidates on Evolutionâ€“and Why it Matters: How to Make Flash Bombs Behind the Prize The Brain Strain
The future of prosthetic limbs
By Staff Writer Homer Gaidarski fter soldiers are wounded in war and sent home, if they have undergone an amputation of an arm or leg, they usually wear a prosthetic limb. This hasn’t changed since the 1940s. “There’s a hook, something out of Peter Pan. And that’s just unacceptable,” says Dr. Geoffrey Ling, an Army colonel and neurologist. When you lose your hand, you’ve lost something that defines you as a human. Anyone who has ever seen the Star Wars movies knows about the idea of biomechanical arms with fully functional hands and fingers controlled by thought. This idea has been dismissed as an impossible and crazy phenomenon, until recently… In 2005, the Defense Department’s Experimental Research Wing (DARPA) created a program for the next generation of prosthetic arms for soldiers returning to the U.S. who had lost arms in battle. They approached Dean Kamen, head of DEKA Research and the inventor of the segway. Kamen began developing what he likes to call his “Luke arm,” which is a high-tech, wired attachable arm and hand. It has 3 processors, that’s equivalent to 3 PCs’ computing power. The prototype had 25 circuit boards and 10 motors. Kamen’s team decided that the arm had to be lightweight, agile, controllable, and modular. Since the
arm is modular, there are separate pieces of the arm allowing customizability for any amputee. From the hand they can add a forearm, an elbow, and even a shoulder socket. Weight is a challenge for making a successful prosthetic arm. They modeled the Luke arm from an average female arm that weighs less than 8 pounds with all the electronics and the battery. Having to wear this arm for 12-24 hours a day would become tiresome, so Kamen’s team created a comfortable way to keep the arm connected. The arm has multiple balloons that inflate at the touch of a button that keeps the pressure displaced over the whole shoulder. Chuck Hildreth was one of the many volunteers for DEKA who helped optimize the Luke arm. He lost both of his arms when he was electrocuted at age of 18. “I’ve been able to do stuff with this that I seriously haven’t been able to do in 26 years.” With the Luke arm, Chuck can handle complex tasks such as picking up cups or even smaller objects such as grapes. But how does he grab objects without grasping too hard? There are 12 microprocessors in the Luke arm, which also allow sensory feedback. A small sensor is in the thumb, which sends a signal to one of the microprocessors, which then goes to a small vibrating motor. The harder a person grips, the more vibration there is from the motor, so the user of the arm gets direct feedback on how hard he is gripping an object. This allows users to hold a glass of water without shattering it. The arm can be controlled in 3 ways: with foot pedals, muscles, and even nerves.
The power of a By Managing Editor Prajan Divakar Most of us know saffron as an exotic spice that has become an increasingly expensive commodity over the last decade (currently valued at approximately nine dollars per gram). But it turns out that this spice is not just a mere flavor enhancer; saffron shows great potential for medicinal uses. Although it has been known for quite some time that saffron can relieve depression and provide aid to the heart, recent 2011 studies at the United Arab Emirates University have shown saffron’s
You may be asking yourself how the nerves can control the arm. When a person’s arm is amputated, they can sometimes feel that their arm is still there. They call this a phantom arm. This is because of the remaining nerves in their arm that would normally control the arm and hand. In order to use these nerves, a technique called “targeted muscle reinnervation” is implemented. This involves connecting the remaining nerves, after the arm is amputated, to another muscle in the body, normally the chest. Then electrodes are implanted over the chest muscles. Therefore, when the person wants to move their arm, the brain sends signals that contract the chest muscles, which sends an electrical signal to the bionic arm, causing it to move. When a person does this, it almost feels like they are using their actual natural arm. “This is an advancement in medical technology. And the beauty of this particular effort is that this is another gift of the American taxpayer to the entire world,” says Dr. Geoffrey Ling. With this arm, amputees will be able to do everyday tasks that able-bodied individuals take for granted. No longer will prosthetic users require assistance from another person. Unfortunately, every prosthetic has a price, and this one sits around hundreds of millions. Hopefully one day, amputees and war veterans alike will all be able to have bionic arms. Maybe Obama’s Health Care system will eventually cover these devices, but for now it is highly unlikely that these magnificent bionic arms will be supported by health care.
potential to aid/accelerate the relief of liver cancer. An experiment was performed in the university involving injections of diethylnitrosamine (DEN) induced liver cancer into lab mice. Careful monitoring of the blood concentrations of various mice with differing quantities of saffron in their diet revealed that the mice with the most saffron intake faced minimal inflammation, cancerous cell production, and
adverse effects from the DEN. This preliminary experiment not only confirmed a potential cure for liver cancer (the third most fatal cancer) but perhaps a substance that might effectively combat other forms of tumors and excessive cell proliferation in the future. Perhaps paying a couple hundred dollars for box of flower stigmas may not be such a bad investment after all.
Bringing sci-fi to life
By Staff Writer Jeffery Wu he scientific world has long been pursuing the possibility of mind reading and communication by only using the mind. However, recently, Gerwin Schalk, an expert biomedical scientist, may have found an important breakthrough. He and a group of other researchers are part of a $6.3 million U.S. Army Project to come up with a thought-helmet, a device capable of detecting and transmitting unspoken speech to soldiers. This new technology is called synthetic telepathy. It works by identifying the brain waves of a person and transmitting them into a readable form of data. This form of technology is extremely beneficial to the military. If used correctly, it allows soldiers to silently communicate among each other to carry out a mission without the need for whispering or hand motions. For example, the Navy Seals who killed Bin Laden
needed to use hand signals to carry out the assassination. By using this thought helmet, they would no longer need to use hand signals and risk compromising a mission. In addition, it would allow for injured or incapacitated soldiers to call in support or first aid. Furthermore, this helmet would not require the need to implant devices deep into the brain. Scientists have long thought that in order to read a person’s mind, they needed to penetrate electrodes deep into a person’s brain. However, new research indicates otherwise. The new thought helmet would keep invasion of the brain to a minimum. Although this breakthrough is remarkable, there is also a question of ethics and morals. Since the creation of this new thought helmet is not yet 100% fail-proof, testing is still needed to guarantee that it works. While testing on monkeys or other animals does raise the question of ethics, the testing on hu-
phoro courtesy cdn.gajitz.com
The art of helmet-telepathy
mans to finally ensure that the helmet is safe to use is very problematic. Few test subjects will be willing to experiment due to the possibility of debilitating long term effects. The U.S. Army also does not want to make this thought-helmet project an inhumane and cruel project of mind control like the CIA did in the 1970s. In addition, if the U.S. Army does develop a thought helmet like this one, they can also read someone else’s mind. While this is very beneficial in certain clandestine missions in order to read the enemy’s minds, it can also be misused. The possibility of reading someone else’s mind might propel them to use it for Homeland Security and furthermore invade privacy by scanning regular civilians at airports. As a result, this would violate the Constitution and create an ethical problem. Thus, although the helmet has strong positive effects, it raises a moral issue too.
The growing cloud By Technology Editor Michael Gilliland The idea of cloud computing was first introduced by the famed cognitive scientist John McCarthy, well known for coining the term “Artificial Intelligence” and his contributions to that field of study, when in the 1960s, he made a bold assertion that “computation may someday be organized as a public utility.” Many developments have been made since those very early days of computing which give credit to McCarthy’s claim. The world is now connected at a speed of almost forty gigabits per second, a vast contrast to the mere science fiction that was a global network in 1960. With more and more companies making a push toward the cloud, McCarthy’s once intrepid declaration is now proved true in the modern web. Time after time Google has shown its preeminence in pioneering new technologies, their presence at the phalanx of cloud pioneers being no exception. Google sports a full complement of tools including an email service, a suite of word processing and presentation tools to rival the collection of Microsoft, and a wide variety of other applications including a music player and a social networking site. The unique element of these applications is that they are all web-based, obviating the need for native programs. Google tested the concept of a completely web-based
system with their experimental Chrome OS CR-48, which has just recently been developed into two new laptops, one Sony and one Acer, available for public purchase. These computers run off of a complete version of Chrome OS, which is an extension of Google’s popular web browser. With their new line, Google has answered a key question. Computers can perform a multitude of tasks through the internet while running only a simple operating system. But what about the rest of us who see the benefits of cloud storage but just don’t want to buy in to a fully stripped computing experience? There are several other ways to reap the benefits of the cloud without giving up the comfort of a hard drive full of your binary belongings. Apple’s upcoming product, iCloud, will provide cloud data storage with push to compatible devices. This function provides great flexibility to users of Apple products. Also, for those who simply wish to free up some space on their hard drive and to have their documents accessible from anywhere by internet, Dropbox and ZumoDrive provide storage for virtually any file type with global in-browser accessibility. Whether you wish to access a single file or your entire music collection through the cloud, new options in the cloud provide an easy solution.
The study of the hough transform through computer vision Staff writer Victor Zhou scratches the surface of advanced computer recognition
omputer Vision is quite an interesting branch of Computer Science. The idea of instructing a computer in the ways which we humans detect and recognize objects seems so simple yet is far from it. As an intern at TotalWire Corp this summer, I explored some of the most popular techniques used in Computer Vision like the Hough Transform. My ultimate goal for the summer was to develop a program that could quickly detect the location and orientation of a human face in any image through the localization of his/her eyes in order to build a 3D image viewer – an image viewer that changes the perspective on an image based on the tilt of the viewer’s head. Software with this kind of ability would have a great number of potential uses. Fiber Detection: I started off with a smaller project in the beginning just to get my feet wet and become comfortable with the programming interfaces for the USB camera I used. The problem I was trying to solve involved the ends of fibers that TotalWire Corp worked with. I was trying to build a program that would grab an image from a USB camera that was facing the end of a fiber and enable the computer to detect the centers of the smaller wires inside the fiber. This project appealed to me because not only would it act as an intermediate step towards my ultimate goal, but it was also a real-world problem that the company I was working with needed to solve. After spending some time thinking about the challenge, I learned about the Hough Transform, a technique used commonly in Computer Vision for detecting imperfect shapes. I decided to implement a modified version of the Hough Transform for circles as a way to detect the circular wire ends and eventually find their centers. After applying a threshold to convert the fiber end image to black (0) and white (255) and rudimentary edge detection,
I ran my modified Hough Transform on the pre-processed image and located the 9 wire centers targeted in the problem. Once I was satisfied with the performance of these core parts of the program, I added extensions to make the program more robust and efficient, most notably an autoexposure feature and an improvement to the pre-processing step of the program that removed the hypodermic tubing of the fiber end. In the end, my finished program could correctly identify the centers of the wires under widely varying light conditions, fiber positions, orientations, and fiber defects close to 100% of the time in under 400ms. Eye Detection: Armed with the experience I had gained from my encounter with fiber detection, I moved on to the task of eye detection. Many of the ideas I had applied to fiber detection could be easily transferred over to eye detection, which made the transition between the two problems much smoother. In this second project, I was trying to build a program capable of locating and tracking the position and orientation of the eyes of a user. I started out using the simple USB camera I had used in my previous project as a makeshift webcam and took pictures of my face for the computer to use to detect the eyes. My decision to track the eyes instead of some other humanoid feature did not come easily. Face detection was also a very viable option, for it has been implemented in many ways already and appears in many places, like cameras. In the end, I chose to track the eyes because of the minute movement detection that eye localization would give me that face localization did not offer – with the eyes, I would be able to track the smallest movements and rotations much more easily. Also, the techniques used to track the eyes could easily be extended to track other facial features,
like the nose, mouth, ears, etc. But how would I track the eyes? The first decision I would have to make would be what approach I would take towards eye detection. Because of the similarity between fiber detection and eye detection, I decided to use the Hough Transform again, but also took up the idea of a multilayered approach to eliminating false positives from the Hough Transform. To start off, I came up with a custom version of the Generalized Hough Transform in order to model the shape of the eyes myself, because it could not be easily described using parametric equations. To make the image easier to work with, I applied an edge detection and threshold but used the Sobel Operator in place of my previous edge detector to increase accuracy. Then, I proceeded to run the Generalized Hough Transform using a custom eye template through the pre-processed image. I took all detected eyes that passed a threshold of “eye-strength” and normalized these eye candidates based on how many imperfections there were in each eye candidate, thus eliminating the advantage that an eye candidate on a patch of dense noise pixels would retain. After scaling the strength of each eye candidate, I picked the top 20 strongest eye candidates to be passed on to the “classifier cascade”, an idea utilized in the well-known Viola-Jones face detector. As each eye candidate was run through the classifier cascade, they would each be subjected to a series of tests that ideally only real eyes would pass. Each test aimed to achieve the highest rate of detection possible, regardless of the number of false positives, because as eye candidates passed through the classifier cascade, legitimate eyes would be detected with a rate close to 100%, and false eyes would be detected with a rate close to 0%. After running all the eye candidates through the classifier cascade, the candidates that
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Cleaning the spill Determination of dynamic wiping efficiency of a nonwoven composite wipe for decontamination of toxic oil spills By Chemistry Editor Kahan Chavda The Gulf of Mexico’s Deepwater Horizon oil spill practically coated the surface of the Gulf with a layer of crude oil. Despite all efforts to eradicate all traces of the oil, crude oil from this disaster still remains in the Gulf, floating on the water and covering the hulls of seagoing vessels. By using an engineered three layer composite wipe called Fibertect ®, the high dynamic wiping efficiency of Fibertect was tested with other materials to determine a suitable way to clean up. Before discussing the experimental method, it would be useful to include a brief description about Fibertect. Fibertect is a product that consists of three separate layers, an outer layer of cotton, an inner layer of an activated carbon complex, and another external layer of cotton. A specific type of cotton with natural hydrophobicity was grown, and this hydrophobicity was amplified before being integrated into the Fibertect wipe. A variety of materials were tested for their absorption of first water and then oil. The materials tested were as follows: LM1 (Cotton), LM2 (Cotton), VC (Cotton), Activated Carbon Complex, Polyester, and Cotton Fibertect. The maximum absorption of each material was determined by immersing a 4.5X5 inch cutting of each material in 100 mL of water and oil and determining how much liquid the cutting retained after a minute of absorption. Next, a dynamic wiping efficiency apparatus was constructed out of a steel sledge and a metal “runway”. The 50% capacity challenge of each material, or half of its maximum absorption, was determined and placed on the metal runway. A 4.5X5 inch cutting was taped to the bottom of the steel sledge, and the steel sledge was run over the runway at a total of two different speeds, 25 cm/s and 5 cm/s. The amount of liquid absorbed was the dynamic wiping efficiency of the material in question. The activated carbon complex alone absorbed a lot of liquid, both oil and water, but left behind a residue of carbon fibers which were potentially carcinogenic. The VC cotton, used in the cotton Fibertect, alone absorbed a lot of oil, but did not absorb much water. The Fibertect sample absorbed up to 10 times its own weight in oil, but did not absorb much water because of the hydrophobic VC cotton layers. After using a thermogravimetric analyzer, it was found that Fibertect also absorbs any vapors that the oil emits. In conclusion, it was determined that Fibertect was the optimal product for absorbing nonpolar liquids like oil, and it was even more suited for cleaning disasters such as the Deepwater Horizon oil spill because of its unique property to not absorb the polar water and to instead absorb up to 10 times its weight in the nonpolar oil.
Hough Transform, continued from previous page would be assumed as eyes, and the detected eyes would have doubles eliminated – any 2 detected eye candidates too close to each other would be merged into one detected eye candidate. Once the basic parts of my eye detector were correctly implemented, I addressed the issue of speed. The original idea that this project stemmed from was a “3D” image viewer – a program on a computer with a webcam that would allow users to enhance their photo viewing experience by tracking the tilt of the viewer’s head and changing the angle of the image being viewed accordingly. In order for the 3D effect to be convincing, the program would need to be able to track the viewer in real time, at a rate of at least 10-20 FPS. Immediately after I completed the essential parts of the program, each loop had a run time of 6-8 seconds, even more unacceptable when taking into account that around 50 loops would be needed each time the eye detection algorithm ran. By cutting out multitudes of small efficiency mistakes here and there, adjusting some thresholds to increase speed while retaining the same accuracy, and redoing some of the basic structure of my algorithm, I was finally able to cut the program’s runtime to about 120 milliseconds, an astounding improvement although still not sufficient to meet the 10 FPS requirement, because 50 loops of 120ms would amount to around 6 seconds. That was the extent to which I was able to improve my efficiency in the
3 weeks I had to work on the eye detection problem. Future Additions/Implications: Since I was satisfied with the end result of the fiber detection program, I will most likely not make any further additions. On the other hand, my eye detection program still has much to improve. I may want to add another layer in my classifier cascade to be able to be more generous with my other two layers. I also plan to utilize some sort of binning procedure to cut down significantly on the amount of processing needed for each loop to enable more flexibility when checking eye shapes, sizes, and orientations. Finally, I plan on using parallel processing to speed up the many loops incorporated in my code by breaking up each task into sections and assigning them each to a core. One of the questions always asked with a project is “What does the research from this project change?” The technology involved in my eye detection program and its future extensions can be applied to many things. The power to be able to locate eyes in an image in real time brings a plethora of possibilities. For example, a TV with an eye detection capability equipped would be able to track where its viewers’ eyes were looking, and dim its screen brightness when viewers look away during commercials or for other reasons. Technology with this capability could potentially have a sizeable marketing advantage over rival products in the future.
Staff writer Victor Zhou recently earned an honorable mention in the computer science division at the Dallas Regional Science Fair, as well and second place awards from Texas Instruments and Pariveda Solutions.
The genetic battle of the sexes By Biology Editor Mitch Lee “If you still thought evolution was about the good of the species, stop thinking so right now.” Matt Ridley makes this provocative suggestion in a chapter from his book Genome: The Autobiography of a Species in 23 Chapters, which takes a refreshingly simple approach to discussing the intellectual breakthroughs that have developed from scientists’ newfound understanding of the human genome. In that chapter, titled “Conflict”, Ridley discusses the recently proposed idea of competitive co-evolution, or sexual antagonism, between the X and Y chromosomes. While doing so, Ridley comes to some interesting conclusions, many of which upset well-established concepts of biology, particularly in regard to evolution. As such, I hope to draw attention to the topic of sexual antagonism, to elucidate facts, and to illustrate the greater significance of the genetic battle between the sexes. In general terms, sexual antagonism refers to the competition between gender-partial genes within the genome of a species. Ridley states that sexual antagonism began when gender-determination made a drastic shift; the presence of a gene, not the temperature of the egg, began to designate gender. For our ancestral tree, the presence of such a gene mandates masculinity while its absence mandates femininity. Because it is found in only males, the sexdetermining gene slowly associated with others genes that benefit masculinity, such as genes for large muscles or aggressive tendencies, as those traits help males to compete and survive. However, such genes are not desirable for females, who would rather spend their energy and dietary resources rearing young. They too, though in response to the rising masculine threat, began to accumulate gender-partial genes (these ‘male’ and ‘female’ genes segregated into what are now the X and Y chromosomes). Soon, these sexually antagonistic genes began to compete for control of the male gender (males have both an X and a Y chromosome), each attempting to outdo the other in a competitive co-evolution that would redefine the course of evolution. Now that we have an understanding of sexual antagonism, the question of its significance becomes an interesting one to investigate. Ridley proposes that sexual antagonism between the X and Y chromosomes has driven evolution to become a largely male vs. female conflict, a conflict that ignores the rules of Darwinian evolution and that can actually become harmful to a species. Ridley explains this inherent danger by proposing a situation in which a gene appears on the X chromosome that instructs the creation of a poison that kills only sperm-cells carrying the Y chromosome (a rather extreme example, but it illustrates his point). Any man carrying this gene would give birth to only daughters, who in turn would give birth to similarly affected sons 50% of the time. Thus, the gene would spread rapidly, unbalancing the male to female ratio to the point of jeopardizing the species. Although Ridley’s model does seem extreme, and possibly unrealistic, several natural examples exist that reinforce Ridley’s conjectures. Ridley himself cites the butterfly species, Acreaencedon, which has reached a near catastrophic gender-ratio shift as a result of sexual antagonism; 97% of its population is female. Considering the above, the significance of sexual antagonism lies largely in its deleterious evolutionary consequences. Ridley also postulates, however, that sexual antagonism
does not necessarily have to result in a negative outcome (though it does always seem to redirect evolution away from the improvement of a species). For instance, Ridley states that a cross examination of the gene that makes humans masculine, called the SRY gene, and that of our close relative the chimpanzee reveals that sexual antagonism may drive diversification within a species, perhaps even speciation. Within the human race, the SRY gene seldom varies from person to person, which indicates that it has a slow mutation rate. The same is also true for SRY’s equivalent in chimpanzees. However, the human SRY gene is drastically different from the gene of a chimpanzee. How can this be? William Amos and John Harwood, leaders in the field of evolutionary biology, propose that sexual antagonism is the key. They argue that, over the course of a species’ development, a gene develops occasionally on the X chromosome that targets, and inhibits, the masculinizing protein produced by genes such as SRY. Thus, natural selection favors mutations of the initial masculinizing gene that are different enough to avoid being targeted and, therefore, are able to spread and rebalance the gender ratio. This process thereby leads to diversification that, although not necessarily harmful to a species, exists outside the realm of Darwinian evolution. Having discussed the specific evolutionary significance of sexual antagonism, the need to understand its implications for us as humans is vital. Ridley’s major point, as I have said, is that sexual antagonism has transformed evolution into a competition between the sexes. But what does that mean for us? Ridley’s answer is that much of human social behavior results from the constant battle between the X and Y chromosomes. William Rice and Brett Holland, two of the leading scholars of sexual antagonism that Ridley cites, postulate that, “the more social and communicative a species is, the more likely it is to suffer from sexually antagonistic genes, because communication between the sexes provides the medium in which sexually antagonistic genes thrive.” Ridley makes the point that if what Rice and Holland says is true, then sexual antagonism is a highly influential force in human evolution, swaying even complex social interaction through control of the most primal instincts and desires. “Suddenly,” Ridley states, “it begins to make sense why relations between the human sexes are such a minefield.” In essence, sexual antagonism has made human evolution a game of seduction and resistance in which each gender tries to gain the upper hand in manipulating the other, all for the sake of levying power behind either the X or Y chromosome. All in all, the most intriguing fact of sexual antagonism is that we may never fully understand its purpose. We have come to a firm understanding of the consequences of competitive co-evolution between the X and Y chromosomes and that it exists as an entity outside the confines of Darwinian evolution. To capture the mystery, Ridley ends his book with a quotation from Bill Hamilton, the man who first proposed the ideas that led to the theory of sexual antagonism: “There had come the realization that the genome wasn’t the monolithic data bank plus executive team devoted to one project—keeping oneself alive, having babies—that I hitherto imagined it to be. Instead, it was beginning to seem more like a company boardroom, a theatre for a power struggle of egoists and factions.”
A new new frontier
By Staff Writer Ohmer Ahmed Despite the slow progression and lack of monumental advances that some might hope from NASA, lately there have been key developments for the future of American exploration in space. NASA officially terminated its thirty year Space Shuttle program as of August 31 earlier this year in hopes of entering a new era consisting of updated technology. Until late this year, NASA had been pioneering space with remarkable innovations by all nations’ standards, but three decades of relative stagnancy on the Space Shuttle has become outdated and frankly, NASA’s next step towards the future is over-due. From mid-2005 until recent months, all of NASA collaborated to create a newly designed rocket with enormous capabilities that would launch Americans into space. NASA designed two rockets, an exploration vehicle, and a lunar lander; Ares I, Ares V, Orion, and Altair were the given names, respectively. This four-piece set of contemporary innovation was the final result of the six year Constellation Program. Constellation provided NASA with
new goals that included broadening the limits of exploration in order to gain insight into undiscovered frontiers. All was set and ready for near take-off, within a year, when President Obama dismissed the program entirely. In his visit to the Kennedy Space Center in October 2010, Obama announced in his space policy speech that there would be an incoming replacement for the Constellation program, which included the Ares I and V rockets. The reasons for Obama’s termination of the program include a restructured financial plan which constrains NASA’s immediate budget to an amount less than the billions required for Constellation to resume. However, the president did increase the funding over the span of the next three years in hope of reaching the new goal. To put it all into a numerical figures, President Obama—as compensation for cutting the program loose—heightened the budget to 55 billion over a longer span of time, eleven billion more than previously pledged in that same period. The replacement for the already developed Ares rockets is now known as the ShuttleDerived Launch Vehicle (SDV), a prospective vehicle that will exhibit a composite form of the two rockets constructed in Constellation. Obama in his policy speech swayed NASA’s focus of probing around environments as far as Mars to low-orbit exploration—something NASA had intended to move far beyond. Further interests of NASA have been cut short by the new authorizations; however, NASA’s plans
haven’t suffered detrimental losses because the Ares rockets will be partially utilized to construct the Orion Multipurpose Crew Vehicle. The objective of this newly designed vehicle is for the transportation of important cargo, equipment, and for the ability to conduct experiments near Earth’s orbit and beyond. On September 14th, NASA publicly announced its official design for a deep-space rocket that would enable manned launches to the ISS, moon, and the much talked about planet Mars. Frustration lingers between Congress and NASA as they tussle between agreements over general significance of exploration and more importantly costs. NASA’s recent announcement means the deep space rocket construction will coexist with the construction of the Orion space vehicle. A total of eleven billion will be spent by the time Orion is finished—5 billion of which has already been allotted. Although both of these projects have plenty of time before launch, they are absolutely instrumental in advanced exploration of outer space. NASA’s Associate Administrator, Bill Gerstenmaier, sums up the importance of the new deep-space vehicle concisely: “This is a tremendous step forward and really puts us in a position to go forward with exploration.” NASA is positively headed in the right direction after climbing out of what may have been a giant setback for the future. In all likelihood, it appears NASA will continue its reign of dominating innovation in space for at least a few decades to come.
By Astronomy Editor Reid Weisberg Get excited, Star Wars fans: the iconic double sunset of Tatooine has been confirmed as scientifically possible. A planet was recently found by NASA’s Kepler mission to be orbiting two suns. Dubbed Kepler-16b, it was discovered by detecting small eclipses in the stars it orbits. The stars, which are both smaller than our sun and known to orbit each other, eclipse each other at regular intervals, but different, more irregular eclipses suggested the existence of a smaller body. Other exoplanets detected in binary systems always orbited a single star, but Kepler-16b has a large orbit around both. Kepler also measured the planets mass, and found it to be around the size of Saturn, so it is probably mainly gaseous. Also, because the stars are not as bright or as hot as our sun, Kepler-16b, though relatively close to its stars, is still outside the habitable, or “Goldilocks” zone, where
liquid water could exist on its surface. Because of the wildly fluctuating relative positions Kepler-16b and its stars have, its temperature can change by up to fifty degrees Fahrenheit in a matter of a few days, usually not going above 100 degrees below zero. This discovery, however, signals an increase in hope for those searching for an Earth-like planet or one that can harbor life. As William Borucki puts it, “Given that most stars in our galaxy are part of a binary system, this means that the opportunities for life are much broader than if planets form only around single stars.” With this discovery, Kepler is marching forward in exoplanetary discovery, and the scientists at NASA are learning more each day. Hopefully, it will inspire people to become a part of the research teams leading us into the future of space exploration. John Knoll of Lucasfilm even commented, “the very existence of this discovery gives us cause to dream bigger.”
research Th e
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In this paper, we discuss and analyze the coronal, sagittal, and axial correction in Lenke 1 patients treated for Adolescent Idiopathic Scoliosis with pedicle screw constructs at two and five years post-op. There is a paucity of long-term data on the surgical treatment of Adolescent Idiopathic Scoliosis (AIS), particularly with pedicle screws. There have been 5 to 10 year follow-up results published on the use of Cotrel-Debousset instrumentation, 5 year results on thoracoscopic anterior instrumentation and anterior instrumented fusion for Lenke type 1 AIS and a published 3 year follow up for treatment of AIS with pedicle screw constructs. Nevertheless, there is a scarcity of data on 5 year results of AIS treatment with all pedicle screw constructs. Our project was aimed towards analyzing the results of 2 and 5 year follow-ups for patients with Lenke type 1 curves treated with pedicle screw constructs. This data will help surgeons and patients to make informed decisions regarding the treatment of AIS. In a pool of 69 patients, 39 were analyzed because they had Lenke type 1 curves. Using lateral erect radiographs, we
Over the past summer, Editor-in-Chief Alex Rothkrug has been a part of research on scoliosis and spine surgery. Two of the papers he contributed to are currently under review for publication in the Journal of Neurosurgery: Spine. Because they have not been published yet, we have chosen to summarize these papers rather than include the actual abstracts.
measured kyphosis from T5-T12, lumbar lordosis from L1 to the sacrum, calculated coronal correction, and measured the central sacral vertical line (CSVL) and C7 plumb line. Using SPSS 12.0.2, we performed Repeated Measures ANOVA tests to calculate statistical significance in the differences of our measurements over the various time periods. The average coronal correction was 65.4% for the main thoracic curve, 65.3% for the compensatory lumbar curve, and 48.3% for the compensatory proximal thoracic curve. There was no significant difference in correction between the 2 and 5 year follow-ups. The improved correction obtained with pedicle screws, compared to hooks, has been attributed to better vertebral grip with a 3-column purchase. Additionally, more direct vertebral
In this paper we discuss the impact of direct vertebral body derotation on the lumbar prominence in Lenke 5C curves. The thoracic rib hump, caused by axial rotation of the spine, is one of the most cosmetically dissatisfying features associated with adolescent idiopathic scoliosis. Advances in instrumentation and surgical techniques such as direct vertebral body derotation (DVBD) have allowed improved correction of the axial plane and the rib hump. Similarly, with thoracolumbar/lumbar curves (lenke 5), the lumbar prominence is usually greater and often associated with waist asymmetry that is a cosmetic concern. Although DVBD has been evaluated in the thoracic spine, little is known of its impact on the lumbar spine. We investigated the outcomes of DVBD on the lumbar prominence. Fifteen patients, upon whom thoracoplasties were
rotation is attainable with pedicle screws. Interestingly, there was a significantly less degree of kyphosis at the 5 year follow-up than during the pre-op period. In order to compensate for the decrease in kyphosis, lumbar lordosis decreased as well. Our results have indicated that coronal, sagittal, and axial correction is maintained and the rate for late reoperation is low.
performed, were excluded. Of the remaining 34 patients, 19 were treated with DVBD (en-bloc, segmental, or both), and 15 patients only received a posterior spinal fusion (PSF). Segmental derotation was defined as application of axial rotatory corrective forces across one vertebral segment at a time, whereas en-bloc derotation constituted corrective forces applied across multiple vertebrae simultaneously. Our control group consisted of patients, with Lenke type 5C curves, treated with only pedicle screw constructs. Using SPSS 12.0.2, we performed student t-tests to calculate statistical significance in the correction between groups. Our results indicated that even though our DVBD group had a 56.2% correction of the lumbar prominence, the control group had a 76% improvement. Statistically, our results show that DVBD does not provide significant improvement to the lumbar prominence.
Preparation of Porous Nanostructures via the Epoxide Addition Method: A Study of pH and Gel Formation with Templating Prajan Divakar Marauo Davis, Geneva R. Peterson, Louisa J. Hope-‐Weeks Department of Chemistry and Biochemistry, Texas Tech University Lubbock, Texas 79409, U.S.A
Abstract: Recently, copper and zinc aerogels have been synthesized using the sol-‐gel method. The gels were prepared using different molar ratios of Cu:Zn and different copper salts. Characterization of the as-‐prepared aerogels involved Brunauer-‐Emmett-‐Teller, Barrett-‐Joyner-‐Halenda, and Powder X-‐ray Diffraction analyses. The Thermogravimetric analysis was then performed to obtain an aerogel containing copper metal and zinc oxide. Overall, the characterization process yielded unexpected results; the annealed aerogel contained large quantities of copper (II) oxide. In addition to the production of copper and zinc containing gels, a pH study of different manganese salt solutions with regard to the anion effect was investigated. Similar trends within the different metal salts regarding pH as a function of time were noted. The change in pH resulted from periodic additions of propylene oxide. Introduction: Porous nanostructures, also known as aerogels, are becoming more and more prevalent in commercial applications today. Their various uses make them especially attractive to research. In addition to requiring environmentally safe materials to produce, aerogels can be implemented as energy-‐storage devices, insulators and optical enhancers . One of their common uses is for catalysis. The combination of copper and zinc oxide is one such aerogel that industries utilize in large scale amounts. These catalysts, however, are produced with alumina that improves their properties but is also financially demanding to produce and/or purchase. Sol-‐gel chemistry offers a solution to this problem with a cost-‐efficient and effective method of creating aerogels . These aerogels may not only contain the substances required for a particular catalyst but also provide a large amount of surface area to facilitate reactions without the use of alumina. The unique properties of aerogels provide them with numerous pore sites within a monolith . In addition, aerogels can be made with templates that can enhance gel properties, such as surface area and porosity, in an inexpensive and effective way. Silica and resorcinol-‐formaldehyde are two commonly used templates . This report will further investigate the possibility of synthesizing copper and zinc oxide aerogels. In addition to the importance of copper and zinc containing aerogels, optimization is also a key component in developing aerogels with maximum efficiency. pH is one such factor that can alter the properties of an aerogel; therefore, another experiment investigating the effect of different anions in manganese salts (with periodic additions of epoxide) on the pH of gel solutions will be discussed in further detail . Both these experiments can ultimately enhance the synthesis of aerogels and make them more beneficial for modern application. Experimental Method: The experimental structure of this entire report is twofold: to synthesize and study copper (Cu) and zinc (Zn) gels with Zn(NO3)2•6H2O and one of three different copper anions (CuBr2, CuCl2•2H2O, and Cu(NO3)2•3H2O) and to study the pH of different manganese salts with regard to the anion effect and the epoxide addition method. For the Cu/Zn gels, five different molar ratios of copper to zinc (1:1, 1:4, 1: 9, 4:1, and 9:1) were used, resulting in a total of fifteen different gels. The total number of moles of metal salts was kept constant at 6.60 mmoles. In this way, the amounts of solvent and epoxide were consistent, and the total volumes before gelation were identical. Preparation of Copper and Zinc Gels: Solution “A”: 1.00 mL of distilled water and 10.0 mL of dimethylforamide (DMF) were placed into a clean, dry beaker. The appropriate amounts of metal salts were then dissolved into the solution (see Table 1) . Solution “B”: 0.792 g (7.20 mmols) of resorcinol were dissolved into a beaker of 10.0mL DMF and 0.910 mL of formaldeyhyde . Since solid resorcinol is stored in a refrigerator, it may be necessary to crush chunks of the substance with a mortar and pestle to make dissolving easier. The amounts of solid in this experiment were measured with a Mettler Toledo digital balance, and the amounts of aqueous substances were measured out using appropriately numbered syringes. Table 1: Masses (g) of Metals Salts Required for Corresponding Molar Ratios of Cu:Zn
1 0.737 — 1
1 0.295 — 4
1 0.147 — 9
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300 250 200 150 100
10 20 30 40 50 60 70 80 2 Theta (degrees)
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100 90 80 Mass Percent (%)
70 60 50 40 30 20 10 0
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7.4 6.9 6.4 5.9
50 100 150 Time(min) *
Mn(CH3COO)2•4H2O 8.6 8.4 8.2 8 7.8 7.6 7.4 7.2 7 6.8
50 100 150 200 250 Time(min) *
6.9 6.8 6.7 6.6 6.5 6.4 6.3 6.2 6.1 6 5.9
50 100 Time(min)
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Solar Cells Galen Gao Dr. Yun-Ju (Alex) Lee Ms. Juan Yi Mr. Jian Wang Dr. Julia Hsu University of Texas at Dallas, summer 2011 Organic solar cells represent a promising route toward low-cost, renewable energy generation; however, a common problem of many organic solar cells is the short diffusion length of excitons, hole-electron pairs created in the active layer by the energy from a photon of sunlight, which recombine if they do not reach an electron donor-electron acceptor heterojunction closer than roughly 10 nm. One solution to this dilemma is to use as the active layer a dispersed heterojunction, in which donor and acceptor layers are mixed, instead of kept separate as they are in conventional silicon-based solar cells, to create multiple junctions while remaining sufficiently thick to absorb enough photons. To optimize device performance even further, an overall electric field, often supplied by transport layers located between the electrodes and the heterojunction, is needed to provide a general direction for the separated holes and electrons to follow, facilitating their diffusion toward their respective electrodes. The way these transport layers build up this electric field is through the difference in their materials’ work functions, the energy gap between the highest occupied molecular orbital (the HOMO or valence band) and the lowest unoccupied molecular orbital (the LUMO or conduction band). The hole transport layer, which attracts positively charged holes, is typically made of a material with high work function because the high electric potential repels electrons and attracts holes. Conversely, the electron transport layer, which attracts electrons, typically is made with a substance with low work function so that the low electric potential attracts electrons and repels holes. It is also important to note that the transport layers must be spread uniformly to prevent the leakage of charge carriers toward the wrong electrode (e.g. electrons flowing through the active layer toward the anode) and shorting of the solar cell through direct contact between the ITO and the active layer. For this reason, most researchers create transport layers with nanoparticles, which will evenly coat a surface without creating macro-sized “chunks” of material. In this report, we present a novel, solution-based method for the fabrication of these transport layers using microwave-assisted synthesis of metal-oxide nanoparticles. In previous experiments, research groups have created these nanoparticles using evaporation, a time-consuming process that requires big, expensive equipment. In an effort to support the basic advantages that organic photovoltaics confer over Silicon-based ones, our work should strive to make this process cheaper and quicker without too much sacrifice in efficiency or performance. Ideally, our method should more easily create particles that are either identical to those produced using the evaporation technique (assuming the evaporation technique produces 100% perfect metal-oxide nanoparticles) or so similar to the accepted standard in characteristics such as work function and particle size that, for the purposes of organic photovoltaics, these particles effectively are the metal-oxide nanoparticles. The development of such a procedure would greatly increase the speed at which nanoparticle transport layer materials can be produced for a much lower price. Materials and Methods In order to synthesize these metal-oxides, we followed similar procedures to create both the Zinc Oxide and Molybdenum Oxide nanoparticles. I first dissolved the appropriate powdered metal-acetylacetonate precursor in an organic solvent, either 1-Butanol or methyl iso-butyl ketone (MIK), at 0.1M concentration. For example, for the first batch of ZnO nanoparticles, we weighed out 131.8mg Zinc Acetylacetonate (Znacac) and dissolved it in the appropriate volume of 1-Butanol to make 5mL of a .1M solution. All solvation was conducted in a controlled atmosphere of nitrogen gas. I then sealed the vial of solution, transferred it out of the nitrogen-filled glove box, and placed it in a single-mode microwave reactor (only one standing wave with its antinode at the center of the reaction chamber ensured uniform heating of the solution). The reactor was programmed to heat the solution in two stages. In the first, the reactor maintained the temperature at 60°C for 3 minutes to ensure complete solvation of the solution before proceeding to the reaction. In the second stage, the reactor increased the temperature to 160°C for the Znacac solution and 200°C for the Moacac solution and then maintained that temperature for another 15 minutes after which the solution was cooled over the course of roughly 8 minutes by blowing cool air over the solution vial. The pressure within the vial was never allowed to exceed 250psi during the two stages. At this point, the Zinc Acetylacetonate had mostly converted into Zinc Oxide nanoparticles, but the Molybdenum Acetylacetonate needed further postannealing. To accomplish this postanneal, I took the intermediary between Moacac and MoO3, visibly changed in color from light to dark brown, out of the microwave reactor and spincoated it onto a glass substrate at 1000rpm for one minute (200µL per 2.54cm x 2.54cm glass slide). Our lab group used two different methods of conducting the postanneal. The first method was to place the slide in a UV-ozone cleaner and run the cleaner for twenty minutes. The second method was to heat the slide on a hotplate at 300°C for five minutes. To confirm the actual conversion of metal-acac into metal-oxide, I used UV-visible spectroscopy, Kelvin probe measurements of work function, and Scanning Electron Microscopy, creating the samples for measurement using the procedure for spincoating described above. I myself took most of the UV-visible spectroscopy and Kelvin probe measurements, but a Ph.D. student operated the SEM to take pictures of the slides I had prepared. I used microscope cover slips as the glass substrate for the UV-visible spectroscopy and glass slides layered with preprinted Indium Tin Oxide (ITO) for the Kelvin probe and SEM measurements.
Final testing of transport layer material efficiacy involved creating actual photovoltaic devices using industry standards of a16mg/mL Poly-3-hexylthiophene (P3HT)/Phenyl-C61-butyric acid methyl ester (PCBM) dissolved in chlorobenzene as the active layer (dispersed Hole Transport Layer / heterojunction), ITO as the bottom, transparent Device # e- Transport Layer electrode, and Aluminum as the top electrode. PEDOT / (none) Figure 1 to the left clarifies the device structure. 1 The P3HT-PCBM was deposited in a controlled, 2 MoO3 / (none) Nitrogen gas environment using a spincoater set 3 MoO3 heated to 300°C to 1000 rpm for one minute (200 µL per 2.54cm / (none) Figure 1 x 2.54cm device); the Aluminum was deposited MoO3 UV/ozoned 20 onto the solar cell in a 10-8 kPa vacuum using an evaporator. We finally heated the 4 minutes / (none) whole device on a hotplate at 140°C as part of standard procedure. Our control sample was created using Poly(3,4-ethylenedioxythiophene) (PEDOT) as the hole 5 PEDOT / ZnO transport layer, as the device will short-circuit should the ITO directly contact Table 1: Devices created the active layer. We created 5 devices in total, shown in Table 1, and tested their generated current, voltage, and efficiency using a solar simulator set to one sun’s intensity. Results Our new procedure for creating metal-oxide nanoparticles was highly successful in converting Moacac and Znacac solutions in 1-BuOH into MoO3 and ZnO respectively. Our tests to confirm this success included visual examination, UV-visible spectroscopy, Scanning Electron Microscopy (SEM), and Work Function. Our visual examination confirmed the creation of nanoparticles, as the particles stayed suspended in solution for upwards of two months after their synthesis. As seen in the Figure 2 on the right, the microwaved solutions of ZnO and MoO3 produced well-mixed, uniform colloids and solutions respectively. In comparison, a microwaved solution of Niacac in 1-BuOH produced a mixture that quickly settled and did not appear to have reacted at all. The difference in suspension between the three mixtures indicates a disparity between their respective particle sizes. We can safely conclude that the ZnO and MoO3 solutions contain particles of size well within the nanoparticle range of roughly 10 nm due to their stability in solution. A closer look with a Scanning Electron Microscope confirmed the Figure 2: Microwaved soluproduction of ZnO nanoparticles roughly 10nm in diameter, as seen tions with different precurin Figure 3. However, MoO3 slides yielded less distinct results. As sors seen in Figure 4 and Figure 5 below, the area imaged appears blank aside from several stray dust particles. While the apparently blank slide does not necessarily imply an absence of MoO3, as the particles may have been too small to appear in the image, it does necessitate further testing. In fact, the visual examination of the MoO3 nanoparticles suggests a particle size smaller than that of the ZnO nanoparticles, Figure 3: ZnO slide, 300kx zoom as the MoO3 solution was much less cloudier and more well-mixed than the ZnO solution. Additionally, the nanoparticles were characterized using UV-visible spectroscopy. As seen in Figure 6, a UV-visible spectroscopy graph, to the left, the conversion of Zinc Acetylacetonate into Zinc Figure 4: MoO3 slide, Figure 5: MoO3 slide, Oxide shifts the solution’s band gap, 300kx zoom 10kx zoom the wavelength of photons at which the substance’s electrons absorb and are excited by the photons, from roughly 310nm to approximately 360nm. The higher absorption of Znacac beyond 350nm is due to light scattering because the powdery Znacac particles are much larger than the ZnO nanoparticles, confirmed by the difference in appearance between a solution of powder (such as Niacac in Figure 2) and a solution of nanoparticles (such as ZnO in Figure 2). When Figure 6: UV-visible spectroscopy of we microwave the solution of Znacac in 1-BuOH, Znacac and ZnO the Znacac absorption peak nearly completely disappears, leaving only the ZnO peak. This change clearly shows that a chemical reaction has taken place, forming nanoparticles, which have a completely different bandgap. A similar graph but with Moacac instead of Znacac is shown to the left in Figure 7. The difference in bandgaps is Figure 7: UV-vis spectroscopy of much harder to see here, as it appears to lie beyond the minimum wavelength our instrument can detect, but a clear drop in absorbance is seen under 330nm, indicating a chemical reaction. Ef- Moacac and MoO3 fects of postannealing the MoO3 nanoparticles are also shown in Figure 7. While having a minimal effect on absorbance, the heat and
We further characterized the synthesized nanoparticles by using a Kelvin Probe to measure work function. For the ZnO nanoparticles, a reading of 4.31eV was obtained, well within the accepted standard range of 4.1-4.3eV. The MoO3 nanoparticles yielded readings of 4.76eV before any postanneal treatment, well below the accepted standard of 5.1-5.3eV. However, after heating the ITO slide coated with the MoO3 on a hotplate at 300°C for five minutes, the work function had changed to 5.50eV. Similarly, after running a coated slide through a UV-ozone cleaner, the work function had changed to 5.24eV. Figure 8 shows the change in work function of MoO3 as a function of the change in temperature. However, the same procedure was not as successful when applied to some other Figure 8: Temperature heated to vs. Work solutes and solvents. As was seen in Figure 2 Function of MoO3 spincoated on an ITO slide above, whereas microwaving Znacac and Moacac in 1-BuOH produced well-mixed, uniform colloids and solutions, microwaving a Figure 9: UV-visible spectroscopy of Niacac solution in 1-BuOH produced a mixture that quickly settled and did not appear to ZnO in MIK and BuOH have reacted at all. Additionally, the use of methyl iso-butyl ketone (MIK) as the solvent instead of 1-BuOH also appears to impair the formation of metal-oxide nanoparticles. This difference is best seen in the absorbance spectra of the two solutions, plotted in Figure 9: when MIK is used as the solvent instead of 1-BuOH, the overall graph is higher, meaning the particles are larger and scatter more light, and the ZnO peak created is smaller relative to the Znacac peak, indicating a lower conversion rate. The solution of ZnO in MIK also settled out over the course of several days, confirming that its contents were indeed larger than the particles within the solution of ZnO in 1-BuOH. Overall, the synthesized transport layers significantly improved device performance when compared to the industry standard control (PEDOT HTL and no ETL). Figure 10, showing current vs. voltage outputs of the devices, appears to the left. Table 2 shows Jsc, the current/area when short-circuited (V=0); the Voc, the voltage when open-circuited (I=0); the fill factor, a measure of how well the device maintains its Jsc as it approaches the Voc for maximum current and voltage output; and the percent efficiency. Overall, the Figure 10: J-V graphs of the 5 devices tested devices’ performance increased when they utilized the transport layers. The only exception to this rule occurred with device 3 (MoO3 with hotplate heating to 300°C) in which we believed the high temperature caused the particles to coalesce, thereby formDevice # Jsc (mA/cm2) Voc (V) Fill Factor % Efficiency ing gaps in the transport layer. 1 (PEDOT/ 7.60 ± 0.593 .475 ± .013 .250 ± .035 .904 ± .202 none) Discussion Regarding the identities of the 2 (MoO3/ 7.39 ± 0.240 .389 ± .007 .362 ± .033 1.04 ± .080 substances synthesized, one can say with great none) certainty that the procedure created Zinc Ox- 3 (MoO3 4.21 ± .164 .247 ± .025 .446 ± .018 .465 ± .075 ide: the Scanning Electron Microscopy, UV- 300°C / none) visible spectroscopy, and Kelvin Probe mea4 (MoO3 UV/ 7.90 ± 1.07 .395 ± .011 .500 ± .023 1.55 ± .253 surements all point to traits that match those none) of Zinc Oxide. Nevertheless, in the unlikely 10.1 ± .713 .556 ± .006 .480 ± .017 2.69 ± .247 possibility that Zinc Oxide nanoparticles were 5 (PEDOT/ ZnO) not created, because we have determined that the solution created contains nanoparticles, Table 2: Table of devices’ performance which spread evenly across a substrate, and has a work function within the scientifically accepted range, we will have created a substance that, for all photovoltaic purposes, functions exactly like Zinc Oxide. However, our certainty that we synthesized MoO3 is shakier. The SEM failed to pick up any readings indicating nanoparticles, and the bandgap of the spincoated solution does not appear on the UV-visible spectroscopy charts, even after postanneal treatment. The only evidence that indicates we have truly synthesized MoO3 nanoparticles comes from the Kelvin Probe. But while this shortage of evidence may discourage one from definitively declaring the substance MoO3 (although for the moment we are convinced), it does not rule out the possibility that the substance we produced is a viable transport layer material. In fact, because we can postanneal the material to have work functions as high as 5.5eV, as long as the material does not allow the ITO to contact the active layer (i.e. it uniformly coats the device surface), this material works as a hole transport layer whether or not it indeed is MoO3. It matters not that
we have or have not synthesized Molybdenum Oxide: we have created a substance that replicates select properties of MoO3 so well that it effectively is MoO3 when used in a photovoltaic device. Indeed, the data collected from the prototype photovoltaic devices indicates an improvement in performance when the devices use the synthesized materials as transport layers. Efficiency and fill-factor improve significantly whenever we use MoO3 as a hole transport layer, especially after postannealing, and the same happens when we apply ZnO as an electron transport layer. Although the efficiencies obtained are below the current organic photovolatics record of ~9.6% using solar cells in tandem, they still represent a step forward when compared to the standard method of mass production using PEDOT as the hole transport layer. In this way, we have created a material that can improve the efficiency of organic solar cells. Additionally, our materials are not as completely converted as possible, as seen by evidence such as the slight bump in the ZnO absorbance graph at 310nm indicating the presence of a small, though still rather significant, quantity of unreacted Znacac. These impurities may also account for the mixture’s slightly higher than normal work function when spincoated on ITO. Although future work may further refine our methods to create purer products and a higher nanoparticle conversion rate, our current procedure already shows significant signs of progress towards more efficient organic solar cells. Many have synthesized Zinc Oxide and Molybdenum oxide nanoparticles before, but the way our research differs from these previous attempts is through our use of a new, less time-consuming method to create the nanoparticles. Previous methods involve slowly evaporating mixtures at high temperatures approaching 1050°C, a very energy-intensive process. Two of the primary benefits of using organic solar cells over traditional Silicon-based solar cells are the organic solar cells’ ability to be cheaply mass produced and their freedom from silicon, which is highly energy-intensive to produce. As a result, this novel method of synthesizing transport layers through catalyzing a reaction with microwaves fully backs the two main advantages of using organic solar cells. Transport layer materials can be produced in less than an hour now while only requiring the energy to heat a material to at most 200°C instead of 1000°C. This benefit is what this new method brings. Conclusions and Future Studies Our research indicated that there is a more time and energy-efficient method of synthesizing ZnO and MoO3 nanoparticles than the method currently used today. While we cannot definitively say that we have synthesized those nanoparticles, more pieces of evidence point toward their creation than not, and the properties we were most interested in reproducing were realized. Similarly, while we definitely did not achieve a 100% conversion rate of metal-acac precursor into metal-oxide nanoparticle, our conversion rate was sufficient for the creation of more efficient photovoltaic devices. We have developed a method for the easy synthesis of particles that are either identical to the accepted standard or so similar in the key characteristics of work function and particle size that, for the purposes of organic photovoltaics, they effectively are the evaporated metal-oxide nanoparticles. Future work on this procedure will definitely focus on its applicability to other known transport layers, increasing nanoparticle conversion rate, and even if it can synthesize some hitherto-unable to-be-produced material that will function as an even better transport layer than Zinc Oxide and Molybdenum Oxide. One possible way to increase nanoparticle conversion rate may be to increase the temperature the solution is microwaved at; however, this would require a higher-powered microwave reactor than the one available to our lab now. Additional possible areas of improvement lay in utilizing different postannealing techniques and use of different solvents besides 1-BuOH, which was the most successful, and Methyl-iso-butyl Ketone. Other metal-acac precursors that appear promising include Vanadium Oxide (V2O3) as a hole transport layer and Aluminum Oxide (Al2O3) and Titanium Oxide (TiO2) as electron transport layers. Additionally, the differences between different post-processing techniques likely requires investigation to further understand when to UV-ozone, when to heat the material on a hotplate, and when simply not to postprocess at all. Any one of the above suggestions is valid as a next step; however, the most likely course of action would be either to test other precursors first for synthesis of nanoparticles with the desired work functions and then in devices for increased efficiency and fill factor or to try other solvents and microwave settings in an attempt to synthesize MoO3 without postprocessing. Doing so would further decrease preparation time, increasing the utility of organic solar cells in replacing silicon solar cells. Many steps still need to be undertaken to make organic solar cells as widespread as silicon solar cells, yet the procedure in this report offers a promising method to mass produce organic solar cells at a much cheaper cost. The efficiency will remain well below that of the silicon photovoltaics, which regularly achieve efficiencies of ~17%, but organic photovoltaics function much more efficiently now with the benefit of transport layers. Some key questions remain regarding what innovative strategies to use to break down these obstacles, but as organic solar cells increase in efficiency and cost-effectiveness, there is no doubt that they will occupy a greater presence within our lifestyles.
A brief look at cancer By Staff Writer Pramukh Atluri Roughly 7.2 million people die from cancer every year, and this number steadily rises. As the second leading cause of death in the United States, cancer has kept scientists on their toes in search for an unknown cure. To further appreciate the research put into stopping this killer, we must first understand the background story of what makes this disease so baleful. A cancer occurs when a group of cells grows uncontrollably because of a mutation in a DNA sequence. The rapidly reproducing cells intrude into surrounding tissue and around the body, which results in the destruction of various bodily functions and tissues. Cancer is mainly caused by environmental factors although genetics can partially influence its presence, such as: tobacco use, poor diet and obesity, radiation, infection, and environmental pollutants. Cell reproduction is an extraordinarily complex process, and these environmental elements enhance the abnormalities within the cells’ genetic material. Although cancer can initially resemble a tumor, it is most often diagnosed by blood tests. Due to the number of citizens who do not receive regular tests, cancer is often found in later and more advanced stages where it is more malignant and relentless. Even though there is no actual cure for cancer, chemotherapy, a combination of drugs into a standardized treatment, is used as the known treatment. It
acts by destroying cancer cells that rapidly divide, which is the one of the main properties of the cells. The drawback is that other cells in the
ferent manner. Instead of having physicians focus on destroying the tumor, using genetargeted treatments should improve not only chemotherapy but also survival rates; the only problem with this is
body, such as in the bone marrow and hair follicles, are also affected since the cells rapidly divide but under normal circumstances, and this leads to common side effects like hair loss and a decreased output of blood cells. This heavy compromise leaves many patients feeling shamed and as if they were a different individual to not only others but also themselves. Furthermore, recent studies have shown that patients with advanced cancer who are concerned with their careers and knowing accurately how long they have left to live are now able to see whether they have days, weeks, or months. New lab scores are able to forecast a score which comprehends into a fairly accurate number of days (0-13, 14-55, or 55+). Also, other studies emphasize the need for cancer to be treated in a completely dif-
that the treatment does not prevent cancer from reoccurring. Even though there hasn’t been a discovery of a profound cure, preventive measures can be taken to limit the chance of cancer occurring. Some of these include staying away from smokers and alcohol, maintaining a healthy diet such as fruits and vegetables while staying away from saturated fats, and taking cancer screenings regularly to catch the disease in its early stages. As scientists and researchers continue their arduous work toward an ever evasive goal, scientific advancement has made the possibility of victory grow closer and closer in the fight against cancer.
Head Photographer Halbert Bai captures the double sunset phenomenon in this photo illustration. First depicted in Star Wars, the double sunset has become a more realistic possibility with scientists’ recent discovery of the planet Kepler-16b. For further information, see Astronomy Editor Reid Weisberg’s article Star Lores on page 9.
editorials When will I ever have to know this? By Editorial Director Galen Gao ook across campus today, and you will hear a common complaint that sounds out from disgruntled students struggling with their classes, science and non-science alike: “When am I ever going to have to use this?” Yes, you will rarely ever come across a serial killer who agrees to let you go only after you have recited the first thirty elements of the periodic table in order, and it’s equally unlikely that Connor Anderson will need to stop and pull out his calculator to compute the trajectory of his next three-pointer to ensure the basketball finds the bottom of the net. Yet common uses of science still exist even in daily life, beyond the professions so meticulously listed in the chart hanging on Mrs. Oprea’s classroom wall. Like it or not, science exists everywhere in our lives, whether we are scientists or not. Take, for instance, the consumption of spicy food. Many people, me included,
can move faster than Mr. Marmion confronted with technology at the sight of anything that looks even remotely spicy. However, in the rare instance that we must force a chili pepper or jalapeno down our own throats, most of us keep a glass of water handy. What many don’t know or consider though, is that the vast majority of spice compounds are nonpolar and therefore highly insoluble in water. We feel it all the time when the burn lingers after each gulp of water, yet for some reason, we stick to water as our savior from the fires of spicy foods. A nonpolar solvent, such as milk or an oily food would be more effective. Just a bit of simple science can save you from a lot of burn and tongueache. (N.B. This does not mean that you can chug a bottle of Tabasco for a bet and then bite a stick of butter: there are other health complications involved too!) Another practical application of science involves lightning and cars. Any half-awake physics student will tell you that the metal chassis of a car, when struck by lightning, will act as a fara-
Inflammation from the Cellular to Organismal Level at UT Southwestern
day cage, redirecting electrical current around the passengers as the bolt finds the path of least resistance to the ground. Yet look online, and you’ll find more explanations pointing to rubber tires than ZUCAs on campus during the spring of 2010. “Why should I care about this?” you may ask. Aside from being able to flaunt your scientific superiority in the face of the hopeless masses’ ignorance, you may think twice before driving that fiberglass-topped convertible through a heavy thunderstorm in the middle of Nebraska flatland. In all honesty though, the chances that lightning will strike your car are infinitesimal, but at least you know why people always harp that you should never touch any metallic part of the car during a storm. Science exists everywhere in life, and we should do our part to try to understand it, even when we have no idea how we’ll use it ever again. Who knows? Maybe you’ll be eating something spicy the next time you drive through a thunderstorm.
Battle of the sexes By Robby Orth
By Astronomy Editor Reid Weisberg In the summer of 2010, I had the opportunity to work in a research lab at UT Southwestern Medical School. I worked in the lab of an MD/PhD gastroenterologist whose research focuses on inflammation from the cellular to the organismal level. By observing slides from the colons of colitic mice, I helped in a project to determine the significance of a gene in the predisposition to colon cancer. I also worked with bacteria cultures and plasmids to check how well the restriction enzymes worked in addition to cleaning up the lab and autoclaving and organizing the equipment. Overall, my experience was insightful and fun. It definitely influenced my thinking as to what I would want to do after college.
Our presidential candidates on evolution -- and why it matters Mitt Romney
President Barack Obama
“I believe that God
“We should encour-
designed the uni-
age schools to teach
schools are there to
verse and created
better science and
teach worldly knowl-
the universe, and I
to teach more about
edge and science. I
believe evolution is
believe in evolution,
most likely the pro-
the gaps and con-
and I believe there’s
cess he used to cre-
a difference between
ate the human body.”
science and faith.”
tives. In particular, crucial evidence for evolution is outright ignored in favor of hyperbolic attacks. My personal favorite creationist denial of science is the argument that 14 million tons of meteorite dust should land on Earth each year, much more than is measured. Aside from the fact that the methodology employed by the author of the paper they cite contained many holes (such as assuming that all nickel-containing particulate matter comes from extraterrestial sources) and that they cite as fact the author’s maximum figure, which by his own admission is a gross overestimate,
phoro courtesy wikimedia.com
By Staff Writer James Rowan Why does a candidate’s view on evolution matter? Local authorities, such as school boards and state education agencies, call the shots when it comes to science curricula. Even the ability to appoint the secretary of education and supreme court justices has little impact on what students learn. While I acknowledge that economic issues are the predominant focus of the 2012 election, I see two problems with the inherent electing of an anti-evolution president. The first is that denial of evolution constitutes a denial of science in favor of ideology. The second is that the stance that evolution should not be taught or should be taught alongside creationism is blatantly unconstitutional. First, any alternative to evolution is necessarily motivated by an epistemology that is, in a word, not science. The scientific method relies on empirical observation and the testing of theories by experiment. Micro- and macro-evolution have been demonstrated by experiment, and no counterexamples exist that would call the theory into question. Scientists studying paleozoology and paleobotany look at data and draw conclusions without an agenda or a vested interest in whether evolution is “right” or “wrong” (two terms, by the way, that are particularly dangerous when describing theories which can never be conclusively proven to be universally either right or wrong). On the contrary, creation “scientists” almost always start from the premise that evolution is wrong—or, more typically, that the account of creation given in the Bible is a true, literal account of the origin of the universe—and work from there, citing everything from outdated papers based on flawed data to theological tracts in an attempt to justify their alterna-
Like all of his predecessors, Obama swore into the presidency in 2008 upon the Bible. This is one of many practices that illustrates the intertwining of politics and religion.
the creationists ignore that that paper was from 1960 and that newer satellite-based measurements are in line with observed meteorite-dust levels on earth. By cherrypicking one paper and ignoring the rest of the literature on the topic, creationists are not doing real science. They’re attempting to appropriate scientific articles and termi-
nology out of context in order to advance their ideology. The ideology-over-evidence mindset of evolution denialists has the potential to wreak havoc on the US—and not just by running our already laughable (see my 2009 Scientific Marskman article) science education system further into the ground. If a politician can casually pass over the views of generations of specialists and experts on a low-stakes matter like evolution, he or she can just as easily ignore the evidence for global warming, for the effectiveness of countercyclical government spending to combat economic contractions, or against weapons of mass destruction in a Middle Eastern country. Regardless of one’s opinion on whether nation-building in Iraq is justified and necessary, the original justification—WMDs—was given by the Bush administration despite evidence to the contrary. Similarly, candidates are increasingly willing to engage in demagoguery by promoting protectionism—the notion that trade should be restricted— despite hundreds of years of economic theory and empirical data showing that it costs more jobs and money than allowing free trade. The risks of refusing to take action on global warming are catastrophic and global, but apparently an ideological opposition to government regulation in free markets is more important to many right-wing politicians. Incidentally, their opposition to regulation and belief that the current system can solve global warming is itself a denial of economic fact: negative externalities are not addressed by pure free markets without allocation of property rights. Equally troubling is what belief in the teaching of creationism says about the
continued on next page
The Nobel Prize indicates some of the most ground-breaking research in the various fields of science. Not to mention the 10 million Swedish Kronor these scientests receive for their contributions. But this year’s Nobel Prize foundation faced an unprecedented event, and some of the scientists have fascinating stories backing their acclaimed research.
By Editor in Chief Alex Rothkrug Chemistry Dan Shechtman, professor at Technion-Israel Institute of Technology and at Iowa State University, and researcher for the US Department of Energy won this year’s chemistry prize “for the discovery of quasicrystals.” What is so unique about Shechtman’s research is that it was widely criticized until now. His own colleagues and even the famous, deceased Linus Pauling argued over the meaning for his results. Awarded the Nobel Prize in Chemistry for his Through rapid-chilling of discovery of quasicrystals, Dan Shechtman is the fourth Israeli to win the prize since 2004. molten aluminum mixed with manganese, to his surprise, Shechtman observed, under an electron microscope, that the atoms were arranged in a particular pattern, yet a non-repeating pattern. Shechtman, though doubting himself at times, was able to give birth to a new field of study (of quasicrystals) through his perseverance. Physics This year’s Nobel Prize for physics went to three scientists: Saul Perlmutter at Lawrence Berkeley National Lab, Brian Schmidt at the Australian National Lab, and Adam Reiss at Johns Hopkins. The prize was awarded “for the discovery of the accelerating expansion of the Universe through observations of distant supernovae.” Gravity was always expected to pull and was the glue holding the solar system together. Einstein’s theory that gravity could also push was never observed until the scientists who were awarded this year’s Nobel Prize discovered a case of this phenomenon. When noticing that the brightness of distant supernovae was dimmer than expected, these researchers concluded that our universe is actually expanding at an accelerated pace rather than what we previously believed to be a decelerated pace.
Medicine The Nobel Prize for Physiology or Medicine was awarded to Ralph M. Steinman at Rockefeller University in New York City “for his discovery of the dendritic cell and its role in adaptive immunity” and Bruce A. Beutler at the Scripps Research Institute in California and Jules A. Hoffmann at the French National Center for Scientific Research “for their discoveries concerning the activation of innate immunity.” The Nobel Foundation has a rule that the Nobel Prize must be awarded to a living individual. This is why Rosalind Franklin was unable to receive the prize for aiding in the discovery of the structure of DNA. Ralph Steinman passed away, due to pan- Bruce Beutler, one of this year’s three winners creatic cancer, three of the Nobel Prize for Physiology or Medicine, completed much of the research that led to his days before the award at UT Southwestern Medical Center in Nobel Foundation Dallas. unknowingly announced the recipients. Because the death of Steinman was unknown before the decision to award him the prize was made, he was still allowed to remain a Nobel Laureate. Dendritic cells are essential in “adaptive immunity,” which substitutes for innate immunity and usually leaves us with antibodies for the disease in the future. When our immune systems are overly active, and for no reason, they actually cause problems. In helping to simplify the workings of the immune system, these scientists’ research will help develop more effective vaccines.
Our presidential candidates on evolution, continued from previous page commitment of some politicians to constitutional freedoms. The establishment clause (“Congress shall make no law respecting an establishment of religion”) guarantees that creationist theories, which, as espoused by right-wing candidates, are almost universally Christian in nature, cannot be taught in public school. Decades of jurisprudence on the first amendment has consistently struck down laws
mandating the teaching of creationism. Indeed, as proven in the Church of the Flying Spaghetti Monster thought experiment, any attempt to provide an all-inclusive, constitutional teaching of religious-based theories of cosmic and human origins is doomed to laughable failure. A willingness to ignore those stipulations of the Constitution that one disagrees would also enable a government to run roughshod over other
basic civil liberties. Although almost nobody votes solely on a candidate’s view on evolution, it is clear that electing a candidate willing to ignore the consensus of trained professionals solely on the basis of ideology would be a step backwards for the American people—a step away from economic prosperity, global prestige, and environmental security and towards a militaristic, theocratic society.
24 The Brain Strain compiled by James Rowan, staff writer
Divide the square into four squares, each of side length 1 in. One of these squares must have two of the five points in it (by the pigeonhole principle). The longest distance between two points in a square with side length 1 in. is less than 1.5 in, so we are done.
Give up? It’s 312211; each number is formed from reading the previous number’s digits aloud. The first number is one 1, so we write 11. The second number is two 1s, so we write 21, and so on. The fifth is three 1s two 2s and one 1, so 312211 is the answer.
Five points are chosen inside a square of side length 2 in. Prove that there are two points that are within 1.5 in. All of them; just divide it into n rectangles with one side length s/n and the other side length s, where s is the side length of the square. For which positive integers n can a square be cut into n congruent polygons?
Find the next number in this sequence: 1, 11, 21, 1211, 111221,…
Although this problem can be approached with techniques from calculus like the intermediate value theorem, a more intuitive solution is given. Send a second monk up on the second day that does exactly what the first monk did on the first day. Since both monks are on the same trail, and since the first moves from bottom to top while the second moves from top to bottom, they must run into each other at some point. At that point in time, the place the monk was on day one is the same as the place he is on day two, since the location of the second monk on day two represents the location of the first monk on day one. A monk leaves from the base of a mountain at 8 a.m. and follows a trail until he reaches the summit at 8 p.m. The next day he leaves the summit at 8 a.m. and follows the same trail until he reaches the base at 8 p.m. Prove that there is some time where the monk is at the same point on both days. No; any one-by-two tile must have one black square and one white square in a chessboard with the usual coloring. But opposite corners have the same color in opposite corners, so there are 30 squares of one color and 32 of the other, and there is no way 2 by 1 squares, each with one black square and one white square, can be used to cover the chessboard.
Make a regular tetrahedron; the key to this problem is thinking outside of the two-dimensional plane.
Make 4 equilateral triangles with 6 toothpicks. Make a 1 by 1 by 1 meter box. Its space diagonal will be longer than 1.5 meters, so the sword will fit.
Two opposite corners of an 8 by 8 chessboard are removed. Can the remaining chessboard be tiled with 2 by 1 tiles? Prove it!
If I have to ship a 1.5 m long sword and the post office won’t accept anything longer than 1 m in any dimension, how do I ship the sword?
The brain strain
Folklore problems and puzzles from Paul Zeitz’s The Art and Craft of Problem Solving
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