What are Black Hat SEO techniques?

Black Hat SEO

In order to attain High Ranking in search engine result page, websites go for various methods and techniques which are characterized by two categories.
The methods which are implemented and acceptable according to search engine guidelines are White Hat SEO, on the other hand, the method which are less acceptable or instructed to avoid in search engine guidelines are “Black Hat SEO”.

Some Black Hat SEO techniques are:

  • Keyword Stuffing
  • Cloaking
  • Doorway Pages or Gateway Pages
  • Link Farming
  • Hidden Text, etc.

3D Printing

3D printing  is a process of making a 3D solid object of virtually any shape from a digital model. 3D printing is achieved using an additive process, where successive layers of material are laid down in different shapes. So this is also known additive manufacturing. It is also considered distinct from traditional techniques of machining, which mostly rely on the removal of material by methods such as cutting or drilling (subtractive processes).

A materials printer usually performs 3D printing processes using digital technology. The first working 3D printer was created in 1984 by Chuck Hull of 3D Systems Corp. Since the start of the 21st century there has been a large growth in the sales of these machines, and their price has dropped substantially.

The 3D printing technology is used for both prototyping and distributed manufacturing with applications in architecture, construction (AEC), industrial design, automotive,aerospace, military, engineering, civil engineering, dental and medical industries, biotech (human tissue replacement), fashion, footwear, jewelry, eyewear, education, geographic information systems, food, and many other fields.


Additive manufacturing takes virtual blueprints from computer aided design (CAD) or animation modeling software and “slices” them into digital cross-sections for the machine to successively use as a guideline for printing. Depending on the machine used, material or a binding material is deposited on the build bed or platform until material/binder layering is complete and the final 3D model has been “printed.”

A standard data interface between CAD software and the machines is the STL File format. An STL file approximates the shape of a part or assembly using triangular facets. Smaller facets produce a higher quality surface. PLY is a scanner generated input file format, and VRML(or WRL) files are often used as input for 3D printing technologies that are able to print in full color.


To perform a print, the machine reads the design from an .stl file and lays down successive layers of liquid, powder, paper or sheet material to build the model from a series of cross sections. These layers, which correspond to the virtual cross sections from the CAD model, are joined or automatically fused to create the final shape. The primary advantage of this technique is its ability to create almost any shape or geometric feature.

Printer resolution describes layer thickness and X-Y resolution in dpi(dots per inch), or micrometers. Typical layer thickness is around 100 micrometers(µm), although some machines such as the Objet Connex series and 3D Systems’ ProJet series can print layers as thin as 16 µm.  X-Y resolution is comparable to that of laser printers. The particles (3D dots) are around 50 to 100 µm in diameter.

Construction of a model with contemporary methods can take anywhere from several hours to several days, depending on the method used and the size and complexity of the model. Additive systems can typically reduce this time to a few hours, although it varies widely depending on the type of machine used and the size and number of models being produced simultaneously.

Traditional techniques like injection moulding can be less expensive for manufacturing polymer products in high quantities, but additive manufacturing can be faster, more flexible and less expensive when producing relatively small quantities of parts. 3D printers give designers and concept development teams the ability to produce parts and concept models using a desktop size printer.


Though the printer-produced resolution is sufficient for many applications, printing a slightly oversized version of the desired object in standard resolution, and then removing material with a higher-resolution subtractive process can achieve greater precision.

Some additive manufacturing techniques are capable of using multiple materials in the course of constructing parts. Some are able to print in multiple colors and color combinations simultaneously. Some also utilize supports when building. Supports are removable or dissolvable upon completion of the print, and are used to support overhanging features during construction.

Additive Processes

Several different 3D printing processes have been invented since the late 1970s. The printers were originally large, expensive, and highly limited in what they could produce.

A number of additive processes are now available. They differ in the way layers are deposited to create parts and in the materials that can be used. Some methods melt or soften material to produce the layers, e.g. selective laser melting (SLM) or direct metal laser sintering (DMLS),  selective laser sintering(SLS), fused deposition modeling(FDM), while others cure liquid materials using different sophisticated technologies, e.g.  stereolithography (SLA). With laminated object manufacturing(LOM), thin layers are cut to shape and joined together (e.g. paper, polymer, metal). Each method has its own advantages and drawbacks, and some companies consequently offer a choice between powder and polymer for the material from which the object is built. Some companies use standard, off-the-shelf business paper as the build material to produce a durable prototype. The main considerations in choosing a machine are generally speed, cost of the 3D printer, cost of the printed prototype, and cost and choice of materials and color capabilities.

Printers that work directly with metals are expensive. In some cases, however, less expensive printers can be used to make a mould, which is then used to make metal parts. 

Extrusion deposition

Fused deposition modeling uses a plastic filament or metal wire that is wound on a coil and unreeled to supply material to an extrusion nozzle, which turns the flow on and off. The nozzle heats to melt the material and can be moved in both horizontal and vertical directions by a numerically controlled mechanism that is directly controlled by a computer aided manufacturing(CAM) software package. The model or part is produced by extruding small beads of  thermoplastic material to form layers as the material hardens immediately after extrusion from the nozzle. Stepper motors or servo motors are typically employed to move the extrusion head.

FDM has some restrictions on the shapes that may be fabricated. For example, FDM usually cannot produce stalactite-like structures, since they would be unsupported during the build. These have to be avoided or a thin support may be designed into the structure which can be broken away during finishing processes.

Granular materials binding

Another 3D printing approach is the selective fusing of materials in a granular bed. The technique fuses parts of the layer, and then moves the working area downwards, adding another layer of granules and repeating the process until the piece has built up. This process uses the unfused media to support overhangs and thin walls in the part being produced, which reduces the need for temporary auxiliary supports for the piece. A laser is typically used to sinter the media into a solid. Examples include selective laser sintering(SLS), with both metals and polymers (e.g. PA, PA-GF, Rigid GF, PEEK, PS,Alumide, Carbonmide, elastomers), and direct metal laser sintering(DMLS).


Selective laser melting (SLM) does not use sintering for the fusion of powder granules but will completely melt the powder using a high-energy laser to create fully dense materials in a layer wise method with similar mechanical properties to conventional manufactured metals.

Electron beam melting(EBM) is a similar type of additive manufacturing technology for metal parts (e.g. titanium alloys). EBM manufactures parts by melting metal powder layer by layer with an electron beam in a high vacuum. Unlike metal sintering techniques that operate below melting point, EBM parts are fully dense, void-free, and very strong.

Another method consists of an inkjet 3D printing system. The printer creates the model one layer at a time by spreading a layer of powder (plaster or resin) and printing a binder in the cross-section of the part using an inkjet-like process. This is repeated until every layer has been printed. This technology allows the printing of full color prototypes, overhangs, and elastomer parts. The strength of bonded powder prints can be enhanced with wax or thermoset polymer impregnation.


Photopolymerization is primarily used in stereolithography (SLA) to produce a solid part from a liquid.

In digital light processing (DLP), a vat of liquid polymer is exposed to light from a DLP projector under safelight conditions. The exposed liquid polymer hardens. The build plate then moves down in small increments and the liquid polymer is again exposed to light. The process repeats until the model has been built. The liquid polymer is then drained from the vat, leaving the solid model. The Envision Tec Ultra is an example of a DLP rapid prototyping system.

Inkjet printer systems like the Objet PolyJet system spray photopolymer materials onto a build tray in ultra-thin layers (between 16 and 30 µm) until the part is completed. Each photopolymer layer is cured with UV light after it is jetted, producing fully cured models that can be handled and used immediately, without post-curing. The gel-like support material, which is designed to support complicated geometries, is removed by hand and water jetting. It is also suitable for elastomers.

Ultra-small features can be made with the 3D microfabrication technique used in multiphoton photopolymerization. This approach traces the desired 3D object in a block of gel using a focused laser. Due to the nonlinear nature of photoexcitation, the gel is cured to a solid only in the places where the laser was focused and the remaining gel is then washed away. Feature sizes of under 100 nm are easily produced, as well as complex structures with moving and interlocked parts.

Yet another approach uses a synthetic resin that is solidified using LED’s.


Additive manufacturing’s earliest applications have been on the toolroom end of the manufacturing spectrum. For example, rapid prototyping was one of the earliest additive variants, and its mission was to reduce the lead time and cost of developing prototypes of new parts and devices, which was earlier only done with subtractive toolroom methods (typically slowly and expensively). With technological advances in additive manufacturing, however, and the dissemination of those advances into the business world, additive methods are moving ever further into the production end of manufacturing in creative and sometimes unexpected ways. Parts that were formerly the sole province of subtractive methods can now in some cases be made more profitably via additive ones.

Standard applications include design visualization, prototyping/CAD, metal casting, architecture, education, geospatial, healthcare, and entertainment/retail.


A chiral-based magnetic memory device without a permanent magnet

Several technologies are currently in use for computer memory devices. However, there is a need for a universal memory device that has high density, high speed and low power requirements. Recent charge-transfer studies indicate that chiral molecules act as an efficient spin filter. Here we utilize this effect to achieve a proof of concept for a new type of chiral-based magnetic-based Si-compatible universal memory device without a permanent magnet.

Types of Memories

  • Dynamic random-access memory is a type of memory that stores each bit of data in a separate capacitor within an integrated circuit.
  • In static random-access memory the word static indicates that, unlike dynamic random-access memory, it does not need to be periodically refreshed, because SRAM uses a bistable circuit to store each bit.
  • Flash memory is a non-volatile memory based on silicon oxide. It is inexpensive and can store data without power for 10 years, but it lacks speed.
  • In magnetic memory, a permanent magnetic layer is separated by a thin isolating layer from another ferromagnet (a free layer) that can be magnetized either parallel or antiparallel to the permanent magnet orientation.

New Concept

  • In recent years, studies of electron transfer through organic molecules have shown that such molecules can introduce quantum mechanical properties, such as discreet energy levels, to the standard electronic components at ambient temperatures.
  • One such effect is electron transfer through chiral molecules which is spin selective.
  • In several studies, the chiral-induced spin selectivity (CISS) effect was established, in which chiral molecules, especially helical ones, can serve as very efficient spin filters.

This can be achieved using low currents. The presented technology has the potential to overcome the limitations of other magnetic-based memory technologies to allow fabricating inexpensive, high-density universal memory-on-chip devices.

HDD – Hard Disk Drive

– It is the conventional disk drive.

– HDD is Hard Disk Drive.

– It has a rotating platter, movement of which will handle all the operations and functionality of the drive.

– It uses magnetism for data storage.

– It also uses a set of read or write heads to perform read and write operations.

– The speed of the drive depends on the platter spin speed

– An example for HDD is Seagate Barracuda.

SSD – Solid State Drive

– SSD is Solid State Drive.

– It has no moving parts.

– Here information is stored in microchips.

– It is much faster.

– It has NAND based flash memory.

– It has non-volatile type of memory, which means that the data can outlive us!

– It has no mechanical arm to read/write data.

– It uses embedded processor called a controller (“brain”).

– This controller will decide what the drive should do – store, retrieve, cache or clean up

– The controller also helps in some additional operations such as error correction, read/write caching, encryption, garbage collection etc.

– An example for SSD is SandForce SATA 3.0 (6 GB/s)


How to Download Historical Bank Statements from HDFC Online Banking

In the HDFC online banking portal, we will be able to download historical bank statements apart from the mini statement. Here are the steps :

1. Login to the online portal.

2. On the home page, select “Download Historical statement” option on the left panel.

3. On the right pane, select the account number of which you want to download the statement.

4. You can select the Previous financial year or specific period to take the statement. In the specific period, you will be able to select the from and to dates.

5. Next choose a format for the statement.

6. Click the Download button.

Now your bank statement for the period selected will be downloaded to your computer.

iOS 7.0 Beta Features

       iOS 7 introduces exciting new features like Control Center, AirDrop for iOS, and smarter multitasking. It also makes your daily routine even more easier, faster, and enjoyable. And while many of the apps does look different, the way you do things feels perfectly familiar. So now the world’s most advanced mobile OS available in its most advanced form.


1       Control Center gives quick access to the controls and apps you always seem to need. Just swipe it up from any screen, the Lock screen too.

       It provides switch widgets to setup and configure Wi-Fi accessories, Airplane mode, display brightness, Bluetooth, Do Not Disturb, control music etc. You can even use it as a torch with the new flashlight. It enables quick access to your timer, calculator, and camera. Never has one swipe given so much control.






         The entirely looking different Notification Center, with new daily overviews, lets you know about new mail, missed calls, to-dos, and more. A new feature called ‘Today’ gives you a convenient summary of the day. Your iPhone reminds you if it’s someone’s birthday, if you’ll need an umbrella, or if traffic will slow down your commute. To access Notification Center from any screen, including the Lock screen, just swipe down.

         Notifications can also now be synced between devices, clearing a notification on an iPhone will also clear it from a paired iPad or Mac, for example.



           Multitasking has always been a smart way to switch between apps. iOS 7 offers up an even more smarter way. It learns your pattern of using apps and can update your content before you launch them. For example, if you tend to check your Facebook app at 9:00 a.m. every day, your feed will be ready and waiting for you. That is, it knows what you want before you do and keeps the content of your app up-to-date.


              Sending a photo or a document to someone right next to you via text or email suddenly feels like too many steps. AirDrop included with iOS 7 lets you quickly and easily share photos, videos, contacts and anything else from any app with other iPhone users nearby. Tap Share button and select the person you want to share with. The rest is done using Wi-Fi and Bluetooth. No setup required. Transfers are encrypted, and are highly secure.


        Recipients can accept or decline what is sent, and accepted items will be saved in appropriate locations. For example, a shared contact ends up in your Contacts, while a shared photo ends up in the Gallery. It will be available on Apple’s latest devices, including the iPhone 5 and the fourth generation iPad, as well as the iPad mini.

       You’re visible in AirDrop to your contacts running iOS 7 by default. But you can also choose your visibility to anyone nearby using iOS 7 or to no one at all.





By adding the Activity sheet, the details of sharing your content is handled for you, no network or setup required. You can directly connect with multiple devices nearby, and let your users easily share information with each other with this technology.







          The entirely redesigned App Store with the same black and white look featured in many of the apps in iOS 7. It is now easier to find apps than ever before with the “Apps Near Me”. It shows you a collection of popular apps relevant to your current location. And a new Kids category spotlights parents and children based on age.

        The iOS 7 App Store will now update apps automatically. Music, too, has been updated with support of the new addition, iTunes Radio, which is free, ad-supported, and available on iOS, Apple TV, and the Mac.


            Losing your iPhone feels really sad. Find My iPhone can help you get it back. New security features in iOS 7 make it harder for someone else to use or sell your device. Turning off Find My iPhone or erasing your device requires your Apple ID and password. Even after your device is erased, Find My iPhone can continue to display a custom message. Also your Apple ID and password are required before anyone can reactivate it, which means your iPhone is still your iPhone, no matter wherever it is.

67. SIRI

            In iOS7, apple has updated siri with advanced features. Siri has been given a “gorgeous” new interface along with new voice option, new look and capability. It introduces new sound waves on the bottom of voice control feature letting you know siri is listening and processing your input. And you will have a choice of male or female version is even easier to understand. Siri has also gotten smarter, so it can now perform tasks like turning on Bluetooth or increasing device brightness, as well as playing voicemails and controlling iTunes Radio. Siri is now integration with Bing, Wikipedia and twitter for fast responds to your request. It takes some other new tasks, like returning calls, playing voice mail, controlling iTunes radio and more.



          ITunes radio is streaming radio with best selection of music. It builds and brings together stations you will love from day. The more you use iTunes Radio, the more iTunes Radio knows what you like to listen to and the more personalized your experience becomes. You can create new station while you listen, and it controls the balance between playing and searching songs. It keeps the history of all the songs you have heard or added to your wish, and you can download the songs from iTunes also.



           Safari is going to receive quite few updates in iOS 7 including an updated tab view, new full screen look and smart search field. With this field, there’s one tap access to favorites, and it also has a new tabbed interface along with parental controls and iCloud keychain integration.

         The new navigation menu in Safari has received an updated design just like the rest of the core apps. One of the biggest changes is how tabs and other features are displayed. Each tab will be shown in a tilted stack so you can see exactly what you’re looking at. To get rid of a tab, just swipe it sideways.

         When you use this new smart search field to search some terms or type URL, safari automatically suggest matching words or sentence to what you are looking for. Safari also has a new view that displays URLs from a user’s Twitter timeline and Reading List has received some performance enhancements. Safari incorporates the new iCloud Keychain functionality, remembering account names, passwords, and credit card numbers, as well as generating unique, hard-to-guess passwords.



             iOS 7 introduces a redesigned camera app that includes photo filters, and incorporates a new “square” capture mode. With a swipe you can capture what you want and the way you want. There are now a total of four camera modes, including Video, Panorama, Still, and Square. With a swipe, you can go from the standard camera, to the video camera, to a square Instagram inspired camera, to the panoramic camera. Further showing the influence that Instagram has, you also have the ability to add one of several filters directly to the photos you take without using a third party app. You can apply filters to still and square photos. Pick a filter and see the effect before you take the picture. Or just take the shot and apply it later. If you ever change your mind and decide no filter is the best filter, you can simply remove it.



         The photos in iOS 7 offering an improved photo organization system, like grouping of your photos and videos based on when and where you took them. iOS knows when and where photos were taken and this information is used to organize photos into folders called “Moments” which is faster and easier to scroll down memory lane. Every photo and video you’ve ever taken appears onscreen, almost like artwork. One interesting aspect of Moments is the ability to zoom out, and selectively pick specific photos from the grouping by tapping and dragging your finger over the photos. Photo streams have received a significant update as well, as you can now share your photos directly into other’s photo streams, and vice versa.

iCloud Photo Sharing has also been enhanced, allowing users to have fully shared photo streams that include both photos and videos.



        iOS 7 is designed to provide enhanced integration with in-dash systems, displaying iOS on in-car monitors to make calls, get messages, and more. Vehicles that are equipped with iOS in the Car can connect to the iPhone 5 and interact with it using the car’s built-in display. iOS in the Car knows when you’re leaving home for work or vice versa and displays traffic conditions and your ETA.


New mobiles that change shape are ‘only a matter of time’ – Guardian, UK

New mobiles that change shape are ‘only a matter of time’!

Made from new intelligent plastics and metals with a memory they will turn into a games console by bending at the edges to give users better grip.

Or, to maintain privacy, the screen will flip up when a password is being typed so passers-by can’t see private information.

The scientists who have invented the shape-altering phones say they could even transform into a sphere to serve as a stress ball.

Dr Anne Roudaut, who led the ‘morphees’ research project at Bristol University said as touch screens continue to evolve it will only be a matter of time until mobile phones automatically change shape to fit whatever they are being used for.

“We believe future mobile phone devices will be able to change shape on their own,” said Dr Roudaut. “For example if you have an app for a game and select it your phone will automatically change shape for you to play it. The best way to describe it is it’s a bit like Transformers.
“Shapes are so important for us as humans. Everything we manipulate around us is to do with shape. Our phones do so much but are always the same shape.”

Dr Roudant has spent the last year working on the project with Professor Sriram Subramanian, from the University of Bristol’s Department of Computer Science, experimenting with different materials that can change shape and could in the future be used in mobile phones. They have built six prototypes the team harnessing the latest technologies to create ‘shape shifting’ material, using intelligent plastics, which could in the future be used for mobile phones.

They will present their research at the CHI 2013 Conference in Paris on Monday, which focuses on human-computer interaction.
Courtesy – Guardian, UK
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