The result is a more tightly bonded mixture that's especially water resistant and more likely to hold its shape over time, according to the study, released Tuesday by the journal Accounts of Chemical Research. What's more, the results suggest sticky-rice mortars become stronger over the years, because the key chemical reactions in the mortar continue to occur.
Sticky rice, the study authors note, has already been successfully used in recent conservation projects, such as at the year-old Shouchang Bridge in eastern China.
The new study, they say, promises even better results for future restorations. Using the team's method, conservators could determine a building's specific mortar formula and mix up a fresh batch to match the ancient recipe.
All rights reserved. The presence of sticky rice didn't surprise Zhang's team either. Exactly what accounts for the mortar's staying power, though, has been a mystery. Sticky-Rice Mortar's Secret Recipe Using chemical analysis, scanning electron microscopy, and other methods, the team discovered that the addition of the rice's amylopectin to the lime's calcium carbonate results in smaller calcium carbonate crystals than in regular mortar.
Share Tweet Email. Read This Next Signs of an extreme planet found in another galaxy. Science Signs of an extreme planet found in another galaxy An odd x-ray signal hints that a Saturn-size world could be the first known planet lurking in the Whirlpool Galaxy 28 million light-years away. Timber salvaged from New York City buildings reveals ancient climate. Environment Planet Possible Timber salvaged from New York City buildings reveals ancient climate Timbers taken from demolished buildings in the city can extend by hundreds of years how far back in time scientists can tell what the climate was.
However, most cultivated rice species Oryza sativa produces white grains, and the wild relative Oryza rufipogon has red grains. The color of rice grains is determined by which colored pigments they accumulate or fail to accumulate, in the case of white rice. For instance, the pro-anthocyanidins that give wild rice grains their characteristic red color are not produced in white rice due to a mutation in a gene controlling pro-anthocyanidin biosynthesis.
The color in black rice is known to be due to anthocyanin pigments, but how these came to be made in the grains was not known. A paper to be published this week in The Plant Cell reveals the answer to the long-standing question of how black rice became black and, moreover, traces the history of the trait from its molecular origin to its spread into modern-day varieties of rice. Researchers from two institutions in Japan collaborated to meticulously examine the genetic basis for the black color in rice grains.
They discovered that the trait arose due to a rearrangement in a gene called Kala4, which activates the production of anthocyanins. They concluded that this rearrangement must have originally occurred in the tropical japonica subspecies of rice and that the black rice trait was then transferred into other varieties including those found today by crossbreeding.
The agricultural way of life, centered around rice, has had a strong influence on the social, economic, political and ideological developments of ancient China. According to Professor Zhang Deci, an expert on cultivation, rice first grew when people, who had lived mainly on hunting, fishing, and fruit collecting, happened to leave some seeds in low-lying areas.
Later, these people began developing the land, making it more suitable for farming. Weeding, rice transplanting, and irrigating all originated in the Yellow River Valley region in the north, and Hanshui Basin region in the northwest.
Archaeologists have confirmed that China started planting rice at least 3, to 4, years ago. In the s, seeds of long-grained non-glutinous rice were unearthed from the Neolithic ruins at Hemudu in Yuyao, Zhejiang Province, the earliest records of rice planting in China, and the world.
By the time the western Zhou Dynasty c. At this time, rice was a central part of aristocratic banquets. The cultivation of rice led to the development of an economic lifecycle centered around agriculture: ploughing in spring, weeding in summer, harvesting in autumn, and hoarding in winter. In ancient China, vast amounts of land, including the present middle and lower reaches of the Yangtze River region and North China region, were suitable for planting rice, with most Chinese working the land in particular ways during the different seasons.
Rice farming influenced many other aspects of the old Chinese economy. For instance, to be viable Chinese farming depended on sophisticated irrigation techniques. Recommended for you. Ammonia synthesis by mechanocatalysis in a ball mill 14 hours ago.
Nature-inspired coatings could power tiny chemistry labs for medical testing and more Oct 22, Oct 22, Load comments Let us know if there is a problem with our content.
Your message to the editors. Your email only if you want to be contacted back. Send Feedback. Thank you for taking time to provide your feedback to the editors. E-mail the story Revealing the ancient Chinese secret of sticky rice mortar. Your friend's email. Your email.
I would like to subscribe to Science X Newsletter. Learn more. Your name. Note Your email address is used only to let the recipient know who sent the email.
0コメント