PDK Centre

04/05/2026

Corrosion (କ୍ଷୟ):
It's the natural process where metals gradually degrade due to environmental chemical reactions (mainly with oxygen and moisture, creating rust on iron). (ଧାତୁଗୁଡ଼ିକର ପରିବେଶୀୟ ରାସାୟନିକ ପ୍ରତିକ୍ରିୟା ଯୋଗୁଁ ହେଉଥିବା ପ୍ରାକୃତିକ କ୍ଷୟ (ଲୁହାରେ କଳଙ୍କ)।)

Stopping/Slowing Techniques:
Creating physical barriers or using sacrificial protection: (ଭୌତିକ ପ୍ରତିବନ୍ଧକ କିମ୍ବା ବଳିଦାନ ସୁରକ୍ଷା ବ୍ୟବହାର:)
1. Painting/Oiling (ପେଣ୍ଟିଂ/ତେଲ ଲଗାଇବା): Forms an impermeable film, physically blocking oxygen and moisture from reaching the metal surface. (ଏକ ଅଭେଦ୍ୟ ଆସ୍ତରଣ ତିଆରି କରି ବାୟୁ ଏବଂ ଜଳକୁ ଧାତୁ ପୃଷ୍ଠକୁ ଆସିବାକୁ ରୋକେ।)
2. Galvanisation (ଜାଲଭାନାଇଜେସନ): Coats iron with sacrificial zinc, which corrodes *instead of* the iron. (ଲୁହା ଉପରେ ଜିଙ୍କର ଆସ୍ତରଣ ଦିଏ, ଯାହା ଲୁହା ବଦଳରେ କ୍ଷୟ ହୁଏ।)

01/05/2026

Oxidation (ଜାରଣ):
Oxidation is a chemical reaction that involves the loss of electrons from an atom or ion. This results in an increase in the oxidation state of that species.

ଜାରଣ ହେଉଛି ଏକ ରାସାୟନିକ ପ୍ରତିକ୍ରିୟା, ଯେଉଁଥିରେ ଗୋଟିଏ ପରମାଣୁ ବା ଆୟନରୁ ଇଲେକ୍ଟ୍ରନ୍‌ର ହ୍ରାସ ଘଟିଥାଏ। ଏହା ଫଳରେ ସେହି ପରମାଣୁ ବା ଆୟନର ଜାରଣ ଅବସ୍ଥାରେ ବୃଦ୍ଧି ଘଟିଥାଏ।

Why Rust is Created in Iron (ଲୁହାରେ କଳଙ୍କ କାହିଁକି ଲାଗେ?)?:
Iron rusts when it is exposed to oxygen and water for an extended period. The oxidation process in iron creates iron oxide, which is the reddish-brown coating known as rust. This reaction can be summarized as:
4Fe + 3O₂ + 6H₂O → 2Fe₂O₃·3H₂O

ଲୁହା ଯେତେବେଳେ ଦୀର୍ଘ ସମୟ ପର୍ଯ୍ୟନ୍ତ ଅମ୍ଳଜାନ ଏବଂ ଜଳ ସହିତ ସଂସ୍ପର୍ଶରେ ଆସେ, ସେତେବେଳେ ଏଥିରେ କଳଙ୍କ ଲାଗେ। ଲୁହାରେ ଘଟୁଥିବା ଜାରଣ ପ୍ରକ୍ରିୟା ଫଳରେ ଲୌହ ଅକ୍ସାଇଡ୍ (Iron Oxide) ସୃଷ୍ଟି ହୁଏ, ଯାହା ଲାଲ୍-ବାଦାମୀ ରଙ୍ଗର ଏକ ଆସ୍ତରଣ ଭାବରେ ଦେଖାଯାଏ ଏବଂ ଏହାକୁ କଳଙ୍କ କୁହାଯାଏ। ଏହି ପ୍ରତିକ୍ରିୟାକୁ ନିମ୍ନଲିଖିତ ଭାବରେ ସଂକ୍ଷେପରେ ବର୍ଣ୍ଣନା କରାଯାଇପାରିବ:
4Fe + 3O₂ + 6H₂O → 2Fe₂O₃·3H₂O

1. Aluminium Oxidation (ଆଲୁମିନିୟମ୍ ଜାରଣ):
Aluminium reacts with oxygen in the air to form a thin, protective layer of aluminium oxide on its surface. This process is called anodizing. The reaction is:
4Al + 3O₂ → 2Al₂O₃

ଆଲୁମିନିୟମ୍ ବାୟୁରେ ଥିବା ଅମ୍ଳଜାନ ସହିତ ପ୍ରତିକ୍ରିୟା କରି ଏହାର ପୃଷ୍ଠରେ ଆଲୁମିନିୟମ୍ ଅକ୍ସାଇଡ୍‌ର ଏକ ପତଳା, ସୁରକ୍ଷିତ ସ୍ତର ଗଠନ କରେ। ଏହି ପ୍ରକ୍ରିୟାକୁ ଆନୋଡାଇଜିଂ (Anodizing) କୁହାଯାଏ। ଏହି ପ୍ରତିକ୍ରିୟା ହେଉଛି:
4Al + 3O₂ → 2Al₂O₃

2. Magnesium Oxidation (ମ୍ୟାଗ୍ନେସିୟମ୍ ଜାରଣ):
Magnesium burns brightly in the presence of oxygen, forming magnesium oxide. The reaction is:
2Mg + O₂ → 2MgO

ଅମ୍ଳଜାନର ଉପସ୍ଥିତିରେ ମ୍ୟାଗ୍ନେସିୟମ୍ ଉଜ୍ଜ୍ୱଳ ଭାବରେ ଜଳେ ଏବଂ ମ୍ୟାଗ୍ନେସିୟମ୍ ଅକ୍ସାଇଡ୍ ଗଠନ କରେ। ଏହି ପ୍ରତିକ୍ରିୟା ହେଉଛି:
2Mg + O₂ → 2MgO

30/04/2026

Acidity: Concept & Remedy | ଅମ୍ଳତା: ଧାରଣା ଏବଂ ପ୍ରତିକାର
Acidity (ଅମ୍ଳତା):
Occurs when the stomach produces excess Hydrochloric Acid (HCl). It causes burning in the chest and stomach.
ପେଟରେ ଅଧିକ HCl ଅମ୍ଳ କ୍ଷରଣ ହେଲେ ଜ୍ୱଳନ ଅନୁଭୂତ ହୁଏ.
Reasons (କାରଣ):
Spicy food, stress, skipping meals, or overusing medicines.
ମସଲାଯୁକ୍ତ ଖାଦ୍ୟ, ମାନସିକ ଚିନ୍ତା ଏବଂ ଠିକ୍ ସମୟରେ ନଖାଇବା.
Neutralization (ପ୍ରଶମନ):
Antacids (Bases) like Mg(OH)_2 react with acid to form salt and water, providing relief.
ଆଣ୍ଟାସିଡ୍ (କ୍ଷାର) ଅମ୍ଳ ସହ ପ୍ରତିକ୍ରିୟା କରି ଲବଣ ଓ ଜଳ ସୃଷ୍ଟି କରେ, ଯାହା ଆରାମ ଦିଏ.

29/04/2026

Industrial Pollution occurs when factories release harmful substances into the environment.

Pollutants & Impact
Dangerous pollutants include Sulfur Dioxide (SO_2), Nitrogen Oxides (NO_x), and Heavy Metals (Lead, Mercury). These cause acid rain, global warming, and severe respiratory diseases.

Control Technologies
Scrubbers: Remove acidic gases from exhaust.
Electrostatic Precipitators: Capture dust particles.
Filtration: Cleans industrial wastewater before discharge.

ଶିଳ୍ପାଞ୍ଚଳ ପ୍ରଦୂଷଣ (Industrial Pollution)
କାରଖାନାରୁ ନିର୍ଗତ କ୍ଷତିକାରକ ପଦାର୍ଥ ପରିବେଶକୁ ଦୂଷିତ କରିଥାଏ।
ପ୍ରଦୂଷକ ଓ ପ୍ରଭାବ: ସଲଫର ଡାଇଅକ୍ସାଇଡ୍ ଏବଂ ଭାରୀ ଧାତୁ (ସିସା, ପାରଦ) ମୁଖ୍ୟ ପ୍ରଦୂଷକ। ଏହା ଅମ୍ଳ ବର୍ଷା ଏବଂ ଶ୍ୱାସକ୍ରିୟା ଜନିତ ରୋଗ ସୃଷ୍ଟି କରେ।
ନିୟନ୍ତ୍ରଣ ପ୍ରଯୁକ୍ତି:
ସ୍କ୍ରବର୍ (Scrubbers): ବିଷାକ୍ତ ଗ୍ୟାସ୍ ଦୂର କରେ।
ଜଳ ପରିଶ୍ରବଣ (Filtration): ଦୂଷିତ ଜଳକୁ ସଫା କରିଥାଏ।

28/04/2026

ମୁଖ୍ୟତଃ ପ୍ରବଳ ବର୍ଷା ଯୋଗୁଁ କ୍ଷାରୀୟ ଅଂଶ ଧୋଇଯିବା, ଅତ୍ୟଧିକ ରାସାୟନିକ ସାର ପ୍ରୟୋଗ ଏବଂ ଗଛର ଚେରରୁ ନିର୍ଗତ ଅମ୍ଳ ଯୋଗୁଁ ମାଟିର pH ସ୍ତର କମିଯାଏ, ଯାହା ଫଳରେ ମାଟି ଅମ୍ଳୀୟ ବା ଏସିଡିକ୍ ହୋଇଥାଏ।

Soil type is determined by the concentration of H^+ ions (Acidic), OH^- ions (Basic), or dissolved salts (Saline).
Identification (ଚିହ୍ନଟ ପ୍ରକ୍ରିୟା):
Use a pH meter or Litmus paper test:
pH less than 7: Acidic (ଅମ୍ଳୀୟ)
pH greater than 7: Basic (କ୍ଷାରୀୟ)
High Conductivity: Saline (ଲବଣାକ୍ତ)
Neutralization Steps (ପ୍ରଶମିତ କରିବା ପ୍ରଣାଳୀ):
Acidic Soil: Add Lime (CaCO_3). This base neutralizes excess acid, raising the pH.
(ଅମ୍ଳୀୟ ମୃତ୍ତିକାରେ ଚୂନ ପ୍ରୟୋଗ କରି ଏହାର ଅମ୍ଳତା କମାଯାଏ।)
Alkaline Soil: Add Sulfur or Gypsum (CaSO_4). These release acidifying ions to lower the pH.
(କ୍ଷାରୀୟ ମୃତ୍ତିକାରେ ଜିପସମ୍ ବ୍ୟବହାର କରି ଏହାକୁ ଚାଷ ଉପଯୋଗୀ କରାଯାଏ।)
Saline Soil: Perform Leaching (flushing with fresh water) to wash away salts, and add Gypsum to improve structure.
(ଲବଣାକ୍ତ ମୃତ୍ତିକାକୁ ପରିଷ୍କାର ଜଳ ଦ୍ଵାରା ଧୋଇ ଦିଆଯାଏ।)



#ପ୍ରଶମନ
#ମୃତ୍ତିକାପ୍ରଶମନ

02/10/2025

08/04/2025

Shortcut keys:-
CTRL+A. . . . . . . . . . . . . . . . Select All
CTRL+C. . . . . . . . . . . . . . . . Copy
CTRL+X. . . . . . . . . . . . . . . . . Cut
CTRL+V. . . . . . . . . . . . . . . . . Paste
CTRL+Z. . . . . . . . . . . . . . . . . Undo
CTRL+B. . . . . . . . . . . . . . . . . Bold
CTRL+U. . . . . . . . . . . . . . . . . Underline
CTRL+I . . . . . . . . . . . . . . . . . Italic
F1 . . . . . . . . . . . . . . . . . . . . . . Help
F2 . . . . . . . . . . . . . . . . . . . Rename selected object
F3 . . . . . . . . . . . . . . . . . . . . . Find all files
F4 . . . . . . .. . . Opens file list drop-down in dialogs
F5 . . . . . . . . . . . . . . . . . . . . . Refresh current window
F6 . . . . . . . . . . . Shifts focus in Windows Explorer
F10 . . . . . . . . . . . . . . . Activates menu bar options
ALT+TAB . . .. . Cycles between open applications
ALT+F4 .. . . Quit program, close current window
ALT+F6 . . Switch between current program windows
ALT+ENTER. . . . . . . . . . . . . . Opens properties dialog
ALT+SPACE . . . . . . . . . . . . . . System menu for current window
ALT+¢ . . . . . . . . . . . . . . . . . . opens drop-down lists in dialog boxes
BACKSPACE . . . . . . . . . . . . . Switch to parent folder
CTRL+ESC . . . . . . . . . . . . . . Opens Start menu
CTRL+ALT+DEL . . . . . . . . . . Opens task manager, reboots the computer
CTRL+TAB . . . . . . . . . . . . . . Move through property tabs
CTRL+SHIFT+DRAG . . . . . . . Create shortcut (also right-click, drag)
CTRL+DRAG . . . . . . . . . . . . . Copy File
ESC . . . . . . . . . . . . . . . . . . . Cancel last function
SHIFT . . . . . . . . . . . . . . . . . . Press/hold SHIFT, insert CD-ROM to bypass auto-play
SHIFT+DRAG . . . . . . . . . . . . Move file
SHIFT+F10. . . . . . . . . . . . . . . Opens context menu (same as right-click)
SHIFT+DELETE . . . . . . . . . . . Full wipe delete (bypasses Recycle Bin)
ALT+underlined letter . . . . Opens the corresponding menu
PC Keyboard Shortcuts
Document Cursor Controls
HOME . . . . . . . . . . . . . . to beginning of line or far left of field or screen
END . . . . . . . . . . . . . . . . to end of line, or far right of field or screen
CTRL+HOME . . . . . . . . to the top
CTRL+END . . . . . . . . . . to the bottom
PAGE UP . . . . . . . . . . . . moves document or dialog box up one page
PAGE DOWN . . . . . . . . moves document or dialog down one page
ARROW KEYS . . . . . . . move focus in documents, dialogs, etc.
CTRL+ > . . . . . . . . . . . . next word
CTRL+SHIFT+ > . . . . . . selects word
Windows Explorer Tree Control
Numeric Keypad * . . . Expand all under current selection
Numeric Keypad + . . . Expands current selection
Numeric Keypad – . . . Collapses current selection
¦ . . . . . . . . . . . . . . . . . . . Expand current selection or go to first child
‰ . . . . . . . . . . . . . . . . . . Collapse current selection or go to parent
Special Characters
‘ Opening single quote . . . alt 0145
’ Closing single quote . . . . alt 0146
“ Opening double quote . . . alt 0147
“ Closing double quote. . . . alt 0148
– En dash. . . . . . . . . . . . . . . alt 0150
— Em dash . . . . . . . . . . . . . . alt 0151
… Ellipsis. . . . . . . . . . . . . . . . alt 0133
• Bullet . . . . . . . . . . . . . . . . alt 0149
• ®️ Registration Mark . . . . . . . alt 0174
• ©️ Copyright . . . . . . . . . . . . . alt 0169
• ™️ Trademark . . . . . . . . . . . . alt 0153
• ° Degree symbol. . . . . . . . . alt 0176
• ¢ Cent sign . . . . . . . . . . . . . alt 0162
• 1⁄4 . . . . . . . . . . . . . . . . . . . . . alt 0188
• 1⁄2 . . . . . . . . . . . . . . . . . . . . . alt 0189
• 3⁄4 . . . . . . . . . . . . . . . . . . . . . alt 0190
• PC Keyboard Shortcuts
• Creating unique images in a uniform world! Creating unique images in a uniform world!
• é . . . . . . . . . . . . . . . alt 0233
• É . . . . . . . . . . . . . . . alt 0201
• ñ . . . . . . . . . . . . . . . alt 0241
• ÷ . . . . . . . . . . . . . . . alt 0247
• File menu options in current program
• Alt + E Edit options in current program
• F1 Universal help (for all programs)
• Ctrl + A Select all text
• Ctrl + X Cut selected item
• Shift + Del Cut selected item
• Ctrl + C Copy selected item
• Ctrl + Ins Copy selected item
• Ctrl + V Paste
• Shift + Ins Paste
• Home Go to beginning of current line
• Ctrl + Home Go to beginning of document
• End Go to end of current line
• Ctrl + End Go to end of document
• Shift + Home Highlight from current position to beginning of line
• Shift + End Highlight from current position to end of line
• Ctrl + f Move one word to the left at a time
• Ctrl + g Move one word to the right at a time
• MICROSOFT®️ WINDOWS® SHORTCUT KEYS
• Alt + Tab Switch between open applications
• Alt +
• Shift + Tab
• Switch backwards between open
• applications
• Alt + Print
• Screen
• Create screen shot for current program
• Ctrl + Alt + Del Reboot/Windows®️ task manager
• Ctrl + Esc Bring up start menu
• Alt + Esc Switch between applications on taskbar
• F2 Rename selected icon
• F3 Start find from desktop
• F4 Open the drive selection when browsing
• F5 Refresh contents
• Alt + F4 Close current open program
• Ctrl + F4 Close window in program
• Ctrl + Plus
• Key
• Automatically adjust widths of all columns
• in Windows Explorer
• Alt + Enter Open properties window of selected icon
• or program
• Shift + F10 Simulate right-click on selected item
• Shift + Del Delete programs/files permanently
• Holding Shift
• During Bootup
• Boot safe mode or bypass system files
• Holding Shift
• During Bootup
• When putting in an audio CD, will prevent
• CD Player from playing
• WINKEY SHORTCUTS
• WINKEY + D Bring desktop to the top of other windows
• WINKEY + M Minimize all windows
• WINKEY +
• SHIFT + M
• Undo the minimize done by WINKEY + M
• and WINKEY + D
• WINKEY + E Open Microsoft Explorer
• WINKEY + Tab Cycle through open programs on taskbar
• WINKEY + F Display the Windows®️ Search/Find feature
• WINKEY +
• CTRL + F
• Display the search for computers window
• WINKEY + F1 Display the Microsoft®️ Windows®️ help
• WINKEY + R Open the run window
• WINKEY +
• Pause /Break
• Open the system properties window
• WINKEY + U Open utility manager
• WINKEY + L Lock the computer (Windows XP®️ & later)
• OUTLOOK®️ SHORTCUT KEYS
• Alt + S Send the email
• Ctrl + C Copy selected text
• Ctrl + X Cut selected text
• Ctrl + P Open print dialog box
• Ctrl + K Complete name/email typed in address bar
• Ctrl + B Bold highlighted selection
• Ctrl + I Italicize highlighted selection
• Ctrl + U Underline highlighted selection
• Ctrl + R Reply to an email
• Ctrl + F Forward an email
• Ctrl + N Create a new email
• Ctrl + Shift + A Create a new appointment to your calendar
• Ctrl + Shift + O Open the outbox
• Ctrl + Shift + I Open the inbox
• Ctrl + Shift + K Add a new task
• Ctrl + Shift + C Create a new contact
• Ctrl + Shift+ J Create a new journal entry
• WORD®️ SHORTCUT KEYS
• Ctrl + A Select all contents of the page
• Ctrl + B Bold highlighted selection
• Ctrl + C Copy selected text
• Ctrl + X Cut selected text
• Ctrl + N Open new/blank document
• Ctrl + O Open options
• Ctrl + P Open the print window
• Ctrl + F Open find box
• Ctrl + I Italicize highlighted selection
• Ctrl + K Insert link
• Ctrl + U Underline highlighted selection
• Ctrl + V Paste
• Ctrl + Y Redo the last action performed
• Ctrl + Z Undo last action
• Ctrl + G Find and replace options
• Ctrl + H Find and replace options
• Ctrl + J Justify paragraph alignment
• Ctrl + L Align selected text or line to the left
• Ctrl + Q Align selected paragraph to the left
• Ctrl + E Align selected
,₹ symbol: ctrl+alt+4
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