Ambient Backscatter And Battery-Free Communication
- Written by Eduardo Dieguez
There is energy in the air all around us at all times. This isn't a pseudo-mystical statement either; the sheer amount of power from radio and television waves in the air is a massive, untapped resource. At least it was, until Washington University hit on a way to use it that's referred to as ambient backscatter.
What is Ambient Backscatter, and How Does it Work?
The idea of ambient backscatter is that it should be possible to use existing transmission waves to power battery-less devices in such a way that they can still perform simple tasks. The theory was that these devices could communicate with one another, act as sensors, and even send simple text messages. There would be no requirement of additional power, and it would make use of an environmental factor that's already filling the area. In fact these devices would work anywhere there's a number of wavelengths filling the air, whether they're for cell phones, Internet, television, or some other application entirely.
The devices are designed so that, rather than using an on-board source of power, they can draw power from the electromagnetic waves in the area. Scientists tested the range from as far as a few feet, to six and a half miles using these devices that rode the radio waves to get their messages sent. Further testing is still in the works, but the initial tests show some serious potential.
What are the Potential Benefits of Ambient Backscatter?
This unusual development has caught hold of the scientific imagination, and the potential for these devices is nearly limitless. For instance, they could be put on a bridge to monitor the integrity of the concrete. When a hairline fracture occurs, the sensor beams a message back on the already existing wavelengths. This requires no changing out, no battery upkeep, no power source; it's just a constant, never-sleeping guardian that keeps watch. The same sensors could be used to watch for fires, for security networks, and a dozen other applications. Simply install, and leave it unless something breaks the sensor so completely that it isn't physically intact anymore.
These devices could, in theory, also be worked into existing electronics that do use batteries so that even when the charge is completely drained some basic forms of communication are still possible. This would also allow for things like text messages to be composed and sent without actually putting a drain on the battery, making phones last longer on a single charge simply by virtue of using less power than they might otherwise do.
A Green Future
There's no use in letting anything go to waste; not even ambient cell phone energy. So if it's possible to send a text, or to monitor a secure location, without spending one iota of power, then who wouldn't take advantage of that? In fact, given the potential these devices offer, it's possible that miniaturized devices will become even more popular. Miniature computers that work free of battery packs, or only on tiny watch batteries, might become the next generation of technology when existing wavelengths can provide the brunt of the heavy lifting needed.
This guest post was provided by Eduardo Dieguez, professional blogger for www.i-Adapters.com. An avid computer enthusiast, Eduardo spends countless hours tinkering with electronics both new and old.
How Does A Coaxial Cable Work
- Written by Michael Alvarez
New advancements in technology are slowly wiping out what we once deemed as “amazing” in the tech field. Bluetooth, for instance, left many in amazement a few years back, but currently, Wi-Fi seems to be taking over in almost all aspects of wireless communication. While technology is indeed changing everything, scientists seem to have had a hard time shaking off coaxial/coax cables.
You’ve probably seen them before on cable TV, or on satellites. However, not many people really understand what goes on in a coax cable and even what’s inside the sheath.
Inside The Coax Cable
The outer plastic sheath that you see on a coax cable covers three components inside it including:
- Copper core
- Dielectric insulator
- Copper shield
Typically, the copper core is responsible for conducting actual electrical signals across the cable. On the other hand, the copper shield and the dielectric insulator reduce magnetic interference in the cable.
Signal Transmission in a Coax Cable
Signals are actually transmitted simultaneously on both the copper core and the copper shield. This is done so that both of these conductors generate their individual electromagnetic fields. These two electromagnetic fields eventually cancel out each other.
Once that happens, the cables can now be placed next to other sensitive electrical devices or even metallic objects, and there won’t be any worries about the cables acting like magnets and interfering with the signal in the copper core.
Besides that, the fact that these electromagnetic fields cancel out each other means that external magnetic fields will also be prevented to some extent.
Specifications For Design of A Coaxial Cable
Even if you have the four basic elements that make up a regular coax cable, it would be difficult to control other factors like attenuation, frequency, and the power handling capability of the cable.
The construction of coax cables goes beyond the four components that it is made of. Factors such as the physical size of the cable, the outside diameter of the inner copper conductor, and the dielectric constant play an important role in the functioning of the coax cable.
Choice of impedance is also crucial when it comes to design since it directly influences the attenuation. Bell Laboratories conducted experiments in 1929 and found out that the best coaxial cable impedances suited for high-voltage applications were 30Ω, 60Ω, and 77Ω.
Coaxial cables with air as the dielectric resulted in an impedance of averagely 77Ω. However, when more effective dielectrics such as solid polyethylene or polyethylene foam are used, the impedance drops to 52-64Ω.
Today’s coax cables can operate at frequencies of up to 2.4GHz, and that makes it worthwhile for use in Radio and TV industries. They were once used for implementing computer networks, especially in the bus topology, but twisted pair cables have replaced them.
All in all, coax cables earn their popularity based on the fact that they are good at transmitting signals at a considerably high frequency with minimal interference.
About the Author
Michael Alvarez has been working in the electronics and technology field for over 20 years. He enjoys sharing his experence with coaxial cable with others; while continuing to grow his knowledge.
Top trends used in web development services
- Written by Tom
The year 2013 brings with it a number of web development and website design trends. Discussed below are just a few recent website development trends that will probably remain popular and useful for the rest of the year.
Large photo backgrounds
An increasingly large number of websites are using large photographic backgrounds recently. These photos, which are often oversized, can quickly grab the attention of the visitor and add to the overall look of a website when done right. They can blend in with the content and layout of the web page to make them more engaging.
Responsive web page layouts are trending since last year, but the focus has shifted a lot over the course of 2012. When the trend began, responsive web pages were made to cater to visitors accessing websites through mobile browsers, but that is not the sole purpose anymore. Responsive web page layouts are now being designed to meet the requirements of various forms of digital media and allow the page to be displayed properly on all devices like desktops, laptops, tablets, smartphones, and other devices that may come up in the near future. The idea is to make the website accessible through various platforms with just a single set of codes.
Illustrations and infographics
Websites are constantly competing for their visitors’ attention, and in recent times, illustrations and infographics have helped in achieving this effectively. Of course, this brings up the challenge of finding designers who have the skills and creativity to create unique and eye-catching info graphics and illustrations for your website. These website development trend illustrations can be used in a lot of ways within your website, but the key to a successful one is to blend it into your website’s branding correctly.
Infinite page scrolling
Infinite page scrolling has been used by some websites in the last few years, but it has only really kicked off among several thousands of websites during the second half of 2012 and, if things go well, all the way through 2013 as well. For instance, Facebook has had it for more than a year now, and Pinterest also adopted this technique this year. In both cases, the change was done really well and makes website navigation a much easier affair than before.
Similarly, Tumblr has also had an infinite scrolling element added to its website, allowing you to blog or repost content from others you follow. Like Facebook, all the posts you see on your account keep going on as you scroll down further.
Tom is a guest blogger who blogs on behalf of Nariel, the leading web development and web design company in New Jersey. For more information please visit their website.
Amazing Cloud Hosting Solutions That Makes Webmasters Happy
- Written by Bob Spiegel
Cloud hosting is a relatively new form of web hosting service and allows you to host your website in one of the best possible server environments, with top speed performance and security. There are various types of cloud hosting solutions that you can find in today’s web hosting providers’ offers. Here are six different types of cloud hosting solutions for you to choose from:
1. Software as a Service (SaaS)
This is a type of cloud hosting solution that will allow you to run your own software into the cloud. In this way, you can easily access the software anywhere, via the internet, using your favorite web browser. This can be a good solution for big corporations that need to create a simple model of software usage. The application does not need to be installed on every computer; instead, it is installed in the cloud, so that everyone within the company can access the software using their web browsers.
2. Platform as a Service (Paas)
This cloud hosting solution is similar to software as a service. But, instead of putting the software package into the cloud, you are putting the entire platform into the cloud. This way, you can install multiple software applications in a single cloud environment or infrastructure. This will give you more benefits for your business, since you’ll be able to create your own cloud computing platform with a group of installed software packages within it.
3. Managed Services
Managed services will let you use the needed applications or custom software made available to you by a cloud hosting provider. There are many applications that you can use, so you can choose the ones that perfectly fit your needs. For instance, you can use security services, spam control services, web monitoring services, and so on, depending on the package provided by the cloud service vendor.
4. Web-based Cloud Services
This cloud hosting solution will allow you to use certain parts of a web service application, in order for you to be able to use it for your own projects. Most times you won’t need to use an entire application in order to utilize a certain functionality of that application. Maybe you only need to use an API from that application, and you can use it in your own web development projects through the cloud, for example.
5. Utility Cloud Services
This service will allow you to rent some of the data storage capacity of your cloud hosting provider. This virtual storage can then be accessed by you from anywhere in the world, provided that you have the necessary login information for it. This solution will allow you to expand your data center and create more virtual storage capacity for your business or organization, which can then give you limitless data storage for your online business.
6. Service Commerce
This type of cloud hosting solution will bring you the option of using several interconnected services that you can access from anywhere. Basically, this is a mix of software as a service and managed service, with a variety of implementations that are customized for your business. You can use this solution to create your own online virtual assistant services, business expense monitoring systems, and so on.
These are a few of the most used cloud hosting solutions that you can choose for your business. And each one of these services offers different pricing plans, which should be flexible enough for you, depending on the type of business that you have.
Bob Spiegel is the blogger behind QuoteColo.com, a company that matches the top colocation hosting providers in U.S.A. and Canada with the business owners that need high quality website hosting services. Bob loves fishing and surfing; you can find out more about him on Twitter at @quotecolo
The Influence Of Photoshop
- Written by Matthew Flax
The Evolution of Photo-Editing
Images cut through all our critical defenses, or so we've been told. Whereas text has to be slowly digested by our brain, images head straight for the nerve centers. This is why images are an essential tool for advertising, and why society is becoming increasingly visual as technology advances.
As the toolsqa photo of Lenin addressing soviet troops was famously altered to remove Trotsky per Wikipedia, complex techniques such as darkroom manipulation and airbrushing have been replaced by more accessible digital editing tools like Photoshop. A consequence of the prevalence of doctored images is that people no longer readily accept what their eyes tell them.
Sometimes the evidence of photo tampering is easy to detect, but, in the hands of a skilled Photoshop artist, manipulated photos can look very convincing indeed.
According to Business Insider, advertising regulators in the USA have taken steps towards banning the use of Photoshop in images promoting cosmetics due to the potential for false advertising. This will also, hopefully, avoid the barrage of Photoshop accusations that routinely greet any controversial image posted on the net.
A Tool for Photographers, Advertisers and Artists
Photoshop can make an old picture look like a new picture, or make a photo look like a painting. Its ability to combine text and graphics in creative ways is a powerful tool for advertising, and its photo-editing capabilities have created awe-inspiring works of art, as well as the mass production of countless hilarious memes.
According to Rafin O’Hara, the tools provided by Photoshop allow photographers to challenge certain limitations, such as:
Time: Old photos can be scanned and loaded into Photoshop, where healing brushes and patch correction can be used to remove the effects of deterioration.
Human error: Mistakes such as bad lighting, red eye, over-exposure, and blotches can be rectified.
Reality: Paintbrush techniques can be used to create fantastical imagery, effectively combining the arts of photography and painting.
So, while some worry about the effects of false advertising, others take the opportunity to unleash their creativity in ways that were never before accessible. Whether your goal is to produce high-quality photographs, create cybernetic snails or simply insert cats into ancient Greek paintings the opportunities presented by Photoshop are numerous.
About The Author
Matthew Flax writes for Now Learning, which offers a range of Photoshop short courses in Australia.
OS X Keyboard Shortcuts
|C||Start from CD|
|D||Start from 1st Partition|
|N||Start from Net Server|
|R||Resets laptop screen|
|⌘V||Unix console msgs|
|Ctrl||Shutdown, sleep, restart|
FTC 16 CFR Part 255 Disclosure
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