One of the dirty secrets of the soft drink and processed food industries is sodium benzoate. It is a benzene compound that is produced by mixing benzoic acid with sodium hydroxide. It is a common preservative in processed foods and soft drinks. It has been associated with a vast array of health problems, including all of our major epidemics. Sodium benzoate is considerably more toxic than either processed sugar or high fructose corn syrup, yet it gets very little media coverage. It is a bona fide poison. Outside of our foods, benzene is the main ingredient of Liquid Wrench, various paint stripper products, rubber cement, and spot removers, due to its highly destructive and solvent qualities. It was discontinued in rubber manufacture in the U.S. because it caused a large percentage of workers to get leukemia.
Sodium benzoate is a synthetic chemical produced when benzoic acid, which is found naturally in some fruits and spices, is combined with sodium hydroxide. Since sodium benzoate contains a natural ingredient, it is probably safe, right? After all, the US Food and Drug Administration (FDA) and the Canadian Health Protection Branch have pronounced this chemical preservative to be acceptable when consumed in low amounts.
In fact, the FDA has granted sodium benzoate GRAS (Generally Recognized as Safe) status, and the so-called safe limit in food is 0.1 percent by weight. In water, the acceptable limit, set by the Environmental Protection Agency, is 5 parts per billion (ppb). But this common food additive, which is found in carbonated sodas, fruit juice products, salad dressings, and fermented foods such as vinegar, wine, and pickles, is not natural nor safe. Here’s the story.
Sodium benzoate is a sodium salt that is present at extremely low levels in berries, apples, plums, cinnamon, and several other natural foods. There’s nothing scary about the chemical in these items. But lab-synthesized sodium benzoate (and its close relative, benzoic acid) are a different story. When these preservatives are added to foods and to the interior of metal cans that contain beverages or liquid foods, they can have a detrimental effect on your health.
For example, a small percentage of people are hypersensitive to sodium benzoate and can experience asthmatic attacks, hives, or other allergic reactions when they consume the preservative. A more common problem, however, is the combination of sodium benzoate and citric acid and/or ascorbic acid (vitamin C). When these ingredients get together, they form benzene, a cancer-causing chemical associated with leukemia and other blood cancers.
எல்லாவற்றையும் மிஞ்சி உங்களிடமிருந்து பீறிட்டு அது வெளிவரவில்லையெனின் அதைச் செய்யாதீர்கள்.
கேளாமலே உங்கள் இதயத்திலிருந்தோ, உங்கள் மனதிலிருந்தோ அல்லது வாயிலிருந்தோ அல்லது உங்கள் வயிற்றிலிருந்தோ அது வரவில்லையெனின் அதைச் செய்யாதீர்கள். வார்த்தைகளைத் தேடிக்கொண்டு உங்கள் கம்ப்யூட்டர் திரையை வெறித்தபடி உங்கள் டைப்ரைட்டரில் குறுக்கி அமர்ந்தபடியிருந்தால் அதைச் செய்யாதீர்கள் உங்கள் படுக்கையில் பெண்கள் வேண்டுமென்பதற்காய் நீங்கள் செய்வதாயிருந்தால் செய்யவேண்டாம். அதைச் செய்வது பற்றி சிந்தித்திருப்பதென்பதே கடும் உழைப்பாகுமானால் அதைச் செய்யாதீர்கள். யாரோ ஒருவரைப் போல நீங்கள் எழுத முயல்வதாயிருந்தால் அதை மறந்துவிடுங்கள். உங்களுள்ளிருந்து அது கர்ஜித்துவெளிப்பட நீங்கள் காத்திருக்க வேண்டியிருந்தால் பொறுமையாயிருங்கள். முதலில் உங்கள் மனைவியிடம் படித்துக்காட்டவேண்டியிருந்தால் அல்லது உங்கள் பெண் நண்பியிடமோ, அல்லது உங்கள் ஆண் நண்பரிடமோ அல்லது உங்கள்பெற்றோரிடமோ அல்லது வேறுயாரோவிடம்- நீங்கள் தயாராக இல்லை அத்தனை பல எழுத்தாளர்கள் போலிருக்காதீர்கள் தங்களை எழுத்தாளர்கள் என்று சொல்லிக்கொள்ளும் பலவாயிரம் மனிதர்களைப் போல் இருக்காதீர்கள் உப்புச்சப்பற்று, சலிப்பாக, பாசாங்கு மிகுந்து சுயகாதலால் கபளீகரம் செய்யப்பட வேண்டாம். உலகின் நூலகங்கள் உங்களைப் போன்ற தரப்பினரால் கொட்டாவி விட்டுதூங்கிவிட்டன. அதில் நீங்கள் சேர்க்காதீர்கள் உங்களின் ஆன்மாவிலிருந்து ஒரு ராக்கெட்டினைப் போல அது வந்தாலொழிய சும்மாயிருப்பது உங்களைப் பைத்தியத்தில் ஆழ்த்திவிடும், அல்லது தற்கொலையில் அல்லது கொலையில் என்றால் ஒழிய அதைச்செய்யவேண்டாம். உங்களுள் இருக்கும் சூரியன் உங்கள் குடலை எரித்துக்கொண்டிருந்தால் ஒழிய அதைச் செய்ய வேண்டாம். நிஜமாகவே அதற்கான நேரம் வந்து விட்டால் நீங்கள்தேர்ந்தெடுக்கப்பட்டிருந்தால் அது தானாகவே செய்துகொள்ளும் அது தொடர்ந்து செய்துகொண்டேயிருக்கும் நீங்கள் சாகும்வரை அல்லது அது உங்களுக்குள் சாகும்வரை வேறெந்த வழியுமில்லை என்றுமே இருந்ததுமில்லை. ............................................ மொழிபெயர்ப்பு :பிரம்மராஜன் சார்.
People size you up in seconds, but what exactly are they evaluating?
Harvard Business School professor Amy Cuddy has been studying first impressions alongside fellow psychologists Susan Fiske and Peter Glick for more than 15 years, and has discovered patterns in these interactions.
In her new book “Presence,” Cuddy says people quickly answer two questions when they first meet you:
Can I trust this person?
Can I respect this person?
Psychologists refer to these dimensions as warmth and competence respectively, and ideally you want to be perceived as having both.
Interestingly, Cuddy says that most people, especially in a professional context, believe that competence is the more important factor. After all, they want to prove that they are smart and talented enough to handle your business.
But in fact warmth, or trustworthiness, is the most important factor in how people evaluate you. “From an evolutionary perspective,” Cuddy says, “it is more crucial to our survival to know whether a person deserves our trust.” It makes sense when you consider that in cavemen days it was more important to figure out if your fellow man was going to murder you and steal all your possessions than if he was competent enough to build a good fire.
While competence is highly valued, Cuddy says it is evaluated only after trust is established. And focusing too much on displaying your strength can backfire.
Cuddy says MBA interns are often so concerned about coming across as smart and competent that it can lead them to skip social events, not ask for help, and generally come off as unapproachable. These overachievers are in for a rude awakening when they don’t get the job offer because nobody got to know and trust them as people.
“If someone you’re trying to influence doesn’t trust you, you’re not going to get very far; in fact, you might even elicit suspicion because you come across as manipulative,” Cuddy says. “A warm, trustworthy person who is also strong elicits admiration, but only after you’ve established trust does your strength become a gift rather than a threat.”
A comparison of the two principal nucleic acids: RNA (left) and DNA (right), showing the helices and nucleobases each employs.
Deoxyribonucleicacid(DNA), the genetic material, carries information to specify theamino acidsequences of proteins. It is transcribed into several types ofribonucleic acid(RNA) includingmessenger RNA(mRNA),transfer RNA(tRNA), andribosomal RNA(rRNA), which function inproteinsynthesis.
BothDNAandRNAare long, unbranched polymers of nucleotides. Eachnucleotideconsists of a heterocyclicbaselinked via a five-carbon sugar (deoxyribose or ribose) to a phosphate group
DNAandRNAeach contain four different bases. Thepurinesadenine (A) and guanine (G) and the pyrimidine cytosine (C) are present in both DNA and RNA. The pyrimidine thymine (T) present in DNA is replaced by the pyrimidine uracil (U) in RNA.
The bases in nucleic acids can interact via hydrogen bonds. The standard Watson-Crickbasepairs are G·C, A·T (inDNA), and A·U (inRNA). Base pairing stabilizes the native three-dimensional structures of DNA and RNA.
Adjacent nucleotides in a polynucleotide are linked by phosphodiester bonds. The entire strand has a chemical directionality: the 5′ end with a free hydroxyl or phosphate group on the 5′ carbon of the sugar, and the 3′ end with a free hydroxyl group on the 3′ carbon of the sugar . Polynucleotide sequences are always written in the 5′ → 3′ direction (left to right).
NaturalDNA(B DNA) contains twocomplementarypolynucleotide strands wound together into a regular right-handed double helix with the bases on the inside and the two sugar-phosphate backbones on the outside. Base pairing (A·T and G·C) andhydrophobicinteractions between adjacent bases in the same strand stabilize this native structure.
Binding ofproteintoDNAcan deform its helical structure, causing local bending or unwinding of the DNA molecule.
Heat causes theDNAstrands to separate (denature). The melting temperature of DNA increases with the percentage of G·Cbasepairs. Under suitable conditions, separatedcomplementarynucleic acidstrands will renature.
Local unwinding of theDNAhelix induces stress, which is relieved by twisting of the molecule on itself, forming supercoils. This process is regulated by topoisomerases, which can add or remove supercoils.
Natural RNAs are single-stranded polynucleotides that form well-defined secondary and tertiary structures. Some RNAs, calledribozymes,have catalytic activity.
யாரும் சனியோட கடுமையால் கடுமையாக பாதிக்க படக் கூடாது என்பதற்காக சித்தர்கள் பரிந்துரைக்கும் மிக எளிய பரிகாரம்...
சனிக்கிழமை அன்று பச்சரிசியை ஒரு கையில் அள்ளி அரிசியாக அல்லது அதை நன்கு பொடி செய்து சூரியநமஸ்காரம் செய்து விட்டு, விநாயகப் பெருமானை மூன்று சுற்று சுற்றி விட்டு அந்த அரிசியை விநாயகரை சுற்றிப் போட்டால்,அதை எறும்பு தூக்கிச் செல்லும். அப்படித் தூக்கி சென்றாலே நமது பாவங்களில் பெரும்பாலானவை நம்மை விட்டுப் போய் விடும். வன்னி மரத்தடி விநாயகராக இருந்தால் , அது இன்னும் விசேஷம். சனிக்கிழமைகளில் இதை செய்யவும். அப்படி தூக்கிச் சென்ற பச்சரிசி மாவை எறும்புகள் தமது மழை காலத்திற்காக சேமித்து வைத்துக் கொள்ளும். எறும்பின் எச்சில் அரிசி மாவின் மீது பட்டதும் அதன் கெடும் தன்மை நீங்கி விடும்.இந்த பச்சரிசிமாவை சாப்பிடுவதற்கு இரண்டரை வருடங்கள் எடுத்துக் கொள்ளும். இப்படி இரண்டே கால் வருடங்கள் வரை எறும்புக் கூட்டில் இருப்பதை முப்பத்து முக்கோடி தேவர்கள் கவனித்துக் கொண்டிருப்பார்கள்.இரண்டரை ஆண்டிற்கு ஒருமுறை கிரக நிலை மாறும்.அப்படி மாறியதும்,அதன் வலு இழந்து போய் விடும்.இதனால், நாம் அடிக்கடி பச்சரிசி மாவினை எறும்புக்கு உணவாக போட வேண்டும். ஓர் எறும்பு சாப்பிட்டால் 108 பிராமணர்கள் சாப்பிட்டதற்குச் சமம். எனவே இது எத்தனை புண்ணியம் வாய்ந்த செயல் என்று தெரிந்து கொள்ளுங்கள். இதனால்,சனிபகவானின் தொல்லைகள் நம்மைத் தாக்காது. ஏழரைச்சனி,அஷ்டமச்சனி,கண்டச்சனி,அர்த்தாஷ்டகச்சனி,சனி மகா தசை நடப்பவர்களுக்கு , இந்த செயல் ஒரு மிக பெரிய வரப்ரசாதம் ஆகும்.
The Terracotta Army (literally "soldier and horse funerary statues") are the Terracotta Warriors and Horses of Qin Shi Huang the First Emperor of China. The terracotta figures, dating from 210 BCE, were discovered in 1974 by several local farmers near Xi'an, Shanxi province, China near the Mausouleum of the First Qin Emperor. The figures vary in height (183-195 cm - 6ft-6ft 5in), according to their role, the tallest being the generals. The figures include warriors, chariots, horses, officials, acrobats, strongmen, and musicians. Current estimates are that in the three pits containing the Terracotta Army there were over 8,000 soldiers, 130 chariots with 520 horses and 150 cavalry horses, the majority of which are still buried in the pits.
The Terracotta Army was discovered in eastern outer suburbs of Xi'an, Shaanxi Province by local farmers drilling a water well 1.5 miles east of Lishan (a mountain). This discovery prompted archaeologists to proceed to Shaanxi Province, China to investigate. The Terracotta Army is a form of funerary art buried with the First Emperor of Qin (Qin Shi Huang, Shi Huang means the first emperor) in 210-209 BCE (he declared himself the first emperor of China in 221 BCE to the end of his life in 210 BCE). Their purpose was to help rule another empire with Shi Huang Di in the afterlife. Consequently, they are also sometimes referred to as "Qin's Armies." Mount Lishan is also where the material to make the terracotta warriors originated. In addition to the warriors, an entire man-made necropolis for the emperor has been excavated.
According to the historian Sima Qian (145-90 BCE) construction of this mausoleum began in 246 BCE and involved 700,000 workers. Qin Shi Huang was thirteen when construction began. Sima Qian, in his most famous history of China, Shiji, completed a century after the mausoleum completion, wrote that the First Emperor was buried with palaces, scenic towers, officials, valuable utensils and 'wonderful objects,' with 100 rivers fashioned in mercury and above this heavenly bodies below which he wrote were 'the features of the earth.' Some translations of this passage refer to 'models' or 'imitations' but in fact he does not use those words.
Recent scientific work at the site has shown high levels of mercury in the soil of Mount Lishan, appearing to add credence to the writing of ancient historian Sima Qian. The tomb of Shi Huang Di is near an earthen pyramid 76 meters tall and nearly 350 square meters. The tomb remains unopened, in the hope that it will remain intact. Only a portion of the site is presently excavated.
Qin Shi Huang's necropolis complex was constructed to serve as an imperial compound or palace. It comprises several offices, halls and other structures and is surrounded by a wall with gateway entrances. The remains of the craftsmen working in the tomb have also been found within its confines, and it is believed they were sealed inside alive to prevent them from divulging information about the tombs.
It was also said as a legend that the Terracotta Warriors were real soldiers, buried with Emperor Qin so that they can guard him in the next life.
Construction
The terracotta figures were manufactured both in workshops by government laborers and also by local craftsmen. The head, arms, legs and torsos were created separately and then assembled. Studies show that eight face moulds were most likely used, and then clay was added to provide individual facial features. Once assembled, intricate features such as facial expressions were added. It is believed that their legs were made in much the same way that terracotta drainage pipes were manufactured at the time. This would make it an assembly line production, with specific parts manufactured and assembled after being fired, as opposed to crafting one solid piece of terracotta and subsequently firing it. In those days, each workshop was required to inscribe its name on items produced to ensure quality control. This has aided modern historians in verifying that workshops that once made tiles and other mundane items were commandeered to work on the terracotta army. Upon completion, the terracotta figures were placed in the pits in precise military formation according to rank and duty.
The terracotta figures are life-like and life-sized. They vary in height, uniform and hairstyle in accordance with rank. The colored lacquer finish, individual facial features, and actual weapons and armor from battle were used in manufacturing these figures created a realistic appearance. The original weapons were stolen shortly after the creation of the army and the coloring has faded greatly. However, their existence serves as a testament to the amount of labour and skill involved in their construction. It also reveals the power the First Emperor possessed, enabling him to command such a monumental undertaking as this.
The four pits associated with the dig are about 1.5 km east of the burial ground and are about 7 meters deep. The outside walls of the tomb complex are as if placed there to protect the tomb from the east, where all the conquered states lay. They are solidly built with rammed earth walls and ground layers as hard as concrete.
Pit one, 230 meters long, contains the main army, estimated at 8,000 figures. Pit One has 11 corridors, most of which are over 3 meters wide, and paved with small bricks with a wooden ceiling supported by large beams and posts. This design was also used for the tombs of noblemen and would have resembled palace hallways. The wooden ceilings were covered with reed mats and layers of clay for waterproofing, and then mounded with more soil making them, when built about 2 to 3 meters higher than ground level. Pit two has cavalry and infantry units as well as war chariots, and is thought to represent a military guard. Pit three is the command post, with high ranking officers and a war chariot. Pit four is empty, seemingly left unfinished by its builders.
There is evidence of a large fire that burned the wooden structures that once housed the Terracotta Army. It was described by Sima Qian, who said that the fire was a consequence of a raid on the tomb by General Xiang Yu less than five years after the death of the First Emperor. According to Sima Qian, General Xiang's army looted the tomb and the structures holding the Terracotta Army, as well as setting fire to the necropolis and starting a blaze that allegedly lasted three months. Because of this, only one statue has survived intact: a statue of a kneeling archer. Despite the fire, however, much of the remains of the Terracotta Army still survives in various stages of preservation, surrounded by remnants of the burnt wooden structures.
In 1999, it was reported that the warriors were suffering from "nine different kinds of mold," caused by raised temperatures and humidity in the building which houses the soldiers, and by the breath of tourists. In addition, the South China Morning Post reported that the figures have become oxidized grey from being exposed to the air, which may cause arms to fall off, and noses and hairstyles to disappear. However, officials have dismissed these claims.
In Daily Planet Goes to China TV Series, the Terracotta Warriors segment reported that the Chinese scientists found soot on the surface of the statues, concluding that the pollution introduced from coal burning plants was responsible for the decaying of the terracotta statues.
The first thing we need to understand is how exactly the lithium-ion battery in your phone works. The name gives us a hint — electricity is carried from one electrode to another using charged lithium ions.
Lithium-ion batteries store, transfer and release energy because of natural chemical reactions. The battery has two electrodes — an anode and a cathode. The cathode is connected to the positive(+)connection on the battery and holds positively charged ions, and the anode is connected to the negative(-)connection and holds (you guessed it) negatively charged ions.
Between the two electrodes is what's called an electrolyte. The electrolyte in a lithium battery is (usually) an organic solvent paste that has a very large number of metallic salts (in most cases, that metal is lithium) as part of its makeup. This makes it electrically conductive — electricity can pass through it. The anode and the cathode are in the electrolyte and separated by a physical barrier so they can't touch.
When you discharge the battery (when you're using your phone and not charging it) the cathode pushes its positively charged ions away and the negatively charged anode attracts them. Electricity flows out from the anode, through your device, then back to the cathode. Yes, electricity travels through a loop and isn't "used up" by the thing being powered. When you charge your phone, the reverse happens and ions travel from the cathode through the electrolyte to the anode.
Lithium is the perfect element for rechargeable batteries: It's lightweight, easy to recharge and holds a charge for a long time.
When these ions come in contact with the charged atoms in an electrode, an electrochemical reaction calledoxidation-reduction (redox)frees the charged electrons to travel out through the battery contacts, which are connected to the electrodes. This continues to charge the lithium ions in the electrolyte until there aren't enough left that can hold a positive charge that's strong enough to move through the electrolyte paste, and your battery will no longer charge.
Lithium is the lightest metal — number three on the periodic table. It's also very excitable, making it easy to create a powerful chemical reaction. This makes it a near-perfect metal to use in a portable rechargeable battery. It's lightweight, easy to recharge and continues to hold a charge for a long time.
From the fiery Note 7 debacles to exploding hoverboards, lithium-ion batteries aren't doing so hot lately. A new study helps to explain how these popular power sources can turn into safety hazards.
In the paper, published in the Journal of the Electrochemical Society, scientists at the Canadian Light Source (CLS) synchrotron looked inside an overworked battery. In this case, they drained a battery until its voltage was below a critical level.
Overcharging or overworking deforms the insides of a battery. (A) shows the inside of a battery before it was misused. (B) shows how misuse causes the original design defects to become even more warped. (C) highlights the areas where warping got worse. Toby Bond, Canadian Light Source
When we overcharge or overheat lithium ion batteries, the materials inside start to break down and produce bubbles of oxygen, carbon dioxide, and other gasses. Pressure builds up, and the hot battery swells from a rectangle into a pillow shape. Sometimes the phone involved will operate afterward. Other times it will die. And occasionally—kapow!
To see what's happening inside the battery when it swells, the CLS team used an x-ray technique called computed tomography.
Inside the battery is an electrode that spirals out from a central point like a jellyroll. The x-ray scan revealed that the bubbles produced during overheating warped and dented this electrode.
Intriguingly, the study authors found that the worst deformation from the gas buildup occurred in areas that had slight defects before the battery was ever over-drained. The authors note that doing more studies like this, on a larger variety of batteries, would improve understanding of how these batteries respond to gas evolution, which could lead to better designs.
As New Scientist notes, it's not clear whether the Samsung Note 7 catastrophes included pillowing or this type of deformation.
A team of researchers at MIT has designed one of the strongest lightweight materials known, by compressing and fusing flakes of graphene, a two-dimensional form of carbon. The new material, a sponge-like configuration with a density of just 5 percent, can have a strength 10 times that of steel.
In its two-dimensional form, graphene is thought to be the strongest of all known materials. But researchers until now have had a hard time translating that two-dimensional strength into useful three-dimensional materials.
The new findings show that the crucial aspect of the new 3-D forms has more to do with their unusual geometrical configuration than with the material itself, which suggests that similar strong, lightweight materials could be made from a variety of materials by creating similar geometric features.
The findings are being reported today in the journal Science Advances, in a paper by Markus Buehler, the head of MIT's Department of Civil and Environmental Engineering (CEE) and the McAfee Professor of Engineering; Zhao Qin, a CEE research scientist; Gang Seob Jung, a graduate student; and Min Jeong Kang MEng '16, a recent graduate.
Other groups had suggested the possibility of such lightweight structures, but lab experiments so far had failed to match predictions, with some results exhibiting several orders of magnitude less strength than expected. The MIT team decided to solve the mystery by analyzing the material's behavior down to the level of individual atoms within the structure. They were able to produce a mathematical framework that very closely matches experimental observations.
Two-dimensional materials—basically flat sheets that are just one atom in thickness but can be indefinitely large in the other dimensions—have exceptional strength as well as unique electrical properties. But because of their extraordinary thinness, "they are not very useful for making 3-D materials that could be used in vehicles, buildings, or devices," Buehler says. "What we've done is to realize the wish of translating these 2-D materials into three-dimensional structures."
The team was able to compress small flakes of graphene using a combination of heat and pressure. This process produced a strong, stable structure whose form resembles that of some corals and microscopic creatures called diatoms. These shapes, which have an enormous surface area in proportion to their volume, proved to be remarkably strong. "Once we created these 3-D structures, we wanted to see what's the limit—what's the strongest possible material we can produce," says Qin. To do that, they created a variety of 3-D models and then subjected them to various tests. In computational simulations, which mimic the loading conditions in the tensile and compression tests performed in a tensile loading machine, "one of our samples has 5 percent the density of steel, but 10 times the strength," Qin says.
Buehler says that what happens to their 3-D graphene material, which is composed of curved surfaces under deformation, resembles what would happen with sheets of paper. Paper has little strength along its length and width, and can be easily crumpled up. But when made into certain shapes, for example rolled into a tube, suddenly the strength along the length of the tube is much greater and can support substantial weight. Similarly, the geometric arrangement of the graphene flakes after treatment naturally forms a very strong configuration.
The new configurations have been made in the lab using a high-resolution, multimaterial 3-D printer. They were mechanically tested for their tensile and compressive properties, and their mechanical response under loading was simulated using the team's theoretical models. The results from the experiments and simulations matched accurately.
The new, more accurate results, based on atomistic computational modeling by the MIT team, ruled out a possibility proposed previously by other teams: that it might be possible to make 3-D graphene structures so lightweight that they would actually be lighter than air, and could be used as a durable replacement for helium in balloons. The current work shows, however, that at such low densities, the material would not have sufficient strength and would collapse from the surrounding air pressure.
But many other possible applications of the material could eventually be feasible, the researchers say, for uses that require a combination of extreme strength and light weight. "You could either use the real graphene material or use the geometry we discovered with other materials, like polymers or metals," Buehler says, to gain similar advantages of strength combined with advantages in cost, processing methods, or other material properties (such as transparency or electrical conductivity).
"You can replace the material itself with anything," Buehler says. "The geometry is the dominant factor. It's something that has the potential to transfer to many things."
The unusual geometric shapes that graphene naturally forms under heat and pressure look something like a Nerf ball—round, but full of holes. These shapes, known as gyroids, are so complex that "actually making them using conventional manufacturing methods is probably impossible," Buehler says. The team used 3-D-printed models of the structure, enlarged to thousands of times their natural size, for testing purposes.
For actual synthesis, the researchers say, one possibility is to use the polymer or metal particles as templates, coat them with graphene by chemical vapor deposit before heat and pressure treatments, and then chemically or physically remove the polymer or metal phases to leave 3-D graphene in the gyroid form. For this, the computational model given in the current study provides a guideline to evaluate the mechanical quality of the synthesis output.
The same geometry could even be applied to large-scale structural materials, they suggest. For example, concrete for a structure such a bridge might be made with this porous geometry, providing comparable strength with a fraction of the weight. This approach would have the additional benefit of providing good insulation because of the large amount of enclosed airspace within it.
Because the shape is riddled with very tiny pore spaces, the material might also find application in some filtration systems, for either water or chemical processing. The mathematical descriptions derived by this group could facilitate the development of a variety of applications, the researchers say.
Source: Massachusetts Institute of Technology Thanks http://3tags.org
நம் முந்தைய தலைமுறை வரை
கொட்டாங்கச்சி அகப்பைகளைதான் பயன்படுத்தி வந்தோம். விறகடுப்பில் மண்பானை
சோற்றை கொட்டாங்கச்சி அகப்பையால் கிளறிவரும்போது வரும் சாதத்தின் வாசனையே தனி.
இப்போதெல்லாம் அகப்பையை அலுமினியம் ஆக்கிரமித்து கொண்டது.சூட்டில்
அலுமினியத்திலிருந்து வெளிப்படும் நச்சு நிச்சயம் நம் உடலை பாதிக்கும்.
திரும்பவும் பாரம்பரியத்தை நோக்கிய பயணத்தில் எனது இயற்கை அங்காடியில்
கொட்டாங்கச்சி அகப்பைகள், தேநீர் கிண்ணம்,சூப் குவளை ஆகியவற்றை
வரவைத்திருக்கிறோம்.
ஆள் பற்றாகுறையாலும், வெளிநாட்டில் இதற்கு கிடைத்த வரவேற்பாலும் இதன் வரத்து குறைவாகவேஇருக்கிறது.
எங்கள் குமரிமாவட்டத்தில் விளையும் தேங்காயில் கிடைக்கும்
கொட்டாங்கச்சியில் மனித உடலுக்கு தேவையான கந்தகம் இருப்பதாக இந்தோனேசியா
வில் இருக்கும் உலக தென்னை கழகம் தன் ஆராய்ச்சி முடிவை
வெளியிட்டிருக்கிறது.
வேறெந்த பகுதியில் கிடைக்கும் கொட்டாங்கச்சியை
தீட்டினாலும் இந்த பளபளப்பு கிடைப்பதில்லை என்பதே குமரி மாவட்ட
கொட்டாங்கச்சிகளின் சிறப்பு. வாருங்கள் தோழர்களே பழமைக்கு மாறுவோம்....!!
தடைகள் என்பவை நம்மை அடுத்த
கட்டத்திற்கு அழைத்துச் செல்ல ஆயத்தம் செய்கிற விசயம். எனவே தடை வரும்போது
தைரியத்தை இழந்து விடாமல், அடுத்த இலக்கை நோக்கிப் பாய்வதற்குத்தயாராக
இருக்கவேண்டும். அதுவும் சாயி பக்தர்கள் என்பவர்கள் சாமான்யமானாவர்கள்
கிடையாது. அவர்கள் புண்ணியம் மிகுந்தவர்கள். பாவங்களும், கர்ம கெடுவினையும்
தீர்ந்த ஒருவன்தான் சாயி வழிபாட்டை எய்த முடியும் என்று பாபாவே உனக்குச்
சொல்லியிருக்கிறார். இப்போது நீ செய்யவேண்டியதெல்லாம், சோர்வை நீக்கி புத்துணர்ச்சி பெறவேண்டியதுதான். மனிதர்கள் போடும் தடைகள் மலைகள் அல்ல,
தாண்டுவதற்குச் சிரமமாக இருக்கும் என்று மலைத்து நிற்பதற்கு. அவையெல்லாம்
மடை திறந்த வெள்ளத்தின் முன்னால் கையால் அள்ளிப் போடப்பட்டுள்ள மணல்
குவியலைப் போன்றவை. உன்னை அவை தடுத்து நிறுத்திவிட முடியாது என்பதை
தைரியமாக நினைத்துக் கொள்.. சிந்தனையை ஒருமுகப் படுத்துதைரியத்தை வரவழை..
கோழைகளைப் போல கூப்பாடு போடாமல், செயலாற்றத் தயாராகு. தடை தளர்ந்து போகும்.
பாபா என்ன சொன்னார் தெரியுமா? நீ தண்டால் எடுக்க ஆரம்பி.
(கடுமையானப் பயிற்சி) பாலைப்பற்றிய கவலை (பலன் பற்றிய கவலை) உனக்கு
வேண்டா. ஏனெனில், உனக்குப் பின்னாலேயே நான் தயாராக ஒரு வட்டிலில் பாலை
வைத்துக் கொண்டு நிற்கிறேன். ஆனால், நான் தண்டால் எடுக்கிறேன், நீர்
எனக்கு வட்டில் வட்டிலாகப் பாலைத் திருப்தியுறும் வரை கொடும் என்று
கேட்டால் (பலனைக் கேட்டால்), ஆ, அதெல்லாம் எனக்குத் தெரியாது என்று
சொல்லிவிடுவேன். செயலாற்றுபவன் துடிப்பு உள்ளவனாக இருக்கவேண்டும் என்பார்
பாபா. (சத் அத்தியாயம் 19) பாபாவின்
இவ்வாக்குறுதியை சத்தியம் என்று எடுத்துக்கொண்டு எவர் செயல்படுகிறாரோ, அவர்
இந்த உலகத்திலும் மேலுலகத்திலும் சந்தோசம் என்றும் சுரங்கத்தைக்
கண்டுபிடித்தவர் ஆவார். இதை எப்போதும் நினைவில் நிறுத்துங்கள். மாணவர்கள்
தேர்வுக்குத் தயாராகிக் கொண்டு இருக்கிறார்கள் என்று சொல்கிறோம். தேர்வு
என்பது என்ன? அது ஒருவிதத் தடை.. அதைத் தாண்ட முடியாதவன் பழைய இடத்திலேயே
இருப்பான், தாண்டியவன் புதிய இடத்திற்குப் போவான். இப்படித்தான் உங்களுக்கு
இப்போது ஏற்பட்டு உள்ள தடைகளும்.. சாயி பக்தர்களாகிய நம்மைப் பொறுத்தவரை
தடை என்பதே நமக்குக் கிடையாது. நாம் யாரை வணங்குகிறோம், அவருடைய சக்தி
என்ன? யார் நமக்குப் பின்னால் இருந்து உதவுவது என்பதையெல்லாம் நாம் தெளிவாக
அறிந்திருக்கும் போது எதற்காக பயப்பட வேண்டும்? ஜெயிப்பதற்காகத்தான் உனக்கு தரப்பட்டுள்ளது ஜெய ஜெய சாயி என்கிற தாரக மந்திரம். ஜெபி.. வெற்றியை வென்றெடு..
