lightingstrom

 petir adalah peercikan listrik statis yang ada di udara.kemunculan petir ini biasanya datang dari atmosfir yang penuh dengan ion listrik.panas yang dihasilkan dari petir ini bisa meleburkan pasir silocon menjadi glass channel biasanya dikenal sebagai fulgurities.sepanjang tahun telah terjadi setidaknya 16 milliar badai petir di dunia ini.terjadinya fenomena alam yang mengerikan ini dikarenakan adanya perbedaan muatan listrik di udara..
dibawah ini beberapa foto ketika badai petir.

indah-indah bukan.dari yang seindah ini terdapat kekuatan yang dashyat.

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Posted in: indonesia,science

bahaya radiasi

from:http://teknologi.kompasiana.com/gadget/2011/06/13/radiasi-oh-radiasigaib-tak-kasat-mata/

Tak terbayangkan berapa banyak radiasi yang ada di sekeliling kita, tanpa disadaripun kita turut sebagai penyumbang radiasi, hemm . . manusia sumber radiasikah ? tidak tentunya, segala macam gadget yang selalu menjadi teman kesayangan kita ternyata dalam jangka panjang dapat menjadi musuh utama kita apabila digunakan secara berlebihan.

Teman radiasi yang sangat dekat ialah handphone, alat komunikasi semua kalangan. Bahkan anak-anakpun sudah mahir menggunakannya. Pada saat kita menerima atau melakukan sms/telpon handphone akan memancarkan gelombang elektromagnetik agar dapat berkomunikasi dengan pemancar operator terdekat. Dalam jumlah kecil radiasi ini tidak berbahaya bagi manusia, tetapi dalam jumlah yang besar akan sangat membahayakan bagi kesehatan manusia.

Besarnya radiasi handphone dinyatakan dengan SAR (Specific absorption rate). SAR adalah nilai maksimum radiasi yang diserap oleh tubuh per satuan berat). FCC (salah satu lembaga di AS) menentukan besarnya SAR untuk handphone adalah maksimal sebesar 1,6 W/kg. Negara-negara di Eropa (European Union) menetapkan besarnya SAR maksimal adalah sebesar 2 W/kg.

Penelitian WHO tentang resiko kanker otak yang ditimbulkan oleh radiasi handphone menunjukkan bahwa radisi yang ditimbulkan tidak terlalu besar untuk dikhawatirkan. Namun penelitian baru yang dilakukan oleh India malah sebaliknya. Prof.Kurish Kumar sang peneliti menyebutkan adanya ancaman kanker untuk remaja dan anak-anak karena radiasi handphone ini, dia juga mengatakan bahaya radiasi juga terdapat disekitar menara Base Transceiver Station (BTS). Berikut kutipannya “Satu BTS bisa memancarkan daya 50-100Watt. Negara yang punya banyak operator selular seperti india bisa terpapar daya hingga 200-400Watt. Radiasinya tidak bisa dianggap remeh, bisa sangat mematikan”. Bagaimana dengan Indonesia ? Bukankah operator selularnya begitu banyak ?

Dari pernyataan diatas, berikut dampak radiasi handphone dan menara BTS tersebut :

1. Resiko kanker otak pada anak-anak dan remaja meningkat 400% akibat penggunaan ponsel. Makin muda umur pengguna ponsel, makin besar resiko yang didapat.

2. Pada orang dewasa penggunaan ponsel 30menit/hari selama 10 tahun dapat meningkatkan resiko kanker dan acoustic neuroma (sejenis tumor yang menyebabkan tuli).

3. Radiasi ponsel juga dapat menurunkan produksi sperma laki-laki sampai 30%.

4. Frekuensi radio pada ponsel juga menyebabkan perubahan DNA pada tubuh dan melepas radikal bebas. Radikal bebas bersifat karsinogenik atau pemicu kanker.

5. Medan elekromagnetik disekitar menara BTS dapat mengurangi sistem kekebalan tubuh, akibatnya tubuh mengalami reaksi alergi seperti ruam dan gatal-gatal.

6. Akibat pemakaian ponsel yang berlebihan , frekuensi radio yang digunakan (900 MHz, 1800 MHz and 2450 MHz) dapat meningkatkan temperatur di lapisan mata sehingga memicu kerusakan kornea.

7. Risiko kelenjar air ludah meningkat akibat penggunaan ponsel secara berlebihan.

8. Medan magnetik di sekitar ponsel yang menyala bisa memicu kerusakan sistem syaraf yang berdampak pada gangguan tidur. Dalam jangka panjang kerusakan itu dapat mempercepat kepikunan.

9. Medan elektromagnetik di sekitar BTS juga berdampak pada lingkungan hidup. Burung dan lebah juga mengalami disorientasi atau kehilangan arah sehingga mudah stress karena tidak bisa menemukan jalan pulang ke sarang mereka.

Masih banyak bahaya radiasi handphone yang “mungkin” saja sudah diketahui kita bersama tapi masih sangat sulit sekali memisahkan handphone dari kehidupan masyarakat. Saat ini sudah 3 miliar orang memakai handphone diseluruh dunia (dan masih akan terus bertambah), bayangkan radiasi yang ditimbulkan dari setiap handphone tersebut apabila digabungkan. Bahkan angka ini lebih besar daripada pengguna rokok. Seperti telah diketahui pengguna rokok meninggal 5 juta orang setiap tahunnya. Bagaimana dengan penggunaan handphone ? kita bisa lihat dalam jangka waktu ke depan.

Saat ini badan lingkungan eropa telah mendorong untuk studi lebih lanjut. Badan independen ini mengungkapkan bahaya ponsel lebih berbahaya dari asbak, merokok, dan bensin timbal. Kepala sebuah penelitian kanker terkemuka di University of Pittsburgh mengirim memo kepada seluruh karyawan mendesak mereka untuk membatasi penggunaan telepon seluler karena kemungkinan resiko kanker.

Sangat sulit memang melepaskan “teman setia” dalam hidup kita, tapi kalo itu sangat berbahaya bagi kesehatan manusia. Wajib dipikirkan lagi ya kawan. Toh, tidak dapat dipungkiri kalau handphone sangat menunjang komunikasi kita dengan orang-orang sekitar, maka dari itu, ada beberapa tips dari Ann Louise Gittleman, PhD, penulis buku bestseller versi harian New York Times, Zapped untuk meminimalisasi radiasi ponsel :

1. Aktifkan speaker

Menggunakan speaker saat berbicara akan mengurangi energi dan tingkat kekuatan radiasi handphone. Semakin jauh dari antena handphone maka semakin sedikit radiasinya. Kabel headset pada banyak ponsel juga bisa digunakan untuk antena, sehingga penggunaan headsetpun tidak bisa meminimalkan radiasi handphone.

2. Lebih baik SMS-an saja

SMS mengurangi paparan radiasi, karena terhindar dari kepala dan tubuh kita, tapi jangan memangku handphone tsb. Karena pada kaum lelaki bisa merusak vitalitas dan motilitas, volume sperma akan meningkat, sehingga tak akan baik pengaruhnya untuk rahim.

3. Pilih profile OFFLINE mode

Saat tidak digunakan usahakan handphone dimatikan, atau paling tidak pilih offline mode, standalone, atau flightmode yang akan mematikan transmitternya.

4. Gunakan bergantian antara kuping kanan dan kiri

Pada saat menelepon jangan terpaku dengan satu pendengaran saja, harus diimbangkan antara kuping kanan dan kiri, secara bergantian. Hal ini bisa membatasi paparan pada satu sisi kepala saja, yang sering dikaitkan dengan meningkatnya risiko tumor otak dan kanker kelenjar ludah pada telinga yang sering digunakan untuk mendengarkan ponsel.

5. Hindari ruang sempit

Karena akan menyebabkan radiasi terpusat pada ruangan tersebut.

6. Perhatikan sinyalnya

Jangan menggunakan ponsel ketika sinyalnya lemah, atau ketika Anda sedang berkendara di dalam mobil yang melaju sangat cepat (kereta api juga termasuk). Pada saat sinyal lemahpun usahakan tidak untuk menerima telepon, karena handphone akan sangat bekerja keras untuk mencari sinyal, dan ini meningkatkan gelombang radiasi dari handphone.

Semoga Bermanfaat

 

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Posted in: fakta,indonesia,science

alien jama dulu

Some people like to say that alien encounters are a recent phenomenon that are based off of the popularity of science fiction novels, television shows, and movies and the rumor of a crash landed UFO in Roswell, New Mexico during the 1940s which sent the world into an “Alien Age” where everyone became obsessed with extraterrestrials and UFOs. Many individuals like to simply shrug away these encounter stories as people who are seeking attention or are merely having intense dreams with images supplied by science fiction characteristics and concepts. Yet, these nay sayers clearly have not done their research. There are many accounts of UFOs and alien meetings in historic human records (indirectly described of course since these ancient did not exactly understand what they were seeing) that reach all the way back to the ancient Egyptian heyday from the fourteenth century BCE. The reports do not stop there. All through write ups and records in Europe there are some stories that definitely seem like alien convergences with random humans of the past.

Egypt

One of the earliest found accounts of unidentified flying objects in the night sky comes from one of the oldest collections of writings that have been preserved into the modern age. Thutmose III reigned over Egypt from about 1504-1450 BCE. During his time of rule, a most peculiar event happened that he ordered be put in his personal annals so that it would be remembered forever after. Several scribes noted a circle of fire entering the night sky. Then, after a few days, these circles of fire became even more numerous in the sky (perhaps a fleet of flying saucers), shining almost as brightly as the sun. However, these circles then ascended higher in the sky on their move toward the south before completely disappearing.

LINK

India

Roughly two millennia ago, epic poems and religious texts were recorded in Sanskrit by the ancient civilization settled in the lands now known as India. These writings included numerous references to flying machines that were called vimanas. The vimanas were mostly chariots of the gods that began being made by Lord Brahma (engineer of the universe and head of the demigods) during the period known as “Treta-yuga” for himself and several of the other demigods. Vimanas came in different nature based shapes but all seemed to incorporate wings. The great seers of Vedic knowledge were also known to construct these machines for wise humans from the detailed instructions that had been written down—including what is known as a mercury vortex engine so that humans could nimbly travel through the skies like the celestial gods.

LINK

Hebrew Bible

Many of the modern religions (the religions of Abraham as they are generally called) do not think of UFO sightings or alien encounters as anything to bother with since there is no mention of such things in their ancient religious texts—Torah, Koran, or Bible. However, in the Hebrew bible, the Book of Ezekiel mentions a vision of a flying vessel that is accompanied by smoke, fire, and loud noises just like our modern spacecrafts. The sky ship might have actually been an ancient encounter with extraterrestrials instead of a mere biblical metaphor.

LINK

Rome

The large expanse of the Roman Empire (through both physical land and extent of time) make it one of the easiest eras of history to study. During the fourth century CE, a Roman historian by the name of Julius Obsequens drew on the works of previous historian Livy and other sources at the time to compile a book of all the peculiar phenomenon of the Empire. His book (called Prodigorium liber) has several examples of what could be considered as UFO encounters throughout Roman history. The chronicler mentions that things like ships were over the Italian sky in 216 BCE, specifically at Arpi where there were round shields in the sky and figures like ships surrounded by fire where in the skies over Capua. A few hundred years later (in 99 BCE) over the Roman territory of Spoletium (which was located in what is now Umbria) it is said that a golden ball of fire fell from the sky. It rested on the ground, shaking, before it rose again to the sky and revolved toward the east. Later accounts of UFOs seen by residents of the Roman Empire go into even greater detail. In 393 CE, a bright globe appeared next to the planet Venus that shown less brightly than the planet itself but several smaller orbs soon joined the vicinity of the main sphere before they smashed onto the large, centered orb to create a single, bright flame that was bigger than the original celestial sphere. This description resembles very closely the modern reports of UFO formations from today—almost 1700 years later!

LINK

Japan

A term equal to our “flying saucer” was actually coined in Japan 700 years before the Western world used it. In 1180, a flying “earthenware vessel” that was unusually shiny was spotted near a mountain in the Kii province before it changed directions to vanish below the horizon, leaving a luminous, smoky trail behind it. One of the first official investigations of a UFO report comes from Japan as well. During an encampment of General Yoritsume and his army in 1235, mysterious lights in the night sky were observed for many hours to be circling and moving in loops to the southwest of the campsite. The General ordered a full scale scientific inquiry. Finally, an end report was submitted to him that contained many of the modern explanations of spacecrafts including the whole thing being a natural phenomenon whereby the wind made “the stars sway.”

LINK

Middle Ages of Europe

Just because the Roman Empire fell and dissolved does not mean that sightings of these celestial crafts ended. A preserved book, now residing in France, that was written in 1493 contains one of the earliest illustrations of a UFO in Europe. Next to the picture (showing a cigar shaped form ringed in flames floating in a blue sky over rolling green hills) is a detailed account of the strange fiery spherical shape that was reported in 1034.

Toward the end of the 12th century in England, there is yet another UFO sighting in north Yorkshire near Begland (Byland) Abbey. While the monks were having their daily evening reflection period, a shiny, flat object that glistened silver in color and closely resembled a very large discus flew across the night sky just over the top of the abbey.

Throughout the 14th and 15th century, countless UFO reports abound all over England. In 1322 CE, the sky over Uxbridge held a “pillar of fire” that was the size of a small boat. It rose from the southern sky then slowly crossed the sky before going north with beams of red flames and light bursting in front of it. 1461 CE saw another report across the Channel this time. The account was of a fiery iron rod shape in the night sky that was almost half the size of the moon. The shape which resembled a ship with fire flowing from it was in the skies over Arras, France for roughly twenty minutes.

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Posted in: inggris,science

cool pc

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test otak

apa yang akan anda pikirkan ketika melihat gambar dibawah ini?

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Posted in: fun

10 teknologi penyelamat bumi

1. Memproduksi Minyak Secara Alami

Ada proses bernama thermo-depolymerization, suatu proses yang sama dengan bagaimana alam memproduksi minyak. Misalnya limbah berbasis karbon jika dipanaskan dan diberi tekanan tepat, mampu menghasilkan bahan minyak. Secara alamiah proses ini menbutuhkan waktu jutaan tahun. Dari eksperiman yang sudah-sudah, kotoran ayam kalkun mampu memproduksi sekitar 600 pon petroleum.

2. Menghilangkan Garam dari Air laut

PBB mencatat, suplai air bersih akan sangat terbatas bagi miliaran manusia pada pertengahan abad ini. Ada teknologi bernama desalinasi, yakni menghilangkan kadar garam dan mineral dari air laut sehingga layak diminum. Ini merupakan solusi yang bisa dilakukan untuk mencegah krisis air. Masalahnya, teknologi ini masih terlalu mahal dan membutuhkan energi cukup besar. Kini para ilmuwan tengah mencari jalan agar desalinasi dapat berlangsung dengan energi lebih sedikit. Salah satu caranya adalah dengan melakukan evaporasi pada air sebelum masuk ke membran dengan pori-pori mikroskopis.

3. Tenaga Hidrogen

Bahan bakar hidrogen dianggap sebagai bahan bakar alternatif bebas polusi. Energi dihasilkan dari perpaduan antara hidrogen dan oksigen. Problemnya adalah bagaimana hidrogen itu dihasilkan. Molekul seperti air dan alkohol harus diproses dulu untuk mengekstaksi hidrogen sehingga menjadi sel bahan bakar. Proses ini juga membutuhkan energi besar. Namun setidaknya ilmuwan sudah mencoba membuat laptop serta peranti lain dengan tenaga fuel cell.

4. Tenaga Surya

Energi surya yang sampai di bumi terbentuk dari photon, dapat dikonversikan menjadi listrik atau panas. Beberapa perusahaan dan perumahan sudah berhasil menggunakan aplikasi ini. Mereka memakai sel surya dan termal surya lain sebagai media pengumpul energi.

5. Konversi Panas Laut

Media pengumpul tenaga surya terbesar di bumi ini adalah air laut. Departemen Energi Amerika Serikat (AS) menyebut, laut mampu menyerap panas surya setara dengan energi yang dihasilkan 250 miliar barel minyal per hari. Ada teknologi bernama OTEC yang mampu mengkonversikan energi termal laut menjadi listrik. Perbedaan suhu antar permukaan laut mampu menjalankan turbin dan menggerakan generator. Masalahnya, teknologi ini masih kurang efisien.

6. Energi Gelombang Laut

Laut melingkupi 70 persen permukaan bumi. Gelombangnya menyimpan energi besar yang dapat menggerakkan turbin-turbin sehingga mengasilkan listrik. Problemnya agak sulit memperkirakan kapan gelombang laut cukup besar sehingga memproduksi energi yang cukup. Solusinya adalah dengan menyimpan sebagian energi ketika gelombang cukup besar. Sungai Timur kota New York saat ini sedang menjadi proyek percobaan dengan enam turbin bertenaga gelombanng air. Sedangkan Portugis justru sudah lebih dulu mempraktikan teknologi ini dan sukses menerangi lebih dari 1500 rumah.

7. Menanami Atap Rumah

Konsep ini diilhami dari Taman Gantung Babilonia yang masuk dalam daftar Tujuh Keajaiban Dunia. Istana Babilonia terdiri atas atap yang ditanami aneka flora, juga balkon dan terasnya. Taman atap ini mampu menyerap panas dan mengurangi karbon dioksida. Bayangkan jika burung-burung dan kupu-kupu berterbangan di sekitar rumah hijau kita.

8. Bioremediasi

Ada proses bernama bioremediasi, yakni memanfaatkan mikroba dan tanaman untuk membersihkan kontaminasi. Salah satunya adalah membersihkan kandungan nitrat dalam air dengan bantuan mikroba. Atau memakai tanaman untuk menetralisir arsenik dari tanah. Beberapa tumbuhan asli ternyata punya daedah untuk membersihkan bumi kita dari aneka polusi.

9. Kubur Barang-barang Perusak

Karbon dioksida adalah faktor utama penyebab pemanasan global. Energy Information Administration (EIA) mencatat, tahun 2030 emisi karbon dioksida mencapai 8000 juta metrik ton. Metode paling sederhana untuk menekan kandungan zat berbahaya itu adalah dengan menguburkan berbagai sumber penghasil CO2 seperti aneka limbah elektronik berbahaya. Namun ilmuwan masih belum yakin bahwa gas berbahaya akan tersimpan aman. Tetap saja kelak akan muncul imbas negatifnya bagi lingkungan.

10. Buku Elektronik

Bayangkan, berapa ton kertas dan berapa banyak pohon harus ditebang bagi seantero dunia jika kita semua harus membeli koran, majalah, novel, buku pelajaran, buku tulis, kertas faks, sampai tisu toilet. Buku elektronik atau surat elektronik yang lebih dikenal dengan e-book dan email memberi kontribusi sangat berarti pada kelangsungan hidup. Dengan teknologi itu, produksi kertas dapat ditekan, sehingga bahan kita tak perlu menebang terlalu banyak pohon.






from:http://www.kaskus.us/showthread.php?t=7088731

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Posted in: indonesia,science

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Posted in: indonesia

10 weirds natural fenom

Mother Nature will never cease to amaze mankind, simply because of her unpredictability. Some of the most fascinating things in life are the natural phenomenons that occur around the world. They have the power to mesmerise us and leave us compelled by their sheer beauty, uniqueness and plain freakishness. Here is a list of ten of the very weirdest, freakish and most fascinating of all the world’s natural phenomena.

1. Old Faithful

Image source - Wikipedia

Yellowstone’s is the world’s best known geyser because of its consistent eruptions nearly every hour. Up to 8,400 gallons of scalding hot water shoot up to the heavens reaching heights of over 100 feet. It was first discovered in 1870 and since then over 30,000 eruptions have been recorded. Like a performing whale at Sea World this geyser attracts thousands of tourists a year.

2. Kelimutu

Image source - Wikipedia

Kelimutu in Indonesia attracts visitors because of its three magnificent crater lakes, all of varying colours.  It is located in the summit of a 1,639  metre high volcano on the island of Flores and the three lakes change their colours frequently. It all depends on the time of the year and their changing mineral content. Although they are prone to regular changes the main colour of Tiwu Ata Polo (the Lake of the Bewitched People) and Tiwu Nuwa Muri Koo Fai (the Lake of Young Men and Maidens) are deep reddish-brown or green. Lying to the west of these is Tiwu Ata Mbupu (the Lake of Old People), which is more of a blue colour.

3. Surtsey

Image source - Wikipedia

In August 1883 the Javanese island of Krakatoa vanished forever from one single, violent explosion. Exactly 80 years later a new volcanic island emerged in its place totally out of the blue. It was discovered that this was caused by a continuing series of less ferocious volcano eruptions beneath the sea south of Iceland. In just two days enough lava and scoria had been thrown to the surface causing an island to form, which measured a third of a mile from end to end. Wind and erosion has diminished its size since its first appearance but this has not deterred some animals setting up home on the island. Residents include seals, puffins, whooper swans, common ravens and various geese.

4. Dead Sea

Image source - ianaloni

As the guy in the picture demonstrates it is perfectly easy to float on the Dead Sea and read a newspaper. The reason for this is that it is 25% salt (normal sea water is around 4-6). Obviously no marine life can live in the Dead Sea either and with the increased density of the water floating is the natural occurrence. The Dead Sea, interestingly, is not only the lowest place on the planet but it is also the hottest, besides the inside of a volcano of course!

5. Petrified Forest

Image source - Wikipedia

Lying just off the Arizona I-40 highway, deep into the desert between Holbrook and Navajo is the Petrified Forest. The “forest” comprises of fallen fossilised trees, mostly Araucarioxylon arizonicum, an ancient species of conifer, which have been mineralised into chalcedony and quartz. This process occurrs after the dead fallen trees become permeated by the mineral content of the sediments in which they are lying. This basically means that the wood of the tree eventually turns to stone.

6. Giant’s Causeway

Image source - Wikipedia

Ireland’s one and only World Heritage site is this gigantic area covered in basalt columns and stones. The 38,000 stone columns were created after the eruption of a volcano around 60 million years ago. The lava rapidly cooled leaving these sightly columns behind. The locals, however, prefer to tell tourists another tale. They say that Fionn MacCumhaill (pronounced Finn McCool) created the area by throwing down enormous chunks of cliff to make stepping stones so that he could get to his lover on the Hebridean island of Staffa, or to walk to Scotland to fight the Scottish colossus, Benandonner. Hence the name of the place.

7. Pitch Lake

Image source - Wikipedia

Pitch Lake is one of Trinidad’s biggest tourist attractions, seeing over 20,000 visitors per year. Unlike any other lake in the world this one is filled with a gloopy, thick mixture of bitumen, clay and saltwater. It covers more than 100 acres and has been used for asphalt, ever since Sir Walter Rayleigh first took some to caulk his ship’s timbers back in 1595. Unsurprisingly there is no life living in this ooze.

8. General Sherman

Image source - Wikipedia

Not including coral reef or spreading fungi this famous Giant Sequoia in California is officially the largest living thing in the world. It is somewhere between 23 and 27 centuries old. Its trunk alone comprises almost 52,000 cubic feet of wood. It proudly stands at 275 feet tall, is more than 36 feet in diameter at its base and has a crown that spreads just over 106 feet! It was named in honour of the American Civil War general, William Sherman, by the naturalist James Wolverton who served under Sherman’s command.

9. Dachstein Caves

Image source - austria-trips

An impressive 150 miles of icy tunnels and spooky caverns make up the Dachstein Caves, Austria’s famous ice caves which are located near Lake Hallstatt. The magnificent ice columns, arches and spikes were formed by swirling air that melted parts of the ice. Deeper underground is a giant glacier but some of the most amazing sights can be seen on the travel down, where some parts of the ice have formed what looks like a huge ice cathedral.

10. Aurora Borealis

Image source - Wikipedia

Otherwise known as the Northern Lights this mysterious yet beautiful natural phenomenon is said to be one of the greatest treasures in life if you are lucky enough to see them for yourself. The name Aurora  Borealis comes from the Roman goddess of dawn, Aurora, and the Greek name for the north wind, Boreas. There is also the Southern Lights aka Aurora Australis – the Latin word for South. The lights are a results of the Earth’s photons colliding with solar winds. You’ll only be lucky enough to see them if you visit certain parts of the Northern or Southern Hemisphere.

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