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Selasa, Mei 28, 2013
Find Email
Find the Person Behind an Email Address
You get an email from a person with whom you have never interacted before and therefore, before you reply to that message, you would like to know something more about him or her. How do you do this without directly asking the other person?
Web search engines are obviously the most popular place for performing reverse email lookups but if the person you’re trying to research doesn’t have a website or has never interacted with his email address on public forums before, Google will probably be of little help.
No worries, here are few tips and online services that may still help you uncover the identity of that unknown email sender.
#1. Find the sender’s location
Open the header of the email message and look for lines that say “Received: from” followed by an IP address in square brackets. If there are multiple entries, use the IP address mentioned in the last entry.
Now paste the IP address in this trace route tool and you should get a fairly good idea about the location of the email sender..Find the other Websites
How to Find the other Websites of a Person?
Say you are on a website example.com and would like to know which other web domains are owned by the same person who owns that example.com website. Is it possible?
Yes there are some easy workarounds (and tools) that can help you find domains owned by an individual or a company though you may not be successful on every hunt. Let’s give it a try!
Step 1: Reverse Whois Lookups with Google
When you register a web domain, your name, contact address, phone number and other details are stored with the domain in a public registry database that anyone can access online using a Whois Lookup tool.
Go to whois.sc and enter the domain name that you are trying to research. This will provide you contact details of the domain registrant and you can then use this data to perform a reverse whois lookup on Google to find other domains of that person.
Replace Phone Number or Street Address in the above search queries with the actual data from the whois database. You may also perform reverse Whois Lookups by name but that may return too many results – phone numbers and postal addresses are more likely to be unique.
Step 2: Perform Reverse IP Lookups
Some domain owners may have opted for “private” registration (Google Appsdoes this for free) and in that case, their contact details won’t be available in the public whois database.
The next option you should try is a Reverse IP lookup. These tools determine the IP address of the server that is hosting a website – example.com in our example – and will then provide you are list of other websites that are hosted on that same server. The logic is that if a person has multiple websites, he could be using the same web server to host them.
You can use Bing to perform a Reverse IP check for any domain or an even easier tool is spyonweb.com – just put the site’s domain and it will show other websites hosted on that server. If you get hundreds of domains in the search results, it possibly means that the person is using a shared host and thus he may not be the owner of all these domains.
Step 3: Reverse Google AdSense Lookups
If a web domain is using Google AdSense ads, you can use Blekko search to find all the other sites on the web that use the same AdSense ID.
View the HTML page source of any website and look for the AdSense string which has a pattern like ca-pub-1234. The numeric part (1234) is the AdSense ID which you can put into Blekko in the following format:
Some of the returned sites could belong to scrapers but you should be able to unearth some legitimate sites as well, if they are also using AdSense.
Step 4. Reverse Google Analytics Lookups
Google AdSense is only popular among content publishers but almost every website is using Google Analytics for traffic statistics. And there are online tools available that can quickly find all websites that are are connected to the same Google Analytics account.
Go to ewhois.com and type the domain name that are you are researching. Next choose the Reverse Google Analytics ID Lookup tab and it should bring a list of all web domains that are connected to the same Google Analytics ID.
This is the most effective option of them all though it would only work for live websites that use Analytics while standard Whois lookups can even find web domains that have only been registered but are not live yet.
Web Development & Web Technologies
How to start your career in Web Development & Web Technologies
Usually we publish articles that are of interest only to the “electronics” community. However today I thought of publishing an article about career opportunities in Web Development & Web Technologies. The reason being the wide opportunities it provides for fresh engineers & graduates. “Cloud Computing” is making a wave and plenty of new job opportunities are posted every week in this area. “Web Development” is a general term which can be used in connection with anything that is related to web & internet. “Web Technologies” refers to technologies that are used to build applications for the web. Examples of technologies used in web may range into many:-
1) Server side languages like PHP, ASP.NET, JSP, Phyton, Ruby
2) Browser side scripting languages like Javascript, JQuery
3) User interface development using HTML/CSS in combination with browser side scripting languages.
Who all can seek a career in Web Development?
Literally any one can! The job of a web developer is that of a programmer who can write efficient codes in various languages used for the web. “Becoming a good programmer” doesn’t actually need any formal education. You just need to decide on which language you want to learn, buy a couple of books for that language, read tutorials on internet & then try your hands on coding. You need to write lots of code yourself, learn by developing simple & small applications initially & then move up yourself to big & challenging applications. That is the only way you can become a good programmer. However having a formal education in the following streams will definitely make your job easier – graduation in mathematics, engineering in computer sciences & electronics, graduation in computer sciences. The reason is these courses teach basics of programming as part of their curriculum. But at the same time any one can become a good programmer by learning themselves. All you need is a taste for logic & programs.
How to begin your career in Web Development?
Very simple – Start learning. First of all decide which language you want to learn. Most people choose open source languages like PHP, Python etc because of the immense resource available over web for self learning. Some others choose ASP.NET & similar others. The choice can be personal for some people. However in my opinion, choose the field you have maximum interest. For example:- choosing PHP as language & MySql as database will help you to work with a range of open source applications likeWordPress (a content management system), Magento (a shoppingcart building software ) and many other open source applications like Joomla, Opencart etc. Choosing Phython as language & PostgreSql as database will help you to work with one of the most promising Open Source ERP software named OpenERP.
Begin your Learning curve
Once you choose the technologies, then its just a matter of buying books & experimenting yourself. I recommend you to read a series of articles written by DollarFry team if you are interesting in PHP & MySql.
1) How Freshers & Beginners in PHP can land a great first job - This article speaks in general about the opportunities for a career in PHP. It also explains what all you should learn and focus to carve a good career in web development using PHP
2) Understanding Web Technologies:- HTML/CSS -JQuery/Javascript-Ajax-PHP & MySql - This article can be consudered as the first chapter of your learning curve. It combines all languages used in PHP based web development (like HTML/CSS, Jquery, Ajax, PHP & MySql as database) into a single example so that you can understand the basic concepts very easily. A must read for everyone interested in PHP.
Similarly Google has a great education material when it comes to Python. You can learn all the basics very easily from Googles tutorial.
I hope you have got a basic idea about the career in web development. If you have any queries, please publish in our comments section.
Inverter Circuit
Inverter Circuit For Beginer Electronic Engineering
This super simple design of an inverter circuit does not limit it in any way from providing a high output power and an efficiency of a good 75%. Learn how to build an inverter that will satisfy most of your power requirement at quite an affordable cost.
The article deals with the construction details of a mini inverter. Read to know how to build aninverter which can provide reasonably good power output and yet is very affordable and sleek.
There may be a huge number of inverter circuits available over the internet and electronic magazines. But these circuits are often very complicated and hi-end type of inverters. Thus we are left with no choice but just to wonder how to build an inverter that can be not only easy to build but also low cost and highly efficient in its working. Well your search for such a circuit ends here. The circuit of an inverter described here is perhaps the smallest as far its component count goes yet is powerful enough to fulfill most of your requirements.
Construction Procedure
This mini inverter circuit can be completed through the following simple steps:
Cut two sheets of aluminum of 6/4 inches each.
Bend one end of the sheet as shown in the diagram. Drill appropriate sized holes on to the bends so that it can be clamped firmly to the metal cabinet.
Also drill holes for fitting of the power transistors. The holes are 3mm in diameter, TO-3 type of package size.
Fix the transistors tightly on to the heatsinks with the help of nuts and bolts.
Connect the resistors in a cross-coupled manner directly to the leads of the transistors as per the circuit diagram.
Now join the heatsink, transistor, resistor assembly to the secondary winding of the transformer.
Fix the whole circuit assembly along with the transformer inside a sturdy, well ventilated metal enclosure.
Fit the output and input sockets, fuse holder etc. externally to the cabinet and connect them appropriately to the circuit assembly.
Parts Required for the circuit diagram
You will require just the following few components for the construction:
R1, R2= 100 OHMS./ 10 WATTS WIRE WOUND
R3, R4= 15 OHMS/ 10 WATTS WIRE WOUND
T1, T2 = 2N3055 POWER TRANSISTORS (MOTOROLA).
TRANSFORMER= 12- 0- 12 VOLTS / 8 AMPS.
AUTOMOBILE BATTERY= 12 VOLTS/ 32AH
ALUMINUM HEATSINK= CUT AS PER THE REQUIRED SIZE.
VENTILATED METAL CABINET= AS PER THE SIZE OF THE WHOLE ASSEMBLY
How to Test it?
The testing of this mini inverter is done in the following method:
For testing purpose connect a 60 watt incandescent bulb to the output socket of the inverter.
Next, connect a fully charged 12 V automobile battery to its supply terminals.
The 60 watt bulb should immediately light up brightly, indicating that the inverter is functioning properly.
This concludes the construction and the testing of the inverter circuit.
I hope from the above discussions you must have clearly understood how to build an inverter which is not only simple to construct but also very affordable to each of you.
It can be used to power small electrical appliances like soldering iron, CFL lights, small portable fans etc. The output power will lie in the vicinity of 70 watts and is load dependent.
The efficiency of this inverter is around 75%. The unit may be connected to your vehicles battery itself when outdoors so that the trouble of carrying an extra battery is eliminated.
Circuit Description
The functioning of this mini inverter circuit is rather unique and different from the normal inverters which involve discrete oscillator stage for powering the transistors.
However here the two sections or the two arms of the circuit operate in a regenerative manner. Its very simple and may be understood through the following points:
The two halves of the circuit no matter how much they are matched will always consist a slight imbalance in the parameters surrounding them, like the resistors, Hfe, transformer winding turns etc.
Due to this, both the halves are not able to conduct together at one instant.
Assume that the upper half transistors conduct first, obviously they will be getting their biasing voltage through the lower half winding of the transformer via R2.
However the moment they saturate and conduct fully, the entire battery voltage is pulled through their collectors to the ground.
This sucks out dry any voltage through R2 to their base and they immediately stop conducting.
This gives an opportunity for the lower transistors to conduct and the cycle repeats.
The whole circuit thus starts to oscillate.
The base Emitter resistors are used to fix a particular threshold for their conduction to break, they help to fix a base biasing reference level.
The above circuit was inspired from the following design by Motorola:
There may be a huge number of inverter circuits available over the internet and electronic magazines. But these circuits are often very complicated and hi-end type of inverters. Thus we are left with no choice but just to wonder how to build an inverter that can be not only easy to build but also low cost and highly efficient in its working. Well your search for such a circuit ends here. The circuit of an inverter described here is perhaps the smallest as far its component count goes yet is powerful enough to fulfill most of your requirements.
Construction Procedure
This mini inverter circuit can be completed through the following simple steps:
Cut two sheets of aluminum of 6/4 inches each.
Bend one end of the sheet as shown in the diagram. Drill appropriate sized holes on to the bends so that it can be clamped firmly to the metal cabinet.
Also drill holes for fitting of the power transistors. The holes are 3mm in diameter, TO-3 type of package size.
Fix the transistors tightly on to the heatsinks with the help of nuts and bolts.
Connect the resistors in a cross-coupled manner directly to the leads of the transistors as per the circuit diagram.
Now join the heatsink, transistor, resistor assembly to the secondary winding of the transformer.
Fix the whole circuit assembly along with the transformer inside a sturdy, well ventilated metal enclosure.
Fit the output and input sockets, fuse holder etc. externally to the cabinet and connect them appropriately to the circuit assembly.
Parts Required for the circuit diagram
You will require just the following few components for the construction:
R1, R2= 100 OHMS./ 10 WATTS WIRE WOUND
R3, R4= 15 OHMS/ 10 WATTS WIRE WOUND
T1, T2 = 2N3055 POWER TRANSISTORS (MOTOROLA).
TRANSFORMER= 12- 0- 12 VOLTS / 8 AMPS.
AUTOMOBILE BATTERY= 12 VOLTS/ 32AH
ALUMINUM HEATSINK= CUT AS PER THE REQUIRED SIZE.
VENTILATED METAL CABINET= AS PER THE SIZE OF THE WHOLE ASSEMBLY
How to Test it?
The testing of this mini inverter is done in the following method:
For testing purpose connect a 60 watt incandescent bulb to the output socket of the inverter.
Next, connect a fully charged 12 V automobile battery to its supply terminals.
The 60 watt bulb should immediately light up brightly, indicating that the inverter is functioning properly.
This concludes the construction and the testing of the inverter circuit.
I hope from the above discussions you must have clearly understood how to build an inverter which is not only simple to construct but also very affordable to each of you.
It can be used to power small electrical appliances like soldering iron, CFL lights, small portable fans etc. The output power will lie in the vicinity of 70 watts and is load dependent.
The efficiency of this inverter is around 75%. The unit may be connected to your vehicles battery itself when outdoors so that the trouble of carrying an extra battery is eliminated.
Circuit Description
The functioning of this mini inverter circuit is rather unique and different from the normal inverters which involve discrete oscillator stage for powering the transistors.
However here the two sections or the two arms of the circuit operate in a regenerative manner. Its very simple and may be understood through the following points:
The two halves of the circuit no matter how much they are matched will always consist a slight imbalance in the parameters surrounding them, like the resistors, Hfe, transformer winding turns etc.
Due to this, both the halves are not able to conduct together at one instant.
Assume that the upper half transistors conduct first, obviously they will be getting their biasing voltage through the lower half winding of the transformer via R2.
However the moment they saturate and conduct fully, the entire battery voltage is pulled through their collectors to the ground.
This sucks out dry any voltage through R2 to their base and they immediately stop conducting.
This gives an opportunity for the lower transistors to conduct and the cycle repeats.
The whole circuit thus starts to oscillate.
The base Emitter resistors are used to fix a particular threshold for their conduction to break, they help to fix a base biasing reference level.
The above circuit was inspired from the following design by Motorola:
Khamis, Mei 23, 2013
Design/Build Small Hydroelectric Turbine
Sample Environmental Project Proposals
Overview
Design/Build Small Hydroelectric Turbine—Energy Reclamation
We have been manufacturing small hydroelectric reaction type turbines for over 10 years. In this project, you will utilize existing hydraulic designs and through miniaturization apply these designs to energy reclamation opportunities that exist in small water companies around the US. In many cases, such water companies waste excess pressure to downstream systems with pressure reducing valves. Currently, the only technology available to reclaim this energy is PAT (pumps as turbines) technology. A true turbine design, which can accommodate varying head pressures and flow through the day and night, will improve energy production in a given application by a minimum of 50%. The PAT technology does not yield the same effect and for this reason does not have widespread application.
Turbine technology can offset many tons of carbon emissions across the country annually. In general, this type of small hydroelectric turbine is considered to have no negative environmental impact because it goes into existing facilities. Additionally, the economics of even small projects are excellent due to this utilization of existing civil works and pipelines. Another key economic factor is the streamlining of the federal licensing process, which allows for a closed conduit exemption instead of a full federal license.
Goals
It is the goal of this project to design, build and install a miniature reaction Francis turbine in a water company in southern Vermont, to be tested and commissioned by February 2008.
The plan is to use the CAD/CAM and rapid prototyping facilities of the engineering labs to reduce costs and production time on these small turbines.
Deliverables
- Utilize CAD techniques to create a complete set of digital production drawings for use in CAD/CAM applications. These drawings and designs will include hydraulics, case design, gate and other components. Due to the homologous nature of turbine design these scalable data will allow the manufacturer of this style turbine in various sizes to be applied in numerous water companies with predictable results.
- Production of tooling components using machine shop resources utilizing rapid prototyping and CAM technologies to fabricate precision casting wax injection molds for very complex 3D turbine parts.
- Test designs in FLUENT or other program to predict results for various scales in production.
- Strength, wear and other mechanical testing for various components within assembly (FMEA – Failure Modes and Effect Analysis).
- Unit built in collaboration with our company and installed at southern VT water company.
- Test production unit against FLUENT predictions.
Required Facilities
- CAD lab
- Digitization facilities, CMM
- Potential machine time to fulfill tooling requirements (CNC milling)
- FLUENT – fluid analysis
Students will be given the opportunity to visit our facility and participate in the device installation at the southern VT water company in February 2008.
Knowledge Areas Needed for Project
- Fluid mechanics
- Solid mechanics
- Product design
- Engineering graphics (CAD/CAM)
- Project management
Proprietary Information and Confidentiality Requirements
- Confidentiality required for sponsor-provided information
- Intellectual property ownership rights retained by sponsor
- Sponsor accepts responsibility to discuss IP ownership directly with the student project team and project advisor
Full-Scale Digester at Dairy Farm
Overview
Continuing a project pursued by ENGS 190 groups in three prior years, students will refine the design and evaluation of an anaerobic digester for conversion of cow manure to methane at a dairy farm. Prototype testing for either the entire process or a portion thereof should be considered, but is not required. The overall objective of the project is to see if investment in a full-scale digester can be justified.
Qualifications: General aptitude and dedication are likely to go a long way in this project. Willingness to work with cow manure required. It would be helpful if at least some group members have familiarity with technical aspects of chemical process design and analysis.
Deliverables
Specific objectives include:
- Critical review of the analysis and conclusions of prior groups.
- Consideration of the extent of prototype testing appropriate and carrying out such testing.
- Identifying key risk factors and ways to ameliorate them.
- Identifying key cost factors and ways to ameliorate them.
- Identifying potential sponsors for a full-scale project, and a proposal to such a sponsor if appropriate.
Required Facilities
Ability to get to the dairy farm (about 20 minutes away) as needed also likely required.
Knowledge Areas Needed for Project
- Chemical engineering
- Biochemical engineering
- Environmental engineering
Proprietary Information and Confidentiality Requirements
None
Sample Environmental Project Proposals
Related Links
Design/Build Small Hydroelectric Turbine—Energy Reclamation
Overview
We have been manufacturing small hydroelectric reaction type turbines for over 10 years. In this project, you will utilize existing hydraulic designs and through miniaturization apply these designs to energy reclamation opportunities that exist in small water companies around the US. In many cases, such water companies waste excess pressure to downstream systems with pressure reducing valves. Currently, the only technology available to reclaim this energy is PAT (pumps as turbines) technology. A true turbine design, which can accommodate varying head pressures and flow through the day and night, will improve energy production in a given application by a minimum of 50%. The PAT technology does not yield the same effect and for this reason does not have widespread application.
Turbine technology can offset many tons of carbon emissions across the country annually. In general, this type of small hydroelectric turbine is considered to have no negative environmental impact because it goes into existing facilities. Additionally, the economics of even small projects are excellent due to this utilization of existing civil works and pipelines. Another key economic factor is the streamlining of the federal licensing process, which allows for a closed conduit exemption instead of a full federal license.
Goals
It is the goal of this project to design, build and install a miniature reaction Francis turbine in a water company in southern Vermont, to be tested and commissioned by February 2008.
The plan is to use the CAD/CAM and rapid prototyping facilities of the engineering labs to reduce costs and production time on these small turbines.
Deliverables
- Utilize CAD techniques to create a complete set of digital production drawings for use in CAD/CAM applications. These drawings and designs will include hydraulics, case design, gate and other components. Due to the homologous nature of turbine design these scalable data will allow the manufacturer of this style turbine in various sizes to be applied in numerous water companies with predictable results.
- Production of tooling components using machine shop resources utilizing rapid prototyping and CAM technologies to fabricate precision casting wax injection molds for very complex 3D turbine parts.
- Test designs in FLUENT or other program to predict results for various scales in production.
- Strength, wear and other mechanical testing for various components within assembly (FMEA – Failure Modes and Effect Analysis).
- Unit built in collaboration with our company and installed at southern VT water company.
- Test production unit against FLUENT predictions.
Required Facilities
- CAD lab
- Digitization facilities, CMM
- Potential machine time to fulfill tooling requirements (CNC milling)
- FLUENT – fluid analysis
Students will be given the opportunity to visit our facility and participate in the device installation at the southern VT water company in February 2008.
Knowledge Areas Needed for Project
- Fluid mechanics
- Solid mechanics
- Product design
- Engineering graphics (CAD/CAM)
- Project management
Proprietary Information and Confidentiality Requirements
- Confidentiality required for sponsor-provided information
- Intellectual property ownership rights retained by sponsor
- Sponsor accepts responsibility to discuss IP ownership directly with the student project team and project advisor
Full-Scale Digester at Dairy Farm
Overview
Continuing a project pursued by ENGS 190 groups in three prior years, students will refine the design and evaluation of an anaerobic digester for conversion of cow manure to methane at a dairy farm. Prototype testing for either the entire process or a portion thereof should be considered, but is not required. The overall objective of the project is to see if investment in a full-scale digester can be justified.
Qualifications: General aptitude and dedication are likely to go a long way in this project. Willingness to work with cow manure required. It would be helpful if at least some group members have familiarity with technical aspects of chemical process design and analysis.
Deliverables
Specific objectives include:
- Critical review of the analysis and conclusions of prior groups.
- Consideration of the extent of prototype testing appropriate and carrying out such testing.
- Identifying key risk factors and ways to ameliorate them.
- Identifying key cost factors and ways to ameliorate them.
- Identifying potential sponsors for a full-scale project, and a proposal to such a sponsor if appropriate.
Required Facilities
Ability to get to the dairy farm (about 20 minutes away) as needed also likely required.
Knowledge Areas Needed for Project
- Chemical engineering
- Biochemical engineering
- Environmental engineering
Proprietary Information and Confidentiality Requirements
None