Slashdot Mirror


User: JaBob

JaBob's activity in the archive.

Stories
0
Comments
60
First seen
Last seen
Profile
(view on slashdot.org)

Comments · 60

  1. Re:This is... on Simple Device Claimed To Boost Fuel Efficiency By Up To 20% · · Score: 1

    Actually, I'd stand by Techron. My Phd mechanical engineering grad student friend who does combustion research puts it in his car every now and then instead of throwing a bottle of other stuff in. I know it's possible that he could be wrong, but with technical stuff, I trust him. Apparently the difference between cheap gas and expensive gas is the additives. Most of it has to do with complex chemistry where you figure that some of the combustion products and byproducts end up making their way around the piston rings, down into the crank. When they mix with oil and deposits on the cylinder walls, bad stuff can happen. Most of the detergent additives try to minimize this, or to help clean stuff like valves/seats. Some of them try to target the compounds that get stuck to parts of the injectors. Not exactly sure about all of it, but I'm pretty sure that he said something along the lines of 'when they say stuff about varnish in an engine, it's not far off from what you put on wood'. Part of his research is trying to develop tools to figure out what the hell happens in the cylinder when we burn gasoline blends. Our current method is about as analytical as 'well, lets burn it and see what happens.'

  2. Re:This is... Probably Just a Heater on Simple Device Claimed To Boost Fuel Efficiency By Up To 20% · · Score: 1

    Even if the engine was pretty fouled, the computer wouldn't allow for conditions where you'd get gasoline autoignition. It's called 'knock' and it's really detrimental to the health of an engine. Instead of a slower, more controlled explosion (low explosive, like black powder), you'd have a sharper spike in pressure (think high explosive, like C4 or TNT) and a shock/mach wave thing that I can't seem to fully wrap around my head yet. I don't know about being a heater, or even needing one. I'd think the increase in pressure of the secondary pump would cause fuel temperatures to rise from the pumping action. And even if it's a heater, there's no more fire hazard with a diesel than what's currently on the road.

    As far as your car getting better mileage when it's warm, it's because the computer has to wait for the right engine conditions to be satisfied before it can start playing with how much fuel it's putting into the cylinders. Until then, it's running on an 'open loop' fuel map which, while not perfect, will allow your engine to run without breaking itself for long enough for it to take over. That's why your car doesn't just shut off when your MAP/MAF sensor or 02 sensor dies - it reverts back to a general safe program.

  3. Re:Classic problem. on Should Organic Chemistry Be a Premed Requirement? · · Score: 1

    Lo, doth thou desire fries with that?

    I'm sorry, maybe I'm just jaded, but what the hell is a liberal arts ed good for now? I wouldn't trust all the liberal arts folks at my school to run a help desk, let alone anything more technical. Trade schools still have their place but the difference between a Mech & Aero degree and say, certs from manufacturers, is that the degree will make you usable in a broad range of applications. That trade school cert is good only for a handful of specific applications. To a point, even an engineering degree is essentially training a librarian - you don't remember every little thing, but you should learn enough to be able to remember where in a book you were exposed to it, so that when you need it you could always go back and refresh yourself on that topic (you did keep your books, right?) After seeing what kind of people make it through even something technical like mechanical engineering, it makes me sad that there's others that almost demean what it means to have a degree. Decades past, it meant something special - now it means that that person spent another four+ years being indoctrinated into blind group think. It's sad that today's BA and BS degrees mean little more than (expensive) glorified high school diplomas. I mean c'mon, how many degree bearing people do you know that couldn't logic their way out of a wet paper sack while facing the exit?

  4. Re:Well, it running diesel is pretty important.... on Ford's 65MPG Due In November, But Not In the US · · Score: 1

    You tax the truckers like that and prepare to see the price of consumer goods in the US skyrocket. While some industries have a decent rail infrastructure, how do you suppose all the stuff you buy gets from where it's made to where it's sold? If you wanna see some of those behaviors changed, charge more for people that don't carpool. Nobody wants that so we're willing to pay in higher fuel usage. And we wonder why some of the world calls us overprivileged.

    The highway infrastructure in the US sucks. It needs major changes, but we don't want to pay for it. Just look at what we do with our bridges.

  5. Re:Does that mean it can run on BIOdiesel? on Ford's 65MPG Due In November, But Not In the US · · Score: 1

    Too bad we didn't keep records - my family had an '81 Rabbit diesel die just short of 2 million miles. It'd been through something like 5 drivers, 2 transmissions, dozens of wheel bearings, two sets of half-axles, etc. all replaced from wear. My brother finally cracked the head between three cylinders and it was $400 for a new head or $400 for the same car, but two years younger. Talk to some truckers, a million miles isn't all that big of an accomplishment. Regular maintenance is a biggie to longer life (pending no other problems with the engine).

  6. Re:Um, what? on Ford's 65MPG Due In November, But Not In the US · · Score: 1

    Well, fuel takes a certain time to burn. While gas burns faster than diesel, even some gas engines can have problems completing combustion. Take funny car engines - there's a reason that flames shoot out of the exhaust - but they're not exactly worried about efficiency but rather getting down the lane quicker. They can stand the lost of that energy because they're just dumping fuel and air in trying to get down first.

    If you think about it, diesels are gas engines that work by detonation (knock). If you throw gas in a diesel engine, you'll get detonation instead of burn. Diesel tends to burn a bit slower and instead of a pressure spike, you get a more sloped increase in cylinder pressure. But it still is more like detonation, so diesel engines have to be built sturdier. Think of it as more of high explosives vs low explosive situation.

    I haven't studied it yet but I'm pretty sure that you inject diesel into the cylinder when you do so that you get as complete a burn as possible. Otherwise you're just throwing fuel out with the exhaust gases.

    Any engine for a given force will produce more power with higher revolutions simply by torque x rpm = power. That's how Honda tends to cheat with their listed power. They technically make the rated power but at nearly absurd revolutions. Who cares if your engine makes 150 HP if you have to be turning 6k RPM? How often do you drive in that range? Personally, I'd love to know how Porsche does what they do with their engines.

  7. Um, what? on Ford's 65MPG Due In November, But Not In the US · · Score: 2, Interesting

    Gasoline burns faster than diesel. You can have more complete combustion sooner in time and therefore can have a higher rpm (less time per power stroke = not burning fuel as the mixture leaves during the exhaust stroke). The reason that they're heavier is that the combustion pressures are generally higher than gas engines, so diesels have to be built sturdier (at least until we get better materials).

    You get better efficiency by increasing the difference in pressures, and since newer diesels are turbocharged, you can force more fuel/air in per power stroke. This has the effect of running on a 'bigger' engine, without all the weight. When we figure out how to reliably get gas direct injection technology to work, eventually running gas in similar parameters that we run in diesels, we'll see more efficient engines. The nice thing about diesels is that you don't break things by running too lean. Running too lean in a gas engine is a great way to have an excuse to go out and buy yourself a new engine.

    The bottom line is that we can get great mileage today with today's technology. Americans (and probably the rest of the world) get sold on being able to accelerate quickly. We'd all be fine with engines that have a peak output of whatever the car needs to be able to push air out of the way at whatever reasonable top speed you want. Rough estimate is something like 50 HP or so for the average car at average highway speeds in the USA. Why do you think that the hobbyists that do it for fun drive the way they do?

    As far as I know, we like diesel locomotives because those diesels power big generators that run 3 phase motors, which deliver constant power. Constant power means many good things when trying to do work - less vibrations, more even wear-and-tear, etc. That, and diesel fuel is a little more transportable than most fuels that we use to make power.

    The problem with diesels on the road is emissions combined with everyone wanting their own car. I understand that many many people have a basic work need to have their own car and have no public transit alternative, but there's a great deal of us that are willing to put up with the hassle and expense of having our own transportation just so we don't have to be at the hassle of other people.

  8. Re:Sparcstation In The Wall on San Fran Hunts For Mystery Device On City Network · · Score: 1

    My physics professor had a similar story: somewhere within the walls of CMU someone had covered a door to a small room with drywall for aesthetic remodeling reasons. The trouble came when a few years later the machine, which had been on since practically the start of the internet, started sending crap signals out over the network. They started looking for it through tracert-type stuff and when they couldn't find it in any of the rooms, someone started tracing wires by hand and found the wire going through the drywall.

    The thing that I wonder is what kind of machine has that kind of uptime? If it was hardware in the NIC failing that caused all the trouble, what the hell made up the rest of the machine?

  9. Re:Note on Units on Spectacular Fossil Forests Found In US Coalmine · · Score: 1

    Ok - Now repeat the problem under the condition that the now 'processed' beer is bottled and sold under the brand 'Budweiser.'

  10. Re:Who you gonna call? on Ghostbusters Is First Film Released On USB Key · · Score: 1

    Ghostbusters

  11. Re:PETA won't be satisfied on Working Towards an Eco-Friendly Fireworks Display · · Score: 1

    With the exception of sick or stupid people, hunters would never shoot for 'painful wounds and long deaths.' All that I remember from ever talking to anyone about hunting is that they always want a clean, quick kill. Not only is it more humane, they keep in mind that when an animal struggles and has a slow death, it tends to make the meat not so good. Like when people exercise, there is a buildup of lactic acid or similar. This does stuff to the tissue that makes it not taste as good as that from a quick death. It's one of the reasons why ocean fishermen carry bats or guns aboard - for a quick dispatch so the damn animal doesn't wreck it's meat or hurt someone aboard. And about the people that hunt just so they can have something stuffed or even worse, just a pair of antlers hanging up... don't get me started... what a damn waste of animal. Luckily many taxidermists will take the meat they can and use it for foodstuffs.

    And as far as filling the land with lead, I'm not so sure about that. For quite sometime now, many folks have been touting lead free shot - but maybe that's only for waterfowl hunting.

  12. Re:Maths has changed / evolved... on Have Mathematics Exams Become Easier? · · Score: 1

    Yeah, less time consuming and more accurate to use a calculator ... right ... so that's why I have to tell other students to be suspicious of what the calc or computer tells them ... because oftentimes their dumb selves enter the numbers in wrong, 'so of course an apple weighs 2.3 tonnes.' I fear the day that my life may one day depend on the things that they design.

  13. Re:thought crime on Senators OK $1 Billion for Online Child Porn Fight · · Score: 1

    So is this what's going to get deep packet inspection mandated? Are they trying to use this to get all the equipment installed for an expanded system? Besides having someone over my shoulder the whole time I'm on the internet, I can't think of any other way for them to know what I'm doing online. This reminds me of the laws in the south against sodomy - how the hell are they going to know what you are doing in the privacy of your own home?
    I guess nobody cares about what liberty really is anymore.

  14. Better than gnome... on Usability Testing Hardy Heron With a Girlfriend · · Score: 1

    My girl is scary bad with technology in general. If it's got more buttons than her phone, she gets freaked out over the smallest problems. On a scale of 0 to 9 she would rate about -15 for patience with technology. I actually convinced her to try out Kubuntu and she seems ok with it, other than hating open office simply because the UI is different from MS office. I don't seem to have a problem with it simply because I may be one of the 15 geeks in the USA that hasn't gotten to know it intimately. She seems to get along with KDE better than Gnome, simply because the layout and menu is similar to windows. YMMV though.

  15. Re:what other ideas of his will come to pass? on DARPA Working On Arthur C. Clarke Weapon Idea · · Score: 1

    I think its more a problem that people en-masse are too stupid to even drive normal cars with any decent competence .

    There, fixed that for ya.
    Personally, I'll be relieved when we automate normal traffic. Boost road densities and you won't need 4 lanes highway in most of the places that the exist now. I think that'd be an easier and cheaper solution than flying cars. And you'd still need about the same amount of automation in systems checks as there would be in traffic control to make sure that things are working safely and efficiently. And they need to be hard set safety rules too... like systems don't check out, you don't leave (and on that note, make it easier to fix the damn thing than to bypass the safety systems). How many people do you know that just drive on and on an on with the check engine light on? I have had a buddy that used to work at a garage tell me how some customers with surprisingly high mileage cars (100+K ... wtf??) came in because their car was acting up, and then later find out that the car never had a single oil change. I for one, do not want those people flying - they scare me enough on the road. And about the pilots: I used to work at a small airport where they flew banners over the jersey shore, and many pilots are just as bad as some of the drivers I've dealt with - so don't say the extra training is all that worthwhile either. Check out how many nonfatal accidents are reported to the FAA each year, then remember that those are the ones that actually get reported.

  16. It's already here. on Microsoft Accommodating Eee With Lightweight XP · · Score: 1

    It's called NLite... I've used it to strip down XP for use on a bunch of P3 450s for a small cluster project in the lab where I spend more time than I should. We were able to strip it down so we could start a .NET based solution to do some combustion research. It actually ran decently fine on anything above 256 MB of ram. While I waited for him to finish up his code, I had them running Grid.org on it to compare it to a C2D Overclocked to 3.2 Ghz with 2 GB ram (this was basically 3 weeks after it first came out), and it only took something like 5 computers to match the throughput that machine. And most of the boxes in the cluster were literal junk from other labs. Before everyone starts flaming me about 'well why didn't you use linux?' - we had a site license and didn't have to pay, he was comfortable with C# and .NET, mono wasn't as mature as it is right now, and yes, the next version of the cluster will probably be linux based.

    I don't know how much you can strip out of something and still make it desirable for an end user though. Most of the gain that we had was simply turning off all the pretty crap and cutting out all the multimedia stuff. When you actually used one as a terminal, it wasn't that bad - it was just kinda ugly.

    Most of the other end users that I talk to (read family that relies on me being the resident geek) would rather have a pretty and slow machine than an ugly fast one. YMMV

  17. Well... on Name For a Community-Owned Fiber Network? · · Score: 1

    Nobody said you have to use network Bob...

  18. Just walk away on Instant Messaging For Introverts · · Score: 1

    I find it quite effective to simply walk away from a person if they take a call when I'm talking to them. And I try to give them the same courtesy by not picking up the damn phone and essentially saying 'hold on, there's something more important than you that I'd rather pay attention to.'

  19. It's Comedy... relax on Daily Caffeine Protects Your Brain · · Score: 1

    Sheesh... comedy is comedy... so you don't like the guy's style. You think that his delivery is juvenile. Maybe you also don't like George Carlin because of his language, or Richard Pryor because of his drug use, Carlos Mencia because of his blatant use of the race card, or Robin Williams because of the sometimes incoherent nature of his presentation. To me comedy comes in many forms - and it's purpose is to shed light on some of those peculiarities of human nature. I would never do or say half the things I have ever heard in comedy routines, but they do poke fun at some of my insecurities and values and make me learn a little bit more about myself. Maybe it's because I've never been very social and that since some of the comedy stuff echoes what I experience, it's a way of feeling less alone or knowing that other people have the same insecurities. Or maybe it's just that people have different tastes and I don't really give a flying fuck what someone on the internet says (because here everyone's important and their opinion is law.) They have experienced things that I may never in my life get to, so I will take any chance to learn about things I may never be exposed to. I like talking to the diverse group of people that I meet - It feels good knowing that no matter what walk of life you come from, there's things that tie us all together.

  20. Cue Louis Black on Daily Caffeine Protects Your Brain · · Score: 1

    This made me jump to Louis Black's rant on eggs... "...What about eggs? Now they're saying eggs are bad for you. ... First they were bad, then they were good... then the yolks were bad but the *stammers* MAKE UP YOUR MIND!! It's breakfast and I gotta eat..." Seriously. I have a family history of diabetes, heart disease, cancer, and depression. I used to be all kinds of concerned with my health and how I should treat myself so I used to read magazines like Men's Health and others, as well as check out what the web said about other health issues. I used to worry about what kind of exercise I was or wasn't getting. I used to really worry about the kind of crap I was eating or if I was getting all the vitamins and whatnot that I should've. I had my subscription for something like 6 years or so, but I quit worrying about that when I used to notice patterns that whatever advice anyone anywhere would ever give, someone else would contradict that later on. I don't have a photogenic memory but I would remember enough to realize this, and so I basically said fuck it... whoever said it first had it right when they said 'almost everything is good in moderation.' Now you can read all kinds of articles on how good fermented beverages are good for you and how they are bad and blah blah blah. Well there's few things that should not be done in moderation (modern refined street drugs for one), but everything else should be handled reasonably well by most people in moderation, but YMMV. Just don't go overboard on any one thing and you should be OK.

  21. Re:Just Don't Look on Users Know Advertisers Watch Them, and Hate It · · Score: 2, Informative

    ...and while you're at it... check in every now and then what gets white-listed and wonder how much longer it's going to be effective for.

  22. Re:So long its not Matlab on Stroustrup Says C++ Education Needs To Improve · · Score: 1

    It's funny to me that you mention MATLAB and how some people want to use it for everything. It is required as part of my undergrad engineering curriculum (and yes, the prof was versed in FORTRAN) and everyone in engineering seems to love it, but when you talk to anyone with even a hint of CS background, they all hate it. My friend just got his MS in mechanical (his panel said that he did enough work to get a PhD, but they couldn't just jump and give it to him), and has past experience managing SQL stuff, has a bunch of MS certs, and some experience in programming FPGAs and camera electronics, and blah blah blah. Basically he's the guy I go to when it comes to anything electronic. I asked him how much to concentrate on MATLAB and he said... don't... use it for making pretty pictures of your data, but do everything else in C++ or C#, whichever I feel more comfortable with as it would run a few orders of magnitude faster. He says that sure, MATLAB is stupid easy to use, so it's alright for a one off quick thing, but if you ever need to program for a real project that needs to run more than a handful of times or needs to run quickly, do the work and program it in a real language. YMMV though.

  23. Re:from the blog on City-Provided Wi-Fi Rejected Over "Health Concerns" · · Score: 1

    Not that I'm an expert on electronics or anything... but doesn't discharging a battery generally cause it to heat up? It never seems to me that the screen part of the flip is all that warm, but that the keypad part of the body is warmer.

  24. Just make a sentry gun on Cubicle Security For Laptops, Electronics? · · Score: 1

    Copy what the guys at http://www.thesentrygun.com/ did, but use some capsicum balls instead.

  25. Re:Never dealt with that sort of problem on Cubicle Security For Laptops, Electronics? · · Score: 1

    As a substitute custodian for the school district where I live (tuition doesn't pay itself), I can tell you that there are some people that don't clean some of the tech rooms for just that reason. And the some of the ones that do still clean the computer labs and such won't touch a damn thing in there except to vacuum/sweep or collect the trash - and we generally never take boxes laying around unless it's clearly marked trash for the same reason - It's too easy to get blamed so it's better to leave it be and have someone complain that it was never cleaned or taken out then to get blamed for theft or stuff being broken.