Buying small packets of silica gel in Mumbai
Since Mumbai is a coastal city, many HAM Radio Operators need to take good care of their Radio Sets, Amplifiers and other equipment which is easily susceptible to moisture. Although there are many sophisticated gadgets like dehumidifiers which are available, Silica Gel is the age old tried and tested method.
Silica Gel can be used to remove any type of moisture from any type of equipment chassis or component.
The problem is finding retail sachets or packets of it.
Today I picked up some sachets of Silica Gel, which were pretty reasonably priced from:
Amrutlal Bhurabhai & Co.
Anand Bhuvan, Ground Floor, 17, Babu Genu Road,
Princess Street, Mumbai - 400002.
+91-22-2201-1023 / +91-22-2201-1024 / +91-22-2201-9187
http://amrut.in
Pricing:
25 gms @ Rs. 8/-
10 gms @ Rs. 5/-
5 gms @ Rs. 3/-
Taxes Extra
* Prices may vary from time to time.
How to convert Figures to Words in MS Excel 2007
This guide will help you to convert number cells in MS Excel 2007 into their corresponding words in Rupees / Paise.
Eg: Convert 5252 to Five Thousand Two Hundred and Fifty Two Only
This guide is especially useful for businessmen, Chartered Accountants and traders, who maintain their data in MS Excel and often print Invoices, Vouchers or Cheques, on which they need to type in the Figure in Words manually.
This tutorial will help you convert the cells typed in figures to words - automatically, using a simple formula. The Microsoft Version is customized for Dollars / Cents.
This version is specifically for Indian businesses which use Rupees / Paise.
Step 1: Open Excel 2007
Step 2: Type Alt + F11 to start the Visual Basic Editor
Step 3: In the Visual Basic Editor go to Insert > Module.
Step 4: When the New Module Workspace opens on the right, copy and paste the following code into it
Option Explicit
'Main Function
Function SpellNumber(ByVal MyNumber)
Dim Rupees, Paise, Temp
Dim DecimalPlace, Count
ReDim Place(9) As String
Place(2) = " Thousand "
Place(3) = " Million "
Place(4) = " Billion "
Place(5) = " Trillion "
' String representation of amount.
MyNumber = Trim(Str(MyNumber))
' Position of decimal place 0 if none.
DecimalPlace = InStr(MyNumber, ".")
' Convert Paise and set MyNumber to Rupee amount.
If DecimalPlace > 0 Then
Paise = GetTens(Left(Mid(MyNumber, DecimalPlace + 1) & _
"00", 2))
MyNumber = Trim(Left(MyNumber, DecimalPlace - 1))
End If
Count = 1
Do While MyNumber <> ""
Temp = GetHundreds(Right(MyNumber, 3))
If Temp <> "" Then Rupees = Temp & Place(Count) & Rupees
If Len(MyNumber) > 3 Then
MyNumber = Left(MyNumber, Len(MyNumber) - 3)
Else
MyNumber = ""
End If
Count = Count + 1
Loop
Select Case Rupees
Case ""
Rupees = "No Rupees"
Case "One"
Rupees = "One Rupee"
Case Else
Rupees = Rupees & " Rupees"
End Select
Select Case Paise
Case ""
Paise = " and No Paise"
Case "One"
Paise = " and One Paisa"
Case Else
Paise = " and " & Paise & " Paise"
End Select
SpellNumber = Rupees & Paise
End Function' Converts a number from 100-999 into text
Function GetHundreds(ByVal MyNumber)
Dim Result As String
If Val(MyNumber) = 0 Then Exit Function
MyNumber = Right("000" & MyNumber, 3)
' Convert the hundreds place.
If Mid(MyNumber, 1, 1) <> "0" Then
Result = GetDigit(Mid(MyNumber, 1, 1)) & " Hundred "
End If
' Convert the tens and ones place.
If Mid(MyNumber, 2, 1) <> "0" Then
Result = Result & GetTens(Mid(MyNumber, 2))
Else
Result = Result & GetDigit(Mid(MyNumber, 3))
End If
GetHundreds = Result
End Function' Converts a number from 10 to 99 into text.
Function GetTens(TensText)
Dim Result As String
Result = "" ' Null out the temporary function value.
If Val(Left(TensText, 1)) = 1 Then ' If value between 10-19...
Select Case Val(TensText)
Case 10: Result = "Ten"
Case 11: Result = "Eleven"
Case 12: Result = "Twelve"
Case 13: Result = "Thirteen"
Case 14: Result = "Fourteen"
Case 15: Result = "Fifteen"
Case 16: Result = "Sixteen"
Case 17: Result = "Seventeen"
Case 18: Result = "Eighteen"
Case 19: Result = "Nineteen"
Case Else
End Select
Else ' If value between 20-99...
Select Case Val(Left(TensText, 1))
Case 2: Result = "Twenty "
Case 3: Result = "Thirty "
Case 4: Result = "Forty "
Case 5: Result = "Fifty "
Case 6: Result = "Sixty "
Case 7: Result = "Seventy "
Case 8: Result = "Eighty "
Case 9: Result = "Ninety "
Case Else
End Select
Result = Result & GetDigit _
(Right(TensText, 1)) ' Retrieve ones place.
End If
GetTens = Result
End Function' Converts a number from 1 to 9 into text.
Function GetDigit(Digit)
Select Case Val(Digit)
Case 1: GetDigit = "One"
Case 2: GetDigit = "Two"
Case 3: GetDigit = "Three"
Case 4: GetDigit = "Four"
Case 5: GetDigit = "Five"
Case 6: GetDigit = "Six"
Case 7: GetDigit = "Seven"
Case 8: GetDigit = "Eight"
Case 9: GetDigit = "Nine"
Case Else: GetDigit = ""
End Select
End Function
Step 5: Hit the Save button on the Toolbar of the Visual Basic Editor or Type Ctrl + S to save the module. In Excel 2007, you will have to save the file as a .xlsm (Macro-Enabled Excel Workbook).
Step 6: In your excel sheet in any cell type the following:
=SpellNumber(A1)
or
=SpellNumber(4253.35)
Where A1 is the cell whose value you want in words.
Note:
This formula will work ONLY within the workbook you have made the changes in. Everytime you want to use it in a new workbook, you will have to perform the steps again.
You will have to enable the macro content in the excel sheet, incase it automatically blocks the macro.
How to download, save or print an E-Ticket from the IRCTC.co.in website to a PDF file
The following steps will enable you to download an e-ticket to your computer in a pdf format for printing at a later time. This guide does not need you to install Adobe Acrobat Distiller / Writer or any paid software.
This guide is useful for persons who want to print an e-ticket issued by Indian Railways Catering and Tourism Corporation (IRCTC) but do not have a printer available at that time, or want to save a soft-copy of the e-ticket on a pen drive or hard disk and transfer it at a later time. This will save the e-ticket in a PDF format adnd is useful for people who do not have Adobe PDF Writer or PDF Distiller and want a Free Solution.
Step 1: Download a PDF Printer Software
Download and install a free PDF printer software.
Options include:
- BullZip BioPDF from http://www.bullzip.com/products/pdf/info.php#download
- doPDF from
OR
Install a paid PDF Printer like Adobe Acrobat or Adobe Distiller or Adobe Writer.
Step 2: Install the software to add the PDF Printer
Simply install it with basic settings. It will automatically add a printer by the name of BioPDF, to your Control Panel.
Step 3: Print the E-Ticket to a file, using the PDF Printer
When you open your e-ticket and select Print ERS, it will open in a new window and ask you to select a printer.
Click on the BioPDF option and click the Print Button. You will be prompted to put in a file name.
Give the file a name and location as required.
Step 4: Use the PDF file to store, copy, print or transfer the E-ticket
Transfer the PDF file to any computer that has a printer and Print your E-ticket.
You can transfer the PDF by email, pen-drive or any other media.
Mobile Number Portability in India
What is Mobile Number Portability (MNP) ?
Mobile Number Portability enables the mobile phone end-user to retain their telephone number without compromising on quality, reliability and operational convenience when they change their service provider in a service area. It requires the originating network to determine the correct destination for a given number and forward the call to the destination network.
Why port? What are the benefits of Mobile Number Portability?
Benefits to subscribers:
- Better quality & bouquet of value-added services offered by any operator
- Competitive tariff package will be offered by all providers
- Survival of the most competent and promising providers in the market
Benefits to mobile network providers and the mobile industry:
- Updated technology and latest sophistication prevent stagnation of resource upgradation
- Healthy competition between providers
What are the requirements for Mobile Number Portability?
An effective MNP system requires a database having information of the networks and associated imported or exported numbers. In India, a central as well as regional databases are being planned. Most countries have a centralized database service managed by a neutral third party. A centralized clearing house for electronically processing the importing / exporting requests also needs to be setup, to minimize the time to port (i.e. to transfer the numbers from one network to another).
Who manages the Ported Number Database?
The number database is managed by a neutral third party. The cost of the database is to be borne by each operator depending on the strength of their subscribers i.e. depending on their market share.
In India, Telcordia Technologies, formerly Bell Communications Research, Inc. has been granted a license by DoT to manage the portability clearing house for Zone 2 (Kolkata, Tamil Nadu including Chennai, Andhra Pradesh, Karnataka, Kerala, Madhya Pradesh, West Bengal, Assam, Bihar, North East, and Orissa).
What are the hurdles / issues faced by the MNP system?
- Handset portability from GSM to CDMA type of networks
- Constant updation of the database to keep it consistent
- SMS routing (i. e. forwarding SMS's between networks)
- routing of Long Distance (National / International) calls
- Altering the National Numbering Plan (which maintains the number format and series allocation of phone numbers for different services)
- Cooperation of all stakeholders and mobile phone service providers
- Dispute Resolution Machinery and Guidelines for mobile service providers
- Coordinated billing for multi-mode facilities
- Porting Fees and guidelines
When will MNP be implemented in India?
MNP was earlier to be implemented as below:
- Phase 1 - 31-Dec-2009: Delhi, Mumbai, Kolkata, Chennai, and circle A service areas (Karnataka, Maharashtra, Gujarat, Andhra Pradesh and Tamil Nadu)
- Phase 2 - 20-Mar-2010: Other Parts of India.
12-May-2010:
MNP will be implemented from 30-Jun-2010 across India, for all circles, zones and operators. The decision was taken by the Department of Telecomm., since most of the providers had not upgraded their network and methods of working, for enabling ease of Number Portability. Testing phase is to be completed by 15-May-2010, by which all providers are to test the porting of dummy numbers and notify the DoT of their success.
Latest Update:
Mobile Number Portability to be implemented from 31-Oct-2010, since most of the Service Providers are still in the testing phase and some have not even bought the necessary equipment.
What is the procedure for porting numbers?
- The end-user must submit a letter to the existing service provider, stating that he/she wishes to transfer their number to a new mobile service operator.
- Within 5 days there will be a subscriber verification and identification by the existing service provider.
- Within 2 days of verification, the application is to be sent to the clearing house to import/export the number.
- The service providers must inform the customer about the exact date and time the porting will take place.
What are the regulations, terms and conditions for porting numbers?
- The mobile number should have been with the current service provider for a term of 90 days or more. This prevents frequent change of provider and reduces the load on the porting database.
- A non-refundable fee, not exceeding Rs. 19 is to be paid to the gaining provider for every porting transaction. This is due to the fact that the gaining provider has to complete more formalities than if they get a new subscription.
- The porting request may be cancelled within 24-hours of making the application, but the porting fee will be non-refundable.
- The portability of the number will be restricted only to a given license service area / circle within a zone. You will not be allowed to shift your number to a provider in another zone/region.
- Post-paid customers can transfer their numbers only if they have cleared all outstanding payments.
- Pre-paid customers who transfer their numbers to a different provider, will forfeit the remaining pre-paid balance in their account, just as if they were terminating their account.
- The gaining provider, is not bound to pay any deposits or outstandings which are due from the old provider.
What is the Statute / Law governing Mobile Number Portability?
The Statute governing mobile number portability is called the Telecommunication Mobile Number Portability Per Port Transaction Charge and Dipping Charge Regulations, 2009. It is to come into effect on 31-Dec-2009, although the date for actual porting has been delayed to March 2010.
Useful Links:
- Telcordia Technologies Joint Venture - http://www.mnpindia.in/index.aspx
- Documents of Department of Telecommunications - http://dot.gov.in/as/MNP/MNPindex.htm
Telecommunication Mobile Number Portability Per Port Transaction Charge and Dipping Charge Regulations, 2009 Bare Act
Source: http://www.trai.gov.in/
Cloud Computing
What is Cloud Computing?
It is just like ordering food from a restaurant. You do not have to bother about the cooking / dishes / heating / re-heating etc. You only have to enjoy the food when it arrives.
Why Cloud Computing?
It is called cloud computing, because everything is internet based and works off the internet, it is not dependant on a certain computer or server or service. It is like a huge pool of information, which is used for multiple mammoth services.
It is called "Cloud" computing because in Network diagrams, we use the cloud as a symbol for the Internet.
Benefits:
- Cloud computing is seen as a way to break the barriers of space / resources and limited capacity of computers, by putting everything on the cloud i.e. the internet. This reduces cost and allows scalability in seconds.
- Instead of running your applications yourself, they run on a shared data center. When you use any application that runs in the cloud, you just log in, customize it, and start using it. That’s the power of cloud computing.
- CRM, HR, accounting etc. Cloud-based apps can be up and running in a few days
- No need to buy servers and software. When your apps run in the cloud, you don’t buy anything. It’s all rolled up into a predictable monthly subscription, so you only pay for what you actually use. Perfect for the Indian Econo-Budgets.
- It also does away with multiple IT Professionals / Support staff, since there is no maintenance required from the users end.
Examples:
Skype / Windows Live / Zoho (which mirakle couriers uses as an ERP) / SalesForce
Frequencies
Very Low Frequency (VLF)
- 3-30 KHz
- Also known as Surface Waves
- Propogation / Transmission through the surface of the earth
- Radiation range is thousands of kilometers
- Requires large transmission power due to absorption by the earth.
- Wavelength is very high
- Huge antenna structures required
- Waveband is not preferred by HAMs
Low Frequency (LF)
- 30-300 KHz
- Progopation same as VLF
- Range same as VLF
- Limitations same as VLF
- This wave band is used for Ship-shore navigational aids.
Medium Frequency
- 300-3000 KHz
- Also known as Tropospheric Waves
- Propogation / Transmission through the troposphere
- Popular Medium Wave (MW)
- Radiation range is upto 700 km during the day but increases during the night
- Requires large transmission power due to absorption by the earth.
- Wavelength is high
- Huge antenna structures required
- Waveband is not preferredby HAMs
High Frequency (HF)
- 3-30 MHz
- Also known as Sky Waves
- Most popular short wave band.
- World Wide Communication for all services including Amateur Bands
- Waves travel from the antenna, into the Ionosphere and reflected to a distant point.
- The wave encircles the globe (circumference of 40,087 Kms) in 150 milliseconds over 300,000 hops.
- The reflected distance depends upon the angle of radiation from the antenna with respect to the earth. Radiation angle determines the distance coverage, which in turn increases the reflected angle. The effect is extended distance coverage. Lowering the antenna height produces the inverse effect.
Very High Frequency (VHF)
- 30 - 300 MHz
- This wave penetrates the ionosphere and does not reflect back to earth, hence long distance communication is not possible.
- It is also known as space wave.
- It is most effective for line of sight communication and local mobile operation.
- The range of this wave is dependant on the height of the antenna. The higher the antenna, the larger the range.
- The normal average range is 50-75 Kms., and with an antenna can extend beyond 100 Kms.
Ultra High Frequency (UHF)
- 300 - 3000 MHz
- Similar to the VHF and also works for Line of Sight Communication (Space Waves)
- Penetration into the ionosphere is even sharper than VHF and thus works very well for satellite communication and outer space communication (like with the moon or space crafts).
- HAMs also use the lower part of this band for local communication just like VHF, but the Line of Sight is more critical here.
Super High Frequency (SHF)
- 3 - 30 GHz
- Similar to UHF and is exclusively used for space communication.
- Requires precise alignment of both Rx and Tx antennas.
- This frequency on commercial bands is used for TV and Radio Relay using Geo Stationery satellites in space and dish antennas on earth.
Extremely High Frequency (EHF)
- 30 - 300 GHz
Robots.txt
Web site owners use the /robots.txt file to give instructions about their site to web robots; this is called The Robots Exclusion Protocol. By writing a structured text file you can indicate to robots that certain parts of your server are not to be cached / accessed / crawled by some or all robots.
- robots can ignore your /robots.txt. Especially malware robots that scan the web for security vulnerabilities, and email address harvesters used by spammers will pay no attention.
- the /robots.txt file is a publicly available file. Anyone can see what sections of your server you don't want robots to use.
- /robots.txt should not be used to hide information.
How to create a /robots.txt file Where to put it The short answer: in the top-level directory of your web server.
The longer answer:
When a robot looks for the "/robots.txt" file for URL, it strips the path component from the URL (everything from the first single slash), and puts "/robots.txt" in its place.
For example, for "http://www.example.com/shop/index.html, it will remove the "/shop/index.html", and replace it with "/robots.txt", and will end up with "http://www.example.com/robots.txt".
So, as a web site owner you need to put it in the right place on your web server for that resulting URL to work. Usually that is the same place where you put your web site's main "index.html" welcome page. Where exactly that is, and how to put the file there, depends on your web server software.
Remember to use all lower case for the filename: "robots.txt", not "Robots.TXT.
What program should I use to create /robots.txt?
- On Microsoft Windows, use notepad.exe, or wordpad.exe (Save as Text Document), or even Microsoft Word (Save as Plain Text)
- On the Macintosh, use TextEdit (Format->Make Plain Text, then Save as Western)
- On Linux, vi or emacs
Points to note
- Wildcards are _not_ supported: instead of 'Disallow: /tmp/*' just say 'Disallow: /tmp/'.
- You shouldn't put more than one path on a Disallow line (this may change in a future version of the spec)
Example
# /robots.txt file for http://webcrawler.com/
# mail webmaster@webcrawler.com for constructive criticism
User-agent: webcrawler Disallow:
User-agent: lycra Disallow: /
User-agent: * Disallow: /tmp Disallow: /logs
- The first two lines, starting with '#', specify a comment
- The first paragraph specifies that the robot called 'webcrawler' has nothing disallowed: it may go anywhere.
- The second paragraph indicates that the robot called 'lycra' has all relative URLs starting with '/' disallowed. Because all relative URL's on a server start with '/', this means the entire site is closed off.
- The third paragraph indicates that all other robots should not visit URLs starting with /tmp or /log. Note the '*' is a special token, meaning "any other User-agent"; you cannot use wildcard patterns or regular expressions in either User-agent or Disallow lines.
Proximity Cards
Proximity card are contactless integrated circuit devices used for security access or payment systems.
- 125 kHz devices or the newer 13.56 MHz contactless RFID cards
- also known as contactless smartcards
- have a range of 0-3 inches in most instances, allowing the user to leave the card in one's wallet, or purse
How do smart cards work ?
Proximity cards use an LC circuit. An IC, capacitor, and coil are connected in parallel. The card reader presents a field that excites the coil and charges the capacitor, which in turn energizes and powers the IC. The IC then transmits the card number via the coil to the card reader. The card readers communicate in Wiegand protocol that consists of a data 0 and a data 1 circuit.
Usage
- identification cards
- keycards
- payment cards
- public transit fare cards
Light Emitting Diode
Why use LEDs ?
LEDs have several advantages over conventional incandescent lamps.
- they don't have a filament that will burn out, so they last much longer
- their small plastic bulb makes them a lot more durable
- They also fit more easily into modern electronic circuits
- the main advantage is efficiency. In conventional incandescent bulbs, the light-production process involves generating a lot of heat (the filament must be warmed). This is completely wasted energy, unless you're using the lamp as a heater, because a huge portion of the available electricity isn't going toward producing visible light. LEDs generate very little heat, relatively speaking. A much higher percentage of the electrical power is going directly to generating light, which cuts down on the electricity demands considerably.
- LEDs are brighter. The LED arrays fill the entire "hole" and have equal brightness across the entire surface, making them brighter overall.
- LED bulbs last for years, while halogen bulbs last for months.
- LED bulbs save a lot of energy. this is useful in battery powered or energy-saving devices
- They do not contain Mercury or any harmful chemical substance which affects the environment, like CFLs.
- LEDs can emit light of an intended color without the use of color filters that traditional lighting methods require. This is more efficient and can lower initial costs.
- When used in applications where dimming is required, LEDs do not change their color tint as the current passing through them is lowered, unlike incandescent lamps, which turn yellow.
- LEDs are do not burn out with frequent on-off cycling, like normal bulbs.
- LEDs, are difficult to damage with external shock and do not break if dropped on the ground.
Prices of LEDs
Until recently, LEDs were too expensive to use for most lighting applications because they're built around advanced semiconductor material. The price of semiconductor devices has plummeted over the past decade, however, making LEDs a more cost-effective lighting option for a wide range of situations.
- more expensive than incandescent lights up front,
- lower cost in the long run can make them a better buy
Usage
- Most cities in the United States are in the process of replacing their incandescent traffic lights with LED units
- Residential Lighting
- security Lighting
- Flashlights - maglite
- Remote controls, such as for TVs and VCRs, often use infrared LEDs.
- Movement sensors, for example in optical computer mice
- In optical fiber cables
- Toys and recreational sporting goods
- In pulse oximeters for measuring oxygen saturation
- Computers, for hard drive activity and power on.
- Sterilization of water and other substances using UV light.
Ping
The Ping utility is essentially a system administrator's tool that is used to see if a computer is operating and also to see if network connections are intact. Ping uses the Internet Control Message Protocol (ICMP) Echo function.
What does ping symbolise?
Ping maybe considered an acronym for the words 'Packet INternet Groper'.
It may have also been adopted from a verb that the US Navy used to describe what its submarines do when looking for objects under the sea. Their subs send out sonar waves and then wait for a return wave when it bounces off something, such as another sub, whale, ocean floor etc. This, in turn, was adopted from bats and dolphins, who navigate in roughly the same way. This is what a system administrator does when Ping is used. As such, Ping has also evolved into a verb in the computer industry, and it is used in somewhat the same manner of the Navy.
How ping works
A small packet is sent through the network to a particular IP address.
This packet contains 64 bytes - 56 data bytes and 8 bytes of protocol reader information.
The computer that sent the packet then waits (or 'listens') for a return packet. If the connections are good and the target computer is up, a good return packet will be received.
PING can also tell the user the number of hops that lie between two computers and the amount of time it takes for a packet to make the complete trip. Additionaly, an administrator can use Ping to test out name resolution. If the packet bounces back when sent to the IP address but not when sent to the name, then the system is having a problem matching the name to the IP address.
The time it takes for the packet to get to the target computer and back again is known as the round trip time. If this takes an extended period of time, it is indicative that something may be wrong.