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Comment: Re:I don't understand how this is a "record" (Score 3, Interesting) 84

Their compression setup makes absolutely no sense to me. The wikipedia article is either wrong, or someone doesn't know what they're doing. When you dive, your body absorbs gasses into your bloodstream. You have to ascend slowly to let the gasses out. Ascend too quickly, and it's like opening a soda bottle in your blood. With a deep dive (say 300 feet), that could take hours. The longer/the deeper you go, the more gasses you absorb, up to a certain point. This is what is meant by a saturation dive. Your body is fully saturated with as much extra gasses as it can hold at whatever depth you're at, working there longer doesn't make you absorb any additional gasses, so the ascent takes the same amount of time, no matter how much additional time you spend at depth.

So, in a saturation dive, you exit the water to a chamber which is at THE SAME pressure as the surrounding water. Which means from a pressure perspective, you don't ascend. You're just getting out of the water. You sit inside the chamber, have some lunch, get some sleep, whatever. You can go back and forth between the chamber and the water without waiting for any decompression.

But with their setup, you exit the water into the moon pool, then go into the Entry lock, where the pressure is adjusted to surface level pressure (ascending). But remember how this can take hours? You're stuck inside the Entry lock, and no one can go in or out of it until you're done.

80 feet isn't horribly deep. You can stay down for 40 minutes and ascend directly, without having to decompress at all. But 8 hours at 80 feet puts you at almost 6 hours of decompression time. seriously.

Comment: Re:A question about space walks. (Score 5, Interesting) 42

by Jjeff1 (#45727405) Attached to: NASA Schedules Space Walks to Fix ISS Pumps; Orbital Sciences Launch Delayed
I read a lot about space, and am a scuba diver, here's my take.

First, diving to 100 meters is going to be fairly dangerous, certainly not something your typical sport diver would do. Beyond 100 feet, you'll increasingly have issues with nitrogen narcosis (you feel drunk), and you'll definitely be in the realm of exotic air mixes (helium instead of Nitrogen, less than surface amounts of O2, etc...). At 100m using normal air, your partial pressure (think concentration) of O2 is 180% of surface level (been a while since I had to do that sort of math), which would be poisonous. Lets just compare to 100 FEET of depth, which a sport diver might do. You could remain at that depth for 10-15 minutes without having to decompress. Stay longer, and you need to sit at depth (say 20 feet) for a while to let the air dissolved in your blood to slowly come out of solution. Go up too fast and it's like opening a bottle of pop, but in your blood. Those bubbles can get caught in your joints, or worse spine, and cause paralysis. Divers that DO engage in deep diving are doing technical diving. Most of the gear is the same as a sport diver, you just carry more of it, particularly tanks and regulators.

But space is worse. First, space suits don't run at normal air pressure, they're down around 4.3 PSI (normal earth is 15). The ISS runs at the same pressure as earth, so donning a space suit is the same as rising UP from depth while diving, you'd get the bends as soon as you open the hatch and exit the ISS (opening the pop bottle). To solve this, when doing an EVA, astronauts breathe 100% O2 for an hour before donning and exiting the ISS.

Second, you have all sorts of cooling issues in space. Your body gives off a lot of heat, and in space, there is no place for that heat to go, so the cooling systems are far more elaborate than any warming systems (often just a hose with hot water being piped down from the surface if you were commercial diving) you might use underwater.

Comment: Re:Insulin levels flucuate, just like blood pressu (Score 4, Informative) 119

by Jjeff1 (#44987189) Attached to: FDA Approves Wearable "Artificial Pancreas"
My brother has a normal insulin pump. They work by continuously pumping in "fast acting" insulin into you (the basal rate), if you eat a meal, you have to calculate by hand the amount of extra insulin needed and press buttons on the unit to deliver the required amount. And yes, it knows that at different times of the day, you need more insulin than others. This is totally separate from the slow acting insulin that type 2 users sometimes take an injection of once or twice a day. If for whatever reason, the insulin delivery doesn't work properly, he'll start to have problems quickly, under a couple hours.

His also has a blood meter which starts beeping if his insulin level falls below a certain level. What his pump doesn't do is automatically change the amount of insulin delivered on the fly. Any change in insulin delivery has to be programmed. If he eats an apple, he has to press buttons to dose himself. If his body chemistry changes and that basal rate needs to be adjusted, it has to be programmed. My understanding from him is that the blood glucose measurement isn't especially accurate, though I can't remember why.

This is just the next generation of those same components. The generation after this, expect to see a unit that does a lot more dosing automatically. I think the technology is there, we just need to clear the regulatory hurdles.

Comment: No - old schools are closed for a reason (Score 4, Informative) 85

by Jjeff1 (#44750951) Attached to: Can Closed Public Schools Become Makerspaces? (Video)
Old schools are generally closed for a reason. Declining attendance comes hand in hand with reduced tax roll, which means less money for maintenance. Even a relatively new school building needs a lot of maintenance. But usually, they're closing OLD schools that require roofs and countless other maintenance items. Asbestos, giant boilers that don't pass safety inspections, etc... I've done work in a school that still has a significant amount of coal sitting in the basement.
Remember these buildings aren't just a big version of your house. You might wire up a new outlet in your house, but you probably don't have the tools or know-how to core 2 foot thick concrete walls or work with 440 volt feeder lines, pneumatically actuated steam radiators or commercial fire alarm systems.

Comment: Re:Reputation (Score 2) 508

by Jjeff1 (#39531531) Attached to: Ask Slashdot: A Cheap, DIY Home Security and Surveillance System?
I'm hardly a weapons instructor or member of law enforcement, but this advice goes against just about everything I know.

- You won't open the door at all if there is a bad guy outside.
- You do need practice, a dozen rounds a year against clay pigeons is a waste. If you actually intend to defend yourself, take a shooting defense course, take several.
- Firing a weapon outdoors is far different than indoors; exposing the family to proper gun safety is a good idea, but outdoor != enclosed space at night.
- Pistol grip... Eh, you can aim and handle recoil far better with a shoulder fired weapon. Again, practice matters here.
- Most bad guys will take off as soon as they realize they have a chance of being caught. Racking a shotgun may scare away someone intent on doing you harm, but the guy there to take your stereo will scram if you flip a light switch.

The main point here is that if you ever have to defend yourself, you're going to be scared, probably in the dark, and probably having not handled your firearm in quite some time. Think quickly, where is the trunk release on your wife's car? Ok, it's dark; which is the SAFE position on your shotgun's safety? If you actually want to effectively defend yourself, you have to understand the most likely scenario under which that will occur. No amount of advice on any web site or book will take the place of regular training and practice.

Comment: OS not the problem (Score 2) 191

by Jjeff1 (#38563322) Attached to: Insiders Call HP's WebOS Software Fatally Flawed
Palm Pre was my first smartphone, so perhaps I'm biased. But the user interface was far superior to andoid or iphone. It is just more intuitive to use, and easier to open apps and manage multiple open applications.

Palm failed due to underpowered hardware. Sprint was the first big carrier, they released the underpowered pre, then nothing to replace it. Pre 2 was never released in the US ( I don't think), same with Pre 3. The real story of the failure of webOS is really about the lack of hardware.

Comment: Re:Fatally flawed because it was web based (Score 2) 191

by Jjeff1 (#38563180) Attached to: Insiders Call HP's WebOS Software Fatally Flawed
What?
My old palm pre is on my desk right now, it operates in airplane mode and works just fine, with no cell plan at all. My data usage was less under palm as compared to my verizon android phone, though I suspect this is because there are more free ad supported apps on android.

Comment: Vbrick (Score 3, Interesting) 126

by Jjeff1 (#38551928) Attached to: Best Software For Putting Lectures Online?
I've worked with schools for years, and can point out some things that may help. First, if the school is in a poorer area, check out your E-Rate eligibility. In some cases, you can pay 10 cents on the dollar for technology. Among the eligible technology would be video streaming, such as vbrick.
The vbrick units are highly scriptable, and you can ( and I have ) programmed them to do as follows:
- user hits the button, as in a physical button on their desk or the wall or whatever
- system records for x minutes
- system uploads video to VOD server
- VOD publishes video to public web server

Yes, you can even have an "on-air" light turn on when the system is recording.
Later on, you can add tags or other information on which people can search your content. You can attach documents, or links to other web-based content. So your video of a lesson has the associated homework, plus link to your states' DOE standards web site or whatever else you want. It can be integrated with moodle or similar systems. You can limit access to video by username/password and/or by IP address. If you want, videos recorded in the high school can be limited to specific users and/or IPs, so lets say the 2nd graders can't watch the sex-ed class. Likewise, you can limit videos on the public internet to your low bit-rate content only.
The critical part here is ease of use. Teachers are asked to do more and more with no new resources. If your solution consists of login to this, click that, then this, etc.... it simply won't get used except maybe by a couple tech-savvy teachers. Of course when those people leave or change positions, your project dies. Then your well intentioned project becomes just another expensive boondoggle. In some ways, spending MORE on a project will guarantee success. Administration may let a 10K project disappear, but probably not a 100K project.

Comment: Waste of time (Score 4, Insightful) 274

by Jjeff1 (#32600746) Attached to: Employee Monitoring
As I tell my customers when they ask, "You can't fix behavioral issues with technology." If employees want to waste time instead of working, they can surf the web or send chain emails. Take that away, they can play solitaire. Take that away, they can gab around the water cooler or stare into space and day-dream. Blocking porn and gambling sites is probably a good idea for liability purposes, but I can't see that it helps productivity.

Most frequently I'm asked to look at log files or email and tell employers things that I simply cannot know. I can tell them that an employee didn't log in to their PC until 10am, but I have no way of knowing when they actually arrived at work.

The IQ of the group is the lowest IQ of a member of the group divided by the number of people in the group.

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