How to see Hidden Files in Pen Drive which is infected by computer virus?

Sometimes USB flash disk(Pen Drives) are infected by computer viruses. When you scan such drives with an antivirus program the folders and files located in your Flash disk(Pen Drive) may get hidden and you cannot see those files by any simples ways whether u change your folder option to Show all Hidden Files and Folders. If Such problem exist here is the Perfect solution for you.To See the hidden Files just follow the steps below.

1. Go to Run
Find Run in all program list from start menu.
Or, Press Start+R from Keyboard.

2. Type cmd and press ok

3. Now Type the drive letter of your USB flash drive.
If it is G: ....Then type G:

To see that whether your files still exist in your Flash Drive or not type the following command line
dir/ah

You can see all your hidden files and folder directories in command prompt

Click above the Image to see it larger.

4. Now Type the command Given below
attrib -h -r -s /s /d G:\*.*

wait some time now till the led in your flash drive blinks.

5. Now open USB flash drive(Pen Drive) now you can see all your hidden files and folders visible.

Ion Exchange Chromatography

Ion exchange Chromatography is the latest chromatographic technique. Use of this technique is increasing day by day in modern world due to its simplicity. In this technique exchangeable labile ions are separated between compounds. The simplest form of ion exchange can be understood by Considering the purification of water.

 

Fig: Schematic Representation of Anion exchange Chromatography.

 

Column Chromatography

Column Chromatography is another technique of Chromatographic separation. In this technique a column packed with an adsorbent is used for the separation process. The mixture that is to be separated is put at the top of the adsorbent material and then an appropriate solvent is poured from the top of the column. As the solvent start moving down the column the separation starts.

                        Fig: A Schematic Representation of Column Chromatography

As the eluent starts to move down different separation bands start to develop in the column indication the separation process taking place in the column. As the time goes the bands becomes more clear and sharp indicating the fine separation of the mixture. At first only the solvent is collected at the beaker below. But as the time passes different compounds move down slowly, making different bands indicating the separation and then they are collected in separate beakers. Those samples collected from column chromatography are then subjected to TLC to check their purity.

Paper Chromatography

Early Botanist Tswett(1900) First developed chromatographic technique, for the separation of leaf pigments. The same scientist is know as Father of Chromatography. Chromatography is a differential migration technique where a molecular species is subjected to a driving force(Mobile Phase), which impels it to move along some path and  a resistance force(Stationary Phase) which opposes the movement.

                                       Fig: Schematic Representation of Paper Chromatography

Paper Chromatography is the most simplest form of Chromatograpic technique. In this method a simple filter paper( usually Whatman 40) is used as a stationary phase. The cellulose in the filter paper acts as a polar stationary phase. Paper Chromatography is widely used as separative and analytical technique.

Thin layer Chromatography??

Thin Layer Chromatography(TLC) is a special application of adsorption chromatography. Here adsorbent is supported on a flat surface. In this chromatographic technique a thin layer of adsorbent is made on a glass surface specially over glass slides. Development of Chromatogram in this technique is accomplished by capillary movement of the solvent upon the thin layer of the adsorbent.

                                             
                                                   Fig: Schematic Representation of TLC.

Most common adsorbent used in TLC in order of importance are

Silica Gel > Alumina > Kieselghur > Cellulose

Common indicator used for developing process in TLC is iodine vapor. Here iodine vapor sprayed in the Chromatoplate after separation, is adsorbed in the area of plates containing organic compounds; brown spots are observed due to I2 charge transfer complex. Using TLC all most all compounds can be detected. This method is non destructive.

Analytical Chemistry/Instrumental analysis

Today we belong to a modern world with domination of electronic equipment everywhere in each and every field. These instruments are the main basis of analytical Chemistry. Before you can proceed to some chemical analysis. You need to know about those instrument and their functions how they actually work. How they are calibrated and how measurement is taken?  Let us take and example suppose you are measuring Sulphuric acid...

For this first you need to know what is the instrumental tolerance of your instrument. If you are measuring the volume using a measuring cylinder then you should know that how much possible error in volume could happen in your measurement. Instrumental tolerance is the error bar of an instrument. For example you may see at the top of your measuring cylinder that it is written 50ml±2ml. It means that if you measure 50ml with the cylinder you may get ±2 ml error. Temperature plays vital role while we are measuring volume, if you are measuring at high temperature your volume may be less more exact volume at NTP, and if you are measuring volume at low temperature your volume may be more than exact volume at NTP. But in above case the amount of material that you will take will be exactly reverse, it means at high temperature you may take less amount of substance because of expansion in volume and in low temperature you may take more amount of substance due to contraction.

Welcome to my Blog!

Hy everyone welcome to my blog. This blog is completely based on my knowledge about analytical chemistry that i have gained.