Tumor meningitides. The symptoms associated with this disease


 Tumor necrosis factor (TNF) is a cell signaling protein (cytokine) involved in systemic inflammation and is one of the cytokines that make up the acute phase reaction. The primary role of TNF is in the regulation of immune cells. TNF, being an endogenous pyrogen, is able to induce fever, apoptotic cell death, cachexia, inflammation and to inhibit tumorigenesis and viral replication and respond to sepsis via IL1 & IL6 producing cells.    Tumor necrosis factor can also be made in the laboratory. It may boost a person’s immune response, and also may cause necrosis (cell death) of some types of tumor cells. Tumor necrosis factor is being studied in the treatment of some types of cancer. It is a type of cytokine. Also called TNF.


The Start Codon of this protein is 176 (ATG) and the Stop Codon of the protein is 875 (TGA)


Tumor Necrosis Factor is 233 amino acids long



Tumor Necrosis Factor protein

7. MSTE drawing


Tumor Necrosis Factor is associates with the disease, Bacterial Toxic shock. This disease occurs within a few hours after infection by certain gram-negative bacteria including E. coli, P, aeruginosa and N. meningitides. The symptoms associated with this disease are decrease in blood pressure, fever, diarrhea and blood clotting in various organs. These are all results of an overproduction of TNF. Monoclonal antibodies to TNF may provide an effective treatment to this disease by binding the free TNF.

Toxic Shock syndrome is a rare but serious medical condition caused by a bacterial infection. It is caused when the bacterium Staphylococcus aureus gets into the bloodstream and produces toxins. Even though Toxic Shock syndrome is linked to superabsorbent tampon use in menstruating women, this condition can also affect men, children, and people of all ages. 

Some symptoms of Toxic Shock syndrome can vary from person to person. In most cases, symptoms appear suddenly. Common signs of this condition include: Sudden fever, low blood pressure, headache, muscle aches, confusion, diarrhea, nausea, vomiting, rash, redness of eyes, mouth and throat and seizures.

Usually when infection occurs, it is because bacteria enters your body through an opening in your skin, such as a cut, sore, or other wound. Experts are not sure why tampon use sometimes leads to Bacterial Toxic Shock syndrome. Some people believe that a tampon left in place for a long period of time attracts bacteria. Another possibility is that tampon fibers scratch the vagina, creating an opening for bacteria to enter your bloodstream.

Toxic shock syndrome is a medical emergency. Some people with the condition have to stay in the intense care unit for several days so that medical staff can closely monitor them. Your doctor will most likely recommend an intravenous (IV) antibiotic to help you fight the bacterial infection in your body. This will require the placement of a special IV line called a peripherally inserted intravenous catheter, or PICC line. You will receive 6–8 weeks of antibiotics at home. If this is the case, an infectious disease doctor will closely monitor you. 

Sometimes, depending on the underlying cause, other treatment methods for Toxic Shock syndrome are necessary. For example, a doctor may need to remove a foreign object from your body if it has triggered a Toxic Shock. These foreign objects can include a vaginal sponge or tampon. If an open wound or surgical wound caused your toxic shock syndrome, the doctor will drain pus or blood form the   wound to help clear up an infection.

Other possible treatments that may be necessary include medication to stabilize blood pressure, IV fluids to fight Dehydration and gamma globulin injections to suppress inflammation and boost your body’s immune system


The following is current research from http://europepmc.org/abstract/med/7339069 on TNF. Tumor Necrosis factor (TNF) is an active element of serum taken from Corynebacterium parvum (C. parvum) infected mice dealt with with lipopolysaccharide (LPS). To discover the production site of TNF, we tried to block TNF manufacturing by the use of the following reagents; carrageenan, hydrocortisone, and trypan blue. Following the injection of a massive dose of carrageenan, administered before C. parvum treatment, TNF production became completely blocked. However, when administered after C. parvum treatment but prior to LPS injection, no blockage became found. Injecting hydrocortisone before the LPS injection also blocked TNF launch. , this treatment, while administered before the injection of C. parvum, had no observable impact on TNF manufacturing. A large dose of trypan blue, administered before the LPS injection, additionally blocked the discharge of TNF. A low dose of trypan blue ended in only partial blockage of TNF production. A large dose of trypan blue, administered prior to C. parvum treatment, also showed partial blockage of TNF production. Macrophage-enriched peritoneal exudate cells (p.c), taken from mice infected with C. parvum, launched TNF into the supernatant after stimulation with LPS. these effects strongly propose that the production site of TNF is located inside the activated macrophage and deeply associated with lysosome.

6 Fred Armisen, Adam Scott, Sarah Silverman, and

6 Best Romantic Netflix Releases in 2017By Alisha Johari, 28-01-2018Are you a Netflix addict like me? The streaming service has certainly brought a revolution changing the way TV shows and movies are made! Be it top Hollywood releases or English movies, everything is available with the entertainment company. Apart from the best and top of Hollywood movies, it releases some Netflix originals as well which one can watch by signing in onto their website or simply download the app. It has been growing exponentially ever since its inception. From comedy to romance, horror, drama, animation, and sci-fi, Netflix had made sure to cover it all. Today in case you’re up for some romance, we have provided with a list of best romantic releases on Netflix:1. Michael Bolton’s Big, Sexy Valentine’s Day SpecialTo acquaint you with the plot: Santa tells the undisputed King of Valentine’s Day Michael Bolton that he needs 75,000 new babies by Christmas to meet toy supply. Henceforth, to fulfill this noble cause, Michael hosts a sexy telethon to plead the world to start making love. The 54-minutes long rom-com features Fred Armisen, Adam Scott, Sarah Silverman, and Maya Rudolph. It is directed by Akiva Schaffer (of The Lonely Island fame) and Scott Aukerman (Comedy Bang! Bang).This one turns out to be a new, wild, sexy and bizarre.  Img Src: Pinterest2. Under the Tuscan SunDiane Lane plays a recently divorced woman who takes a vacation to Tuscany. Hold your breath and dive in those incredible picturesque shots of the Italian countryside and follow her character’s entertaining quest to find love. The 1 hour 52 minutes romantic comedy is directed by Audrey Wells. Are you up for it?  3. BrooklynIf you are a romantic streamer, then surely this romantic drama will steal your heart right away. It is an Oscar-nominated and BAFTA award-winning directed by John Crowley. What is it about? An Irish immigrant landing in 1950s Brooklyn and falling in love with a local. When her past shows up, she must choose between two countries and the lives that exist within.  Img Src: Netflix4. Before MidnightIf you look a little harder, you’ll find interesting and engaging rom-com on Netflix than Hollywood. The third movie in a trilogy that began with 1995’s Before Sunrise and continued with 2004’s Before Sunset, Before Midnight revisits the same couple—Jesse and Céline, played by Ethan Hawke and Julie Delpy. The movies work best in tandem, and each one holds its own self-contained narrative with this one being the strongest of all. Go watch it if you haven’t already. Img Src: Pinterest5. Sleeping with Other PeopleStarring Alison Brie and Jason Sudeikis as Lainey and Jake, the movie features two teens that lost their virginities to each other during a one-night stand in college. A decade later, they bump into each other in New York and decide to renew their friendship. It effectively captures the male-female friendship between two independent people. Neither of them is hung up on the fact that they hooked up back in college. Sounds interesting! Img Src: Pinterest6. Beautiful CreaturesThis one is based on the first of a four-book YA series by Kami Garcia and Margaret Stohl. It tells you the story of two South Carolina teens: Ethan played by Alden Ehrenreich who falls for the enigmatic Lena Duchannes played by Alice Englert, who turns out to be the scion of a family of witches. Later when the story unfolds we get to know that there’s a lot of business about good witches and dark witches and how good witches go bad because of a curse. If you are looking for audacity, fun, humor, and charm then this one is one of the best Netflix releases. The phenomenal cast deserves applause for their outstanding performances. Which one you’ve seen already or are planning to watch? Do let us know your views and opinions in the comment section below. For latest Hollywood films and Hollywood updates keep following us!(Note: Numerous Netflix titles drop off the streaming service monthly so the availability of titles may change)Keywords included:-Hollywood releases, list of Hollywood films, English movies, best Hollywood movies, top Hollywood movies, best Netflix releases, list of best romantic releases, Hollywood, Hollywood updates, latest Hollywood films.

1. lama sesudah itu, cahaya juga diidentifikasi sebagai


tahun 1870 Maxwell mengusulkan landasan teori mengenai listrik dan magnet. Teori tersebut terdiri atas 4 persamaan
fundamental yang merangkum semua pengetahuan tentang listrik dan magnet pada
saat itu. Persamaan-persamaan tersebut adalah





Dalam perangkat
persamaan-persamaan diatas,


 merepresentasikan dua besaran pokok listrik
dan magnet, yaitu kuat medan listrik

 dan induksi magnetik



 mempresentasikan sumber medan-medan tersebut,
yaitu muatan listrik ruang

 dan rapat arus listrik


Sumbangan besar
Maxwell pada pengetahuan listrik dan magnet adalah keberhasilannya dalam
menyatukan semua kaidah yang dikenal di bidang listrik dan magnet pada saat itu.
Hal itu dicapainya dengan merumuskan apa yang telah dirumuskan oleh Faraday
(1791-1867). Berdasarkan seperangkat persamaan fundamental tersebut, Maxwell memperoleh
suatu solusi yang berupa persamaan gelombang. Berdasarkan hal tersebut maka
muncul ramalan tentang adanya gelombang elektromagnetik, sesuatu yang belum
teramati oleh para ilmuwan pada saat itu.

Heinrich Hertz
(1857-1894) menyelidiki implikasi eksperimental dari persamaan-persamaan
Maxwell. Sebagai guru besar pada sekolah tinggi teknik di Karlsruhe, Hertz
melaksanakan percobaan-percobaan yang pada akhirnya menunjukkan adanya
gelombang elektromagnetik.   Tidak lama
sesudah itu, cahaya juga diidentifikasi sebagai gelombang elektromagnetik.
Sifat gelombang cahaya didukung oleh bukti-bukti eksperimental, seperti persamaan
Young dan difraksi. Bukti-bukti ini telah lama diperoleh sebelum tahun 1871.

Meskipun sifat
gelombangnya telah mantap di sekitar abad ke-19, ada beberapa percobaan tentang
cahaya dan listrik yang sulit dijelaskan dengan sifat gelombang dari cahaya itu
sendiri. Pada tahun 1888, Hallwachs mengamati bahwa suatu keping logam Zn akan
kehilangan muatan listrik negatifnya bila disinari dengan cahaya ultraviolet.
Akan tetapi apabila muatan keping itu mula-mula positif, maka keping tidak
mengalami kehilangan muatan.  Ditemukan
pula bahwa suatu keping yang netral akan memperoleh muatan positif apabila
disinari. Kesimpulan yang ditarik dari pengamatan-pengamatan diatas adalah
bahwa cahaya ultraviolet mendesak keluar muatan listrik negatif dari permukaan
keping logam yang netral. Gejala ini dinamakan efek fotolistrik.

Pada Gambar 2.1
dibawah ini digambarkan alat untuk mempelajari efek fotolistrik. Alat tersebut
terdiri atas tabung hampa udara yang dilengkapi dengan dua elektroda


dihubungkan dengan sumber tegangan arus searah (DC). Pada saat alat tersebut
dibawa ke dalam ruang gelap, maka amperemeter tidak menunjukkan adanya arus
listrik. Akan tetapi pada saat permukaan target

 (Katoda) disinari maka amperemeter menunjukkan
adanya arus listrik. Hal ini menunjukkan adanya aliran arus listrik. Aliran
arus ini terjadi karena adanya elektron yang terlepas dari permukaan

 bergerak menuju kolektor

 (yang selanjutnya disebut elektron foto).
Apabila tegangan baterai diperkecil sedikit demi sedikit, ternyata arus listrik
juga semakin mengecil dan jika tegangan terus diperkecil sampai nilainya
negatif, ternyata pada saat tegangan mencapai nilai tertentu (

amperemeter menunjuk angka nol yang berarti tidak ada arus listrik yang mengalir
atau tidak ada elektron yang keluar dari keping


 ini disebut sebagai potensial henti, yang
nilainya tidak tergantung pada intensitas cahaya menyinari.

Beberapa hasil pengamatan
mengenai efek fotolistrik adalah sebagai berikut:

kinetik elektron tidak bergantung pada intensitas cahaya. Energi kinetik dapat
diukur secara eksperimen melalui hubungan


dibuat grafik besar potensial henti sebagai fungsi dari frekuensi cahaya yang
digunakan untuk menyinari permukaan katoda, maka diperoleh suatu garis lurus. Hal
ini menunjukkan bahwa untuk setiap macam bahan katoda, terdapat suatu harga

tertentu (frekuensi ambang),
dimana bila digunakan frekuensi cahaya di bawah harga tersebut maka efek fotolistrik
tidak lagi terjadi (pengamatan Millikan di tahun 1914 dan mendapat hadiah nobel
di tahun 1923).


Fundamental of Physics Halliday & Resnick 10th Ed., 2014

Gambar 2.1 Efek Foto Listrik

pengamatan itu secara grafik dicantumkan pada Gambar 2.2. Kedua sketsa tersebut
sangat penting karena mendukung perumusan pengertian mengenai paket energi
cahaya atau dikenal dengan sebutan foton. Pada Gambar 2.2a, diketahui bahwa

 tidak bergantung pada intensitas cahaya yang digunakan,
yang berarti energi kinetik elektron yang mengalir juga tidak dipengaruhi oleh
intensitas cahaya. Penggunaan intensitas cahaya yang lebih besar hanya akan
memperbesar kuat arus yang dihasilkan, yang menandakan semakin banyak elektron
yang mengalir. Dari grafik pada Gambar 2.2b, diperoleh kesimpulan bahwa ketika
frekuensi yang digunakan adalah

 (frekuensi ambang), maka dihasilkan
energi kinetik minimum (nol) dari elektron. Energi kinetik elektron akan
bertambah jika frekuensi yang digunakan lebih besar dari

ada efek fotolistrik yang teramati jika frekuensi yang digunakan lebih kecil

. Grafik eksperimental yang
diperoleh oleh Millikan untuk katoda dengan permukaan natrium, frekuensi
potongnya adalah sekitar 4,39×1014


Terdapat dua
fakta eksperimental yang ternyata tidak dapat diterangkan dengan menggunakan
teori gelombang cahaya, yaitu:


 yang besarnya ditentukan melalui pengukuran

 , tidak bergantung dari intensitas cahaya. Menurut
teori gelombang, vektor medan listrik

 dari gelombang cahaya yang dipergunakan akan
bertambah besar apabila intensitas ditingkatkan. Oleh sebab itu, gaya

 pada elektron juga bertambah. Maka menurut
teori gelombang, energi kinetik

 juga bertambah apabila intensitas
ditingkatkan. Secara eksperimen hal itu tidak terpenuhi.

ada suatu frekuensi ambang

dimana pada semua frekuensi

 ternyata efek fotolistrik tidak terjadi meskipun
intensitas sinar yang dipergunakan tinggi. Menurut teori gelombang, efek
fotolistrik dapat terjadi untuk semua frekuensi asal intensitas cahaya cukup
besar untuk mendesak elektron keluar dari katoda.

menerangkan fakta eksperimental tentang efek fotolistrik dengan teori yang baru,
cahaya tidak dapat dianggap sebagai gelombang. Hal ini merupakan aspek utama
dari teori kuantum Einstein.  Dalam
postulatnya Planck mengkuantisasikan energi yang dapat dimiliki osilator,
tetapi tetap memandang radiasi termal dalam rongga sebagai gejala gelombang. Untuk
dapat menerangkan efek fotolistrik, Einstein meluaskan konsep kuantisasi Planck.
Einstein menggambarkan bahwa apabila suatu osilator dengan energi (

pindah ke suatu keadaan dengan energi

maka osilator tersebut memancarkan suatu paket energi elektromagnetik (foton).
Dimana h merupakan konstanta Planck.



Sumber: Modern Physics for Science and
Engineering, 2012.

Gambar 2.2 (a) Grafik kuat arus
terhadap frekuensi pada intensitas cahaya yang berbeda. (b) Grafik potensial
henti terhadap frekuensi


 Terdapat beberapa karakteristik dari foton
dalam proses fotolistrik menurut Einstein, yaitu:

saat meninggalkan permukaan dinding rongga, foton tidak meluas dalam ruang
seperti gelombang, melainkan tetap terpusat (terkonsentrasi) dalam suatu volume
yang sangat kecil.

merambat dengan kecepatan


energi tersebut terkait dengan frekuensi dari gelombang cahaya sesuai dengan


proses fotolistrik, sebuah foton secara keseluruhan diserap oleh elektron yang
ada di permukaan logam.

Dari penjelasan di atas, jelas
sekali bahwa di sini konsep gelombang tidak dipergunakan.

Teori kuantum
Einstein digunakan untuk menjelaskan gejala fotolistrik. Hukum kekekalan energi
apabila dipergunakan dalam proses fotolistrik, akan menghasilkan hubungan
sebagai berikut


elektromagnetik dalam bentuk foton

 mengenai permukaan katoda dan kemudian diserap
oleh elektron yang berada pada permukaan katoda tersebut. Seluruh energi foton
diserap oleh satu buah elektron, apabila energi yang terserap

 cukup besar maka elektron akan mampu untuk
meninggalkan permukaan katoda. Dalam usaha ini diperlukan energi untuk
mengatasi gaya-gaya di permukaan katoda sebesar

Selisih antara energi yang diserap

 dan energi yang diperlukan untuk mengatasi
gaya permukaan

akan menjadi energi kinetik elektron

seperti yang ditunjukkan oleh Persamaan (2.6).

 adalah energi yang diperlukan elektron untuk
melawan gaya tarik oleh ion-ion logam di permukaan dan energi kinetik yang
hilang karena tumbukan-tumbukan elektron tersebut dalam logam. Apabila gaya
tarik-menarik tersebut minimum dan juga tidak ada energi kinetik yang hilang
karena tumbukan, maka

 dapat dituliskan menjadi


 adalah harga terendah untuk



 berharga minimum,

maka tentunya energi kinetik elektron akan berharga maksimum

. Hukum kekekalan energi akan memberikan


 disebut sebagai fungsi kerja bahan katoda yang
bersangkutan, harganya khas untuk setiap macam logam.


 secara eksperimental dapat diukur melalui
penentuan potensial henti

. Karena energi kinetik dapat
dituliskan seperti pada Persamaan (2.5), maka



Terlihat adanya hubungan
yang linier antara


seperti yang secara eksperimental diperoleh oleh Millikan. Dengan demikian
dapat diterangkan kenapa

  tidak bergantung pada intensitas sinar.


artinya elektron meninggalkan permukaan logam dengan energi kinetik sama dengan
nol, maka

dan oleh karena itu


ungkapan diatas

 adalah frekuensi cahaya minimal yang masih
dapat mendesak elektron keluar dari permukaan logam, tetapi elektron yang terlepas
itu tidak memiliki energi kinetik (


 dapat diketahui secara pasti. Apabila
datang foton dengan frekuensi dimana

 maka foton tersebut tidak lagi mampu untuk
mendesak elektron keluar dari permukaan logam. Ketika

 maka hal ini berarti


 merupakan frekuensi ambang. Bagaimanapun
besarnya intensitas cahaya, cahaya tidak akan mampu melepaskan elektron dari
katoda jika frekuensi cahaya tersebut lebih kecil dari

Teori kuantum Einstein dapat memberi penjelasan yang memadai tentang efek
fotolistrik. Frekuensi ambang

 tidak dapat dijelaskan dengan teori gelombang.

Contoh 2.1

Emiter dalam sebuah tabung
fotolistrik memiliki panjang gelombang ambang 6000 ?. Tentukan panjang
gelombang cahaya yang datang pada tabung jika tegangan  henti cahaya ini 2,5 V.
Fungsi kerja adalah

Persamaan fotolistrik memberikan




Contoh 2.2

Kalium disinari dengan cahaya
ultraviolet dengan panjang gelombang 2500 Å. Jika fungsi kerja dari kalium
adalah 2,21 eV, berapakah energi kinetik maksimum dari elektron yang
Persamaan fotolistrik memberikan


2.    EFEK

 Dalam teori kuantum cahaya dianggap bahwa perjalanan
foton dalam ruang (dianggap dengan kecepatan

tidak menyebar sebagaimana halnya dengan gelombang, tetapi tetap terkonsentrasi
dalam bagian yang sangat kecil dalam ruang.

Pada tahun
1923, Compton memberikan kesimpulannya mengenai hamburan sinar-X oleh materi. Dalam
naskah ilmiahnya, “A Quantum Theory of the
Scattering of X-Ray Light Elements”, Compton menerangkan percobaannya
tentang hamburan sinar–X. Diamatinya bahwa panjang gelombang sinar–X yang
terhambur berbeda dengan panjang gelombang sinar–X sebelum hamburan, perubahan
panjang gelombang tersebut ternyata juga tergantung dari sudut hamburan.

kesimpulannya, Compton menyebutkan bahwa teori yang dikembangkannya didasarkan
pada pengandaian bahwa setiap elektron yang berperan dalam proses hamburan
Compton, menghamburkan suatu kuantum cahaya yang utuh (foton). Teori ini juga
berlandaskan pada hipotesis yang menyatakan bahwa kuantum-kuantum cahaya datang
dari berbagai arah tertentu dan dihamburkan pula dalam arah-arah tertentu
(tidak acak). Hasil eksperimen yang dilakukan untuk menjelaskan teori tersebut menunjukkan
bahwa foton juga memiliki momentum linear. Kesimpulan tersebut memiliki dampak
yang besar, karena foton juga ditandai dengan suatu besaran fisika yang lain,
yaitu momentum linear.

Sketsa susunan
percobaan Compton dapat dilihat pada Gambar 2.3. Pada eksperimen sesungguhnya,
Compton mengukur ketergantungan intensitas hamburan sinar-X terhadap panjang
gelombang pada tiga sudut hambur yang berbeda, yaitu 45°, 90°, dan 135°.
Panjang gelombang diukur dengan sebuah spektrometer kristal yang berputar, dan
intensitas ditentukan melalui sebuah detektor. Sinar-X monokromatik dengan
panjang gelombang

 = 0,71 Å dijadikan sebagai berkas sinar masuk.
Target yang digunakan terbuat dari karbon yang memiliki nomor atom kecil,

 =12. Hal ini disebabkan karena atom-atom

 kecil memiliki elektron yang berikatan lemah
dengan persentase yang lebih besar.  Grafik
intensitas terhadap panjang gelombang hasil eksperimen oleh Compton dapat
dilihat pada Gambar 2.4. Terdapat dua puncak pada grafik tersebut, satu puncak

 dan pergeseran puncak pada panjang
gelombang yang lebih besar

Pergeseran puncak pada ?’ disebabkan
oleh hamburan sinar-X dari elektron-elektron yang hampir bebas.


Sumber: Modern Physics 3rd Ed.,

Diagram skematis percobaan Compton

Sinar-X yang
telah menumbuk elektron akan kehilangan sebagian energinya yang kemudian
terhambur dengan sudut hamburan sebesar

 terhadap arah semula. Berdasarkan hasil
pengamatan ternyata sinar-X yang terhambur memiliki panjang gelombang yang
lebih besar dari panjang gelombang sinar-X semula. Hal ini dikarenakan sebagian
energinya terserap oleh elektron. Jika energi foton sinar X mula-mula

 dan energi foton sinar-X yang terhambur

 dalam hal ini

sedangkan panjang gelombang yang terhambur menjadi tambah besar yaitu

Dengan mengasumsikan bahwa sinar-X berperilaku seperti partikel,

 diprediksi oleh Compton bergantung pada sudut.

Pada Gambar 2.4,
terlihat bahwa panjang gelombang baru setelah hamburan

 bergantung pada sudut hambur

Puncak yang tidak bergeser pada

 disebabkan oleh hamburan sinar-X dari elektron
yang terikat kuat dengan atom-atom karbon. 
Compton dapat menerangkan terjadinya pergeseran panjang gelombang dengan
menganggap bahwa berkas sinar-X terdiri dari foton-foton yang berperilaku
sebagai partikel. Bahwa foton-foton itu dalam tumbukannya dengan
elektron-elektron bahan penghambur mengikuti hukum-hukum mekanika.

Sumber: Modern
Physics 3rd Ed., 2005

Gambar 2.4 Intensitas sinar-X
terhambur terhadap panjang gelombang pada empat sudut berbeda

mengetahui momentum linier foton, digunakan teori kuantum Einstein yang
menyatakan bahwa energi foton E
bergantung dari frekuensi radiasi, yaitu


Sedangkan energi
relativistik total suatu partikel yang bergerak dengan kecepatan ? adalah



 adalah massa partikel apabila partikel tak
bergerak dan

 adalah kecepatan rambat cahaya. Karena
kecepatan foton adalah

dan energinya


 harus sama dengan nol, jadi foton harus
dianggap sebagai partikel dengan massa diam sama dengan nol.

Energinya hanya
energi kinetik saja, sehingga pernyataan umum energi total adalah


Untuk foton yang tidak
bermassa, persamaan di atas menjadi


Dari ungkapan itu diperoleh


Hubungan ini dipergunakan
untuk menelaah tumbukan antara foton dan elektron.

Misalkan sebuah foton sinar-X menumbuk suatu elektron
dari bahan penghambur. Karena energi foton sangat besar dibandingkan dengan
energi ikatan elektron dalam bahan, maka secara praktis elektron dapat dianggap
sebesar elektron bebas. Situasi awal situasi akhir diperlihatkan pada Gambar


Sumber: Pearson Physics,

2.5 Deskripsi
Hamburan Compton


Berdasarkan hukum
kekekalan momentum linier pada arah


dan pada arah



 adalah momentum akhir elektron dan

 adalah momentum akhir foton. Perkalian
Persamaan (2.15) dan (2.16) dengan

 masing-masing menghasilkan



Kuadrat dari persamaan
tersebut memberikan



Hasil penjumlahan kedua
persamaan di atas memberikan


Dengan menggunakan hukum
kekekalan energi, untuk elektron diketahui bahwa


Dengan menyamakan persamaan
di atas dengan Persamaan (2.12), maka diperoleh





maka diperoleh


Dengan mensubstitusikan
Persamaan (2.25) pada Persamaan (2.21), maka diperoleh


Hubungan ini akan kita
sederhanakan dalam panjang gelombang sebagai pengganti frekuensi dari persamaan
di atas maka





 adalah perubahan panjang gelombang sinar-X
karena hamburan. Besaran

  dinamakan sebagai panjang gelombang Compton,

Hasil yang telah dipresentasikan
dalam bentuk persamaan Compton, menyatakan bahwa perubahan panjang gelombang

 hanya bergantung dari sudut hamburan

 dan tidak dari panjang gelombang maupun
intensitas sinar-X.


Contoh 2.3

Tentukan fraksi perubahan
panjang gelombang sinar-X yang mula-mula memiliki panjang gelombang 0,400 Å
dan mengalami hamburan Compton pada sudut 90° dari sebuah
Persamaan hamburan Compton memberikan




Sebuah permukaan natrium disinari
oleh cahaya dengan panjang gelombang 0,300 nm. Fungsi kerja dari natrium adalah
2,46 eV. Tentukan

(a)  Energi
tiap foton dalam elektron volt.

(b)  Energi
kinetik maksimum dari elektron yang terlepas.

(c)  Panjang
gelombang cutoff dari natrium.

2.    Eksperimen memperlihatkan bahwa fungsi kerja
dari logam cesium adalah 2,10 eV. Tentukan frekuensi ambang dan panjang
gelombang foton yang mampu memproduksi emisi foto dari cesium.

3.    Jika energi maksimum yang diberikan pada
sebuah elektron dalam hamburan Compton adalah 45 keV, berapakah panjang
gelombang foton datang?

4.    Sebuah foton dengan panjang gelombang 0,0500
nm terhambur pada sudut 30°. Tentukan panjang gelombang foton terhambur.

5.    Dengan membandingkan hasil hamburan Compton
antara cahaya tampak dan sinar-X, jelaskan kenapa dalam eksperimen hamburan
Compton foton yang digunakan adalah foton sinar-X dan tidak menggunakan cahaya

Your this position. I would like to discuss

Your name:
Emily Davies-Miller
Address : 819 D Avenue National City, CA
Contact details : 310 980 1428
Email address : [email protected]



name : University of California, Los Angeles
Company’s name : UCLA
Address : Los Angeles, CA 90095



I am a clinical
psychologist with thirteen years of experience; I currently work at University
of California, San Diego as a Head Clinical Psychologist. I have enclosed my CV
for your attention.

Below are
my abilities and knowledge which I suspect you are seeking for this clinical
psychology position.

Have a widespread understanding
of the principles and the methods involved in the research and diagnosis
in this field.

Have treated several patients
who have mental disorders and other psychological issues.

I am aware
that clinical psychologists are sought out highly in our present-day society,
and the growth and integrity of health centers is important towards improving
the health care in our country. I believe my proficiencies and experience is
something you are seeking for this position.

I would
like to discuss this more and learn more about the listed position to prepare
myself for a future interview. You can call me at 310-980 1428 or email me at [email protected]

Thank you
so much for considering me as a potential candidate. 


Emily Davies-Miller

Enclosure: resume and work experience

Demand, the contrary. In the graphs shown below,

Demand, supply, and externalities are fundamental economic concepts that governments and individuals alike can apply to make informed decisions on what and what not to produce.In an article by The Guardian, a study shows that the demand for biofuels is increasing global food prices, with prices being the amount of money that must be paid to acquire a given product.Demand is a curve that displays the quantity of a good or service that consumers are willing to purchase at a given price in a specific time period. Supply is a curve that shows the amount of a good or service that producers are willing to supply to the market at a given price and at a specific time. Although, at first glance, it seems as if an increase in demand for biofuels resulting in an increase in food prices contradicts the law of demand, which states that as the demand of a good or service increases, its price decreases, it is quite the contrary. In the graphs shown below, the relationship between biofuels and food crops is depicted.As demand for biofuel increases due to government regulations (Bd1 to Bd2), the supply for biofuels (Bs1 to Bs2) also increases due to government policies, according to the article; “There has been a surge in the production of biofuels in Europe and the US since the early 2000s, backed by policies designed to cut use of fossil fuels, such as the first EU biofuel directive in 2003.” As a result of the biofuel market’s supply and demand both increasing, market equilibrium also increases. In this case, market equilibrium is the price at which demand and supply are equal, achieving maximum efficiency. According to the law of supply, which states that as the supply for a good or service increases, the price must increase as well, the supply of food crops will increase when the supply of biofuels increases. This is due to food crops being a capital good for biofuels, with a capital good being a good used for the production of another. Because it is necessary for food crops to be supplied in order to produce biofuels, it is only natural that the supply for food crops to increase as the supply for biofuels increases.Finally, in accordance with the law of supply, as the supply for these food crops increases, the resulting price of foods must increase as well. This demonstrates the laws of supply and demand as changes to biofuel’s supply and demand result in an increase in a related capital good; food crops.In addition to supply and demand being demonstrated in this article, negative externalities of production is also a significant theory displayed in this article. Negative externalities of production are simply costs that third parties must suffer from as a result of a transaction between producers and consumers. And as the supply for biofuels increases as a result of government regulations, food prices begin to increase. Furthermore, the use of certain food crops in the production of biofuels actually create worse emissions than the fossil fuels that biofuels were meant to replace. The marginal social cost (MSC), which includes the price increase of foods as well as worse carbon emissions, is much higher that the marginal private costs (MPC) of firms. MSC is the cost provoked by the production or use of a good or service, including costs to the whole of society and producers themselves. On the other hand, MPC are the costs suffered by only the producer for the making of a certain good or service. MSB, marginal social benefit, is the total benefit society receives. As a result of MSC being higher than MPC, welfare loss occurs. This is what society pays as a result of allocative inefficiency of resources caused by negative production externalities.However, as with nearly all problems, negative externalities of productions can be solved. In this article, this is displayed through the UK’s legislation, which is simply a law being enacted, to “cap its use of food-based biofuels at 4% of UK road fuel next year, dropping to 2% by 2032.” This demonstration of legislation as a solution to negative production externalities is a direct linkage to microeconomics.With precise inspection of this article, the fundamental principles of supply, demand, and negative externalities of production can be applied to allow governments to decide the fate of food-based biofuels and ultimately the well-being of their citizens with food prices on the rise.

Traditionally, is an operation or series of operations

Traditionally, companies used advertising to inform and to attract consumers
so they would finally buy the product(s) and/or service from those companies.
Advertising means the action of calling something to the attention of the public,
especially by paid announcement (Merriam-Webster, 2015). In today’s world,
advertising uses every possible media to get its message through (Economictimes,
2016). However, unfortunately, advertising only has small and short-termed
effectiveness on sales, since according to Andrews’ statement in 2008, advertising
campaigns only try to induce people to consume the goods or services the company
offers. Aitchison (2004) also stated another disadvantage of an advertising campaign,
which is the fact that same idea of advertising cannot work universally, and it can be
an obstacle to the operation especially when controversies arose.
Thus, as an alternative to reduce the risk of advertising, a social campaign can
be considered as another tool that can gain customers’ attention in today’s
competitive market. Social Campaign is an operation or series of operations
energetically pursuing to accomplish a particular purpose through mass media; and
the communicative aim is to break down an undesired behavior that tends to influence
thoughts, feelings, behavior, and current knowledge (Andrews, 2008). Social
campaign often relates to particular social or environmental problems, and the
objective is to use the social issue to create value by scaling down those problems.
For some companies, the social campaign is a part of their CSR activities that is
presumed can attract customers’ attention in the previous chapter. It is classified as
’cause marketing’—a new term refers to a type of marketing where public causes are
used as a promotional strategy and hence links to sales (BusinessDictionary, 2016).
More precisely, what differs social campaign when compared to advertising is
the art of persuasion veiled in the content. They often do so through joining forces
with nonprofit organizations and focusing advertising campaign on those
philanthropic relationships instead of only promoting the product (Stengel, 2013).
Additionally, according to Andrews, the content should be a message that is potential
to raise people’s awareness and able to influence the audiences not to perform a
particular undesired activity or behavior. Hence, what makes social campaign unique
is that campaigns on social issues implicitly inducing public to do something they
value. When the company shares the same value as the consumers do, consumers will
be convinced that they can actually support the company to alleviate the issue (Levy,
2015)—means that social campaigns enable consumers to contribute something for
the society, and this advantage is considered more ‘rewarding’ than the products’
benefits (Community Tool Box, 2015).

Though describe the struggle of saving money or

Though Latin America has improved on it economic inequality, such as Brazil and Mexico, there is still a lot of work to be done to catch up to other nation around the world. In Latin America the richest earn forty-eight percent of total income, while the poorest only earn one percent.This speaks volumes to the economic inequality because in rich countries the gap is twenty-nine to three percent. Gender roles in Latin America still exist and in order for to move forward, women voices cannot be ignored. These roles are by shaped cultural values and beliefs. In Deborah Cohen’s essay, From Peasant to Worker: Migration, Masculinity, and Making of Mexican Workers in the US, she discusses the Bracero Program and the patriarchal values of the workers. Throughout the essay, Cohen talks a lot about what these male Mexican migrants thought to be “women’s work and men’s work.” Men describe the struggle of saving money or his claim to proper masculinity be part undone by doing the women’s work. Rather than save the little money they had, some workers would pay a women to do their laundry. This shows how ingrained the patriarchal values were instilled in these men. It is important that Latin America deals with its problem of inequality because without equality not everyone has access to the opportunities within the nation. For instance, income inequality and having access to good education go hand in hand. High socio-economic inequality allows for chaos and this also allows rationale for military intervention.   It has been difficult for the development of democratic government because there was no government to start from.Military also has a strong presence in the Latin American government since the New World. In 1974, dictator Lieut. General Jorge Rafael Videla took over Argentina his goal was to “eradicate alleged subversion.” During this time, the junta closed the National Congress, banned trade unions, and civil government under military control. This resulted in less than a decade 9,000-30,000 people being killed and kidnapped. A group of fourteen mothers gathered at the Plaza de Mayo in order to protest the disappearance of their children, though political protest was not allowed. This was important because it brought light and put faces to the number of people who were missing. At first, the military left the mothers alone, however it did not last long. The military began to the women from entering the plaza.  It even went as far as having secret police to stalk, some were killed and kidnapped, the mothers. Though the attempts to hide what was going on failed, it still shows how much power the government has. People lived in fear of the Argentina government because they knew that they could end up “disappearing”. In August 2008 after their police chief was murder, twenty members of the Villa Ahumada in Chihuahua resigned. Those who stayed would cover their identities by wearing mask and some even moved their families to the United States. On the other hand, there are members on the police who started working for the cartel and accepting brides. Though the members of the police force started working for the cartel to protect themselves, it does not erase the fact that themselves are now cartel members. Latin America is considered the most violent region in the world, with gang violence being tied to most homicides. The clip titled, Mexico’s Drug Gangs Fight for Control, talks about how much control the drug cartels’ activities have on Mexican society. Residents who once a popular tourist destination, now live in daily fear. The battle for control between multiple gangs led and still leads to increase of drugs, kidnapping, and human trafficking. In the video, people expressed concerns that military presence wasn’t enough to protect them from the violence.

At materialism is related to the increase of

At present, the rate of youth crime is continuously increasing all over the world. In this essay, reasons for the increase in youth crime and some of the possible solutions will be discussed.        The first reason is family. That is, the way a child is raised up from his/her family is related to the increase of youth crime.  Youths with broken family are more likely to commit crime than those with warm family. This is because youths with broken family have no one to guide what is right and what is wrong. In addition, youths who grow up in a violent family have the risk of commit crime.      The second reason is financial problem. Youths from low income family struggle, and this may influence them to commit crime. To clarify, they may decide to do something illegally for their survival. Also, materialism is related to the increase of youth crime. Some youths need money to fulfill their needs.   Although the youth crime rate is getting higher from the reasons mentioned above, there are some possible solutions for this problem. The first solution is to strengthen the relationship between family members. This can be done by guiding and reminding parents that warm family is the key to lower youth crime. The second solution is to educate theyouths about financial management and making financial plan. With this solution, financial problem will be solved permanently.   In conclusion there are ways to tackle such problems. Firstly, one of the ways to combat the problem is to have stricterpunishment. Although, as discussed above, it can be outside factors that lead to crime, it is still important to have severe punishmentsTo deter teenagers from crime. All too often, because they are young, the courts are too they too should be punished if theirchildren commit crime. To sum up several factors have led to increases in youth crime, but measures are available to tackle this problem.                           undefined undefinedThe length of the text: 1951 (No spaces: 1786)

Abstract. our novel approach on dental extraction forceps

Abstract. Even though tooth extraction is one of the common surgical procedure
in dental field, it needs an extensive knowledge and practical experiences when
handling the dental extraction equipment. Otherwise, it will be more complex or
even at worse case, it causes damages to patients’ mouth area. So, it is very
important to have a sound knowledge on the instruments to be used, especially
on extraction forceps. So, the knowledge on extraction forceps should be
disseminated properly. After identifying this need, as a first stage we
gathered the information regarding the dental extraction forceps from the
experts in the field. Then we started developing ontology as a second stage. Finally
the developed ontology was evaluated in two folds; by using inbuilt tools and
by ontology experts as an iterative approach. We strongly believe that our novel
approach on dental extraction forceps ontology can support the dental students,
dentists as well as their assistants to improve the knowledge and helpful in learning
practices. Our next step is to model the ontology for whole extraction process
and to develop a knowledge management system on dental extraction forceps.

Keywords: dental
forceps, ontology, knowledge sharing, health care, extraction


A tooth is one of
the hardest part in most of the vertebrates which is calcified structure and
situated inside jaws 1. Tooth performs a very important function of the body which is
breaking down of foods. It also gives aesthetic value to appearance of a person.
Dentistry is a branch of medicine which deals with the dentition, and related
structures and tissues in the face. A dental extraction is the removal of teeth
from the dental alveolus in the alveolar bone 1, 2. There are many reasons for dental extractions, but mainly done if
a tooth has been damaged by decay or broken 3. Other reasons are such as a crowded mouth, infection,
supernumerary or malformed tooth, and even because of cosmetic purposes (to
remove tooth of poor appearance). The branch of dentistry that deals primarily
with extractions is oral surgery 1. There are two types of extractions performed in the dental field:

A simple extraction, which is
performed on a tooth which can be seen inside the mouth. In a simple extraction
procedure, the dentist will hold the tooth with specialized pliers called
“extraction forceps” and move them front and back in order to loosen the tooth
from the jaw before getting rid off the tooth 1, 4.

A surgical extraction, which is
a more complex procedure done by the surgeon.

The forceps is an exaggerated version pair
of pliers. It is made up of three parts; the blades, the joint and the handles.
In general, forceps which are designed for the extraction of anterior (front)
teeth in the maxilla (upper), the blades and handles are in the same line while
for the maxilla posterior (back) teeth the handles form a curve with the
blades. In forceps used for the extraction of mandibular (lower) teeth the
blades and handles are at an angle of approximately ninety degrees between them

Sometimes different terminologies are used to express the same concept.
Due to the unstructured, incomplete, general nature and varied formats of the information,
the knowledge is not reaching everybody 5. Further, computers needs to understand the
meaning or semantics of the information clearly. Semantic web enables this
understandings to computers 6. Ontologies are powerful mechanism for representing knowledge
presented in semantic web 7.

Ontologies are
widely used for various purposes such as knowledge management, e-commerce,
natural language processing, intelligent integration of information and
semantic web 8.

Ontology provides
a structured view of domain knowledge and act as a repository of concepts in
the domain 9. This structured view is essential to facilitate knowledge sharing,
knowledge aggregation, information retrieval, and question answering. Ontology
provides precise and well-defined relationships, strong semantic capabilities,
inference mechanism, and reasoning support. Therefore, ontology can be used to
find a response to queries within a specified context in the domain of dental
extraction 7, 9, 10. According
to Thomas Gruber 11 “an ontology is an explicit
specification of a conceptualization”.

Further, the
context has also been decided to con?ne the study to a particular Sri Lankan
hospital. The key reasons are based on the geographical location of the
researcher, practicality and ease of access to those hospitals and
comparability of research data due to hospital’s same jurisdiction, same
economic and regulatory regimes governing their operation.

The aim of this work is to contribute to an
improvement in the management and usage of dental extraction forceps in hospitals
by developing an ontology-driven solution that organizes and describes clearly
related knowledge.

The remainder of the paper is organized as follows. Section 2
describes the literature review and the related work. Section 3 discusses the contextual
information while section 4 explains the need for a new dental extraction
forceps ontology. Section 5 describes designing approach for modelling dental
extraction forceps. The ontology evaluation and verification methods are
described in the section 6. Section 7 concludes this paper and presents
directions for future work.

Related work and literature

Modelling knowledge by using ontologies in the
medical domain is an active research field 12. Even though health sector is being supported by number of
biomedical ontologies such as GALEN, the Uni?ed Medical Language Source, the
Systemic Nomenclature of Medicine which focus on general scope of the
biomedical domain 13, and the Gene Ontology (GO) which is one of the earliest and most
frequently used vocabularies 14, there are a very few ontology on dental domain on the health
sector. Ontology-based systems provide reusable terminology resources and they
can be used to improve the management of complex systems for different context
information which can be captured and validated 12.

The information needed for a domain may be
available from leaflets, and mass media in different formats such as text,
audio, video 9. The
use of ontologies in health domain mainly focused on the representation and
re-organization of medical terminologies. Ontologies
can help build more powerful and more interoperable information systems in
healthcare. The
most significant benefit that ontologies in the health sector is its ability to
support integration of knowledge and data 15. Even though ontologies are used in the information system (IS)
design, the ontology development in health sector is more challenging because
of its complexity and the level of detail in it 13.

Having discovered this research gap we have
focused on our attention to develop a dental extraction forceps ontology to
represent information needs according to tooth extraction context. That is, we
intend to develop an ontology-based knowledge framework to manage extraction
forceps-related knowledge. This would assist the doctors and their assistants
in the dental hospitals to manage extraction forceps knowledge.

Contextual Information

According to Dey 16, context is any information which can be used to describe the
situation of a participant in meaningful way. Our main target groups are
dentists and people associated with dental in Sri Lanka such as assistants in
dental hospitals, researchers and information specialists. In order to identify
dental extraction context clearly, we have extracted domain speci?c knowledge by
using the following reliable knowledge sources;

Related field experts from Sri
Lankan universities, Sri Lankan hospitals by using formal and informal
interviews, discussions.

Research articles, online
articles and books 1-4, 17-20.

Newspapers, radio and

By analyzing information gathered from
various sources, we have identi?ed what information is required by the dentists
and other related personnel. We identified the information needed to dentists
and their assistants in the form of questions for our study. Some of them are
in Table 1.

1. Dental Extraction Problems

What are the tooth of child and adult?

What are the different types of

What are the positions of the tooth
located in the mouth?

Which is the most suitable extraction
forceps to extract a particular tooth?

Which is the most suitable extraction
forceps to extract a particular tooth if the crown is damaged, i.e. if only
root is there?

What are the different shapes of

Need for a New Dental
Extraction Forceps Ontology

There are 32 teeth on an adult called as permanent dentition and 20
teeth on a child called as primary dentition. Further each tooth has a crown
and a root. Generally when extraction is done, the root also comes with the
crown. But in some special cases like broken tooth, while extracting crown,
roots stays in the jaw socket 4. Further, some
teeth are very difficult to extract from its socket for various reasons, such
as tooth’s position, the shape of the tooth roots and the integrity of the

During the extraction process, the force to be applied should strictly
be limited to the tooth that is to be extracted. Many cases of simple
extraction procedures, before proceeding the extraction process, the forces are
diverted from the tooth to areas such as bone surrounding the tooth, in order to
ensure adequate bone removal.

All the tooth in human are not in same shape and size. So, each tooth
needs to be extracted using different types of dental extraction forceps. Choosing
the appropriate extraction forceps is the important part for the protection for
jaws and other neighboring tooth which will be affected if the forceps slips
away while extracting. If the specific extraction forceps are not used for a
tooth, then there will be more complications 21 such as incomplete extraction in which a tooth root remains in the
jaw, prolonged bleeding, swelling,
bruising, nerve injury or even
extraction of wrong tooth 1.

Further, if proper extraction forceps are used by the dentist, his or
her extraction will be easy as each extraction forceps are made by using the
knowledge of physics. For example, extraction forceps are made smaller in size
for children in order to apply less force and larger in size for adults in order
to apply more force. If we take another example, tooth on deep end in the jaw
(wisdom tooth) needs a different mechanism to extract than the tooth in the
front part of the jaw (incisors) 4. So extraction forceps are made “L” shape for deeper end and straight
for central area. Therefore, usage of specific extraction forceps for specific
tooth is very important for patients’ health as well as for the easiness of the

The information and knowledge needs to be
provided in a structured and complete way and in a context speci?c manner. Ontologies
emerge as one of the more appropriate knowledge management tools for supporting
knowledge representation, processing, storage and retrieval. By considering the
importance of sharing the knowledge on dental extraction, ontology for dental extraction
forceps is developed.

Our Design Approach

Figure 1 describes the basic steps in the roadmap
of our ontology modelling approach.

1. Our design methodology

main focus is on simple extraction, more specifically on extraction forceps
because these extraction forceps plays an important role on tooth extraction 4. Grounded theory was used for data
collection. According to Strauss 22 grounded theory is a general methodology for developing theory in
grounded data through systematically gathering and analysing. One of the key
feature of grounded theory is that both data collection and analysis are
interrelated and iterative. So, we can start analysis as soon as the first data
are collected 23. Two dentists with extensive knowledge on dental (mainly on
extraction) and an expert on ontology engineering took part.

Competency Questions (CQ) are a set of
questions that the ontology must be capable of answering using its axioms 24. CQs work as requirement’s speci?cation of the dental extraction
forceps ontology. If CQs contains all the necessary and suf?cient axioms that
correctly answer the CQs, it is possible to know whether an ontology was
created correctly 7. Our ontology aims to answer competency questions. Some of them
shown in table 2.

2. Some competency questions

Which tooth are in upper left side of an

Which extraction forceps is needed to
extract the root of left second premolar of an adult?

What is the tooth of lower left central
incisor of a child in the mouth?

Which extraction forceps is needed to
extract the normal left central incisor of a child?

Which extraction forceps are S shaped?


We get the
relevant data in order to answer these problems through extensive literature
survey and expert collaboration. We categorized the “Person” into two; “Adult”
and “Child”. The “Parts” of the tooth is divided into “Crown” and “Root”.
“Positions” also categorized as “Upper”, “Lower”, “Left” and “Right”. Tooth
have “Specific Names”. They were classified into “Molar”, “Premolar”, “Canine”
and “Incisor”.

There are three international standard
systems for naming teeth: the universal numbering system, the palmer notation
method and the two-digit FDI world dental federation notation. In this paper,
we followed two-digit FDI world dental federation notation WHO and by other
organizations such as the International Association for Dental Research. It
provides a system for designating teeth or areas of the oral cavity using two
digits 17. We declared these notations into “ToothNotation” class.

Since there are no standards for forceps
classification, we formalized the forceps into two main category; Crown Forces
and Root Forceps. Here what we meant by crown is the full tooth which includes
both parts; crown and root. Further we divided each forceps into many sub
classes. The high level class hierarchy is shown in Figure 2

2. The high-level class hierarchy of dental extraction forceps

The basic high level ontology concepts are
identi?ed as Person, Tooth, Tooth Parts, Tooth Specific Name, Forceps, and
Position. Secondly, sub-classes of defined high-level ontology concepts, their
properties and their relationships are also identified. For example, Tooth
Specific Name has Canine, Incisor, Pre-molar and Molar as its sub-classes and
Lateral Incisor and Central Incisor are sub-class of Incisor. These sub classes
are related to their superclass by “is a”
relation 7.

Making the ontology manually is tedious and time-consuming task 9. According to Vasanthapriyan 7, the principles, methods and tools for initiating, developing and
maintaining ontologies are investigated in ontology engineering approach. There
are many different methodologies proposed to model the ontologies in many
literatures 24-27.
After reviewing all, we selected Grüninger and Fox’s methodology 24 for our work as it publish a formal approach for designing the
ontology and also it provides a framework for evaluating the developed ontology

Grüninger and Fox’s methodology 24 focuses on building ontology based on ?rst-order logic (FOL) by
providing strong semantics. The associative relationships are to identify the
concepts and relationships with meaningful relations, and to de?ne the
relationships and their inverse relationships. Table 3 shows some associative
relationships including their inverse.

3. Associative relationships with inverse.





hasSpecificName, isSpecificNameOf



hasUsedToPluck, isPluckedBy



hasPosition, isPositionOf






hasCrown, isCrownOf



Datatype properties
link an individual to an XML Schema Datatype value or an rdf literal. In other
words, they describe relationships between an individual and data values. A
datatype property can also be used in a restriction to relate individuals to
members of a given datatype.













The ontology was
implemented by using the Protégé-OWL Ontology Editor 5.1. Part of the dental
extraction forceps ontology is shown in the figure 3

3. Part of dental extraction forceps ontology

In our scenario, we introduce Description
Logic (DL) which is a decidable fragment of FOL since we are designing with OWL
2 Web Ontology Language 28 for sematic web. We have evaluated the competency questions to see
whether the ontology meets the dentists’ requirements during the internal
design process. The DL expressions have been used to query the ontology. For
this purpose, we used DL query facility which is available in Protégé-OWL Ontology
Editor 5.1. Some of the DL query and their answers are shown in table 4.

5. Some of DL query used and their outputs

Competency questions

DL query


What forceps are used to pluck T55

Forceps and hasUsedToPluck
value T55

Instances (2)

What are the dentitions which consists
specific name canine?

and hasSpecificName value Canine

Instances (8)

What is the position of T34 dentition?

Position and
isPositionOf value T34

Instances (1)
·   LowerLeft

What is the specific name of T28

and isSpecificNameOf value T28

Instances (1)
·   ThirdMolar

Ontology Evaluation and

Internal Evaluation

In order to avoid the defects when using
the ontology, its quality should be verified and validated 29. So, the last stage of our methodology consisted of an evaluation
of the ontology by experts in the ?eld ontology and by using inbuilt FaCT++
1.6.5 reasoner.

Further, in order to detect potential
pitfalls which can lead to modelling errors, we used an online ontology
evaluator called OOPS! (http://oops.linkeddata.es/)
29. This evaluator evaluates human understanding, logical consistency,
modelling issues, real world representation and semantic applications for the
developed ontology. The summary of the pitfall encountered, brief description
and description of how those are handled are shown table 5.

6. Pitfall, description and solution proposed




Missing annotations (156 cases | Minor)

Human understandable comments not

Included the ontology annotations

Missing domain or range in properties
(11 cases | Important)

Object and (or) datatype properties
without domain or range

Added the missing domain and range

Inverse relationships not explicitly
declared (32 cases | Minor)

Proper inverse relationship are not

Included missing inverse relationships

Using different naming conventions in
the ontology (8 cases | Minor)

Ontology elements are not named on same

Corrected by using uniform naming

Expert Evaluation

We evaluated the
ontology with the help of ontology expert by examining the de?ciencies of the
artifacts we used. The expert is not an author and not related to our research
team. There were many methods to evaluate the ontologies in literature 7. Our ontology expert considered the following layers to perform
evaluation; (a) syntax, (b) structure, (c) semantics and (d) representation. The
main objectives of expert evaluation are; (a) whether the software testing
ontology meets its’ requirements, standards, (b) coverage of the software
testing domain and (c) checking for internal consistencies.

This methodology allows us a better focus because
each level has a different evaluation objective. Table 6 summarizes the aspects
of the evaluation method used and Table 7 shows the suggestions and
improvements highlighted by the ontology expert. Based on Ontology expert’s
responses, comments, and suggestions the ontology was redeveloped.

7. Discussion topic of ontology expert



Discussion topic


Syntax of the formal language used

Standard syntax is used


Correctness of the concepts and the

Whether is describes is-a relationship
between concepts

Tools used in checking structure


Terms used to represent the knowledge

Understandable names of concepts and


Structural representation of the

Proper taxonomy

8. Review summary of ontology expert

Discussion topic

Ontology expert

Standard syntax is used

Manchester syntax was followed

Whether is describes is-a relationship
between concepts

All concepts follows is-a relationships

Tools used in checking structure

Whole ontology was viewed using OntoGraph

Understandable names of concepts and

2 concepts and 8 object properties do
not have understandable names.

Proper taxonomy

Clearly viewed in OntoGraph

Conclusions and future works

Tooth extraction is
one of the common surgical procedure in the field of dental, which mainly
depends on knowledge and experience of the dentists. Therefore in this
research, great importance is given to knowledge for dental extraction forceps,
and the potential benefits of managing dental extraction forceps knowledge, an
ontological approach to represent the necessary dental extraction forceps
knowledge within the dentists’ context was developed 10.

Identification of the suitable extraction
forceps for the given case is resolved by developing a domain ontology on
dental extraction forceps. Designing this type of ontology is not a simple
task, because we need to gain vast domain knowledge. This research presents
dental extraction forceps ontology to represent dental extraction forceps
domain knowledge which includes dental extraction forceps concepts, properties
and their relationships. We believe our dental extraction forceps ontology can
support other hospitals to improve the sharing of knowledge and learning

Our future works have two main parts.
Firstly we are planning to expand our research to whole extraction process
which includes all the devices used in the extraction process. Secondly, the
development of knowledge management portal for our expanded research in order
to disseminate the knowledge on dental extraction process. Even though previous
work has demonstrated knowledge sharing methods for various domains such as
software testing 7, 10, economics 30 etc., a very little research into dental knowledge sharing using
domain ontologies has been conducted. So our plan is to develop of knowledge management
portal in the domain of dental extraction.


We acknowledge the
experts and other personnel who directly and indirectly involved in order to
complete the research work successfully.

My radioactive material is the greatest. It begins

My hypothesis was “After
each shaking about half of the remaining pennies would be heads-up 
and half of them tail-down. The number of
pennies removed after each shaking cannot be the same. It will always be
approximately half of what it was on the previous shaking,
because the starting number for each shaking will be only about half
of what it was the previous time. Half- Life is the time taken for the radioactivity of
a specified isotope to fall to half its original value. The term radioactive is
applied to substances which aren’t stable and break down into lighter elements.
A radioactive sample emits the most radiation as soon as it is formed or
isolated. The reason is that that is when the concentration of the radioactive
material is the greatest. It begins to decay immediately and as it does, the
concentration of radioactive material in the sample gets less. This process can
take milliseconds or millions of years depending upon the rate at which the
substance breaks down. The reason it’s important is that we need to know how
long a radioactive material will take to decay to the point that there is so
little left that it no longer poses a threat to life. One of the problems with
nuclear plants as they are currently designed is that they produce a lot of
radioactive waste products. The problem is what do you do with this stuff which
can be deadly for thousands of years. While radioactive waste keeps building up
and being temporarily stored, usually at the nuclear plant where it was made.
The reason knowing such things is important is that knowing the length of time
a radioactive substance will exist is a factor which should be considered in
making the stuff. No, I don’t think the shape of the curve on the graph would change if it
were increased to 20 seconds. This is why radioactive contamination is dangerous in
the environment and hard to remove. Even though large amounts of the material
may decay very quickly at first, smaller amounts can linger for a long
time. No, I don’t think the shape of the curve on my graph would change if I started
with a smaller sample. I don’t think the shape or the curve of the graph would
change if it were increased by 20 seconds or if it started with a smaller
amount of pennies.