How To Clean Laptop Screen And Keyboard - Best Way For Clean Up
If you work continuously on the laptop, then obviously it will also be dirty, although most people do not pay any special attention to its cleanliness. Even if some people clean the laptop in a wrong way, there are full chances of it getting damaged. Keeping these things in mind, today we are going to give you some very common but important laptop cleaning tips, with the help of which you can keep your laptop clean and fit.
The NASCAR season is set to start in about a month on the world famous Daytona International Speedway. For years, this sport has been enjoyed by millions because of the unique combination of perfectly engineered cars and quick driver reflexes.
https://www.youtube.com/watch?v=kwIQX1IVtps
Not so pretty or thrilling. Accidents and injuries play a huge part in car racing and can be generalized to all cars. Safety is something that has not yet fully been addressed. From the recalls of airbags to poor breaking systems, there is undoubtedly a problem with the car itself. But there is a bigger danger when a human becomes involved. We are prone to distractions, and despite the campaigns against drunk driving and now distracted driving, death tolls are exorbitantly high.
Which is why with a new era of NASCAR racing, focused on safety and speed, it's only natural to see the progress of the rumored "smart car"- one that has a brain of its own. This smart car could potentially follow the speed limit, alert cars around it to make proper lane changes, and take legal overtakes.
The two prominent examples of smart cars are the Google Car and MARTA. The Google Car is still in development (unveiled in December but there is some time before it hits the market), but has awesome features like stopping for pedestrians, obey traffic signals, and avoid obstructions. However, "common sense" and dealing with snow are not yet programmed into the car. In addition, large car manufacturers like GM are opening talks with Google to ensure that the car market is not monopolized by Google. MARTA is a project in the works that will not be "person free" but will incorporate a lot of smart technology for use in the next few years.
2015 is a big year for NASCAR. Perhaps it will be one for smart cars as well.
12/5 Artificial intelligence- Your Brainiac Friend or Worst Enemy
Change stops for no one. Right now, not only is our technology advancing at a rapid rate, but the rate itself is going up quickly. Innovation and mechanization have made our lives better. but should there be a limit to progress?
In the past, our worst fears regarding innovation never quite manifested- at least not in ways that we expected. America has transformed from a primarily agricultural country to one with a large manufacturing and tech industry without too many bumps, and Earth wasn’t invaded by martians because of the moon landing. But in an interesting Wall Street Journal article about Artificial Intelligence shows the many drawbacks that are obscure.
Mechanization has, unlike the goal of allowing workers to take on more creative tasks, trained workers in pushing a button,thus lowering morale. It is just one of the many examples of how powerful artificial intelligence is. Machines are taking over manual labor and are more funtional than human beings. They are being trained in communication (things I remember from Most Human Human) using the Turing test. They are even encroaching on things considered “only human” like chess, music, and even art. Perhaps the most human characteristic is creativity (something I always believed). Yet, a recent study showed that using Computer-Aided Design before brainstorming diminishes creativity. But no worries, scientists are training computers to become computers to be creative by making random connections. Actually, that is a huge concern. Without creativity, we lose one of our main characteristics. What part of a human can’t be replicated by AI?
Although I am sure the debate over AI started way before September, technology giant Elon Musk’s warning that AI is our biggest existential threat, his article struck a chord. Without a proper regulatory framework for robotics, we will be overwhelmed in the future. Currently, the Federal Aviation Administration regulates drones, but as NPR points out, this is completely inappropriate. This following video really opened my eyes to the problems with AI.
https://www.youtube.com/watch?v=7Pq-S557XQU
Change stops for no one, but we can start preparing for these changes now.
9/25 Nuclear Power? Global Perspectives on this Mega-Power
The concept of nuclear power itself is very powerful. Harnessing the fundamental forces keeping atoms together still seems like science fiction even today. Yet, nuclear power is very much a real deal. It can alleviate our dependence on natural gas, coal, or fossil fuels. However, it comes at a cost. Disasters like Fukushima Daiichi, Chernobyl, and Three Mile Island have left the public weary of nuclear power. Following the Fukushima Daiichi disaster, the international community turned away from nuclear power.
However, the environment or human error aren't the only threats to power plants. Late on Wednesday night, there was a bomb threat on the Palo Verde Nuclear Complex in Arizona. Although the threat wasn't credible as there are many levels of security surrounding the facility, safety of nuclear power remains a pertinent issue.
Considering the number of nuclear power plants in the United States, I'm not surprised that security is such a key issue. Outside of the United States, however, safety of nuclear power plants isn't guaranteed. Bomb threats on plants in Iran leave the international community shocked. Nuclear power in the wrong hands could mean threats for any country. That is why the IAEA has such an important job- which includes evaluating nuclear power plants for safety. We need to recognize that disasters don't have to be because of the environment, or human error. Perhaps in the future, once better security measures are in place, a future of mainly nuclear power will transition from science fiction into reality.
Collecting some wisdom on LiPo batteries into one post, since this is a topic of constant debate in my mind.
TL;DR
Charge the packs carefully (at 0.5-1C) and make sure your altimeter can handle the output current you'll be dumping. Resistors in series with the e-match or power supply can help if there will be a dead short on the line (e.g., HEI).
Time on the pad is the biggest determining factor for sizing your battery; know the current draw of your altimeter and do the math to figure out how big of a pack you'll need. (A 9V is 550 mAh.)
Packs are labeled in terms of their cell configuration (mS/nP has m series cells and n parallel cells) and output current capacity (xC, max discharge rate in mA is (x)(capacity in mAh)).
LiPos have lots of benefits -- size, weight, power density -- but also drawbacks -- fragility, not knowing the current state of the battery, the need to be recharged. (That last one sounds frivolous but it's really kind of obnoxious; I can't how many times I've left for the field fully prepped, only to find that I forgot to charge my tracker battery.) One other big concern is short circuit current. From Adrian A:
Hard shorts can and do happen on occasion in ematch circuits for deployment charges, and they happen often for rear-installed motor ignitors, and they happen pretty much 100% of the time in head-end ignition systems.
His solution? Watch your total energy budget:
That's why I like the really small Lipos, 130 mAhr or 160 mAhr. They are very abuse-resistant, they don't put out enough current to damage Featherweight altimeter outputs even in a short, and they still have enough capacity for a long sit on the pad plus a long flight. 95% of of problems that people have with lipos in rocketry would have been prevented by just using a smaller cell.
This seems like a bad way to "fix" the problem (undersize intentionally to avoid an engineering error). What if it's cold? What if your battery is old? John Derimiggio (of MARSA) talks about battery life:
The altimeter i use cooks along at 20ma and my rechargeables are rated at 230mah. I chose to divide that by 4 for a factor of safety so i recharge after 3 hours of use. If i were using 500mah alkalines i would use a 3x safety factor and retire the battery after 7 hours of use regardless of how many flights i can get on it.
cerving (of the Eggtimer) does the math for pyro firing :
If your altimeter uses 10 ma at 9v and the rocket sits for 30 minutes from the time that you power it on until you shut it off (not uncommon in my experience), that's 9V x .01A x 1800 secs = 162 J. If the pyro uses 3A at 9V (which is actually a lot nowadays) and fires for .5 sec (which is also a long time for an ematch), that's only 13.5 J. The trick is that it's a lot easier for the 9V battery to come up with 10mA than 3A, so it better be fresh... if it's showing under 90% on your DVM under a reasonable load (about 1A, or 10 ohms) then it's probably best to use a new battery.
bobkrech sums it up nicely:
Lifetime in hours = Capacity / current draw = 130 mah / 1.5 ma = 86 hours. 90% of that is 78 hours.
Firing a 10 amp igniter for 1 second reduces the battery capacity by 10000 ma x 1 s / 3600 s/h = 2.78 mah if the bridgewire doesn't burn out. That reduces the run time by 2.78 mah / 1.5 ma = 1.85 hours per each 1 second 10 amp event. Most e-matches are much lower. The all-fire current for a Quest e-match is 350 ma and usually results in a burned out bridgewire, but if it doesn't the max drain is likely to be 350 ma x 1 s and the reduction in capacity is 350 ma x 1 s / 3600 s/h = 0.1 mah and the run time reduction is 0.1 mah / 1.5 ma = 0.067 hours = 4 minutes per pyro event.
Of course, this Lipo capacity argument becomes moot if you just do like Perfectflite does and design the outputs for massive current, as Peter put it in an e-mail:
The HA45 output FETs were intentionally grossly overrrated so this would never be an issue. They can handle over 30 amps of current.
One potentially limiting factor is the reverse polarity protection diode, which is rated at 5 amps. Unfortunately no super high current diodes exist that would fit without making the HA45 larger, hence the 5 amp limit.
The good news is that if you ever blow the diode, you will lose power to the continuity check circuitry so you would be informed pre-launch by lack of continuity beeps. Not so with the output FETs (which is why we over-rated them): if an output FET ever blows you wouldn't know about it until it failed to fire your charge.
Their current unit, the Stratologger, has outputs rated at 10A and pulls 1.5 mA at 9 V. On a 2S LiPo, it still pulls something less than 2 mA, so even a 150 mAh pack
Of course, the other way to fix it would be to prevent the hard short in the first place. Peter continues:
If you wanted to add a 1 to 2 ohm resistor in series with the battery that would be OK -- the power to the altimeter would drop slightly when the charges fire but the altimeter can withstand a total loss of power for several seconds so it wouldn't affect operation. Or you could go the bulkier route of adding a resistor in series with each ematch, but that's not necessary.
As for care and feeding of Lipos, several people recommend charging a LiPo at 0.5 to 1C -- the charge/discharge rate in mA is the number of Cs multiplied by the capacity of the battery in mAh (e.g., a 160 mAh 40C battery should be charged at or below 0.16 A and can discharge at 160*40=6400 mA).
This 12v charger received lots of recommendations on TRF (from people like bobkrech and dlb who know what they're talking about).
Each cell is 3.7V nominal, 4.2V fully charged. For most modern applications, 2S (7.4V) LiPo batteries work well (e.g., this one at 180 mAh). Legacy units that need at least 9V need a 3S pack (e.g., this one, same capacity).
The rated discharge (xC) of the pack is the rate at which the pack can discharge without dropping voltage significantly. The short circuit discharge current is much higher, which brings us back to the the first part of this post.
And that's probably enough for now. The TL;DR is at the top.
