Tuesday, December 27, 2005

Sunday, December 25, 2005

Flow of gases in exhaust tubes: physical conditions, factors (gases, heat, sound)

When exhaust gases leave the combustion chamber their temperature is around 900°C and they travel at speeds lower than the speed of sound. Therefore due to the explosions in the combustion chamber they give off heat, and they give off sound due to pressure variations (compression and decompression of air).

Why do internal combustion engines, either 4-stroke or 2-stroke, even need exhaust systems?


Internal combustion engines need exhaust systems mainly for the following reasons:

  • to improve power and torque delivery characteristics
  • to lead hot combusted exhaust gases away
  • to muffle the sound, i.e. reduce noise emissions (where the intended use of the engine has to be taken into consideration)

Saturday, December 24, 2005

歌詞 - Colors

I see green
I see red
I see blue
I see black
I see coffee on the table

And our black and white photo
And over the green mountain
I can see all these rainbow

Lets sing a song in red
Lets sing a song in blue
Lets sing a song with colour in you
Lets sing a song in black
Lets sing a song in blue

Without the rainbow
I'd still sing a song with you

Friday, December 16, 2005

Wednesday, December 07, 2005

The only stupid question is the one you never ask.
Anonymous

Monday, December 05, 2005

Sunday, November 13, 2005

Saturday, November 12, 2005

Oracle Import/ Export

exp scott/tiger file=emp.dmp log=emp.log tables=emp rows=yes indexes=no
exp scott/tiger file=emp.dmp tables=(emp,dept)

imp scott/tiger file=emp.dmp full=yes
imp scott/tiger file=emp.dmp fromuser=scott touser=scott tables=dept

Saturday, October 08, 2005

Any fool can write code that a computer can understand. Good programmers write code that humans can understand.
Martin Fowler

Saturday, September 10, 2005

Using Tag Library in JSP (for JBoss 4.0 Application Server)

1. in the first line of the JSP file add
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
(or any required tag library)
2. in the deployment descriptor (web.xml), you need to add the following in the <web-app> tag
...
xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee web-app_2_4.xsd"
version="2.4"
...
List TABLEs, SEQUENCEs or INDEXes in Oracle:

-- list TABLEs
SELECT object_name FROM user_objects WHERE object_type = 'TABLE';

-- list SEQUENCEs
SELECT object_name FROM user_objects WHERE object_type = 'SEQUENCE';

-- list INDEXes
SELECT object_name FROM user_objects WHERE object_type = 'INDEX';
Create user in Oracle:

-- create the user with username//password
CREATE USER username IDENTIFIED BY password;

-- grant appropriate role to the user
GRANT CONNECT TO username;
GRANT RESOURCE TO username;
Treeview development in web page:

Tuesday, August 09, 2005

Sunday, August 07, 2005


Day 14 of the seed! Posted by Picasa
There's something about going riding with your friends - a feeling of freedom, a feeling of joy - that really can't be put into words. It can only be fully shared by someone who's done it.

captured from Motrocyclist (Aug-2005)