Sunday, December 9, 2012

Catalytic Converter

Catalytic converter is a device that put into vehicle muffler to reduce air pollution. The device contains hexagonal ceramics (like bee nest) layering aluminium oxide and it is filled with catalytic metal like platinum (Pt), palladium (Pd) and rhodium (Rd). Exhaust gas of vehicle is passed through hot catalytic chambers so CO gas and hydrocarbon compounds are oxidized, whereas oxides of nitrogen (NOx) are reduced.

Initially, catalytic converter is specified for oxidation process. Now, the converter is designed for analyzing both oxidation and reduction reactions that its influence becomes better for environment. Converter is designed to have wide surface that will be efficient in changing poisonous gases into non-pollutants.

Problem arises when catalytic converter must be heated first (≥600K) to be effective. Such condition prevents catalyst work effectively when a new machine is started and at the first journey. Converter with electric heating has been designed, but it may empty car storage battery. In 1994, researchers in Tutfs University, USA had a new idea, namely by involving reversible dehydration of lithium bromide (LiBr). When the vehicle is running and the machine becomes hot, hydrated LiBr is dehydrated. As it is rehydrated, the energy released can be used to heat catalytic converter just before ignition. But, the process has not yet been adopted commercially.

It is important to note that catalytic converter can only be used for vehicle using petrol without a lead because it can damage the function of its catalysts. In addition, pollutant will settle on catalyst surface and poisonous that the catalyst must be changed every five or six years.

Sunday, August 19, 2012

Comparement of IT

When traced back, there are several milestone developments in technology that significantly contributes to the existence of ICT today. The first is finding telephone by Alexander Graham Bell in 1875. The findings are then followed up with the deployment of communication networks with a cable wrapped around the entire American continent, and even then followed the installation of trans-Atlantic communications cable. This is the first massive infrastructure that was built humans to global communication. Entering the 20th century, precisely between the years 1910 to 1920, realized wireless voice transmission through the first AM radio broadcast (Lallana, 2003:5). Wireless voice communications quickly growing rapidly, and then even followed by audio-visual transmission without cables, a form of broadcast television in the 1940s. The first electronic computer operations in 1943, followed by stages miniature of electronic components through the discovery of the transistor in 1947, and integrated circuit (integrated electronics) in 1957. The development of electronics technology, which is the cornerstone of ICT at this time, get a golden moment in the cold war.

Science and technology competition between the Western bloc (United States) and Eastern Bloc (former USSR) actually spur technological development through the efforts of electronic miniaturization of electronic circuit for controlling the spacecraft as well as the machines of war. Miniaturization of electronic components, through the creation of an integrated circuit, at its peak gave birth to a microprocessor. Microprocessor that is the 'brains' of computer hardware, and continue to evolve until today.

On the other hand, the rapidly growing telecommunications device when it began to implement digital technology replaces analog technology that has shown maximum limits of its exploration. Digitalization of telecommunications equipment and computers converge with that from the beginning is a device that adopts digital technology. This convergence product that currently appear in the form of a cell phone. On top of telecommunications and computing infrastructure this is the content of the content (content) in the form of multimedia messages, get a great place to grow. Telecommunications convergence of multimedia computing is the primary characteristic of the 21st century, as the 18th century is characterized by the industrial revolution. When the industrial revolution to make the machines as a substitute for 'muscle' human so digital revolution (for multimedia convergence-telecommunication computation) occur through the implementation of digital technology) to create machines that replace (or at least improve the ability of) the 'brains' of man.

Indonesia has used the term telematics (Telematics) for the purpose of more or less the same with the ICT that we know today. Encarta Dictionary describes as telecommunication + informatics Telematics (telecommunication + informatics) despite earlier word meaning science of data transmission. Processing and distribution of information through telecommunications networks open many opportunities to be utilized in various fields of human life, including education. Ideas for using machine-learning, making simulation of complex processes, animation difficult processes described, very attractive interest learning practitioners. Additionally, the possibility to serve the learning that is not constrained time and place also can be facilitated by ICT. In line with that start popping up various jargon beginning with E, ranging from e-books, e-learning, e-laboratory, e-education, e-Library, and so forth. The prefix e-means which is implicitly understood electronics technology based on digital electronics.

Thursday, May 24, 2012

3. Operators in Pascal

3.1 Assignment Operator 
Used to give value to a variable. 
x: = 1 + 2; 
a: = a +1;

3.2 Arithmetic Operators  

Used to do the sums. 
example: a + b 

Used to make cuts. 
example: x - 1 

Used to perform multiplication. 
example: a * b 

Used to make distributions. 
example: 7/3 

For integer division. 
10 div 5, will produce 2 
10 div 3, will produce 3 

Used to calculate the remaining share. 
10 mod 5, will result in 0 
10 mod 3, will produce 1

Wednesday, March 21, 2012

2. Pascal statements

Used to clean / clear the screen. 

write / writeln  
Used to display text or value of a variable on the screen.Difference between the write writeln is at the cursor position after the statement is executed. On write, the cursor will be behind the text, while the writeln, the cursor will be on the next line. 
write ('example'); 
writeln ('example'); 
writeln (a), (showing the contents of a variable) 
write ('Hello', a); 

read / readln 
Used to read and enter a value that is inputted through the keyboard into a variable. 
readln (a), (insert the data inputted into the variable a) 
readln; (waiting for the user presses the enter button before proceeding to the next statement)

Thursday, January 5, 2012

A. Program Structure

Here is a sample source code of a Pascal program:  

sample program; 

uses  crt; 

a: string;

write ('Enter your name:');
readln (a);
writeln ('Hello', a);

Contains the name / title of the program, in this case the 'example'.

Contains a list of units to be used in the program, namely 'crt'. Unit is a separate program module and used to store related processes/function. As in the example, 'uses crt' means the program uses a unit called 'crt', which contains a collection of routines (procedures and functions) to control PC. If the program uses more than one unit, then each unit separated by commas (example: uses crt, dos ;). 

var (declaration)
Contains a list of variables to be used in the program (in this example is 'a') and its data type (string), or can be called with the variable declaration. In addition to the variables, other declarations needed a program include: 
  • Declaration of data types 
  • Declaration of constants 
  • Variable declaration 
  • Declaration procedure
  • Function declaration 
  • Label declaration 

Examples of constant and variable declarations: 

n = 100; 
a: integer; 

Contains statements that will run the program. Examples of statements are clrscr, writeln, readln, etc.. These statements should be in the begin-end block.