Earthquakes cannot be forecast, but engineers can prepare for them. Seismic-isolation systems use concrete (水泥), rubber and metal to reduce quake damage. But such adaptations are expensive. Engineer Jian Zhang of the University of California, Los Angeles, says the system can increase building costs by 20 percent. Although these systems might save more than they cost over time, builders in some areas may not have the money for them.

A new seismic-isolation method uses the physics of rolling to create a simpler, lower-cost choice with easily found things: used tennis balls. The team of Michalis Vassiliou, an engineer, based its method on an early form of seismic isolation that rolls a shaking building to a stop the way a skater comes to rest. By separating a building from the ground with a layer of balls, rolling isolation changes horizontal shaking into a soft rocking movement and uses friction to reduce the shaking.

The researchers built a cheap model consisting of four filled tennis balls between two concrete boards, and they found that it withstood simulated (仿造的) earthquake shaking while supporting eight kilonewtons (千牛顿) of force per ball — about twice what isolation systems might experience under one-story houses. The balls had to contain exactly the right amount of the concrete mixture to reduce the shaking without cracking during tests.

Zhang, who didn’t take part in the study, says that the work is valuable. But she notes that the results are basic. Vassiliou agrees that next steps will mean creating and testing a larger model with hundreds of tennis balls. Vassiliou says that he has received money to test the system on the ground to improve the invention. “For this to actually be applied,” he adds, “you need to develop it with engineers from developing countries so that it actually deals with their needs.”

The biggest challenge faced by travelers especially those who like to have a hiking trip is how to ensure a steady supply of clean clothes. Now, thanks to a great invention called Scrubba Wash Pack, that worry may be a thing of the past.

The portable washing machine was invented by Ash Newland in 2010, while planning to climb Mt. Kilimanjaro. Struck by the limited packing space, he got inspiration from traditional washboards to create a bag that could be used to clean clothes. Then he gave up his career as a lawyer and focused on perfecting the bag’s design. By 2012, the bag was ready for the public. It weighed only 180 grams and required very little storage space, making it perfect for anyone wishing to travel light.

Not surprisingly, the bag worth 55 dollars was an instant hit with travelers, university students and even passengers. However, Newland was not satisfied. He still saw a disadvantage with his invention – dirty clothes had to be carried around in a separate bag! The recently introduced Scrubba Wash Pack solves that problem.

In order to make the pack active, dirty clothes are placed inside the bag along with two to three liters of water. The bag is then shut tightly to ensure all air is squeezed out and the clothes are massaged (揉搓) for a few minutes. After a quick wash, they are clean and ready to be dried. According to Newland, the pack can clean anything from jeans to smelly socks! What’s even

The best part is that the 99-dollar pack that will be available for sale later this year, only weighs 300 grams and is completely foldable, making it easy to store when it’s not in use. With the Scrubba Wash Pack, wandering through foreign cities searching for a washing shop, or paying for washing machines may soon be a thing of the past!

Discovering the proper classification for each piece of household waste before throwing it out—and avoiding fines of up to 50,000 yuan—has become as simple as taking a photo thanks to the efforts of a group of young programmers.

They have applied speech and picture recognition technologies to apps and other smartphone services to guide Shanghai residents through China's first mandatory garbage-separation plan. The rules require every citizen and institution to classify waste into four categories-recyclables, kitchen waste, hazardous waste and residual waste—with a long list of items in each category. Previously, everything went into one dustbin, and the dramatic change has made many Shanghai residents worried. Many residents say they are struggling to master the details quickly.

To smooth the process and raise public awareness, Shanghai government launched a campaign featuring posters and TV programs introducing garbage-sorting techniques.

“It has become a lasting topic for my family's mealtime discussions,” 27-year-old Shanghai resident Fang Chengxiang said. He said they used the Internet to find out how to classify waste properly. “I would often Baidu the name if I got confused,” Fang said, referring to China's leading search engine.

Most of the apps and services, which began springing up last month in app stores, on messaging tool WeChat and mobile payment service Alipay, allow users to type in the name of waste to identify which category it belongs to.

One of the apps using speech recognition is What Garbage, whose downloads topped 130,000 in the first week after it was released early this month.

It was designed by zzz studio, a team made up of a programmer, an advertising art director and a visual designer. Since they all have 996 jobs—meaning they work from 9 am to 9 pm six days a week—the app was designed in what little spare time they have.

Liu Yiyi, 23, a member of the studio, said it was designed to help people through the transition period, and it especially helps people sort ambiguous items. Actually, Liu Yiyi added, as Chinese become accustomed to rules, people will use the apps less often.