don't the solar core pressure estimates assume a non-metal core? They looks like gas pressure equations to me...
Obviously there's the temperature dimension still to explore - star cores are likely much warmer than 83 Kelvin.
Monitors, like many electronic devices today, have factory-use port that is usually not intended for use after the product ships. The "flaw" to fix is allowing unsigned firmware to be accepted on this port. Or at least cover it with foil tamper tape...
Some transformers can have high efficiency when running at light loads - but that means you just paid extra for an oversized transformer. In general, copper losses go up with the square of load current and iron (core) losses go up with the square of voltage. Of course a 30MW transformer will be designed for higher efficiencies - no one wants to pay for 10MW of losses or deal with all that heat.
Super capacitors are a super pain to design for. The charge/discharge curve is far worse than any battery. They have permanent capacitance degradation if held at rated voltage or at high temp, so you can't top them up and hold the energy for a rainy day. Its expensive/challenging to design circuits to pull the last few volts out, so typical designs have them stacked in series for high voltages with degraded peak load efficiency (ESR). Poor part tolerance combined with charge/discharge cycles requires active balancing ($$$). In the end designs need WAY more total energy storage than useful/usable energy storage.
Compared to gasoline (according to wikipedia), 300kJ is about 0.01 Liters of gasoline = about 1 cent worth. So 1 penny worth of kinetic energy is lost every time you have to emergency stop on the freeway with your SUV? At normal highway speeds its less than half that energy (E=1/2 m v^2).
"the technology still producing electricity after over 12,000 compression and release cycles"
So, assuming an average walking speed that's about *2 hours* before you need new pants.
Washing the clothes would most definitely wear them out! And think about what detergent would do to this...
I dunno about that. I entered my monthly usage and estimated hourly usage rates, then removed the tax breaks (I'm in Canada), and $1/watt is still "unfeasible". I reduced it to $0.10/watt, and finally I have payback in 15 years!
The "100 Hz" spec refers to the modulation frequency (on-off cycling) of the micro-wave source. Microwaves by definition fall in the range of 300MHz to 300GHz, with most home-use ovens operating between 2-4GHz.
My company uses a flash filesystem from Intel for flash in our products. It features "wear-leveling", but a big problem is that in our system ~50% of the storage space has static files that are never modified, so that area is never erased. The wear-leveling only works well if ALL the files are modified frequently. If we fill the flash up with files and then modify only one file 100,000 times (can be done in about an hour or so), the product is dead.
A big challenge for simply swapping these for a battery is the voltage vs. discharge curve for capacitors - it is very steep compared to lithium and NiMH, so without internal (boost) regulation, replacement cells would appear dead well before the energy was completely discharged.
Another common side effect of cold is a (temporary) reduced battery voltage. This can trick some cameras into thinking the battery is dead before even trying to extract the charge from it. My canon suffers from a one-shot syndrome when the temperature gets anywhere near 0C.
I've noticed (from reading datasheets in the past) that many battery chemistries have very high leackage characteristics if stored hot, but the benifits often diminish rapidly around room temp.
I believe the 1 minute resolution was for the reported data and not the actual analog sampling rate. The 1 minute data may (should) be the RMS of the all the samples collected during that minute.
His device seems to be a prototype version of the Veris H663. The released version of the device apparently samples at 1280Hz and reports data every second.
The "phase information" you mention is good to have, but only if the power is at just one frequency. The fact is that computers (as with most devices running of a switching power supply) draw current as a short pulse during the peaks of the input voltage waveform (with no phase angle between voltage and current at the fundamental frequency). Often the 60Hz component (or whatever the fundamental frequency) makes up only half the RMS current. And since these harmonics are only dominant in the current and not the voltage waveform, the real power consumed by a computer will typically be ~50% x RMScurrent x RMSvoltage (even though the phase angle is zero).
My company is already shipping with Millennial Net's embedded solution (though not the "Zibee" model http://www.millennialnet.com/content.cfm?section=2.04).
They claim the new model is "zigbee ready" (firmware upgrade whenever the stack is finalized). http://www.millennialnet.com/content. cfm?section=2.03
In my job, I have to tend and interpret a lot of data so I cringed when I learned how weather stations report "average" temperature. It is usually just the mid-point of the day's min and max temperature! For example:
http://www.climate.weatheroffice.ec.gc.ca/climate_ normals/climate_info_e.html#1
Since the min/max temp is strongly influenced - by several degrees in just a few hours - by cloud cover (solar heating by day and cooling by the open sky at night), the error on this "statistic" can be very significant when compared to a more meaningful average (average of 24 measurements from each hour).
I'm also curious how the average/mean temperature is computed for a small region (which presumably is fed into the global "average"), since there are many varied micro-climate zones within a 50 mile radius of where I live (valleys vs. mountains vs. shoreline vs. inland) where min/max temperatues usually have 5C spread.
I thought I'd read once that water vapor is a very potent "green house" gas - but it rarely ever gets mentioned. Is is because it can't be mesured easily due to its uneven distribution (unlike CO2)?
I have a similar "I have no rights to my work" clause. But I do get a big $1 check for every granted patent and shiny plaque from www.patentawards.com.
Or perhaps it's just because there's more people in more cities with news crews looking for a story to sell... Kinda like the "DEEP FREEZE" headlines in the pacific northwest last week where it was just below freezing for almost two days straight!
Any city with significant growth will experience a corresponding temperature rise (urban heat island).
There are so many problems with "average temperature" measurement. Even if you're looking at data from one location, the daily AVG temperature is usually just the mid-point of the day's high and low - which may not give a fair representation. Defining the average temperature over a region with sparse clusters of weather stations is far more complex and much less accurate. And them I think of the thermometers 80 or 100 years ago - probably blown glass tubes filled with mercury and stuck to a board with hand-drawn ticks...
Something isn't right with this picture - copper is very dense! From my calculations an 820 pound brick of solid copper is only 12 inches by 12 inches by 18 inches.
Today Stirling-powered solar dishes at the Sandia test facility operate at 30 percent efficiency while delivering grid-ready alternating current. In contrast, 30-percent-efficient solar cells are direct current and drop to 16 percent efficiency by the time they generate grid-ready ac. And that's on a hot day. Efficiency can drop as low as 10 percent on a cool day.
It sounds like they're saying that solar cells are more efficient when hot? I think solar cells actually have better performance when cold (just like the sterling engine).
Slashdot Mirror
don't the solar core pressure estimates assume a non-metal core? They looks like gas pressure equations to me... Obviously there's the temperature dimension still to explore - star cores are likely much warmer than 83 Kelvin.
networkworld
tomsguide
this will pick an entire field... certainly smaller options exist, but i doubt the ROI would be worth it - much like this gardening bot...
assume 2000 g of tread mass per tire (~20%)
assume 4 tires
6.1mg / 4 tires = 1.525 mg tire wear "emissions" per vehicle km per tire
assume total tire wear is 10x higher than "emissions": 15.25 mg total tire tread wear per vehicle km per tire
allows for ~131,000 km of tire life.
I am not so sure about the rational of classifying "re-suspension" as an "emission" however.
20W output at 66% full load efficiency
Some transformers can have high efficiency when running at light loads - but that means you just paid extra for an oversized transformer. In general, copper losses go up with the square of load current and iron (core) losses go up with the square of voltage. Of course a 30MW transformer will be designed for higher efficiencies - no one wants to pay for 10MW of losses or deal with all that heat.
Compared to gasoline (according to wikipedia), 300kJ is about 0.01 Liters of gasoline = about 1 cent worth. So 1 penny worth of kinetic energy is lost every time you have to emergency stop on the freeway with your SUV? At normal highway speeds its less than half that energy (E=1/2 m v^2).
"the technology still producing electricity after over 12,000 compression and release cycles" So, assuming an average walking speed that's about *2 hours* before you need new pants. Washing the clothes would most definitely wear them out! And think about what detergent would do to this...
I dunno about that. I entered my monthly usage and estimated hourly usage rates, then removed the tax breaks (I'm in Canada), and $1/watt is still "unfeasible". I reduced it to $0.10/watt, and finally I have payback in 15 years!
The "100 Hz" spec refers to the modulation frequency (on-off cycling) of the micro-wave source. Microwaves by definition fall in the range of 300MHz to 300GHz, with most home-use ovens operating between 2-4GHz.
My company uses a flash filesystem from Intel for flash in our products.
It features "wear-leveling", but a big problem is that in our system ~50% of the storage space has static files that are never modified, so that area is never erased. The wear-leveling only works well if ALL the files are modified frequently. If we fill the flash up with files and then modify only one file 100,000 times (can be done in about an hour or so), the product is dead.
A big challenge for simply swapping these for a battery is the voltage vs. discharge curve for capacitors - it is very steep compared to lithium and NiMH, so without internal (boost) regulation, replacement cells would appear dead well before the energy was completely discharged.
I thought the ice at the poles is only "out of the glass" if it is resting on bedrock, and not floating as sea ice?
Another common side effect of cold is a (temporary) reduced battery voltage. This can trick some cameras into thinking the battery is dead before even trying to extract the charge from it. My canon suffers from a one-shot syndrome when the temperature gets anywhere near 0C.
I've noticed (from reading datasheets in the past) that many battery chemistries have very high leackage characteristics if stored hot, but the benifits often diminish rapidly around room temp.
I believe the 1 minute resolution was for the reported data and not the actual analog sampling rate. The 1 minute data may (should) be the RMS of the all the samples collected during that minute.
His device seems to be a prototype version of the Veris H663. The released version of the device apparently samples at 1280Hz and reports data every second.
The "phase information" you mention is good to have, but only if the power is at just one frequency. The fact is that computers (as with most devices running of a switching power supply) draw current as a short pulse during the peaks of the input voltage waveform (with no phase angle between voltage and current at the fundamental frequency). Often the 60Hz component (or whatever the fundamental frequency) makes up only half the RMS current. And since these harmonics are only dominant in the current and not the voltage waveform, the real power consumed by a computer will typically be ~50% x RMScurrent x RMSvoltage (even though the phase angle is zero).
I think it's possible that magnetic disturbances and solar flares would show that mass can be redistibuted rapidly in our sun.
I think the magnetic field would oscilate proportional to the number of stators times the RPM... and of course there are harmonics.
There could also be much higher frequency EM emmisions depending on it's make-up (eg. PWM switcher for speed control).
But I'm sure neither of these are as intense as the 10,000 RMP high curent motor that spins the platters.
My company is already shipping with Millennial Net's embedded solution (though not the "Zibee" model http://www.millennialnet.com/content.cfm?section=2 .04).
. cfm?section=2 .03
They claim the new model is "zigbee ready" (firmware upgrade whenever the stack is finalized).
http://www.millennialnet.com/content
In my job, I have to tend and interpret a lot of data so I cringed when I learned how weather stations report "average" temperature. It is usually just the mid-point of the day's min and max temperature! For example: http://www.climate.weatheroffice.ec.gc.ca/climate_ normals/climate_info_e.html#1
Since the min/max temp is strongly influenced - by several degrees in just a few hours - by cloud cover (solar heating by day and cooling by the open sky at night), the error on this "statistic" can be very significant when compared to a more meaningful average (average of 24 measurements from each hour).
I'm also curious how the average/mean temperature is computed for a small region (which presumably is fed into the global "average"), since there are many varied micro-climate zones within a 50 mile radius of where I live (valleys vs. mountains vs. shoreline vs. inland) where min/max temperatues usually have 5C spread.
I thought I'd read once that water vapor is a very potent "green house" gas - but it rarely ever gets mentioned. Is is because it can't be mesured easily due to its uneven distribution (unlike CO2)?
I have a similar "I have no rights to my work" clause. But I do get a big $1 check for every granted patent and shiny plaque from www.patentawards.com.
It's all about the motivation...
Or perhaps it's just because there's more people in more cities with news crews looking for a story to sell...
Kinda like the "DEEP FREEZE" headlines in the pacific northwest last week where it was just below freezing for almost two days straight!
Any city with significant growth will experience a corresponding temperature rise (urban heat island).
There are so many problems with "average temperature" measurement.
Even if you're looking at data from one location, the daily AVG temperature is usually just the mid-point of the day's high and low - which may not give a fair representation.
Defining the average temperature over a region with sparse clusters of weather stations is far more complex and much less accurate.
And them I think of the thermometers 80 or 100 years ago - probably blown glass tubes filled with mercury and stuck to a board with hand-drawn ticks...
Something isn't right with this picture - copper is very dense! From my calculations an 820 pound brick of solid copper is only 12 inches by 12 inches by 18 inches.
Today Stirling-powered solar dishes at the Sandia test facility operate at 30 percent efficiency while delivering grid-ready alternating current. In contrast, 30-percent-efficient solar cells are direct current and drop to 16 percent efficiency by the time they generate grid-ready ac. And that's on a hot day. Efficiency can drop as low as 10 percent on a cool day.
It sounds like they're saying that solar cells are more efficient when hot? I think solar cells actually have better performance when cold (just like the sterling engine).
I think what the article meant to say was 25% of the world's "man-made" greenhouse gasses.
I thought water vapour was the most significant greenhouse gas?