Alhamdulillah...
3 Siswa SMPN SBBS sampai di Pontianak kemarin malam (28 Juni 2012)
Esok dan Lusa mereka akan mengikuti Ujian OSN SMP...
Kami mengharap DOA dari semuanya
Semoga ALLAH SWT memberikan mereka Kemudahan dan Hasil yang terbaik dalam OSN 2012... Amin...
Jumat, 29 Juni 2012
Kalender Pendidikan Tahun Pelajaran 2012/2013
Berikut adalah Kalender Pendidikan tahun Pelajaran 2012/2013
Semoga dapat bermanfaat...
Kalender Pendidikan 2012/2013
Semoga dapat bermanfaat...
Kalender Pendidikan 2012/2013
Selasa, 26 Juni 2012
Discovery of Material With Amazing Properties
ScienceDaily (June 24, 2012) —
Normally a material can be either magnetically or electrically
polarized, but not both. Now researchers at the Niels Bohr Institute at
the University of Copenhagen have studied a material that is
simultaneously magnetically and electrically polarizable. This opens up
new possibilities, for example, for sensors in technology of the future.
The results have been published in the scientific journal, Nature Materials.
The "8-armed
candlestick" in this unusual image of the measurements is proof that
the "walls" of the domains in TbFeO3 repel each other at certain
temperatures and therefore lie at a fixed distance from each other. The
signal from the "ordinary" chaotic domain walls would more resemble a
fly swatter. (Credit: Niels Bohr Institute)
Surprising test results
"We have studied the rare, naturally occurring iron compound, TbFeO3, using powerful neutron radiation in a magnetic field. The temperature was cooled down to near absolute zero, minus 271 C. We were able to identify that the atoms in the material are arranged in a congruent lattice structure consisting of rows of the heavy metal terbium separated by iron and oxygen atoms. Such lattices are well known, but their magnetic domains are new. Normally, the magnetic domains lie a bit helter-skelter, but here we observed that they lay straight as an arrow with the same distance between them. We were completely stunned when we saw it," explains Kim Lefmann, Associate Professor at the Nano-Science Center, University of Copenhagen.
They were very strange and very beautiful measurements and it is just such a discovery that can awaken the researchers' intense interest. Why does it look like this?
Explaining physics
The experiments were conducted at the neutron research facility Helmholtz-Zentrum in Berlin in collaboration with researchers in Holland, Germany, at ESS in Lund and at Risø/DTU. They would like to get a general understanding of the material and with the help of calculations; and have now arrived at a more precise image of the relationship between the structure of the material and its physical properties.
"What the models are describing is that the terbium walls interact by exchanging waves of spin (magnetism), which is transferred through the magnetic iron lattice. The result is a Yukawa-like force, which is known from nuclear and particle physics. The material exhibits in a sense the same interacting forces that hold the particles together in atomic nuclei," explains Heloisa Bordallo, Associate Professor at the Niels Bohr Institute.
It is precisely this interaction between the transition metal, iron, and the rare element, terbium, that plays an important role in this magneto-electrical material. The terbium's waves of spin cause a significant increase in the electric polarization and the interaction between the ions of the elements creates one of the strongest magneto-electrical effects observed in materials.
"Through these results we found a new pathway to discover and develop new multiferroics," emphasize the researchers in the group. Now it is up to further research to determine whether this new effect could lead to new applications of these materials with the amazing physical properties.
Story Source:
The above story is reprinted from materials provided by University of Copenhagen, via EurekAlert!, a service of AAAS.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Journal Reference:
- Sergey Artyukhin, Maxim Mostovoy, Niels Paduraru Jensen, Duc Le, Karel Prokes, Vinícius G. de Paula, Heloisa N. Bordallo, Andrey Maljuk, Sven Landsgesell, Hanjo Ryll, Bastian Klemke, Sebastian Paeckel, Klaus Kiefer, Kim Lefmann, Luise Theil Kuhn, Dimitri N. Argyriou. Solitonic lattice and Yukawa forces in the rare-earth orthoferrite TbFeO3. Nature Materials, 2012; DOI: 10.1038/nmat3358
Minggu, 24 Juni 2012
Jawa Tengah Juara Umum Festival dan Lomba Seni Siswa Nasional (FLS2N) Tahun 2012
Untuk melihat dokumentasi Festival dan Lomba Seni Siswa Nasional (FLS2N) Tahun 2012 silahkan klik gambar di bawah ini.
http://pdkjateng.go.id/
Jumat, 22 Juni 2012
Researchers Estimate Ice Content of Crater at Moon's South Pole
ScienceDaily —
NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft has returned data
that indicate ice may make up as much as 22 percent of the surface
material in a crater located on the moon's south pole.
Elevation
(left) and shaded relief (right) image of Shackleton, a 21-km-diameter
(12.5-mile-diameter) permanently shadowed crater adjacent to the lunar
south pole. The structure of the crater's interior was revealed by a
digital elevation model constructed from over 5 million elevation
measurements from the Lunar Orbiter Laser Altimeter. (Credit:
NASA/Zuber, M.T. et al., Nature, 2012)
"The brightness measurements have been puzzling us since two summers ago," said Gregory Neumann of NASA's Goddard Space Flight Center in Greenbelt, Md., a co-author on the paper. "While the distribution of brightness was not exactly what we had expected, practically every measurement related to ice and other volatile compounds on the moon is surprising, given the cosmically cold temperatures inside its polar craters."
The spacecraft mapped Shackleton crater with unprecedented detail, using a laser to illuminate the crater's interior and measure its albedo or natural reflectance. The laser light measures to a depth comparable to its wavelength, or about a micron. That represents a millionth of a meter, or less than one ten-thousandth of an inch. The team also used the instrument to map the relief of the crater's terrain based on the time it took for laser light to bounce back from the moon's surface. The longer it took, the lower the terrain's elevation.
In addition to the possible evidence of ice, the group's map of Shackleton revealed a remarkably preserved crater that has remained relatively unscathed since its formation more than three billion years ago. The crater's floor is itself pocked with several small craters, which may have formed as part of the collision that created Shackleton.
The crater, named after the Antarctic explorer Ernest Shackleton, is two miles deep and more than 12 miles wide. Like several craters at the moon's south pole, the small tilt of the lunar spin axis means Shackleton crater's interior is permanently dark and therefore extremely cold.
"The crater's interior is extremely rugged," said Maria Zuber, the team's lead investigator from the Massachusetts Institute of Technology in Cambridge in Mass. "It would not be easy to crawl around in there."
While the crater's floor was relatively bright, Zuber and her colleagues observed that its walls were even brighter. The finding was at first puzzling. Scientists had thought that if ice were anywhere in a crater, it would be on the floor, where no direct sunlight penetrates. The upper walls of Shackleton crater are occasionally illuminated, which could evaporate any ice that accumulates. A theory offered by the team to explain the puzzle is that "moonquakes"-- seismic shaking brought on by meteorite impacts or gravitational tides from Earth -- may have caused Shackleton's walls to slough off older, darker soil, revealing newer, brighter soil underneath. Zuber's team's ultra-high-resolution map provides strong evidence for ice on both the crater's floor and walls.
"There may be multiple explanations for the observed brightness throughout the crater," said Zuber. "For example, newer material may be exposed along its walls, while ice may be mixed in with its floor."
The initial primary objective of LRO was to conduct investigations that prepare for future lunar exploration. Launched in June 2009, LRO completed its primary exploration mission and is now in its primary science mission. LRO was built and is managed by Goddard. This research was supported by NASA's Human Exploration and Operations Mission Directorate and Science Mission Directorate at the agency's headquarters in Washington.
For more information on LRO and the Lunar Orbiter Laser Altimeter, visit: http://lunar.gsfc.nasa.gov
Story Source:
The above story is reprinted from materials provided by NASA.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Journal Reference:
- Maria T. Zuber, James W. Head, David E. Smith, Gregory A. Neumann, Erwan Mazarico, Mark H. Torrence, Oded Aharonson, Alexander R. Tye, Caleb I. Fassett, Margaret A. Rosenburg, H. Jay Melosh. Constraints on the volatile distribution within Shackleton crater at the lunar south pole. Nature, 2012; 486 (7403): 378 DOI: 10.1038/nature11216 \
http://www.sciencedaily.com/releases/2012/06/120620141159.htm
Kamis, 21 Juni 2012
Panduan dan Kisi-kisi OSTN Tingkat Jawa Tengah Tahun 2012
Silahkan lihat di sini untuk melihat Panduan dan Kisi-kisi OSTN Tingkat Jawa Tengah Tahun 2012.
http://pdkjateng.go.id/
http://pdkjateng.go.id/
Rabu, 20 Juni 2012
Neutrons Escaping to a Parallel World?
ScienceDaily (June 15, 2012) — In a paper recently published in European Physical Journal (EPJ) C,
researchers hypothesised the existence of mirror particles to explain
the anomalous loss of neutrons observed experimentally. The existence of
such mirror matter had been suggested in various scientific contexts
some time ago, including the search for suitable dark matter candidates.
Researchers
hypothesize the existence of mirror particles to explain the anomalous
loss of neutrons observed experimentally. (Credit: © Pix by Marti /
Fotolia)
Berezhiani believes it could be interpreted in the light of a hypothetical parallel world consisting of mirror particles. Each neutron would have the ability to transition into its invisible mirror twin, and back, oscillating from one world to the other. The probability of such a transition happening was predicted to be sensitive to the presence of magnetic fields, and could therefore be detected experimentally.
This neutron-mirror-neutron oscillation could occur within a timescale of a few seconds, according to the paper. The possibility of such a fast disappearance of neutrons -- much faster than the ten-minute long neutron decay -- albeit surprising, could not be excluded by existing experimental and astrophysical limits.
This interpretation is subject to the condition that the earth possesses a mirror magnetic field on the order of 0.1 Gauss. Such a field could be induced by mirror particles floating around in the galaxy as dark matter. Hypothetically, the earth could capture the mirror matter via some feeble interactions between ordinary particles and those from parallel worlds.
Story Source:
The above story is reprinted from materials provided by Springer, via EurekAlert!, a service of AAAS.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Journal Reference:
- Zurab Berezhiani, Fabrizio Nesti. Magnetic anomaly in UCN trapping: signal for neutron oscillations to parallel world? The European Physical Journal C, 2012; 72 (4) DOI: 10.1140/epjc/s10052-012-1974-5
Jumat, 15 Juni 2012
Undangan Pembinaan/Training Center Kontingen OSN SMP Jawa Tengah Tahun 2012
Untuk
mengetahui isi undangan Pembinaan/Training Center Kontingen OSN SMP
Jawa Tengah Tahun 2012 silahkan klik gambar di bawah ini.
http://pdkjateng.go.id/
Optical Displays from Water and Air
ScienceDaily (June 14, 2012) —
For many years, scientists have been pursuing ways to mimic the
perplexing capability of the lotus leaf to repel water. Lotus leaves
hate water so much that droplets effortlessly roll off the surface,
keeping it clean from dirt. Now an international team of researchers led
by Aalto University have come up with an entirely new concept of
writing and displaying information on surfaces using simply water. They
exploit the unique way a trapped layer of air behaves on a
lotus-inspired dual-structured water-repelling surface immersed under
water.
Water is applied to a surface but the surface does not get wet. (Credit: Image courtesy of Aalto University)
The researchers lead by Dr. Robin Ras at Aalto University in Finland, University of Cambridge and Nokia Research Center Cambridge fabricated a surface with structures in two size scales: microposts that have a size of ten micrometers and tiny nanofilaments that are grown on the posts. On such a two-level surface the air layer can exist in two different shapes (wetting states) that correspond to the two size scales. The researchers found that one can easily switch between the two states locally using a nozzle to create over- or underpressure in the water, in order to change the air layer to either state.
"The minimal energy needed to switch between the states means the system is bistable, which is the essential property of memory devices, for example," Academy Research Fellow Dr. Robin Ras points out. However, there is a feature that makes it all the more interesting: there is a striking optical contrast between the states due to a change in the roughness of the water-air interface. "Combined with the optical effect, the surface is also a bistable reflective display."
The switching only involves a change in the shape of the air layer − nothing happens to the solid surface itself. This is demonstrated by writing shapes on the surface underwater (making use of the contrast between the states) and taking the sample out of water: the surface emerges completely dry, and no traces of the writing remain.
The method for manipulating the air layer with the nozzle was developed by Tuukka Verho, graduate student in Aalto University. He was able to show that the reversible switching can be done with precision in a pixel-by-pixel fashion.
"This result represents the first step in making non-wettable surfaces a platform for storing or even processing information," says Academy professor Olli Ikkala. Until now, lotus-inspired surfaces have been mainly developed for applications like self-cleaning, anti-icing or flow drag reduction. This research is a landmark example how the Nature teaches materials scientists towards functional materials.
An article entitled "Reversible switching between superhydrophobic states on a hierarchically structured surface" is published in PNAS, Proceedings of the National Academy of Sciences of the USA, and provides more in depth information about this project.
Watch a video: http://www.youtube.com/watch?v=AEWPIjLbrSE
Story Source:
The above story is reprinted from materials provided by Aalto University.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Journal Reference:
- T. Verho, J. T. Korhonen, L. Sainiemi, V. Jokinen, C. Bower, K. Franze, S. Franssila, P. Andrew, O. Ikkala, R. H. A. Ras. Reversible switching between superhydrophobic states on a hierarchically structured surface. Proceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1204328109
Soal OSN SMP 2011 - Lengkap
Berikut ini adalah kumpulan soal - soal OSN SMP tahun 2011 yang meliputi bidang Matematika, Fisika, Biologi dan IPS. Soal - soal tersebut terdiri dari OSN di tingkat Kabupaten hingga Nasional. Semoga dapat bermanfaat. Terimakasih
Rabu, 13 Juni 2012
3 Siswa SMPN SBBS lolos menuju OSN tingkat Nasional
Alhamdulillah....
Sebelumnya kami ucapkan terimakasih atas doa dan dukungan segenap
civitas akademika SMPN SBBS. Dengan segala daya upaya yang telah kita
lalui, 3 siswa SMPN SBBS berhasil lolos menuju OSN tingkat Nasional yang
akan diadakan di Pontianak, 28 Juni - 4 Juli 2012.
Kami tetap menharap doa serta dukungan untuk siswa - siswa tersebut
hingga prestasi mereka tetap membanggakan di tingkat Nasional...
berikut adalah daftar nama siswa SMPN SBBS yang lolos :
1. AJI LUHUR B I F (Matematika)
2. MAULANA WILDAN SEPUTRA (Biologi)
3. TOHARI CATUR PAMUNGKAS (Fisika)
PEMBERITAHUAN PESERTA OLIMPIADE SAINS NASIONAL (OSN) SMP
PEMBERITAHUAN
PESERTA OLIMPIADE SAINS NASIONAL (OSN) SMP
TINGKAT NASIONAL
TAHUN 2012
Sebagai tindak lanjut dari seleksi Olimpiade Sains Nasional SMP Tingkat Provinsi yang diselenggarakan oleh Kementerian Pendidikan dan Kebudayaan pada tanggal, 2 Juni 2012, di setiap ibukota provinsi, maka berdasarkan Keputusan Direktur Pembinaan Sekolah Menengah Pertama (SMP), Nomor 1370/C3/KP/2012, tanggal 12 Juni 2012, nama-nama sebagaimana tersebut di bawah ini adalah yang berhak mengikuti seleksi OSN Tingkat Nasional yang akan diselenggarakan tanggal 28 Juni sd. 4 Juli 2012 di Pontianak.
Pemberitahuan ini sekaligus sebagai undangan resmi, agar nama-nama yang tertera di dalam Daftar Peserta OSN SMP Tingkat Nasional Per Provinsi dapat segera menghubungi Dinas Pendidikan Provinsi masing-masing peserta. Biaya akomodasi dan konsumsi selama mengikuti kegiatan serta biaya transportasi dari ibukota provinsi asal peserta ke Pontianak pulang-pergi ditanggung Panitia Pusat.
http://dikdas.kemdiknas.go.id/content/newsletter/osn/pemberitahua-2-2-2.html
NuSTAR to Drop from Plane and Rocket Into Space
ScienceDaily (June 11, 2012) —
NASA's NuSTAR mission is scheduled to launch from Kwajalein Atoll in the
central Pacific Ocean on June 13, no earlier than 8:30 a.m. PDT (11:30
a.m. EDT). The observatory, which will hunt for black holes and other
exotic objects using specialized X-ray eyes, will be launched from a
Pegasus XL rocket carried by an Orbital Science Corporation L-1011
"Stargazer" plane. The plane will take off from Kwajalein Atoll an hour
before launch, flying out over the Pacific Ocean.
The Orbital
Science Corporation's "Stargazer" plane is shown releasing its Pegasus
rocket. NASA's NuSTAR will also launch from a Pegasus carried by the
Stargazer plane. (Credit: Orbital Sciences Corporation)
Why launch from the air? Plane-assisted launches are less expensive than those that take place from the ground. Less fuel is needed to boost cargo away from the pull of Earth's gravity. NuSTAR is part of NASA's Small Explorer program, which builds focused science missions at relatively low costs.
If all goes as planned, the following milestones will occur on June 13. Times listed are for a launch at the start of a four-hour window.
Takeoff
The Stargazer carrier aircraft, with the Pegasus launch vehicle and NuSTAR spacecraft strapped to its belly, will take off from Kwajalein's Bucholz Auxiliary Airfield an hour before launch, and climb to an altitude of about 39,000 feet (11,900 meters). This should occur around 7:30 a.m. PDT (10:30 a.m. EDT).
The Drop
The carrier aircraft will release the Pegasus rocket at 8:30 a.m. PDT (11:30 a.m. EDT). The rocket will free-fall for about five seconds before igniting.
Ignition
At about 8:30 a.m. PDT (11:30 a.m. EDT), the rocket carrying NuSTAR will ignite. Its first-stage motor will burn for 70 seconds and then drop away. The second-stage motor will burn for about a minute-and-a-half.
Splitting the Nose Cone
While the second stage is burning, pyrotechnic devices will be fired to release the nose cone, or fairing, that encapsulates the observatory. NuSTAR will be exposed to space for the first time. This event is scheduled to occur around 8:33 a.m. PDT (11:33 a.m. EDT).
Separating From the Rocket
At about 8:43 a.m. PDT (11:43 a.m. EDT), 13 minutes after the initial release from the Stargazer, NuSTAR will separate from the Pegasus rocket's third stage. At this point, NuSTAR will be in its final orbit -- a low-Earth equatorial orbit at an altitude of approximately 340 miles (600 kilometers) and an inclination of six degrees.
Phoning Home
When NuSTAR separates from the Pegasus, the satellite's system that controls its orientation in space, or "attitude," will begin to stabilize it, and the spacecraft solar arrays will be deployed. Around this time, its first signal will be received on the ground via NASA's Tracking and Data Relay Satellite System. Over the following week, NuSTAR personnel will perform a series of checkouts to ensure that all spacecraft subsystems are operating nominally.
Deploying the Boom
Roughly one week after launch, engineers will command NuSTAR to deploy its lengthy 33-foot (10-meter) boom, allowing the telescope to focus X-ray light into crisp images. Unlike visible-light telescopes, X-ray telescopes require a long distance between the mirrors and detectors to focus the light. It's a bit like wearing glasses a few feet away from your face.
Science operations are expected to begin about 30 days after launch.
On launch day, live commentary and coverage will be broadcast online beginning at 7 a.m. PDT (10 a.m. EDT) at http://www.nasa.gov/nustar and at http://www.ustream.tv/nasajpl2 .
NuSTAR is a Small Explorer mission led by the California Institute of Technology in Pasadena and managed by NASA's Jet Propulsion Laboratory, also in Pasadena, for NASA's Science Mission Directorate in Washington. The spacecraft was built by Orbital Sciences Corporation, Dulles, Va. Its instrument was built by a consortium including Caltech; JPL; the University of California, Berkeley; Columbia University, New York; NASA's Goddard Space Flight Center, Greenbelt, Md.; the Danish Technical University in Denmark; Lawrence Livermore National Laboratory, Livermore, Calif.; and ATK Aerospace Systems, Goleta, Calif. NuSTAR will be operated by UC Berkeley, with the Italian Space Agency providing its equatorial ground station located at Malindi, Kenya. The mission's outreach program is based at Sonoma State University, Rohnert Park, Calif. NASA's Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.
Launch management and government oversight for the mission is the responsibility of NASA's Launch Services Program at the Kennedy Space Center in Florida.
For more information, visit http://www.nasa.gov/nustar and http://www.nustar.caltech.edu/ .
Story Source:
The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.
http://www.sciencedaily.com/releases/2012/06/120611195728.htm
Undangan Peserta Festival dan Lomba Seni Siswa Nasional (FLS2N) Tahun 2012
Klik gambar di bawah ini untuk mengetahui isi dari Undangan Peserta Festival dan Lomba Seni Siswa Nasional (FLS2N) Tahun 2012.
http://pdkjateng.go.id/
Selasa, 12 Juni 2012
Pengumuman Tenaga Honorer Kategori I yang Memenuhi Kriteria
Menindaklanjuti Surat Edaran Menteri Pendayagunaan Aparatur Negara dan
Reformasi Birokrasi Nomor 03 Tahun 2012 tentang Data Tenaga Honorer
Kategori I dan Daftar nama Tenaga Honorer Kategori II, dengan ini kami
umumkan nama-nama Tenaga Honorer Kategori I yang Memenuhi Kriteria di
lingkungan Kementerian Pendidikan dan Kebudayaan hasil verifikasi Tim
BKN dan BPKP sebagaimana daftar terlampir.
Untuk proses selanjutnya terkait waktu dan persyaratan penyampaian
berkas usulan pengangkatan CPNS, akan diinformasikan lebih lanjut.
Demikian pengumuman ini disampaikan, atas perhatiannya diucapkan terima kasih.
Lampiran:
http://kemdiknas.go.id/kemdikbud/pengumuman/354
Mendikbud: Tanamkan Karakter Konsisten kepada Anak-anak
Jakarta
– Menteri Pendidikan dan Kebudayaan (Mendikbud) Mohammad Nuh
mengatakan, perlu menanamkan karakter konsisten kepada anak bangsa. Hal
tersebut merupakan inspirasi dari buku biografi mantan Menteri
Pendidikan Nasional, Yahya Muhaimin. “Jadi segala sesuatu kalau
konsisten itu ibarat batu yang ditetesi terus meskipun itu tetesan
kecil, akan sangat berpengaruh,” katanya.
Peluncuran buku yang berjudul “Tiga Kota Satu
Pengabdian” itu berlangsung cukup meriah di Gedung A Kemdikbud, Jakarta,
(12/6). Acara dibuka dengan tarian Saman dari Aceh. Kemudian selain
dihadiri Mendikbud M. Nuh, acara peluncuran juga dihadiri beberapa tokoh
nasional, di antaranya Amien Rais, Akbar Tandjung, dan Adhyaksa Dault.
Buku biografi Yahya Muhaimin, “Tiga Kota Satu Pengabdian”, ditulis
Badruzzaman Busyairi, seorang penulis kelahiran Brebes, Jawa Tengah.
Menteri Nuh mengatakan, ia sudah cukup lama
mengenal Yahya Muhaimin. Ia mengenalnya sebagai seorang guru besar,
birokrat, intelektual, dan seseorang yang sangat santun dalam
menyampaikan pandangan dan pendapat. Menteri Nuh juga mengaku banyak
bertanya dengan mantan Mendiknas era Presiden Abdurrahman Wahid itu
mengenai kementerian pendidikan, “Dan beliau dengan senang hati
menjawab,” ujarnya.
Buku “Tiga Kota Satu Pengabdian” mengupas
perjalanan hidup Yahya Muhaimin di tiga kota, yaitu Bumiayu, Yogyakarta,
dan Jakarta. Dalam buku ini pembaca diajak memahami tiga dimensi
perjalanan hidupnya, yaitu perjalanan akademis, perjalanan
keterlibatannya di lembaga sosial keagamaan dan persinggungan dengan
dunia politik, dan perjalanan persahabatannya dengan tokoh besar negeri
ini, di antaranya Abdurrahman Wahid dan Amien Rais. (DM)
http://kemdiknas.go.id/kemdikbud/berita/393
17 Siswa Berkebutuhan Khusus Ikut SNMPTN di UNJ
Jakarta
--- Sebanyak 17 siswa berkebutuhan khusus ikut melaksanakan Seleksi
Nasional Masuk Perguruan Tinggi Negeri (SNMPTN) di Universitas Negeri
Jakarta, Selasa (12/06). Para peserta SNMPTN yang berasal dari
pendidikan khusus dan layanan khusus (PKLK) ini dibantu oleh dua orang
pengawas dalam mengerjakan soal-soal SNMPTN.
“Yang ikut (SNMPTN) disini ada tuna daksa, tuna
netra, dan tuna rungu. Semuanya harus diberi layanan,” tutur Menteri
Pendidikan dan Kebudayaan, Mohammad Nuh, usai menyemangati siswa PKLK
tersebut.
Dari 17 orang yang seharusnya mengikuti ujian,
baru 15 orang yang telah siap mengerjakan soal saat waktu tanda ujian
dibunyikan. “Dua lagi belum hadir,” kata Mendikbud.
Mendikbud mengatakan, PKLK akan diperkuat hingga
ke pendidikan tinggi. Rencana tersebut telah dituangkan dalam rancangan
undangan-undang pendidikan tinggi. “Di perguruan tinggi harus menyiapkan
pendidikan untuk anak-anak berkebutuhan khusus, selama ini kan baru
sampai sekolah menengah,” katanya.
Peningkatan layanan khusus bagi anak berkebutuhan
khusus akan dilakukan baik terhadap siswa yang kebutuhannya mengikat
maupun yang temporer (dalam masa sakit). Dalam SNMPTN kali ini, tingkat
kesulitan soal bagi siswa berkebutuhan khusus setara dengan siswa
reguler. Hanya dalam pelaksanaannya, siswa berkebutuhan khusus diberi
tambahan waktu 30 menit. (AR)
http://kemdiknas.go.id/kemdikbud/berita/392
Kuota Penerimaan SNMPTN Naik 10 Persen
Jakarta
--- Panitia Seleksi Nasional Masuk Perguruan Tinggi Negeri (SNMPTN)
2012 menyiapkan kurang lebih 15-16 ribu kursi tambahan bagi calon
mahasiswa baru angkatan 2012. Berarti ada kenaikan 10 persen dari kuota
awal penerimaan 164.697 kursi.
“Prinsipnya secara nasional sepuluh persen, tapi
teknisnya ada di PTN,” kata Menteri Pendidikan dan Kebudayaan Mohammad
Nuh dalam konferensi pers di kantornya, Jakarta Senin (11/06).
Mendikbud mengatakan, setiap PTN memiliki
pertimbangan untuk menentukan program studi mana yang harus ditambah.
“Bisa jadi ada PTN yang menambah sembilan persen, namun di PTN lain
sebelas persen”, katanya.
Ada dua pertimbangan yang mendukung pengambilan
kebijakan ini. Pertama, infrastruktur PTN yang memungkinkan untuk
menambah kuota. Kedua, perbaikan dalam rasio jumlah mahasiswa terhadap
jumlah dosennya. “Kami berani menambah sepuluh persen, karena masih ada
ruang pengoptimalan volume dan kualitas infrastruktur dan dosen,”
katanya.
Kebijakan untuk menaikkan kuota sepuluh persen
diambil dengan mempertimbangkan kenaikan jumlah pendaftar yang mencapai
14 persen. Meskipun penambahan kursi tidak sebanyak kenaikan jumlah
pendaftar, namun dengan adanya penambahan ini akan memperluas kesempatan
calon mahasiswa baru untuk sekolah di PTN pilihannya. (AR)
http://kemdiknas.go.id/kemdikbud/berita/387
Masyarakat Dihimbau Tak Tertipu Calo SNMPTN
Jakarta
--- Seleksi Nasional Masuk Perguruan Tinggi Negeri (SNMPTN) jalur tulis
akan dilaksanakan selama dua hari, 12-13 Juni 2012. Untuk
mengantisipasi adanya usaha percaloan yang dilakukan secara tidak
bertanggung jawab oleh pihak-pihak tertentu, ketua SNMPTN, Akhma Loka,
mengimbau masyarakat untuk lebih rasional dan lebih berhati-hati dengan
rayuan dan bujukan pihak-pihak tertentu untuk memberikan imbalan jika
mereka nanti dinyatakan lulus. “Mereka tidak melakukan apapun untuk
kelulusan Anda, jadi jangan tertipu!,” ujar Akhma Loka, di Kantor
Kementerian Pendidikan dan Kebudayaan, Senin (11/06).
Dia menggambarkan, jika ada seratus orang yang
diyakinkan pelaku bahwa nomor ujian mereka akan muncul pada saat
kelulusan, dan setidaknya ada dua nomor ujian yang benar dinyatakan
lulus, maka akan sangat merugikan masyarakat. Pasalnya, ada pihak yang
memberikan imbalan atas apa yang tidak dilakukan calo tersebut.
Akhma Loka juga mengimbau agar peserta SNMPTN yang
akan melaksanakan ujian besok pagi, dapat melihat lokasi ujian sehari
sebelum pelaksanaan. “Jangan sampai ketika datang besok, mereka
kebingungan di mana lokasinya,” tuturnya.
Demikian pula untuk kelengkapan ujian seperti alat
tulis dan tanda peserta harap dibawa. Untuk peserta yang memilih
jurusan seni dan olah raga, diimbau untuk teliti melihat lokasi dan
kelengkapan dalam ujian keterampilan yang akan dilaksanakan tanggal
14-15 Juni mendatang. (AR)
http://kemdiknas.go.id/kemdikbud/berita/388
Perguruan Tinggi Negeri Dilarang Naikkan Biaya Pendidikan
Jakarta
--- Menteri Pendidikan dan Kebudayaan Mohammad Nuh melarang perguruan
tinggi negeri (PTN) menaikkan biaya pendidikan yang berasal dari
mahasiswa. “Tidak ada kenaikan SPP (sumbangan pembinaan pendidikan),
karena sudah dapat bantuan operasional perguruan tinggi negeri,” katanya
seusai melakukan inspeksi mendadak di hari pertama Seleksi Nasional
Masuk Perguruan Tinggi Negeri (SNMPTN) di Universitas Negeri Jakarta
(UNJ), Selasa (12/06).
Mendikbud menjelaskan, saat ini pemerintah
menerapkan sistem insentif dan disinsentif bagi semua PTN. Jika sumber
dana sebuah PTN berasal dari masyarakat, maka secara otomatis penerimaan
yang berasal dari pemerintah akan dikurangi. Namun jika pendanaannya
didapat dari kerja sama dengan industri dan penelitian, maka pemerintah
akan memberi insentif tambahan. “Tambahannya disesuaikan dengan
koefisien proporsionalitasnya,” kata Mendikbud.
Untuk itu, selain memberi bantuan operasional
kepada perguruan tinggi negeri, Mendikbud menyampaikan akan terus
mendorong tumbuhnya kerja sama antara PTN dengan industri. “Jangan
sekali-sekali menaikkan dari sisi masyarakat, karena akan diberi
disinsentif,” tegasnya. (AR)
http://kemdiknas.go.id/kemdikbud/berita/391
Physics Lecture - 2 - Acceleration
Berikut adalah video pembelajaran tentang percepatan. Silahkan diunduh dan selamat belajar
Physics Lecture - 2 - Acceleration
Physics Lecture - 2 - Acceleration
Humanoid Soccer Championship 2012
ScienceDaily (June 11, 2012) —
In a number of recent Hollywood hit films, robots do all kinds of
spectacular things, from battling it out in boxing rings to saving the
world from alien invaders. Seagate Technology is helping university
students in Thailand bring those futuristic visions a little closer to
reality.
In the
Thailand Humanoid Robot Soccer Championship students designed their own
soccer-playing machines. (Credit: Image courtesy of ResearchSEA)
Seagate supported the Thailand Humanoid Robot Soccer Championship, in
which students designed their own soccer-playing machines. Hanuman Team
from King Mongkut's University of Technology Thonburi (KMUTT) emerged
as champions of this year's competition. The team won a cash prize of
200,000 baht and will represent Thailand at the World Robocup Soccer
Humanoid League 2013 in Osaka, Japan, next year. Thanyaburi Tonkla Team
from Rajamangala University of Technology Thanyaburi (RMUTT) 100,000
baht as the first runners-up.
Thailand's Humanoid Robot Soccer Championship 2012 was jointly
organized by Seagate Technology (Thailand) Limited, the Thai Robotics
Society (TRS), FIBO of King Mongkut's University of Technology Thonburi
and the National Electronics and Computer Technology Center (NECTEC).
This year saw 11 teams from 8 universities battling for the chance to
represent Thailand in the World Robocup Soccer Humanoid League 2013.
"TRS is confident that these competitions foster hands-on technical
learning and collaboration -- which are key qualities for success in our
digital world," said Dr. Thavida Maneewan, president of the Thai
Robotics Society. "Students exchange ideas and valuable experiences with
one another, which ultimately benefits them and our society."
"NECTEC is pleased to support Thai university students in using
knowledge gained from their classrooms and applying it in a creative
competition such as this one," added Dr. Pansak Siriruchtapong,
executive director of National Electronics and Computer Technology
Center(NECTEC) "We hope that the Humanoid Robot Soccer contest will also
emphasize the importance of technology in helping further our country's
innovation and economic future."
"We hope that the Humanoid Robot Soccer contest will also emphasize
the importance of technology to enhance their learning and skills
development and increase innovation capability for young Thai people."
Story Source:
Senin, 11 Juni 2012
Quantum Computers Move Closer to Reality, Thanks to Highly Enriched and Highly Purified Silicon
ScienceDaily — The quantum computer is a futuristic machine that could operate at speeds even more mind-boggling than the world's fastest super-computers.
SFU physicist Mike Thewalt and grad student Kamyar Saeedi with a sample of highly isotopically enriched silicon - its unique properties could advance quantum computing. (Credit: Image courtesy of Simon Fraser University)
Research involving physicist Mike Thewalt of Simon Fraser University offers a new step towards making quantum computing a reality, through the unique properties of highly enriched and highly purified silicon.
Quantum computers right now exist pretty much in physicists' concepts, and theoretical research. There are some basic quantum computers in existence, but nobody yet can build a truly practical one -- or really knows how.
Such computers will harness the powers of atoms and sub-atomic particles (ions, photons, electrons) to perform memory and processing tasks, thanks to strange sub-atomic properties.
What Thewalt and colleagues at Oxford University and in Germany have found is that their special silicon allows processes to take place and be observed in a solid state that scientists used to think required a near-perfect vacuum.
And, using this 28Si they have extended to three minutes -- from a matter of seconds -- the time in which scientists can manipulate, observe and measure the processes.
"It's by far a record in solid-state systems," Thewalt says. "If you'd asked people a few years ago if this was possible, they'd have said no. It opens new ways of using solid-state semi-conductors such as silicon as a base for quantum computing.
"You can start to do things that people thought you could only do in a vacuum. What we have found, and what wasn't anticipated, are the sharp spectral lines (optical qualities) in the 28Silicon we have been testing. It's so pure, and so perfect. There's no other material like it."
But the world is still a long way from practical quantum computers, he notes.
Quantum computing is a concept that challenges everything we know or understand about today's computers.
Your desktop or laptop computer processes "bits" of information. The bit is a fundamental unit of information, seen by your computer has having a value of either "1" or "0."
That last paragraph, when written in Word, contains 181 characters including spaces. In your home computer, that simple paragraph is processed as a string of some 1,448 "1"s and "0"s.
But in the quantum computer, the "quantum bit" (also known as a "qubit") can be both a "1" and a "0" -- and all values between 0 and 1 -- at the same time.
Says Thewalt: "A classical 1/0 bit can be thought of as a person being either at the North or South Pole, whereas a qubit can be anywhere on the surface of the globe -- its actual state is described by two parameters similar to latitude and longitude."
Make a practical quantum computer with enough qubits available and it could complete in minutes calculations that would take today's super-computers years, and your laptop perhaps millions of years.
The work by Thewalt and his fellow researchers opens up yet another avenue of research and application that may, in time, lead to practical breakthroughs in quantum computing.
Journal Reference:
- M. Steger, K. Saeedi, M. L. W. Thewalt, J. J. L. Morton, H. Riemann, N. V. Abrosimov, P. Becker, H.- J. Pohl.Quantum Information Storage for over 180 s Using Donor Spins in a 28Si 'Semiconductor Vacuum'.Science, 2012; 336 (6086): 1280 DOI:10.1126/science.1217635
Jumat, 08 Juni 2012
Physics Lecture 1 - Introduction to Physics
Materi Pembelajaran Fisika dalam Bahasa Inggris yang disampaikan oleh B Roberts. Selamat Balajar...
Physics Lecture 1 - Introduction to Physics
Physics Lecture 1 - Introduction to Physics
Kamis, 07 Juni 2012
Lomba Karya Ilmiah Inovatif Pembelajaran Guru SMA dan SMK
Klik tulisan di bawah ini untuk mengetahui informasi tentang
Cassini Plasma Spectrometer Turns Off
ScienceDaily —
The Cassini plasma spectrometer instrument (CAPS) aboard NASA's Cassini
spacecraft was turned off between Friday, June 1 and Saturday, June 2,
when a circuit breaker tripped off after the instrument experienced some
unexpected voltage shifts.
Artist concept of Cassini spacecraft. Image credit: NASA/JPL Artist concept of Cassini spacecraft. (Credit: NASA/JPL)
More details about whiskers on the CAPS instrument can be found here: http://www.jpl.nasa.gov/news/news.cfm?release=2012-078 .
The cause is still under investigation, but engineers will be looking into this issue over the next few months.
Cassini launched in 1997 and has been exploring the Saturn system since 2004. The project completed its original prime mission in 2008 and has been extended twice. Cassini is now in its solstice mission, which will enable scientists to observe seasonal change in the Saturn system through the northern summer solstice.??
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington.
For more information about the Cassini mission, visit: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .
Story Source:
The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.
Splitting the Unsplittable: Physicists Split an Atom Using Quantum Mechanics Precision
ScienceDaily —
Researchers from the University of Bonn have just shown how a single
atom can be split into its two halves, pulled apart and put back
together again. While the word "atom" literally means "indivisible," the
laws of quantum mechanics allow dividing atoms -- similarly to light
rays -- and reuniting them. The researchers want to build quantum
mechanics bridges by letting the atom touch adjacent atoms while it is
being pulled apart so that it works like a bridge span between two
pillars.
Maximilian
Genske, Noomen Belmechri, Andreas Steffen and Dr. Andrea Alberti
working. (Credit: Copyright Barbara Frommann/Uni Bonn)
Dividing atoms? What sounds like nuclear fission and radioactivity is, however, a precision process using quantum mechanics. The laws of quantum mechanics allow objects to exist in several states simultaneously. This is what the so-called double-slit experiment is based on, where a particle can go through two slits at the same time. The Bonn scientists working with Prof. Dr. Dieter Meschede from the Institute for Applied Physics of the University of Bonn succeeded in keeping a single atom simultaneously in two places that were more than ten micrometers, or one hundredth of a millimeter, apart. This is an enormous distance for an atom. Afterwards, the atom was put back together undamaged.
The atom has a split personality
The fragile quantum effects can only occur at the lowest temperatures and with careful handling. One method is cooling a cesium atom enormously using lasers -- to a temperature of a tenth of a million above absolute zero -- and then holding it with another laser. This laser beam is key to splitting the atom. It works because atoms have a spin that can go in two directions. Depending on the direction, the atom can be moved to the right or the left by the laser like on a conveyor. Key is that the atom's spin can be in both directions simultaneously. So, if the atom is moved to the right and left at the same time, it will split. "The atom has kind of a split personality, half of it is to the right, and half to the left, and yet, it is still whole," explained Andreas Steffen, the publication's lead author.
The parts compare their "experiences"
But you cannot see the split directly; if you shine a light on the atom to take a picture, the split will collapse immediately. The atom can then be seen in several images; sometimes on the left, sometimes on the right -- but never in both places. And yet, the split can be proved successfully by putting the atom back together. Thus an interferometer can be built from individual atoms that can, e.g., be used to measure external impacts precisely. Here, the atoms are split, moved apart and joined again. What will become visible, e.g., are differences between the magnetic fields of the two positions or accelerations since they become imprinted in the quantum mechanical state of the atom. This principle has already been used to very precisely survey forces such as Earth's acceleration.
Quantum systems as tools?
The Bonn scientists, however, are looking for something else: simulating complex quantum systems. Many physicists have been hoping for a long time to be able to simulate so-called topological isolators or plant photosynthesis -- phenomena that are hard to capture with modern super computers -- using small quantum systems. The first steps on the way to such simulators could consist of modeling the movement of electrons in solid bodies, thus gaining insights for innovative electronic devices. Examples for this are Dirac motion of electrons in a single graph-layer or the emergence of artificial molecules from interacting particles. But for this purpose, individual atoms would not only have to be well controlled, but also linked according to quantum mechanical laws since where the crux of the matter lies is exactly in a structure made up from many quantum objects.
A cog in a gearbox
"For us, an atom is a well-controlled and oiled cog," said Dr. Andrea Alberti, the team lead for the Bonn experiment. "You can build a calculator with remarkable performance using these cogs, but in order for it to work, they have to engage." This is where the actual significance of splitting atoms lies: Because the two halves are put back together again, they can make contact with adjacent atoms to their left and right and then share it. This allows a small network of atoms to form that can be used -- like in the memory of a computer -- to simulate and control real systems, which would make their secrets more accessible. The scientists believe that the entire potential of controlling individual atoms this precisely will become apparent over time.
Journal Reference:
- A. Steffen, A. Alberti, W. Alt, N. Belmechri, S. Hild, M. Karski, A. Widera, D. Meschede. Digital atom interferometer with single particle control on a discretized space-time geometry. Proceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1204285109
Perangkat Pembelajaran Fisika SMA Berkarakter Kelas X
Perangkat Pembelajaran Fisika Kelas X [Download]
Suharlan SH, MM, Prestasi OSN di Tiap Daerah Harus Merata
Melalui
OSP yang mengerucut pada OSN, PLH Kasubdit Kelembagaan dan Peserta
Didik, Suharlan SH, MM berharap semua Dinas Kebupaten Kota mengapresiasi
kegiatan-kegiatan olimpiade sains, mulai dari tingkat Kabupaten Kota,
Provinsi hingga Nasional. Proses seleksi dan mekanisme yang berlangsung
selama ini sudah berjalan dengan baik dan Dinas Kabupaten Kota juga
menyambut baik dengan menganggarkan dana APBD sehingga kompetisi ini
betul-betul selektif dan bergengsi.“OSN merupakan kebanggaan peserta didik, sekolah dan orang tua. Siswa yang berhasil lolos di tingkat Kabupaten Kota saja sudah membuat mereka dan juga orang tuanya bangga, apalagi jika lolos hingga tingkat provinsi, nasional, atau bahkan internasional. Rasa bangga itu bukan lagi menjadi hal yang mutlak, namun telah berbaur dengan rasa haru sebab dapat membawa nama Indonesia di kancah olimpiade sains tingkat internasional.” Tambah Suharlan.
Pada OSN kali ini semua sekolah diberi kesempatan yang sama untuk berperan serta, baik itu sekolah swasta maupun negeri. Jadi tidak ada prioritas pada sekolah tertentu, dan kegiatan ini tidak didominasi oleh sekolah-sekolah yang bagus saja, sekolah yang berada di pelosok pun memeroleh kesempatan yang sama untuk berkompetisi di tingkat nasional maupun internasional. Dan budaya ini sudah mulai dirasakan manfaatnya baik bagi siswa, sekolah maupun Dinas Kabupaten Kota. Karena OSN merupakan kegiatan yang penseleksiannya berjenjang, mulai dari tingkat sekolah, Kabupaten/Kota, Provinsi hingga Nasional, event ini sudah sesuai dengan kebijakan pemerintah di dalam Peraturan Menteri bahwa kegiatan-kegiatan kompetisi yang perlu ditingkatkan. Kami berharap pemenang di tingkat Kabupaten Kota, khususnya Bupati dan Walikota dapat memberikan apresiasi kepada para siswa yang turut dalam olimpiade tersebut dan ini sesuai dengan Peraturan menteri di mana intansi terkait memiliki kewenangan untuk memberikan penghargaan dan care kepada mereka. Olimpade sains bidang studi ini bukan hal yang menakutkan lagi, dan peserta sudah merasa ‘enjoy’ dengan bidang studi yang diminati. Contohnya bidang studi kimia, di situ para peserta terlihat betul menikmati pelajaran tersebut dan budaya untuk meneliti melalui laboratorium-laboratorium kimia kini semakin diminati siswa.
Menghadapi OSN tahun ini masing-masing Kabupaten Kota sudah mulai mempersiapkan diri sebelum maju ke tingkat provinsi. Begitu pun ke tingkat nasional, tiap provinsi juga telah menyiapkan timnya dengan persiapan yang matang melalui kompetisi-kompetisi yang mereka adakan sebelumnya. “Kabupaten Kota dan Provinsi telah menyalurkan dana untuk kegiatan ini. Jadi keseriusan mereka pada dunia pendidikan di Indonesia tampak jelas dan ini merupakan gejala positif sehingga sistem yang kita bangun semakin lama semakin berkembang. OSN yang semula dianggap sebagai esklufisme sekarang sudah tidak lagi. Itu yang penting. Bahkan sekolah-sekolah dari daerah pun sudah berani berkompetisi.” Papar Suharlan. “Kami menghimbau agar tiap sekolah melakukan pembinaan secara intensif sebelum mengirimkan siswa-siswinya ke tingkat nasional. Semoga kegiatan ini dapat berjalan sukses dan memeroleh ilmuwan-ilmuwan muda yang siap berlomba di tingkat internasional,” lanjutnya. Sukses untuk para peserta. Rinda/Fanny
http://siswapsma.org/index.php?option=com_content&view=article&id=208:prestasi-osn-di-tiap-daerah-harus-merata&catid=38:osn&Itemid=65
Olimpiade Sains Provinsi 2012, Siswa SMA Se-Indonesia Unjuk Prestasi di Bidang Sains
Lebih
dari 13.000 siswa-siswi terbaik yang mewakili masing-masing
kabupaten/kota di seluruh Indonesia unjuk prestasi dalam olimpiade sains
tingkat provinsi. Mereka terpilih setelah sebelumnya mengikuti seleksi
olimpiade sains di tingkat kabupaten/kota pada 4 – 5 April 2012.
Pelaksanaan seleksi Olimpiade Sains Provinsi (OSP) 2012 diselenggarakan
serentak pada tanggal 5 – 6 Juni 2012 di 33 provinsi. OSP kali ini akan
melombakan delapan bidang studi, yaitu matematika, fisika, kimia,
biologi, komputer, astronomi, ekonomi, dan kebumian (geo sains). Peserta yang sukses berkompetisi di tingkat provinsi, selanjutnya akan berlaga dalam perhelatan akbar Olimpiade Sains Nasional (OSN) yang akan diselenggarakan di Jakarta, pada 2 - 7 September 2012. Peraih medali pada OSN 2012 akan diseleksi melalui pembinaan bertahap untuk mewakili Indonesia di ajang olimpiade sains internasional 2013.
PLH Kasubdit Kelembagaan dan Peserta Didik Direktorat Pembinaan SMA, Suharlan SH menyampaikan, tujuan dari rangkaian kegiatan olimpiade sains secara berjenjang ini adalah untuk menjaring siswa-siswi yang memiliki potensi, khususnya di bidang sains. Selain itu diharapkan mereka dapat menumbuhkan budaya kompetitif yang sehat, meningkatkan wawasan pengetahuan, “Setiap siswa memeroleh kesempatan dan peluang yang sama untuk meraih prestasi di ajang olimpiade sains, mulai dari tingkat kabupaten hingga nasional. Mereka diharapkan mampu berkompetisi di delapan bidang studi yang dilombakan. Dengan demikian, peningkatan prestasi bisa tercapai di tiap daerah,” ujar Suharlan.
http://siswapsma.org/index.php?option=com_content&view=article&id=207:olimpiade-sains-provinsi-2012&catid=38:osn&Itemid=65
Rabu, 06 Juni 2012
Kisi-Kisi dan Materi Uji Olimpiade Sains SMA Bidang Informatika/Komputer Tahun 2012
Bundel
pembahasan soal Olimpiade Sains Informatika berisi kumpulan soal dari
OSK, OSP, dan OSN tahun 2010-2011 (+OSK 2012) yang telah dipilih dan
dikategorikan sesuai dengan jenis soalnya, disertai dengan tingkat
kesulitannya. Bundel pembahasan soal ini ditujukan untuk pembimbing dan
peserta yang kesulitan mencari materi mengenai persiapan Olimpiade Sains
Informatika.
Untuk mengunduh materi-materi di atas silahkan klik pilihan di bawah ini.
source : http://pdkjateng.go.id/ 6 Juni 2012, Transit Venus (Gerhana Venus) Terakhir Abad Ini
Rabu 6 Juni 2012, planet Venus akan melintas di depan Matahari
dan akan menghasilkan bayangan yang mana tidak ada seorang pun yang
hidup hari ini akan melihat lagi fenomena ini dalam hidupnya, sebab
fenomena transit Venus
ini kemungkinan baru akan kembali hadir pada tahun 11 Desember 2117
nanti, lama sekali bukan. Kita beruntung sebab fenoena transit Venus ini akan dapat dilihat di 7 benua termasuk antartika. Kemungkinan transit Venus ini akan berlangsung selama 7 jam.
Seperti Gerhana Matahari, untuk melihat transit Venus ini kita diharuskan menggunakan pelindung mata, sebab cahaya Matahari dapat merusak Retina kita jika kita melihatnya secara langsung tanpa perlindungan. Fenomena transit Venus ini juga bisa disebut sebagai Gerhana Venus. (Adi Saputro/ astronomi.us)
Seperti Gerhana Matahari, untuk melihat transit Venus ini kita diharuskan menggunakan pelindung mata, sebab cahaya Matahari dapat merusak Retina kita jika kita melihatnya secara langsung tanpa perlindungan. Fenomena transit Venus ini juga bisa disebut sebagai Gerhana Venus. (Adi Saputro/ astronomi.us)
http://www.astronomi.us/2012/06/6-juni-2012-transit-venus-gerhana-venus.html
Senin, 04 Juni 2012
Northern Lights Process Like Untangling Twisted Strands of Spaghetti?
ScienceDaily (June 1, 2012) — A University of Iowa researcher wants you to visualize a plate of spaghetti when you think of the northern lights.
Diffuse gas—called plasma—flows outward from the sun as the “solar
wind” and carries with it solar magnetic field lines that become
entangled with the Earth's own magnetic field lines. Location of "holes"
were detected in indicated pink layers, near Earth. (Credit: Image
courtesy of NASA.)
That's because Jack Scudder, UI professor of physics and astronomy,
and his colleagues have reached a milestone in describing how the
northern lights work by way of a process called "magnetic reconnection."
The details are contained in a paper published in the June 5 issue of the journal Physical Review Letters; however, the process is best imagined as untangling twisted strands of spaghetti.
Diffuse gas -- called plasma -- flows outward from the sun as the
"solar wind" and carries with it magnetic field lines ("spaghetti") from
the sun.
The entanglement between magnetic field lines (spaghetti) from the
sun and other field lines (spaghetti) anchored in Earth's core occurs
when these field lines are brought together by gusts of solar wind.
"In the process of smoothing this entanglement, one or more holes are
created that now link field lines, with one originating in the sun and
the other in the Earth's metallic core," says Scudder. "This linkage
allows charged particles to cross a previously forbidden boundary that
separates the Earth's volume from the sun's. The formation of these
inter-connections represents a stress reduction. The aurorae are a
byproduct of this change in how the strands of spaghetti are connected,
since with the hole, charged particles from the sun are now allowed
access into the atmosphere below the Earth's magnetic shield."
One result is the beautiful colors of the northern lights. "Most
effects of solar weather that have an earthly influence gain entrance
through holes of this type that are in place when a solar disturbance
hits," Scudder says. "In this sense the sites of reconnection are the
'keyholes' for the intrusion of solar weather into near Earth space.
"After more than 30 years of research, my colleagues and I have
announced a milestone discovery in astrophysics -- the first
experimentally resolved and unequivocal site of collision -- less
magnetic reconnection, in which magnetic field energy is converted into
energetic particles," Scudder says. "When this process occurs,
previously separated volumes of space become interconnected by magnetic
fields, providing new highways for the prompt interchange of high
temperature gases."
Because magnetic reconnection is thought to occur elsewhere in the
universe, Scudder and his colleagues are delighted to have observed
evidence of a hard-to-see hole.
In astronomical terms, the size of a hole is relatively small --
about 1 kilometer in diameter seen at a distance of 57,000 kilometers
from Earth. If magnetic reconnection were occurring on the surface of
the sun, at another star, or at a planet in another solar system,
scientists would never be able to see it, Scudder says. Consequently,
Scudder's work is all the more important because it serves to "bench
test," or prove, an astrophysical process that humankind will never be
able to directly corroborate in deep space.
In addition to being small, the hole Scudder observed was in constant motion.
Because the hole was in an unknown state of motion relative to the
spacecraft, it could have been traversed many times previously without
having been detected. To correct for this situation, researchers
developed new techniques to reduce the time interval between "snapshots"
by a factor of 11 using the same detector and without flying a new
detector.
"This 'trick' is like having access to a microscope for the first
time to re-examine data that was thought to have been acquired too
slowly to find these holes. Resolving these holes in magnetic fields is
somewhat similar to looking at stagnant water through a microscope for
the first time and seeing the writhing molecular behavior that was only
suspected previously," he says.
Scudder and his colleagues were able to observe the magnetic
reconnection site in space by using data from NASA's Polar spacecraft
and its Hydra, MFE and EFI experiments. Scudder says the process he
observed is active not just in creating the northern lights, but many
other astronomical phenomena as well.
"The experimental documentation of the physical process that enables
this phenomenon provides the first support of the prevailing theories
for explaining the production of solar flares, x-rays from black holes,
as well as the causes of the aurorae that brilliantly light up the polar
skies," he says.
The manner in which Scudder and his associates made the landmark
observation involved five different comparisons across three independent
detectors to reinforce the detection, similar to the teamwork involved
in professional sports.
As part of NASA's Polar/Hydra program at the UI, data from three
separate experiments were shown to reproduce the extreme signatures
predicted by computer models of the process. These signatures were so
unusual that nothing approaching their extremes had been recorded in 50
years of space research. Using the largest computer resources at NASA,
the National Science Foundation, and the U.S. Department of Energy, the
reference computer models solved six trillion equations of motion in
order to predict the observations for the three experiments.
By showing scientists what combinations of observations can help
identify these regions, Scudder's work will save time and energy for
researchers preparing to explore magnetic reconnection in detail by
using NASA's Magnetospheric Multi-Scale (MMS) mission set for launch in
2014.
Scudder's collaborators and co-authors include UI graduate students
R.D. Holdaway and J.Y. Lopez. His other colleagues are H. Karimabadi and
V. Roytershteyn of the University of California, San Diego; W.S.
Daughton of the Los Alamos National Laboratory, N.M.; and C.T. Russell
of UCLA.
The UI Department of Physics and Astronomy is part of the College of Liberal Arts and Sciences.
The research was funded in part by grants from NASA, the National Science Foundation, and the U.S. Department of Energy.
Journal Reference:
- J. D. Scudder, R. D. Holdaway, W. S. Daughton, H. Karimabadi, V. Roytershteyn, C. T. Russell, and J. Y. Lopez. First Resolved Observations of the Demagnetized Electron-Diffusion Region of an Astrophysical Magnetic-Reconnection Site. Phys. Rev. Lett., June 1, 2012 DOI: 10.1103/PhysRevLett.108.225005
Expanding the Genetic Alphabet May Be Easier Than Previously Thought
ScienceDaily — A
new study led by scientists at The Scripps Research Institute suggests
that the replication process for DNA -- the genetic instructions for
living organisms that is composed of four bases (C, G, A and T) -- is
more open to unnatural letters than had previously been thought. An
expanded "DNA alphabet" could carry more information than natural DNA,
potentially coding for a much wider range of molecules and enabling a
variety of powerful applications, from precise molecular probes and
nanomachines to useful new life forms.
A new study led by scientists at The Scripps Research Institute
suggests that the replication process for DNA -- the genetic
instructions for living organisms that is composed of four bases (C, G, A
and T) -- is more open to unnatural letters than had previously been
thought. (Credit: © Dmitry Sunagatov / Fotolia)
The new study, which appears in the June 3, 2012 issue of Nature Chemical Biology,
solves the mystery of how a previously identified pair of artificial
DNA bases can go through the DNA replication process almost as
efficiently as the four natural bases.
"We now know that the efficient replication of our unnatural base
pair isn't a fluke, and also that the replication process is more
flexible than had been assumed," said Floyd E. Romesberg, associate
professor at Scripps Research, principal developer of the new DNA bases,
and a senior author of the new study. The Romesberg laboratory
collaborated on the new study with the laboratory of co-senior author
Andreas Marx at the University of Konstanz in Germany, and the
laboratory of Tammy J. Dwyer at the University of San Diego.
Adding to the DNA Alphabet
Romesberg and his lab have been trying to find a way to extend the
DNA alphabet since the late 1990s. In 2008, they developed the
efficiently replicating bases NaM and 5SICS, which come together as a
complementary base pair within the DNA helix, much as, in normal DNA,
the base adenine (A) pairs with thymine (T), and cytosine (C) pairs with
guanine (G).
The following year, Romesberg and colleagues showed that NaM and
5SICS could be efficiently transcribed into RNA in the lab dish. But
these bases' success in mimicking the functionality of natural bases was
a bit mysterious. They had been found simply by screening thousands of
synthetic nucleotide-like molecules for the ones that were replicated
most efficiently. And it had been clear immediately that their chemical
structures lack the ability to form the hydrogen bonds that join natural
base pairs in DNA. Such bonds had been thought to be an absolute
requirement for successful DNA replication‑ -- a process in which a
large enzyme, DNA polymerase, moves along a single, unwrapped DNA strand
and stitches together the opposing strand, one complementary base at a
time.
An early structural study of a very similar base pair in double-helix
DNA added to Romesberg's concerns. The data strongly suggested that NaM
and 5SICS do not even approximate the edge-to-edge geometry of natural
base pairs -- termed the Watson-Crick geometry, after the co-discoverers
of the DNA double-helix. Instead, they join in a looser, overlapping,
"intercalated" fashion. "Their pairing resembles a 'mispair,' such as
two identical bases together, which normally wouldn't be recognized as a
valid base pair by the DNA polymerase," said Denis Malyshev, a graduate
student in Romesberg's lab who was lead author along with Karin Betz of
Marx's lab.
Yet in test after test, the NaM-5SICS pair was efficiently
replicable."We wondered whether we were somehow tricking the DNA
polymerase into recognizing it," said Romesberg. "I didn't want to
pursue the development of applications until we had a clearer picture of
what was going on during replication."
Edge to Edge
To get that clearer picture, Romesberg and his lab turned to Dwyer's
and Marx's laboratories, which have expertise in finding the atomic
structures of DNA in complex with DNA polymerase. Their structural data
showed plainly that the NaM-5SICS pair maintain an abnormal,
intercalated structure within double-helix DNA -- but remarkably adopt
the normal, edge-to-edge, "Watson-Crick" positioning when gripped by the
polymerase during the crucial moments of DNA replication.
"The DNA polymerase apparently induces this unnatural base pair to
form a structure that's virtually indistinguishable from that of a
natural base pair," said Malyshev.
NaM and 5SICS, lacking hydrogen bonds, are held together in the DNA
double-helix by "hydrophobic" forces, which cause certain molecular
structures (like those found in oil) to be repelled by water molecules,
and thus to cling together in a watery medium. "It's very possible that
these hydrophobic forces have characteristics that enable the
flexibility and thus the replicability of the NaM-5SICS base pair," said
Romesberg. "Certainly if their aberrant structure in the double helix
were held together by more rigid covalent bonds, they wouldn't have been
able to pop into the correct structure during DNA replication."
An Arbitrary Choice?
The finding suggests that NaM-5SICS and potentially other,
hydrophobically bound base pairs could some day be used to extend the
DNA alphabet. It also hints that Evolution's choice of the existing
four-letter DNA alphabet -- on this planet -- may have been somewhat
arbitrary. "It seems that life could have been based on many other
genetic systems," said Romesberg.
He and his laboratory colleagues are now trying to optimize the basic
functionality of NaM and 5SICS, and to show that these new bases can
work alongside natural bases in the DNA of a living cell.
"If we can get this new base pair to replicate with high efficiency and fidelity in vivo, we'll have a semi-synthetic organism," Romesberg said. "The things that one could do with that are pretty mind blowing."
The other contributors to the paper, "KlenTaq polymerase replicates
unnatural base pairs by inducing a Watson-Crick geometry," are Thomas
Lavergne of the Romesberg lab, Wolfram Welte and Kay Diederichs of the
Marx lab, and Phillip Ordoukhanian of the Center for Protein and Nucleic
Acid Research at The Scripps Research Institute.
The study was supported in part by a grant from the National Institutes of Health.
Journal Reference:
- Karin Betz, Denis A Malyshev, Thomas Lavergne, Wolfram Welte, Kay Diederichs, Tammy J Dwyer, Phillip Ordoukhanian, Floyd E Romesberg & Andreas Marx. KlenTaq polymerase replicates unnatural base pairs by inducing a Watson-Crick geometry. Nature Chemical Biology, 03 June 2012 DOI: 10.1038/nchembio.966
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