Friday 28 August 2015

Makan Aiskrim 'Liquid Nitrogen?' - Boleh atau Tidak

Aiskrim 'liquid nitrogen' ialah aiskrim yang disejukkan dengan menggunakan cecair nitrogen atau juga dikenali sebagai 'liquid nitrogen'. Istilah 'nitrogen' mungkin memberikan persepsi yang berbeza bagi setiap individu. Ia lebih dikenali ramai sebagai unsur kimia yang bersifat gas merangkumi gas yang terbanyak di ruang atmosfera. Tetapi bahan yang digunakan untuk menghasilkan aiskrim ini adalah gas nitrogen yang dimampatkan dan disejukkan kepada  bentuk cecair. Secara ringkasnya, ia dikenali sebagai cecair nitrogen atau 'liquid nitrogen' dan suhunya adalah bersamaan -196 darjah Celcius.

Bagaimana untuk membuat aiskrim 'liquid nitrogen?'
Ambil sebuah mangkuk dan campurkan secawan susu penuh krim, 1/2 cawan krim putar, 1/2 cawan susu pekat manis dan 1 sudu kecil esen vanila. Kemudian, kacau sehingga sebati. Ambil cecair nitrogen dan curahkan ke dalam mangkuk adunan sedikit demi sedikit sambil mengacau campuran sehingga campuran bertekstur separa pepejal seperti aiskrim. 
Aiskrim sudah tersedia untuk dimakan.

Apa yang berlaku?
Semasa menuang cecair nitrogen ke dalam mangkuk, kelihatan kepulan asap-asap putih. Asap-asap ini adalah wap air yang bersifat sejuk dan mudah meruap. Nitrogen daripada cecair nitrogen tadi tidak bercampur dengan adunan bahan-bahan aiskrim kerana ia telah tersejat ke udara atmosfera dengan kadar yang sangat cepat dan sebahagian daripadanya bercampur dengan wap air. Jadi tiada unsur nitrogen yang bercampur dengan adunan aiskrim di dalam mangkuk tadi. 

Tetapi jika nitrogen tersejat ke udara, kenapa perlu guna cecair nitrogen untuk buat aiskrim? Ini disebabkan suhu cecair nitrogen yang sangat rendah dan keadaan fizikalnya yang teramat sejuk, berperanan utama untuk menyejukkan campuran bahan-bahan yang digunakan untuk membuat aiskrim dengan kadar segera.

Maka, jawapannya adalah aiskrim 'liquid nitrogen' BOLEH dan selamat untuk dimakan! 

Ikuti pautan di bawah untuk mengetahui cara lain untuk membuat aiskrim:

 Kunjungi Petrosains di Aras 4, Suria KLCC sekiranya anda ingin mencuba untuk membuat ais krim 'liquid nitrogen' dan pelbagai aktiviti menarik bertemakan 'A Slice Of Life' sehingga September 2015! Maklumat lanjut boleh diperolehi di!

Posted by Ayu

Thursday 20 August 2015

Light it up with wind!

“What we need to do is really improve energy efficiency standards, develop in full scale renewable and alternative energy and use the one resource we have in abundance, our creativity,”
                                                                                                                                                    Lois Capps.

In this era of globalization, to cater to humanity’s ever-increasing demand on natural resources and our high-consumption modern lifestyle, energy resources are quickly becoming scarce. As if the disaster of depleting energy resource is not enough, to make matters worse, the use of fossil fuel to generate energy for our everyday activities is contributing air-polluting particles to the environment, and adds to the accumulation of greenhouse gases that is directly linked to global warming (feeling the heat, anyone?). 

Indeed, we should be concerned, and as such, it is only logic that everyone practices energy efficient routines. Simple habits as you go about your daily life, such as switching off and unplugging electrical appliances when not in use, using energy-saving electrical appliances, and utilizing natural lighting and ventilation, not only helps to reduce your energy usage, but also saves you money. However, though seemingly simple, many of us do not even bother to do our part. Even the thought of where our nation gets its electrical supply seems to be unclear to a lot of people. Try asking a group of secondary school students what they think is the main source of Malaysia’s electric generation, and the majority will answer hydropower, instead of natural gas and coal.

Realizing the importance to enhance the public, especially the youths’ understanding towards energy efficiency, Malaysian Gas Association (MGA) collaborated with Petrosains, and thus, the ‘Energy Efficiency Program’ was initiated. The program kicked-off in August 2014, and will end this August. With the purpose of raising awareness among students on the energy resources in Malaysia, as well as promoting the importance of using energy efficiently, representatives from Petrosains visited a total of 43 secondary schools, involving more than 2000 students. An interesting part of this visit-to-school program is that the students are given materials to build their own wind turbine, as an effort to expose them to alternative and green energy resources. 

By using materials that are easily sourced out, the students were excited to find out that they are capable of building a functioning wind turbine that could light up a small LED light. In fact, you can do it at home too, what’s important is that your wind turbine design consists of a main frame structure that will hold everything together, the stator structure which includes the copper coils connected to an LED light, as well as magnets attached to the turbine structure that is free to spin, and is close to the copper coils to generate electricity. Upon completion, the wind turbine will be tested to see if the LED light could light up.

Let’s watch some snippets of the program:

It is hoped that by experiencing the hardship to generate even just a small amount of electricity, the students would appreciate the underlying message of the program. To strive for an energy efficient lifestyle is to help towards a sustainable environment, society and economy. To put it in the perspective of an ancient Indian proverb:

"Treat the earth well: it was not given to you by your parents, it was loaned to you by your children. We do not inherit the Earth from our Ancestors, we borrow it from our Children."

Shared by Yati & Faisal
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