Bantal Pintar Penghenti Ngorok

Terganggu dengan dengkuran pasangan atau merasa tak nyaman dengan kebiasaan mengorok Anda? Kini tak perlu khawatir, dengan sebuah bantal ciptaan ilmuwan Jerman, ngorok tak lagi jadi masalah.

Solusi atasi ngorok ini digagas ilmuwan Jerman dengan sebuah bantal yang terhubung dengan komputer yang memungkinkan untuk mengubah posisi kepala seseorang sampai suara dengkuran berhenti.

Adalah Daryoush Bazargani, profesor ilmu komputer dari Universitas Rostock yang menemukan bantal pengatur dengkur dan memamerkan prototype bantal pintar tersebut pada konferensi kesehatan di Jerman, Rabu (03/07), seperti dilansir dari Reuters.

"Bantal ini terhubung dengan sebuah komputer seukuran buku yang diletakkan di meja sebelah tempat tidur. Komputer tersebut akan menganalisa suara dengkuran," papar Bazargani.

"Komputer akan mengatur sirkulasi udara, yakni dengan memperkecil atau memperbesar kapasitas udara dalam bantal, sehingga posisi kepala akan berubah. Proses ini dilakukan sampai aliran udara yang keluar melalui hidung menjadi lancar dan suara dengkuran bisa diminimalkan," lanjut Bazargani.

Tak hanya menghentikan suara dengkuran, bantal ergonomis ini juga berfungsi sebagai alat pijat leher. Bisa dibayangkan khan nikmatnya dipijat saat kita tertidur, suara dengkur pun tak ada lagi. Kelebihan bantal pintar ini dilirik beberapa perusahaan Amerika yang antusias memproduksinya secara massal.

Sementara kepada media Bazargani mengaku menciptakan bantal tersebut agar tidur bisa lebih nyaman, mengingat dirinya sendiri juga seorang pendengkur. (reuters/rit/kpl)

The Advantage of Keeping Quiet

The Hawaiian Islands have long been known as a natural laboratory for studying evolution. Zuk et al. have assessed the effect of the selective pressure of parasitoid flies on Teleogryllus field crickets introduced to the island of Kauai. Female flies locate male crickets when they call to female crickets, and lay their eggs on the cricket; the larvae burrow into the host and consume it from within, eventually killing it. Over just 20 generations, the singing males dwindled in abundance owing to the selective pressure from the parasitoid, and a new, silent type of male—known as flatwings—became prevalent. Given that the song functions as a signal to potential mates, how do the flatwing males attract female partners?

Field experiments suggest that the silent males congregate around the few remaining singers,
increasing the chance of intercepting inquisitive females (who have possibly relaxed their
requirement that the male keep singing up to the moment of mating). Thus, natural selection has not only had a rapid population genetic effect; there has been a behavioral response as well. It remains to be seen, however, if the singing males are now too rare to support the local parasitoid population, or if the singing males will disappear entirely (and, if so, whether the crickets will find a new solution to the problem of finding mates). — AMS

Internet domain for Asia launched

Bidding has begun for prime new pieces of internet real estate with the launch of the .asia domain name. The regional domain comes after the launch of the European-based .eu name last year and aims to join .com and .net as a widely used website suffix.

Edmon Chung, from DotAsia - a Hong Kong-based group that won the right to set-up the domain - said on Tuesday: "The .asia domain acts like a channel or a portal, showing your commitment to the Asia market as a whole. It provides an easier way to direct customers to your products," he said.

"Our research has found that Asia is one of the most searched-for terms and by having a .asia website, your ranking on Google or Yahoo will become much higher."

Prices for website addresses can range from as little as $10 to several hundred dollars, depending on their desirability, Chung said.

Businesses with trademarks, governments and official bodies will be allowed to register website addresses ending with the suffix during the initial offer period. Meanwhile, the general public will be allowed to bid from February.

Firms and global brands from both inside and outside Asia were likely to be interested, and the suffix would act as a complement to country-specific domains such as .cn for China and .jp for Japan, Chung said.

Auction

He expects tourism bodies to be some of the first groups bidding for domain names, especially those with Asia-specific slogans, such as Hong Kong's "Asia's World City" and "Malaysia. Truly Asia."

The initial bidding period will be used to try and prevent disputes between organisations and individuals vying for a specific domain name, Chung said.

If several claims are deemed equally valid, they will eventually be settled by an auction run by the non-profit group.

Leading domains, which include .asia, country-specific suffixes and around 20 generic names, such as .biz or .org, are regulated by the US-based Internet Corporation for Assigned Names and Numbers - with specific addresses sold through registrars. [aljazeera]

In a Vacuum, No One Sees You Splatter

Nature may abhor a vacuum, but a vacuum abhors a mess. In the absence of air, a droplet of liquid can crash into a smooth surface without splattering, report physicists Lei Xu, Sidney Nagel, and colleagues at the University of Chicago, Illinois.

“I was very surprised to see [the splash] go away and this beautiful smooth spreading of the droplet emerge as the air pressure was reduced,” says Mark Robbins, a theorist at Johns Hopkins University in Baltimore, Maryland. Robbins says he would have assumed that the splashing depended on the properties of the liquid alone.

The splash spits out a ring of smaller droplets, and Xu and Nagel were studying their sizes and speeds when they discovered that pumping away the surrounding air eliminated the splash altogether. Within a tall vacuum chamber, the researchers released droplets of alcohol from various heights onto a dry glass plate. They recorded the resulting splashes with a high-speed video camera as they varied the pressure in their apparatus, Nature may abhor a vacuum, but a vacuum abhors a mess. In the absence of air, a droplet of liquid can crash into a smooth surface without splattering, report physicists Lei Xu, Sidney Nagel, and colleagues at the University of Chicago, Illinois.

“I was very surprised to see [the splash] go away and this beautiful smooth spreading of the droplet emerge as the air pressure was reduced,” says Mark Robbins, a theorist at Johns Hopkins University in Baltimore, Maryland. Robbins says he would have assumed that the splashing depended on the properties of the liquid alone.

The splash spits out a ring of smaller droplets, and Xu and Nagel were studying their sizes and speeds when they discovered that pumping away the surrounding air eliminated the splash altogether. Within a tall vacuum chamber, the researchers released droplets of alcohol from various heights onto a dry glass plate. They recorded the resulting splashes with a high-speed video camera as they varied the pressure in their apparatus, sucking it down as low as 1% of atmospheric pressure. The droplets struck the surface with speeds ranging from 2 to 7 meters per second, and for a given speed, the researchers found they could suppress the splash by lowering the pressure below a specific threshold.

The researchers explain the results with a simple theory. As a drop strikes the surface, liquid spreads sideways at supersonic speed, creating a shock wave.The shockwave pushes back on the liquid, and if that force is greater than the internal forces holding the liquid film together, the shock wave lifts it off the surface and creates a splash. Reducing the pressure reduces the force the shock wave exerts.

Ironically, the theory predicts that a thicker liquid should splash more easily than a thinner one. The researchers tested this prediction by dropping three types of alcohol with different viscosities. As predicted, the more viscous the alcohol, the lower the pressure needed to prevent splashing, the researchers reported. They also confirmed that a weighty gas such as krypton produced splashes at lower pressure than a lighter gas such as helium did.

“It’s just the sort of thing all physicists should do,” saysWalter Goldburg, an experimenter at the University of Pittsburgh, Pennsylvania.

“They spotted a nonintuitive phenomenon and pursued it” to a complete understanding. Xu and Nagel speculate that the odd phenomenon could make a splash with technologists, as it might be used to control splatter in industrial processes such as spray coating and inkjet printing.

Water Treatment Plants

Long-term ingestion of low concentrations of arsenic is detrimental to human health, yet in several countries around the world, large populations are constantly exposed to drinking water contaminated with arsenic. In Bangladesh, arsenic concentrations exceed World Health Organization guidelines in 60% of the groundwater. Arsenic can be removed by filtration and via adsorbents, such as natural zeolites, but there still is a need for simple and cost effective methods using materials that are readily available in developing countries.

Al Rmalli et al. show that the dried pulverized roots of the water hyacinth can rapidly remove arsenic from water. The method is effective for both arsenite [As(III)] and arsenate [As(V)] and requires comparatively little material (50 mikrogram of As are adsorbed per gram of roots in 24 hours). Water hyacinths grow abundantly in ponds, lakes, and rivers in Bangladesh, India, and other tropical and subtropical countries. The simplicity of the method suggests that these plants may be useful in the treatment of drinking water, particularly in rural areas. — JFU

A Star Is Reborn

As they grow old, stars with approximately the mass of our Sun experience explosive flashes just before their nuclear furnaces shut down. These flashes expel the stars’ outer shells and leave behind hot dense remnants called white dwarfs. Most of these remnants simply cool down, but some can experience a late explosion that restarts nuclear burning and expands them into giant stars again.

Hadjuk et al. (p.231;see the Perspective by Asplund) report observations and a stellar model of V4334 Sgr, a “born again” giant that reignited in 1992 and that was discovered by amateur astronomer Sakurai. The subsequent temperature drop of V4334 Sgr is 100 times faster than had been expected. The calculated mass ejection rates suggest that reignition events contribute unexpectedly large amounts of carbon and carbonaceous dust to the interstellar medium.

Teknologi Nuklir Tidak Hanya untuk Listrik

Di balik ketakutan masyarakat terhadap bahaya radiasi nuklir, ternyata ilmu pengetahuan dan teknologi (iptek) nuklir dapat dimanfaatkan untuk mempermudah kehidupan manusia.

Selain sebagai pembangkit listrik, iptek nuklir juga sering digunakan pada bidang kedokteran, kesehatan, kosmetik serta keamanan dan daya simpan bahan pangan. Di bidang kedokteran, pemakaian radioisotop dan sinar radioaktif dapat digunakan untuk diagnosis penyakit yang akurat seperti kanker dini dan untuk terapi (kedokteran nuklir dan radiologi).

Teknik radioisotop dapat digunakan di dalam (in vivo) dan di luar (in vitro) tubuh. ”Diagnosis yang akurat pada kanker dini akan sangat menolong penyembuhan pasien. Informasi yang akurat tentang sifat organ tubuh dapat diperoleh melalui kombinasi pemakaian isotop dengan komputer,” kata Konsultan Sterilisasi Radiasi dan Bank Jaringan P3TIR Badan Tenaga Nuklir Nasional (Batan) Nazly Hilmy.

Radiasi juga dapat digunakan untuk mensterilisasi alat kesehatan seperti alat kedokteran, obat, bahan biomaterial atau jaringan biologi, kosmetik, dan bahan pengemas. ”Juga produk bank jaringan seperti alograf, yaitu jaringan yang ditransplantasikan dari manusia ke manusia lain untuk pengobatan, misalnya jaringan amnion, tulang, dan jaringan lunak,” terangnya.

Sementara itu, untuk keamanan dan daya simpan bahan pangan, penggunaan radiasi pengion pada dosis sedang sudah mampu menekan dan sekaligus mengeliminasi pertumbuhan bakteri patogen karena molekul asam deoksiribonukleat (DNA) yang ada di dalam inti selnya mengalami kerusakan tanpa berakibat negatif pada kualitas sensori dan nutrisi bahan pangan yang disinari.

”Penyinaran tersebut tidak menyebabkan makanan tersebut menjadi radioaktif. Unit keamanan pangan WHO telah menegaskan bahwa iradiasi pangan merupakan bagian dari teknologi pangan yang positif dan nyata untuk masyarakat,” kata peneliti di Pusat Aplikasi Teknologi Isotop dan Radiasi Batan Zubaidah Irawati.

Dia mengungkapkan, aplikasi dan implementasi iradiasi pangan yang bertujuan meningkatkan keamanan dan memperpanjang daya simpan hanya akan terwujud apabila ditunjang oleh sosialisasi dan diseminasi iptek nuklir suatu komoditas pangan strategis. (CR-01/sindo)