A postcard or post card is a rectangular piece of thick paper or thin cardboard intended for writing and mailing without an envelope. There are novelty exceptions, such as wood postcards, made of thin wood, and copper postcards sold in the Copper Country of the U.S. state of Michigan, and coconut "postcards" from tropical islands.
In some places, it is possible to send them for a lower fee than for a letter. Stamp collectors distinguish between postcards (which require a stamp) and postal cards (which have the postage pre-printed on them). While a postcard is usually printed by a private company, individual or organization, a postal card is issued by the relevant postal authority.
I'm a Mac user, so have suffered for decades from Apple's lower battery life compared to PCs, and I've heard similar complaints about batteries for their phones and other consumer portables. Apple may have the clout due to high volume, but that's not enough: if they haven't figured it out by now I don't see why that would suddenly change. I haven't heard a good explanation of why batteries for their portables don't last as long: maybe there is one. If so, I'm sure interested.
I agree about Apples' run time but the main problem may not be so much the battery but the ever-increasing demand for processing power for the electronics.
I would thnk that if it's possible to get better batteries that Apple has more clout than anyone on earth (because of their production quantities) to twist the arm of suppliers. I'll bet that if one of us could come up with a better battery that Apple would beat a path to our door.
For every battery (rechargable) that the DOD buys that Apple buys 1000 of them.
Actually you can send tens to hundreds of watts wirelessly over some distance (meters) by using resonant tuned circuits. There is a lot of research going on in this area by TV manufacturers who want their big screen TVs to hang on the wall with no wires, and Sony and others have demonstrated prototypes that send hundreds of watts a few meters without wires. But they are still to big and inefficient for real world use.
Aluminum foil hat wearers aside, the cancer risk of non-ionizing radiation has proved to be a non-issue. A couple billion people are exposed to high levels of RF radiation next to their heads on a daily basis, and have been in increasing numbers for 20 years since cell phones became ubiquitous. Since brain cancer rates have not materially changed over that time it is reasonable to conclude that such radiation does not cause cancer.
I'm not sure what kind of range you would need for this to be practical on the battlefield, but the power levels are pretty low - probably a few watts on a constant basis with a very small battery to level out the bumps - so with some more research it may yet be possible.
Or, we could just figure out how to put a fusion reactor into a cell phone :0)
I agree with Ann that Apple does not have a good reputation for long battery life, but does have a history of battery problems.
And I hve not seen anything posted about energy harvesting providing anything close to a minimum requirement for soldiers applications. The possible exception is he passage sensing things that are able to detect infiltrators. Energy harvesting will need a large breakthrough in order to become more widely useful. And I don't see anything on the energy harvesting horizon.
Although Apple may have the most motivation for making batteries lighter and smaller, they sure don't have the best track record at making them last very long. Their reputation here is pretty dismal. And I agree with William, different sizes does not sound like what soldiers need: they need one battery size that can work for multiple devices.
Thebgoal is less weight for the same power, which is why they would be wearable instead of :liggable" battery packs. But what is really needed is a way to assure that there is ALWAYS power available for the night vision equipment and the night vision gunsights.
Having a bunch of different battery sizes is an effective means of assuring that the most important battery sizes will not be available when needed. But a single size would not be suitable for all applications. So there does exist a challenge there.
My money is on Apple. The DOD should be talking to them. If there is a way to make batteries lighter/smaller Apple has more motivation than anyone else on earth. As far as wireless charging, this has never worked and (I hate to use the word never) but it never will. If you could send more than more a few milliwatts for any distance you'd probably kill or damage the person wearing the receiver or "at best" give them cancer. And NO I'm not paranoid about cell phone/brain disorders.
Also I don't understand how "wearing" the battery changes the kg/W-hr ratio of the technology.
Maybe I should call myself "grouchatnorcross". This just sounds like another way for DOD to spend money on studies with no useful return.
Earlier this year paralyzed IndyCar drive Sam Schmidt did the seemingly impossible -- opening the qualifying rounds at Indy by driving a modified Corvette C7 Stingray around the Indianapolis Motor Speedway.
Wearables are changing the way we see ourselves. With onboard sensors that have access to our bodies, we are starting to know our physical selves like never before, quantifying our activity, our heart rate, breathing, and even our muscle effort.
Last week, the bill for reforming chemical regulation, the TSCA Modernization Act of 2015, passed the House. If it or a similar bill becomes law, the effects on cost and availability of adhesives and plastics incorporating these substances are not yet clear.
This year, Design News is getting a head start on the Fourth of July celebration. In honor of our country and its legacy of engineering innovation -- in all of its forms -- we are taking you on an alphabetical tour through all 50 states to showcase interesting engineering breakthroughs and historically significant events.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.