Jadwal Mid Semester

MID SEMESTER SCHEDULE

IMMANUEL BILINGUAL CLASS

ODD SEMESTER, SCHOOL YEAR 2016-2017

Date / Day	Subject	Time
Monday, 26 Sept 2016	Science	06.40 – 08.40
Monday, 26 Sept 2016	Agama	09.00 - 10.30
Tuesday, 27 Sept 2016	English	06.40 - 08.40
Tuesday, 27 Sept 2016	IPS	09.00 - 10.30
Wednesday, 28 Sept 2016	Math	06.40 - 08.40
Wednesday, 28 Sept 2016	Mandarin	09.00 - 10.30
Thursday, 29 Sept 2016	BI	06.40 - 08.40
Thursday, 29 Sept 2016	PKN	09.00 - 10.30

         Teknologi hologram tak terlepas dari peran Denis Gabor, Fisikawan asal Hungaria yang lahir pada tahun 1900. Gabor memulai pendidikannya di bidang fisika saat umur 15 tahun kemudian menjadi seorang ilmuan di Inggris. Gabor membuat sebuah penelitian yang kemudian menjadi pondasi holography modern. Gabor menemukan teknologi hologram secara tak sengaja ketika bekerja di perusahaan British Thomson Houston. Saat itu, Gabor sedang meneliti bagaimana memperbaiki mikroskop elektron. Gambar hologram statis tiga dimensi pertama kali diproduksi pada tahun 1960-an setelah sinar laser ditemukan. Hasil penelitian Gabor yang kreatif dan inovatif membuat dirinya menjadi salah satu penemu terkemuda di abad ke-20 dan meraih Penghargaan Nobel di bidang Fisika pada tahun 1971. 

1.    Pengertian Hologram

Hologram adalah produk dari teknologi holografi. Hologram terbentuk dari perpaduan dua sinar cahaya yang koheren serta dalam bentuk mikroskopik. Hologram bertindak sebagai gudang informasi optik. Informasi-informasi optik itu kemudain akan membentuk suatu gambar, pemandangan, atau adegan. Hoilogram merupkaan jelmaan dari gudang informasi (information storage) yang mutakhir. Kelebihan hologram ialah ia mampu menyimpan infomrmasi, yang di dalamnya memuat objek-objek 3 dimensi (3D). Tidak hanya objek-objek yang biasa terdapat di foto atau gambar pada umumnya. Seperti yang ada pada skema pemandangan yang sebenarnya. Hologram dari suatu objek yang tersebar dapat direkonstruksi dari bagian kecil keseluruhan gambar. Walaupun, penyusutan dari ukuran hologram, dapat menyebabkan penurunan perspektif dari gambar, resolusi, dan tingkat kecerahan dari gambar.

DIffusion and Osmosis In Our Daily Life

Continuing from my previous post, now it is the diffusion and osmosis in our daily life. Diffusion can be found everywhere in our daily life. For example, in the respiratory system, when we inhale oxygen it enters the nose and into the trachea, bronchi, bronchioles, and end up in the alveoli where the exchange of oxygen and carbon dioxide occurs. The oxygen is needs to be transferred to the blood stream, this is where diffusion happens. When we inhale, the alveoli will have more oxygen than the blood stream meaning that the alveoli has a higher concentration of oxygen than the blood stream so diffusion occurs and transfer the oxygen from the alveoli to the blood stream. This is one of the important roles of diffusion.

Another example is in the taking in of carbon dioxide and releasing oxygen in plants. First, the air will certainly have more carbon dioxide than what the leaves have, causing the air to have a higher concentration of carbon dioxide than the plants. In this occasion diffusion occurs from the air to the plants. Then through the process of photosynthesis plants produce starch and oxygen. When plants produce oxygen, they will have a higher concentration of oxygen than the air causing diffusion to happen again. Diffusion plays an important role because without diffusion carbon dioxide can’t enter the plants and photosynthesis will not happen which will also impact every other living things because there will be too much carbon dioxide and too little oxygen.

Diffusion and Osmosis

Diffusion is the movement of particles through a concentration gradient from a high concentration to a low concentration. Diffusion is a passive process which means it doesn't need energy. Diffusion can happen in liquid and gas but not in solid because the particles in solid materials are tightly packed together. Diffusion in gas happens all the time in our daily life for example there is a sock 1 meter away from us but we can smell the socks, this happens because of diffusion.

Diffusion also happens in liquid, to prove that we have conducted an experiment. First, we prepared a container with water and food dye. We put in several drops of food dye and in a few minutes without mixing it the food dye becomes evenly spread out meaning diffusion happened. In this experiment, first the spot where we drop food dye has a high concentration than the other spots without food dye because of the difference of concentration the particles of the food dye will move and diffusion happens.

The next topic we are going to discuss is osmosis. Osmosis is a special case of diffusion where water moves from a high concentration to a low concentration through a permeable membrane. Osmosis is a special case of diffusion meaning that it is also a passive process which doesn't need energy. To understand more about this concept we have conducted an experiment. First, we prepared two eggs and put it in two containers. Next, we need to expose the permeable membrane by putting it in vinegar for 3 days.

Like the picture, the eggs will become like a rubbery egg and it will change in color and increase in size. After doing this, we put the egg into a hypertonic solution and a hypotonic solution. A hypertonic solution is a solution that has more solute than water molecules while a hypotonic solution is a solution with more water molecules than solute. In this experiment, we use syrup as the hypertonic solution and we use water for the hypotonic solution then we leave it for around 8 hours. The result is that the egg in the hypertonic solution shrink in size while the egg in the hypotonic solution increase in size. 

This proves that osmosis happens. When we put it in a hypotonic solution, where there are more water molecules than solute meaning that the water concentration in the solution is higher than the water concentration of the egg. So, the water will move from the solution to the egg making the egg increase in size. The opposite happens when the egg is put into a hypertonic solution, the egg has a higher water concentration than the solution so the water leaves the egg causing it to shrink. 

With these two experiments, we have proven diffusion and osmosis and how the molecules move. Hope this is useful and to know more about the importance of osmosis and diffusion, wait for my next post. Thank you for reading.