Monday, December 21, 2015

Navigation systems around the world

Blogger Tricks

Friday, November 6, 2015

Biogas Plant PPT

Biogas typically refers to a mixture of different gases produced by the breakdown of organic matter in the absence of oxygen. Biogas can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste or food waste. It is a renewable energy source and in many cases exerts a very small carbon footprint.
Biogas can be produced by anaerobic digestion with anaerobic bacteria, which digest material inside a closed system, or fermentation of biodegradable materials.
Biogas is primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulfide (H2S), moisture and siloxanes. The gases methane, hydrogen, and carbon monoxide (CO) can be combusted or oxidized with oxygen. 

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Wednesday, September 9, 2015

Holographic Microbattery

Creation of miniature devices is on the rise. Many miniaturized devices like medical implants, flying insect-like robots, sensors, wireless transmitters and tiny cameras have been invented. 

To give you an idea of the scale, this image shows the battery’s electrodes in a 2mm by 2mm square on a glass wafer sitting on a fingertip. (Image courtesy University of Illinois)

Recently, a team of engineers at the University of Illinois, Urbana-Champaign demonstrated that porous, three-dimensional electrodes can boost a lithium-ion microbattery’s power output by three orders of magnitude, as first reported in Chemical & Engineering News. But now the team has gone a step further, and has optimized the electrode structure with holograms, the three-dimensional interference patterns of multiple laser beams, in order to generate porous blocks that could used as a sort of scaffolding for building electrodes.

The result: a holographic microbattery that’s only 2mm wide and 10 micrometers thick, with an area of 4mm squared, and 12% capacity fade. The researchers said it’s compatible with existing fabrication techniques, and ideal for large-scale on-chip integration with all kinds of microelectronic devices, including medical implants, sensors, and radio transmitters. Batteries like this could power implants small enough to track certain aspects of someone’s health in real time, and without the comparatively vast bulk of existing blood glucose and cardiac monitors, just to cite one example.
This isn’t the first time we’ve seen such tiny microbatteries developed. Back in 2013, researchers 3D-printed a battery that’s just 1mm wide, and in 2014, we saw a graphene-based microbattery that could also power implants. But it’s arguably the most sophisticated and realistic design yet. On the slightly larger front, last month a team of Stanford researchers developed an aluminum graphite battery that could charge up a smartphone in just 60 seconds. But in the end, it may be no surprise that holograms help us engineer better batteries — after all, we could be living inside a hologram all this time.

Saturday, May 2, 2015

Difference: Viruses, Worms, Trojans, and Bots


Viruses, worms, Trojans, and bots are all part of a class of software called malware. Malware or malicious code (malcode) is short for malicious software. It is code or software that is specifically designed to damage, disrupt, steal, or in general inflict some other “bad” or illegitimate action on data, hosts, or networks.

There are many different classes of malware that have varying ways of infecting systems and propagating themselves. Malware can infect systems by being bundled with other programs or attached as macros to files. Others are installed by exploiting a known vulnerability in an operating system (OS), network device, or other software, such as a hole in a browser that only requires users to visit a website to infect their computers. The vast majority, however, are installed by some action from a user, such as clicking an e-mail attachment or downloading a file from the Internet.

Some of the more commonly known types of malware are viruses, worms, Trojans, bots, back doors, spyware, and adware. Damage from malware varies from causing minor irritation (such as browser popup ads), to stealing confidential information or money, destroying data, and compromising and/or entirely disabling systems and networks.

Malware cannot damage the physical hardware of systems and network equipment, but it can damage the data and software residing on the equipment. Malware should also not be confused with defective software, which is intended for legitimate purposes but has errors or bugs.

Classes of Malicious Software

Two of the most common types of malware are viruses and worms. These types of programs are able to self-replicate and can spread copies of themselves, which might even be modified copies. To be classified as a virus or worm, malware must have the ability to propagate. The difference is that a worm operates more or less independently of other files, whereas a virus depends on a host program to spread itself. These and other classes of malicious software are described below.


A computer virus is a type of malware that propagates by inserting a copy of itself into and becoming part of another program. It spreads from one computer to another, leaving infections as it travels. Viruses can range in severity from causing mildly annoying effects to damaging data or software and causing denial-of-service (DoS) conditions. Almost all viruses are attached to an executable file, which means the virus may exist on a system but will not be active or able to spread until a user runs or opens the malicious host file or program. When the host code is executed, the viral code is executed as well. Normally, the host program keeps functioning after it is infected by the virus. However, some viruses overwrite other programs with copies of themselves, which destroys the host program altogether. Viruses spread when the software or document they are attached to is transferred from one computer to another using the network, a disk, file sharing, or infected e-mail attachments.


Computer worms are similar to viruses in that they replicate functional copies of themselves and can cause the same type of damage. In contrast to viruses, which require the spreading of an infected host file, worms are standalone software and do not require a host program or human help to propagate. To spread, worms either exploit a vulnerability on the target system or use some kind of social engineering to trick users into executing them. A worm enters a computer through a vulnerability in the system and takes advantage of file-transport or information-transport features on the system, allowing it to travel unaided.


A Trojan is another type of malware named after the wooden horse the Greeks used to infiltrate Troy. It is a harmful piece of software that looks legitimate. Users are typically tricked into loading and executing it on their systems. After it is activated, it can achieve any number of attacks on the host, from irritating the user (popping up windows or changing desktops) to damaging the host (deleting files, stealing data, or activating and spreading other malware, such as viruses). Trojans are also known to create back doors to give malicious users access to the system.

Unlike viruses and worms, Trojans do not reproduce by infecting other files nor do they self-replicate. Trojans must spread through user interaction such as opening an e-mail attachment or downloading and running a file from the Internet.


"Bot" is derived from the word "robot" and is an automated process that interacts with other network services. Bots often automate tasks and provide information or services that would otherwise be conducted by a human being. A typical use of bots is to gather information (such as web crawlers), or interact automatically with instant messaging (IM), Internet Relay Chat (IRC), or other web interfaces. They may also be used to interact dynamically with websites.

Bots can be used for either good or malicious intent. A malicious bot is self-propagating malware designed to infect a host and connect back to a central server or servers that act as a command and control (C&C) center for an entire network of compromised devices, or "botnet." With a botnet, attackers can launch broad-based, "remote-control," flood-type attacks against their target(s). In addition to the worm-like ability to self-propagate, bots can include the ability to log keystrokes, gather passwords, capture and analyze packets, gather financial information, launch DoS attacks, relay spam, and open back doors on the infected host. Bots have all the advantages of worms, but are generally much more versatile in their infection vector, and are often modified within hours of publication of a new exploit. They have been known to exploit back doors opened by worms and viruses, which allows them to access networks that have good perimeter control. Bots rarely announce their presence with high scan rates, which damage network infrastructure; instead they infect networks in a way that escapes immediate notice.

Best Practices for Combating Viruses, Worms, Trojans, and Bots

The first steps to protecting your computer are to ensure that your OS is up to date. This means regularly applying the most recent patches and fixes recommended by the OS vendor. Secondly, you should have antivirus software installed on your system and download updates frequently to ensure that your software has the latest fixes for new viruses, worms, Trojans, and bots. Additionally, you want to make sure that your antivirus program can scan e-mail and files as they are downloaded from the Internet. This will help prevent malicious programs from reaching your computer. You may also want to consider installing a firewall.
Source Cisco,Wikipedia

Friday, April 10, 2015

What the Earth would look like if all the ice melted

We learned last year that many of the effects of climate change are irreversible. Sea levels have been rising at a greater rate year after year, and the Intergovernmental Panel on Climate Change estimates they could rise by another meter or more by the end of this century.

As National Geographic showed us in 2013, sea levels would rise by 216 feet if all the land ice on the planet were to melt. This would dramatically reshape the continents and drown many of the world's major cities.

Source:Business Insider

Tuesday, February 10, 2015

5 Steps to stop Facebook spam

Once again the spam videos are being posted on 
Facebook friend's wall or friends are being tagged on the spam videos.

  • Beware the Facebook 'Magnet' scam: Experts warn 'malicious tag' campaigns are rising - and can infect 55,000 users a day
  • The scam works by tagging no more than 20 friends in a malicious post
  • This post is typically a video designed to lure the victim to click on it
  • Number of tagged friends is always 20 and the video is always different
  • Once a victim clicks on a link, they're prompted to update Flash Player
  • The virus then takes control of a device and installs other malicious files
  • Once infected, the victim inadvertently posts the link to their own Facebook feeds, tagging another 20 people.
Here are some steps which could save you from getting embarrassed.
1.Don't click on the post
(It may be seductive..still ignore the post)

2.Change your privacy settings from Public to Friends

3.Block or Remove Apps 

Avoid using apps/games which tell about your personality or make predictions about your future or anything personal related to you. Basically they all spread spam.Similarly the apps/games like changing color or fonts of Facebook they all spread spam. If already using block 'em immediately.

When you block an app or game, it won't be able to access any of your Facebook information or send you any requests. If you no longer want an app or game to contact you, please remove it.

To block an app or game:
  1. Click  in the top right of Facebook and select Settings.
  2. Click Blocking in the left column.
  3. In the Block apps section, type the name of the app or game you want to block. To unblock an app or game, click Unblock next to its name.
If you received a request from an app or game and you want to block it:
  1. Go to the App Center and click Activity at the top.
  2. Click x next to the request.
  3. Click Block [App/Game Name]? and click Confirm.

4.Change Timeline and Tagging Settings

5.What can I do to keep my account secure?

Here are a few things you can do to keep your account safe:
  • Pick a unique, strong password. Use combinations of at least 6 letters, numbers and punctuation marks and don't use this password for any of your other accounts. You can also use a password safe like LastPassKeePass or 1Password to set and remember unique passwords for your account. Learn how to change your password.
  • Think before you click. Never click suspicious links, even if they come from a friend or a company you know. This includes links sent on Facebook (ex: in a chat or story) or in emails. If one of your friends clicks a spam link, they could accidentally send you or tag you in spammy posts. If you see something suspicious on Facebook, report it. You also shouldn't download things (ex: a .exe file) if you aren’t sure what they are. Learn more about recognizing suspicious emails.
  • Watch out for fake Pages and apps/games. Be suspicious of Pages promoting offers that are too good to be true. If in doubt, check to see if a Page is verified. Also be mindful when you install new apps or games. Sometimes scammers use bad apps and games to gain access to your Facebook account.
  • Don't accept friend requests from people you don't know. Sometimes scammers will create fake accounts to friend people. Becoming friends with scammers allows them access to spam your Timeline, tag you in posts and send you malicious messages. Your real friends may also end up being targeted.
  • Never give out your login info (ex: email address and password). Sometimes people or pages will promise you something (ex: free poker chips) if you share your login info with them. These types of deals are carried out by cybercriminals and violate the Facebook Statement of Rights and Responsibilities. If you're ever asked to re-enter your password on Facebook (ex: you're making changes to your account settings) check to make sure the address of the page still in the URL (web address).
  • Log in at Sometimes scammers will set up a fake page to look like a Facebook login page, hoping to get you to enter your email address and password. Make sure you check the page's URL before you enter your login info. When in doubt, you can always into your browser to get back to the real Facebook. Learn more about phishing.
  • Update your browser. The newest versions of internet browsers have built-in security protections. 

Monday, February 2, 2015

उपभोक्तावादी संस्कृति PPT in Hindi

उपभोक्ता वादी संस्कृति के चलते विज्ञापनों के मकडज़ाल में फंसकर आज की युवा पीढ़ी दिग्भ्रमित होती जा रही है। शरीर पंचभौतिक तत्वों से मिलकर बना है तथा इसे योग के अनुशासन से ही ठीक रखा जा सकता है परंतु आज विज्ञापनों के फेर में सौंदर्य प्रसाधनों तथा स्वास्थ्य वर्धक पेयों के नाम पर रासायनिक मिश्रणों के उपयोग से न केवल अपनी त्वचा का नाश कर रहे हैं अपितु गंभीर बीमारियों से भी ग्रसित होते जा रहे हैं। मानसिक गुलामी के चलते हमने अपनी दिनचर्या को भी बिगाड़ दिया है। आज दुनिया के अधिकांश देश जहां योग की पद्घति को अपना कर अपना जीवन सुधार रहे हैं वहीं हम आज भी योग का लाभ लेने में संकोच कर रहे हैं।
Preview (पूर्वावलोकन)

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