thinker_jeff

Engineers at Oregon State University have discovered a way for the first time to create successful "CIGS" solar devices with inkjet printing, in work that reduces raw material waste by 90 percent and will significantly lower the cost of producing solar energy cells with some very promising compounds.

High performing, rapidly produced, ultra-low cost, thin film solar electronics should be possible, scientists said.

The findings have been published in Solar Energy Materials and Solar Cells, a professional journal, and a patent applied for on the discovery. Further research is needed to increase the efficiency of the cell, but the work could lead to a whole new generation of solar energy technology, researchers say.

"This is very promising and could be an important new technology to add to the solar energy field," said Chih-hung Chang, an OSU professor in the School of Chemical, Biological and Environmental Engineering. "Until now no one had been able to create working CIGS solar devices with inkjet technology."

Part of the advantage of this approach, Chang said, is a dramatic reduction in wasted material. Instead of depositing chemical compounds on a substrate with a more expensive vapor phase deposition -- wasting most of the material in the process -- inkjet technology could be used to create precise patterning with very low waste.

"Some of the materials we want to work with for the most advanced solar cells, such as indium, are relatively expensive," Chang said. "If that's what you're using you can't really afford to waste it, and the inkjet approach almost eliminates the waste."

One of the most promising compounds and the focus of the current study is called chalcopyrite, or "CIGS" for the copper, indium, gallium and selenium elements of which it's composed. CIGS has extraordinary solar efficiency -- a layer of chalcopyrite one or two microns thick has the ability to capture the energy from photons about as efficiently as a 50-micron-thick layer made with silicon.

In the new findings, researchers were able to create an ink that could print chalcopyrite onto substrates with an inkjet approach, with a power conversion efficiency of about 5 percent. The OSU researchers say that with continued research they should be able to achieve an efficiency of about 12 percent, which would make a commercially viable solar cell.

In related work, being done in collaboration with Greg Herman, an OSU associate professor of chemical engineering, the engineers are studying other compounds that might also be used with inkjet technology, and cost even less.

Some approaches to producing solar cells are time consuming, or require expensive vacuum systems or toxic chemicals. OSU experts are working to eliminate some of those roadblocks and create much less costly solar technology that is also more environmentally friendly. New jobs and industries in the Pacific Northwest could evolve from such initiatives, they say.

If costs can be reduced enough and other hurdles breached, it might even be possible to create solar cells that could be built directly into roofing materials, scientists say, opening a huge new potential for solar energy.

"In summary, a simple, fast, and direct-write, solution-based deposition process is developed for the fabrication of high quality CIGS solar cells," the researchers wrote in their conclusion. "Safe, cheap, and air-stable inks can be prepared easily by controlling the composition of low-cost metal salt precursors at a molecular level."

This work was supported by the Daegu Gyeongbuk Institute of Science and Technology, the U.S. Department of Energy and OSU's University Venture Development Fund, which helps donors receive tax benefits while sponsoring projects that will bring new technology, jobs and economic growth to Oregon.

http://www.scienceda...10628133022.htm

Abstract

Teenagers are often impulsive. In some cases this is a phase of normal development; in other cases impulsivity contributes to criminal behavior. Using functional magnetic resonance imaging, we examined resting-state functional connectivity among brain systems and behavioral measures of impulsivity in 107 juveniles incarcerated in a high-security facility. In less-impulsive juveniles and normal controls, motor planning regions were correlated with brain networks associated with spatial attention and executive control. In more-impulsive juveniles, these same regions correlated with the default-mode network, a constellation of brain areas associated with spontaneous, unconstrained, self-referential cognition. The strength of these brain–behavior relationships was sufficient to predict impulsivity scores at the individual level. Our data suggest that increased functional connectivity of motor-planning regions with networks subserving unconstrained, self-referential cognition, rather than those subserving executive control, heightens the predisposition to impulsive behavior in juvenile offenders. To further explore the relationship between impulsivity and neural development, we studied functional connectivity in the same motor-planning regions in 95 typically developing individuals across a wide age span. The change in functional connectivity with age mirrored that of impulsivity: younger subjects tended to exhibit functional connectivity similar to the more-impulsive incarcerated juveniles, whereas older subjects exhibited a less-impulsive pattern. This observation suggests that impulsivity in the offender population is a consequence of a delay in typical development, rather than a distinct abnormality.

http://www.pnas.org/content/early/2011/06/20/1108241108.abstract

In other words, he isn't trusting a source blindly at all, he's trusting a source that verifies sources of its own and does so well and consistently. He mentions, also, that people shouldn't do so blindly and *should* go back to verify sources themselves, specially when reporting an article further down the internet chain.

I agree with this point 100%.

On the Science Forums you can find many posters who trusted and cited the sources they googled. Sometimes they cited them only because the keywords matched. One of the poster even told me that he had not read the articls, however, he used the articles to argue with me. I was so surprised!

To well verify a source is not easy job at least to me.

I would pick one after I travelled through the most of the countries in the world.

Generally, all populations identify features associated with health as those indicative of beauty, so there might be some transcultural features which all people would agree on as being attractive.

I heard this a lot, however, where are the scientific studies?

In the history a generation of people in China identified feature of beauty as skinny. How do you explain for that?

Very interesting study. Of course I reflected on my own life experiences to understand the concepts. Immediately what came to mind is being the new kid in a school. There are always clicks and a person is either on the inside or the outside. The benefits of being inside the click are social acceptance and possibly more. Being on the outside is of course social rejection, and this can take the form of painful punishments, because victimizing others is a way to gain status. This is so for gangs or cooperate folks, laughing at the dummies who are economic victims. To be on the inside, it is necessary to pick on someone. Among girls this is generally limited to verbal slurs against the victim, but it can include acts of violence. Seriously, if one does not go along with this abusive behavior, one does not remain an accepted member of group, and may become a target of this social rejection. With youths form violent gangs, or cooperate executives, this can be dangerous.

Noel Card, a psychologist at Arizona University, who writes about adolescent relationships gone wrong in the latest issue of the Developmental Psychology journal, said results from 26 studies involving 23,000 children showed 35% of youngsters had at least one “antipathetic relationship”.

The weight of previous research has suggested that only harm can come from hostility, but this was skewed by studies of the small number of children who are so different from their classmates that they suffer complete “peer rejection”. Once this is factored out, the damaging effects are slight.

Researchers at Strathclyde University in Glasgow studied 100 children aged nine to 13 and asked them for their accounts of being bullied and of being befriended by a fellow pupil.

Donald Christie, a professor of childhood studies at the university, said: “When we asked them to tell us about the time somebody did something mean or nasty, we had chapter and verse. We couldn’t write it down fast enough. But when we asked them to tell us when somebody did something nice, we had blank looks.

Link: http://www.timesonline.co.uk/tol/news/uk/education/article7133986.ece

I'm not saying that everyone has the same idea of beauty and ugly. I am just wondering how do you think about the beauty competitons. Does every girl have the same chance to win?

ugliness is subjective

Right.

If a girl heard "ugliness" about her looking, she should subjectively think the other way instead of blaming her parents.

There is no scientific support yet. But, you should have your answer by common sense, right?

Abstract

Understanding cooperation and punishment in small-scale societies is crucial for explaining the origins of human cooperation. We studied warfare among the Turkana, a politically uncentralized, egalitarian, nomadic pastoral society in East Africa. Based on a representative sample of 88 recent raids, we show that the Turkana sustain costly cooperation in combat at a remarkably large scale, at least in part, through punishment of free-riders. Raiding parties comprised several hundred warriors and participants are not kin or day-to-day interactants. Warriors incur substantial risk of death and produce collective benefits. Cowardice and desertions occur, and are punished by community-imposed sanctions, including collective corporal punishment and fines. Furthermore, Turkana norms governing warfare benefit the ethnolinguistic group, a population of a half-million people, at the expense of smaller social groupings. These results challenge current views that punishment is unimportant in small-scale societies and that human cooperation evolved in small groups of kin and familiar individuals. Instead, these results suggest that cooperation at the larger scale of ethnolinguistic units enforced by third-party sanctions could have a deep evolutionary history in the human species.

Link: http://www.pnas.org/content/early/2011/06/03/1105604108.abstract

If you like such kind of news, here is one even more unbelievable.

http://www.dailytech.com/Japanese+Make+Delicious+Nourishing+Steaks+From+Human+Feces/article21932.htm

The reason I called it worthless is because the effect of adrenaline and other stress hormones on aggression were well known (and were the exact effects reported), but they dismissed these already known results in favour of the result they were trying to prove.

 

Essentially, the only "new" information that can be got from that is that stressful situations video games can be stressful.

You said "video games can be stressful" that I agree with you. The game players on both of violent game and non-violent game should be all stressful, and should be all effected to their adrenaline and other stress hormones. The difference of adrenaline and other stress hormones on aggression between these playings had not be published.

They took a known effect (that stressful situations make people more aggressive) and then put that in a certain situation (violent games) and then said it was the violent games that did it.

 

Sorry, there is already a known factor that accounts for the effect, then you can't just publish something else as causing that effect unless you show the original cause was either not present or not in effect (and violent games are stressful), or the effect was greater than the original cause can account for.

Here is still the same logical problem - You assume that violent games are stressful but non-violent games are not. Do you have a source to support that?

Not only that, they published results that actually disprove their conclusions by the results of player who played the violent games a lot, but didn't get the same brain activity. Did it occur to them that players who are use to playing those games would not be as stressed by the situation than players who don't play them often?

This is good evidence that the player who played the violent games a lot before might have long-term effect on aggression. Quote: "the smaller the brain response to violent photos, the more aggressive participants were. Participants who had already spent a lot of time playing violent video games before the study showed small brain response to the violent photos, regardless of which type of game they played in the lab."

Alright. If we understand the conclusion of the research in the same way, I will give my point about this discussion, which is the answer to the question you asked initially.

abnormally?

 

Thinker_jeff,

 

Abnormally, but maybe not "incorrectly".

The neural network of the blind person has been mapped abnormally, which is working incorrectly when the person becomes a newly sighted one.

I did not subscribe to the article, but I got its drift. The important part to me, is that the newly sighted person rapidly mapped the visual information to what they already knew the world was like.

You've missed the most important point of the research, which is in the title - "The Newly Sighted Fail To Match Seen With Felt". The process about "cross-modal mappings developed rapidly" was after "a lack of immediate transfer" which means newly sighted person cannot know the world by looking without touching.

Unfortunately I don't have right to send you a copy of the paper.

But that is my point: These studies are virtually worthless because you can cherry pick the result you want and assume a conclusion not actually supported by the study to reach the conclusion you want.

Like I said in post #14, skepticism in science is necessary. However, when you say "these studies are virtually worthless" I think you have gone too far. Due to the complication in social psychology we have very few studies to result the absolute conclusions. If you used such standard, the Journal of Experimental Social Psychology would be worthless, and the peers who reviewed the research would be worthless as well.

I think such study provided valuable information about certain impact of violent video games. Yes, the impact was short-term effect in the study so that we need to study the long-term effect next. What's wrong with that? Why can't we publish the short-term effect first?

Some scientists like to assume a conclusion too soon, and some others like to be skeptical. That is all right. Each side can do their work to find the truth which will help the research in this field.

Personnally, I will try to tell my children about this study and ask them what would be the long-term impact if they played such game very much.

Jeff

 

Great Minds think alike ...

 

unfortunately the second half of that aphorism is that

 

...idiots seldom differ

I'm not sure what that means.

Anyway, I hope that we are helping OP in the same direction.

I guess the issue here is how do you deal with challenges to established authority, such as knowledge and definitions from textbooks, etc. If a textbook defines something like potential energy in a way that has shortcomings, what basis would you have for questioning the textbook's authority?

#1, when the new empirical data does not support the knowledge in the textbook.

#2, when the logic of the new facts does not support the statment in the testbook.

Scientists have produced the world's most powerful optical microscope, which could help us to understand the causes of many diseases. Writing in the journal Nature Communications, the team have created a microscope which shatters the record for the smallest object the eye can see, beating the diffraction limit of light.

Previously, the standard optical microscope could only see items around one micrometer -- 0.001 millimeters -- clearly.

But now, by combining an optical microscope with a transparent microsphere, dubbed the 'microsphere nanoscope', the Manchester researchers can see 20 times smaller -- 50 nanometers ((5 x 10-8m) -- under normal light. This is beyond the theoretical limit of optical microscopy.

This greatly-increased capacity means the scientists, led by Professor Lin Li and Dr Zengbo Wang, could potentially examine the inside of human cells, and examine live viruses in great detail for the first time.

The scientists, from the School of Mechanical, Aerospace and Civil Engineering, now believe they can use the microscope to detect far smaller images in the future. The new method has no theoretical limit in the size of a feature that can be seen.

The new nano-imaging system is based on capturing optical, near-field virtual images, which are free from optical diffraction, and amplifying them using a microsphere, a tiny spherical particle which is further relayed and amplified by a standard optical microscope.

Professor Li, who initiated and led the research in collaboration with academics at the National University and Data Storage Institute of Singapore, believes their research could prove to be an important development.

He said: "This is a world record in terms of how small an optical microscope can go by direct imaging under a light source covering the whole range of optical spectrum.

"Not only have we been able to see items of 50 nanometers, we believe that is just the start and we will be able to see far smaller items.

"Theoretically, there is no limit on how small an object we will be able to see.

"The common way of seeing tiny items presently is with an electron microscope, and even then you cannot see inside a cell -- only the outside. Optical fluoresce microscopes can see inside the cells indirectly by dying them, but these dyes cannot penetrate viruses.

"Seeing inside a cell directly without dying and seeing living viruses directly could revolutionize the way cells are studied and allow us to examine closely viruses and biomedicine for the first time."

Among other tiny objects the scientists will be able to examine are anodized aluminum oxide nano-structures, and nano-patterns on Blue-Ray CVC disks, not previously visible with an optical microscope.

Link: http://www.sciencedaily.com/releases/2011/03/110301121952.htm

Although if you try to get a grip on this issue on a population basis, you have to explain why there has been a dramatic drop in crime rates everywhere in the developed world ever since violent video games came into popularity.

No, I disagree.

The crime rates are much much more complicate issues than effect of violent video games. There are a lot of factors related with crime rates in which violent video game is only one of them. Richness may be a positive factor to reduce the crime rate which has been a dramatic increase in the developed world. Scientists have to design experiments to study the factors one by one, typically not all together.

I think we always have to be extremely suspicious whenever science, especially the science of pure statistical correlations without any demonstration of actual causal mechanisms, just happens to support programs of social control, censorship, and stultification desired by social busy-bodies. For example, the Hope Commission study in Ontario in 1950 'found' that mandatory Christian religious training should be maintained in Ontario public schools because it had been 'demonstrated' to be the best way to increase and maintain public support for democracy. Similarly, a survey in 1959 showed that half of all U.S. medical students believed that masturbation was physically harmful.

Yes. Not only the publics should be suspicious to the conclusion of a science research, other scientists should be suspicious also. It happened and happens all the time and is a part of culture of science.

Scientists have known for years that playing violent video games causes players to become more aggressive. The findings of a new University of Missouri (MU) study provide one explanation for why this occurs: the brains of violent video game players become less responsive to violence, and this diminished brain response predicts an increase in aggression.

"Many researchers have believed that becoming desensitized to violence leads to increased human aggression. Until our study, however, this causal association had never been demonstrated experimentally," said Bruce Bartholow, associate professor of psychology in the MU College of Arts and Science.

During the study, 70 young adult participants were randomly assigned to play either a nonviolent or a violent video game for 25 minutes. Immediately afterwards, the researchers measured brain responses as participants viewed a series of neutral photos, such as a man on a bike, and violent photos, such as a man holding a gun in another man's mouth. Finally, participants competed against an opponent in a task that allowed them to give their opponent a controllable blast of loud noise. The level of noise blast the participants set for their opponent was the measure of aggression.

The researchers found that participants who played one of several popular violent games, such as "Call of Duty," "Hitman," "Killzone" and "Grand Theft Auto," set louder noise blasts for their opponents during the competitive task that is, they were more aggressive than participants who played a nonviolent game. In addition, for participants that had not played many violent video games before completing the study, playing a violent game in the lab caused a reduced brain response to the photos of violence an indicator of desensitization. Moreover, this reduced brain response predicted participants' aggression levels: the smaller the brain response to violent photos, the more aggressive participants were. Participants who had already spent a lot of time playing violent video games before the study showed small brain response to the violent photos, regardless of which type of game they played in the lab.

"The fact that video game exposure did not affect the brain activity of participants who already had been highly exposed to violent games is interesting and suggests a number of possibilities," Bartholow said. "It could be that those individuals are already so desensitized to violence from habitually playing violent video games that an additional exposure in the lab has very little effect on their brain responses. There also could be an unmeasured factor that causes both a preference for violent video games and a smaller brain response to violence. In either case, there are additional measures to consider."

Bartholow said that future research should focus on ways to moderate media violence effects, especially among individuals who are habitually exposed. He cites surveys that indicate that the average elementary school child spends more than 40 hours a week playing video games more than any other activity besides sleeping. As young children spend more time with video games than any other forms of media, the researchers say children could become accustomed to violent behavior as their brains are forming.

"More than any other media, these video games encourage active participation in violence," said Bartholow. "From a psychological perspective, video games are excellent teaching tools because they reward players for engaging in certain types of behavior. Unfortunately, in many popular video games, the behavior is violence."

Other authors in the study include Christopher Engelhardt, graduate student in the MU Department of Psychological Sciences, and researchers from The Ohio State University and VU University of Amsterdam in the Netherlands. The journal article, "This Is Your Brain on Violent Video Games: Neural Desensitization to Violence Predicts Increased Aggression Following Violent Video Game Exposure," will be published in a forthcoming edition of the Journal of Experimental Social Psychology.

Link: http://munews.missou...ri-study-finds/

I am assuming that since the blind person understood geometry, they "knew" what a circle was, and a square, and what a straight line was, and so forth. Not unlikely they could hold a ball in their hands, and move their hands around it and tell you it was a sphere. Or walk in a straight line.

 

The world we internalize is already correct, and stays correct, regardless of which aspects of it we discover and add to our model of it. Presumably the blind person we are talking about still had the senses of taste, smell, touch, and hearing, and could explore the world, and be told about the world, and internalize many of the characteristics of the world, enough to build a sensible model of it, that fit together, the way the model of a "normal" person's would.

 

Not surprising that a brain deprived of one of the senses it had evolved to work with, would develop "abnormally", but much of the apparatus evolution bestowed upon that blind person, in terms of the functioning of memory and the ability to sense their own body, and its position within the space and time it found itself in, remained intact. Perhaps, given the way that persons brain rewired and repurposed functional units of the brain, their brain developed "normally" exactly the way it could, under the circumstances.

It just happened that a new study was published on Nature Neuroscience, which answers your question very well.

Abstract: http://www.nature.co...ll/nn.2795.html

"The Newly Sighted Fail To Match Seen With Felt"

"Would a blind subject, on regaining sight, be able to immediately visually recognize an object previously known only by touch? We addressed this question, first formulated by Molyneux three centuries ago, by working with treatable, congenitally blind individuals. We tested their ability to visually match an object to a haptically sensed sample after sight restoration. We found a lack of immediate transfer, but such cross-modal mappings developed rapidly."

The "concave surface" is better wording.

Another question - if the aircraft surfaces were made of transparent materials to radar and the internal materials were radar visible, is it the aircraft still visible to radar?

I feel that the negative gossip is more or less related with dangerous to the listener. To survive in the world, it is nothing more important than keeping safe. I assume that evolution makes people more sensitive (consciously and unconsciously) to the dangerous hints than other hints.

How do you define "Superpower Nation"? It seems that every post focused on economy only.

See the definition by Wiki: http://en.wikipedia.org/wiki/Superpower

In terms of radar invisibility, the blades need not be the classic airfoil shape. They can be angular or diamond shaped, which ruins their aerodynamics, but deflects the radar. You just put on a bigger rotor and more powerful engine, and it makes up for the reduced lift from the rotors. Look at the F-117, which is shaped such that it reflects radar, no matter which direction it comes from. There is no reason why you couldn't apply the same principles to a helicopter. The pics I've seen seem to show some sort of sharp corner on a surface of what seems to be a rotor blade. A big no-no in subsonic aerodynamics, because it reduces the lift and increases the drag drastically, but it would greatly reduce the radar cross section of the rotor blades. The tail rotor, which is much more clearly shown in pics, seems to be masked, and has stumpy blades with a very short chord - basically taking a minimalist approach. The helicopter must be a real bitch to control, but I guess that wasn't really one of the designers' priorities...

Thanks for understanding my question.

The approach you explained should help to reduce the radar visibility. But, I still question if it can be as good as the F-117.

Mathematically, a curved surface can reflect radar wave back more than a flat surface unless the flat surface right agaist the radar. This is one of the reasons that a fixed-wing aircraft can be designed invisible by radar. The helicopter has to rotate its blades so that you must create a envelope of the blades all the time. This envelope is curved, no matter how you design it.