Posted in Uncategorized

periphery of a tubular

Since previously I have been dealing with lot of calculation of a tubular member, there is an interesting yet fun discovery (which I believe some people may have found it too) where you can find more than one way to calculate the cross-section area of the tubular member.

You see when you have a tubular member or a pipe, the area of the cross-sectional circle can be measured by using the equation

A = π r^2…..(1)

This is a common equation for calculating the area considering the tubular member is rigid.

The circumference of the circle (C) can be calculated as

C = 2 π r…..(2)

In a real application, we deal with a lot of tubular member which has an inner diameter (id) and outer diameter (od).

When we calculate the cross-section area of this tubular, the equation (1) becomes

A = π r.outer^2 – π r.inner^2

where r is the radius of the tubular member


A = (π/4) (od^2 – id^2)

For example,

with od = 6 mm,

id = 5 mm

The cross-section area will be

A = (π/4) (6^2 – 5^2) = 8.639 mm^2

In other analysis, we can calculate the cross-section area by breaking off the tubular such that

A = (thickness of tubular) * (the circumference of outer tubular member)


t = thickness of tubular

Substituting parameter provided from the example, we can get

A = (0.5 ((od) – (id))) * (2 π r.outer)

A = (0.5 (6 – 5)) * (2 π (6/2)) = 9.425 mm^2

In logical thinking, both ways of calculating the cross-section area should have been resulting the same.

There is a deviation around,

δ = (9.425 – 8.639) / 8.639 = 9.09 %

Quite interesting, isn’t it ?

Posted in daily life, Uncategorized

best way to operate windows 7

Windows 7 has been the best operating system since its popularity for the amount of users all around the world among all other system. From March 2014 until January 2015, statistics show about half of overall windows users use windows 7.

Windows Statisctic Users

For all people who like to use windows 7, I have experienced some best way to operate it. Sometimes you need this so that you do not have to move your hands to use your mouse. These all some of the useful shortcuts if you want to use your computer effectively using  windows 7 :

1. If you want to leave your desk for awhile, you can press Windows button + L. It will put your laptop on the ‘locked mode’ suddenly. You save your time without using mouse pad.

2. When you want to find some documents or see other things in your laptop, you will firstly open the explorer, and open ‘My Computer’. To get a shortcut, just press Windows + E.

3. Your boss is coming when you are playing games in your pc. Don’t worry, just press Windows+D, Desktop screen will save you 😀

4. If you want to find a recorder application in windows, you can do it in shortcut by pressing Windows+R, then type psr.exe. Enter. Tadaaa… Start recording !

5. You can see a cool stuff when you press Windows +R and type osk. Enter. and yess. Virtual keyboard !

6. If you find your object in the screen (either a picture or sentences) very small to you, you can adjust it by pressing Windows + ‘+’ or ‘-‘ (zoom in or zoom out).

7. During surfing on the internet, you can switch your tab by pressing Ctrl + Tab. This will be useful if you have a lot of things to do (googling, literature research, downloading, etc.)

8. I know you can press Windows button to open ‘Start’ program. Other way to do it is by pressing Ctrl+Esc.

So there are some of the ways the best and the effective one to operate windows 7 that I have found. Hopefully it will be useful for you.

Posted in poem

untitled star

9198837soul in rock n roll

i get so high and i can feel it

in and out my plain, running through my vein

it’s my sunshine, it’s my rain

i am here in my mold

a million different people

from one day to the next

like a sky full of star

get lighter the more it gets dark

such a heavenly view


turn my magic on

we are legends every day

we are diamonds taking shape

shining like a diamond

rolling with the dice

having river for a soul

heart of steel is growing

with fire in eyes

standing on the ledge

show the wind how to fly




Posted in Travelling

travelling to oslo

This journey is in February 2013. I was having an appointment with the embassy for a new passport of mine (btw, I am really happy for this part, because for once in my life my passport will be labelled as ‘made in Embassy of Indonesia in Oslo’, not Immigration office Indonesia :)) ). I had 2 days to look around all the notable place in here. First of all, after having been travelling to some cities in Europe, I would like to say Oslo is my favorite one. The population is not too crowd, transportation is very good (bus, train, commuter, mass rapid transport), the environment is really enjoyable (especially water, this one actually in all area of Norway, I guess they have the best water tap on earth!)

The thing about travelling, I want to visit some place that is really new to me. That is why I had my plan to visit 3 places there and I would like to say it is ‘a must’ to visit these if you ever have a plan to go to Oslo. First place is Holmenkollen. It is a very large ski area for skiing competition (I don’t know in particular about skiing, but every international ski competition is usually held here). I am lucky I visit Oslo still at its snow season. Even though there is no event at that time, enjoying being in a place that would never be existed in my home country is the pleasure I like when I visit this place.

Second place is the Ice Bar in the middle of the city. I know by googling about this bar, where not only norway have it, but also almost every 4 season country have it. The place is really awesome. All the things inside are made of ice, even the utensils (glasses and stuff)

Last one (of course not the least) is Vigeland Park. This is a great park with human statues spread all over the place. The special thing about this place is the various expressions of the human statue, both in individual or groups, even in naked. This is a very good place if you want to make funny pictures.

There are other interesting places in Oslo besides my suggestions.  Nobel Peace Price Museum, Viking Ship Museum, Kon-Tiki Museum are one of them. If you have a chance to visit this city, I suggest you put them on your list.


Posted in offshore

subsea technology

Recently deep water technology has been widely known as one of promising field in oil and gas business in offshore region. As I share and talk with colleague and friends, subsea technology is one of the options to be applied in deep water sector. An exploration of oil and gas is increased along with the demand of the use of this non-renewable energy in the future. Even though currently I have not yet directly involved in the subsea industry, I hope someday I can be the specialist in this area.

When I was in my master study in Norway, I had a chance to attend a class that can describe this subsea world in a brief and comprehensive explanation, called Subsea Technology class. It is a good and recommended class to be followed since the subject is very interesting and new (for me). During the class we have an opportunity to write a paperwork explaining any subsea field in anywhere. It should be something unique and have a special configuration or items included in the subsea system. I, with my colleague, decided to write our project about a subsea field in Indonesia, a small one, located in north region of Indonesia. Detail of introduction can be seen at the bottom.

In the class we also have a chance to subscribe to a very cool, yet very informative website about subsea technology, in This link is a great website describing all subsea equipment and its function in a detail description and with a great image, also cool video. Since I have been graduated, I can not access it anymore but you can try to subscribe it (but you have to pay much more than when I was in my master :d).

Here a snap shot from (click the picture)


To summarize, this website will tell you lot of information about each of equipment, instrument, and tools in every system above. There are also some videos regarding the subsea tools installation when it is being placed in the field.

Introduction, Kepiting Field – Indonesia

The Kepiting Field is a small oil field, owned by Conocophillips Indonesia, comprises of 2 wells located in Natuna Sea, Indonesia at distance of approximately 1000 km of Jakarta. This marginal field has been profitably active for oil and gas production from October 1986 to August 1989. The water depth is 90 m with relatively mild environmental condition and is out of the trails of Southern China Sea’s typhoon such that it is generally calm all over the year. Maximum 100-year storm wave height (hmax) is 12 m and the significant wave height (hs) is 5.8 m. During December and January the weather is most severe, at when the 4.6 m wave height and 56 km/h wind may occur and can last up to 10 days. The Kepiting Field has a limited production capacity of 4500 BPD of oil per well. This limitation is intended to avoid excessive fines production of the reservoir. The hydrocarbon is characterized as waxy crude oil (35% wax contained) and has pour point of 100o F (38o C). With specific gravity of 39o API (0.83 g/cm3), it is considered as sweet crude oil.

Posted in daily life

hemat perpanjangan sim

Sejak dicetak, Surat Izin Mengemudi (SIM) berlaku selama 5 tahun. Setelah itu, sebagai WNI yang baik dan taat hukum SIM diperpanjang lagi untuk masa waktu yang sama. Saya mau sharing untuk proses perpanjangan SIM (A dan C), terutama di Bekasi. Tujuan sharing saya di sini agar kita bisa menghindari calo yang suka menawarkan jasa sampai harga pelayanannya 2X lebih besar dari perpanjangan SIM secara mandiri.

Tahap perpanjangan SIM yang saya ikuti yaitu:
Pertama, kita membuat Surat Keterangan Dokter. Untuk SAMSAT Bekasi, surat ini dapat dibuat di belakang kantor SAMSAT. Harga pembuatan surat ini, biasanya berwarna hijau, sebesar 25 ribu saja per SIM.
Kedua, kita membayar biaya perpanjangan SIM yang dikelola oleh SAMSAT. Untuk SIM A biaya yang dibutuhkan sebesar 80 ribu, sedangkan untuk SIM C 75 ribu.
Ketiga, kita membayar premi asuransi yang ditangguhkan melalui SIM yang kita buat. Biayanya sebesar 30 ribu per SIM.
Keempat, kita ke loket tiket pengisian form untuk mendapatkan form permohonan perpanjangan SIM. Setelah form diisi dan syarat surat2 yang saya sebutkan sebelumnya terpenuhi, seluruhnya dikembalikan ke loket yang sama dan kita tinggal tunggu foto.
Terakhir setelah selesai foto, nama kita akan dipanggil untuk diberikan SIM yang baru untuk masa waktu 5 tahun ke depan.

Jadi intinya proses pemanjangan SIM ini nggak ribet kok. Kalau kita mau ngurus sendiri bisa dan malah mengurangi pengeluaran uang. Saya mengurus perpanjangan SIM A dan C menghabiskan waktu total kurang lebih setengah jam (termasuk foto) dan biaya sebesar 265 ribu.

Rinciannya, 50 ribu untuk Surat Keterangan Dokter (25 ribu per SIM) 60 ribu untuk premi asuransi (30 ribu per SIM) 155 ribu untuk biaya perpanjangan SIM (80 ribu untuk SIM A dan 75 ribu untuk SIM C)
Awalnya sebelum saya urus sendiri, saya sempat ditawari oleh calo di luar kantor polisi. Rata2 mereka menawarkan 300 ribu per SIM nya, total 600 ribu.

Jadi, setelah saya ikuti prosesnya, ternyata mudah dan hemat kan ?