Thursday, 15 February 2018

Limau mandarin dan gejala sakit tekak?



Menjelang musim perayaan pasti kita semua dapat melihat banyak limau mandarin dijual di kebanyakkan tempat. Tidak kira sama ada seseorang itu menyambut perayaan ini atau tidak, sudah pasti kita semua akan memakannya kerana rasanya yang manis dan kandungan vitamin C yang banyak dalam buah ini.

Memang benar limau mandarin sangat kaya dengan vitamin C dan ia sepatutnya menghalang kita daripada pelbagai penyakit. Namun begitu, bilangan pesakit yang menghidap gatal dan sakit tekak serta batuk bertambah sekali ganda dalam musim perayaan. Apa pula kaitannya dengan limau mandarin tersebut? Mengapa ada yang mengatakan sekiranya kita makan buah ini terlalu banyak akan menyebabkan sakit tekak?


Sebenarnya tidak ada kena mengena jika kita makan limau lalu akan sakit tekak. 

Pengusaha buah-buahan memang ada menggunakan sejenis bahan kimia iaitu Sulphur dioxide. Buah limau ini akan direndam terlebih dahulu ke dalam cecair yang mengandungi bahan kimia tersebut sebelum ia dimasukkan ke dalam kotak untuk tujuan melindungi kulit limau dari dijangkiti bakteria, kulat dan serangga dan secara tidak langsung ia bertindak sebagai bahan pengawet supaya ia dapat  bertahan lama sebelum dipasarkan. Video di bawah menunjukkan limau direndam di dalam cecair sebelum ia dipeketkan.



Apakah pula kesan Sulphur dioxide yang terdapat pada kulit limau  tersebut kepada manusia? 

Ia boleh menyebabkan radang dan kesakitan tekak yang teruk, demam dan gejala batuk kering yang berpanjangan. Ia juga boleh menyebabkan sakit perut dan radang usus. Terdapat juga kes alahan seperti radang kulit dan serangan penyakit lelah.

Namun, menurut pemantauan yang dibuat oleh Kementerian Kesihatan Malaysia sekitar tahun 2015 menyatakan tiada Suphur dioxide pada buah-buahan segar termasuk limau mandarin yang diimport masuk ke negara kita. Sekiranya ada, kadar Sulphur dioxide yang dibenarkan adalah tidak melebihi 10mg. 


Apapun jua, langkah berjaga-jaga lebih baik di ambil oleh semua agar kita dapat menjaga kesihatan. Berikut adalah langkah berjaga-jaga yang dicadangkan.

Bagaimana cara untuk mengatasi masalah ini?
1: Basuh atau rendam dahulu buah limau ini dan kemudian barulah dimakan.
2: Pastikan jari yang terkena kulit limau yang tidak dibasuh tidak tersentuh dengan isi limau yang hendak dimakan. 
3: Sekiranya perlu, pakailah sarung tangan plastik ketika mengopek limau!



Sumber:  Dr Rosli Abd Jalil





Posted by Ayu

Petrosains Blogger 

Wednesday, 14 February 2018

Will Salt Help Water Boil Faster?



The Queen's Head

Is she losing her head?


 Credit: Taiwan News

Credit: Taiwan Today

The elegant Queen’s Head strikes a sad and forlorn looking structure.  Like a sentinel looking towards the distance and maybe thinking of her fate?  Exposed to the elements daily.  Abused, molested and exploited by humans.  Is there any hope for The Queen to survive this endless onslaught?

What is The Queen’s Head?
The Queen’s Head can be found at the Yehliu Geopark which is located on a cape known as the Yehliu Promontory at Taiwan’s northern coast.   A distinctive feature of the cape is the hoodoo rocks that dot its surface.  
Said to resemble Queen Elizabeth I from some angles, it is a piece of rock shaped by nature.  The age of the rock is assessed to be about 4,000 years, but got its shape after the top part of the mushroom rock fell at about 1962 - 1963.

What are hoodoo rocks?
Hoodoo by definition is “A column or pinnacle of weathered rock” (Oxford Living Dictionaries). Also called fairy chimneys, earth pyramids, and tent rocks; it is irregular in shape and sometimes takes the form of faces, animals or familiar objects. 
It occurs where several layers of soft rock, e.g. sandstone which is a type of sedimentary rock, are capped with a thin layer of harder rock. Over time, openings in the protective outer rock allow the softer rock beneath to wear away through a process called weathering.  The agents of weathering are wind, sun, and rain.  Some of the thin caps of harder rock remain
and protect the soft rock that sits directly beneath it. Over time, most of the rock disappears, leaving behind the occasional rocky tower, often with a larger cap on the top. 

Hoodoo rocks are found all over the world, especially in high, dry, and rocky regions.  Some places where hoodoo rocks can be found: Goreme Valley and Cappadocia, Turkey, Putangirua Pinnacles in Wairarapa, New Zealand and Bryce Canyon National Park, Utah.  
The rocks at Yehliu are different from most as they are some of the only hoodoos known to form in a seaside environment.   At Yehliu, besides having to content with the agents of weathering, it is also at risk from typhoons and earthquakes. 

Credit: Wikimedia Commons

Credit: Yehliu Geopark


Future of The Queen’s Head
In 2016, park authorities announced their concern that the neck of the rock, which has lost 12cm of circumference in the past eight years, could give way soon.  Observe the image above – there’s a noticeable change in its neck width from 1969 to 2010.
What are authorities doing to save it?  As tourists don’t seem to take heed of warnings by park staff to not touch or climb on the Queen’s Head, a replica has been built. In addition to that, the authorities have tested out a special nanotechnology paint designed to slow down erosion.  

Replicas of other rock formations facing the similar fate as the Queen’s Head have also been constructed.  Managing humans to control further destruction is still possible, but managing nature are challenging!
Tourist dollars are very much needed to maintain the geopark, but at what cost?  There needs to be a balance as well as a change in the attitude of tourists.  We hope the Queen’s Head will be there to greet visitors in many years to come and that efforts to save it will be successful.  It will be a great loss when that unfortunate day comes when The Queen loses it head!


References
1. Taiwan’s Yehliu Geopark Is Like Disneyland for Rock Lovers
2. Taiwan's celebrated Queen's Head rock formation at risk
3. Yehliu Geopark
4. Taiwan's ancient Queen's head at risk of being beheaded
https://www.taiwannews.com.tw/en/news/3213235
5. Hoodoo
6. Scientists Say: Hoodoo
7. Amazing Places to See Hoodoos (PHOTOS)




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