ROMANIAN	NOTA AUTORULUI : Pot aparea oricand modificari in acest document. Autorul isi rezerva dreaptul de a modifica textul fara o prealabila notificare. Deoarece autorul mai are si multe alte lucruri de factut acest document poate contine cateva/multe greseli.
ENGLISH	AUTHOR'S NOTE : This document is to be changed without notice. The author reserves the right to change the document without any notice. Due to the fact that the author has many other things to do this document may contain few/many mistakes.

I started writeing this document during years 2007-2008. Some(or more) paragraphs were written during 2009-2011.

Last summer('07-'08) I had so much need of an electrical power source ...
But all photovolatic panels were to $$$ for me ...
So ... I was searching on the net for a solutions: how to buid Silicium photovoltaic panels ...
Well..... to difficult for Silicium but I found some easy to make Copper Solor Panels,
a cooker made from Aluminum foil (for summer time) ....
and a thermal solar panel.
So I thought to make a HUGE aluminum concave-mirror wich could reflect all light to a small spot
and like (some LASER effect) it will heat my thermo-electric generator wihich could produce
electic current.
But soon I realized, will searching with google that I could use a special small [4cm/4cm] Silicium
photovoltaic panel instead of the temperature-to-electricity converter ....
I found that I could focus a lot of light to a very small Silicium Photovoltaic Panel [4cm/4cm]
That would decrease ENOURMOUSLY the price .... of a 5 meters sqare Silicum Array of Photovoltaic Panels ...
The mirror can be made using cheap Aluminum foil, found everywere ...
Or for whom is easy : a big (in fact huge) lens ...
By this - reflecting light using a concave mirror - the light can be processed using
additionl lens, mirrors, phase shifters, polarizers, filters and so on ....
A huge spherical concave mirror can be build - which can be harder to assembly by hand .... There are lots of projects over the internet relating heating water .... It's not quiet easy to make your own "perfect" spherical parabolic mirror .... so I choosed to use a array of relativly small plane mirrors built using cheap aluminium foil... For heating water I choosed to use glass botles and plastic botles ... After experienceing a lot of colors for botles ( COLORS ARE VERY IMPORTANT ) I've came to the conclusion that blue,greem,white,yellow are very bad colors ... Instead BROWN is extreamly efficient. This very important when you try to build your own solar heater ! I can repeat this IT IS VERY IMPORTANT ! (brown materials are 90% more efficient than other colors) In the spring time (like april and may) the amount of water that you call heat all the day is no more that 3-6 L. In the summer time things are different; you can heat -- all the day -- more than 72L - 100L. I used 11 BROWN botles of 2 L. I used : - 7-8 mirrors of 30x30cm - 1 mirror of 50x60cm - 1 parabolic mirror of 20x40cm

A much more professional way to heat water is to use a huge mirror made up of steel "table" polished with alluminium foil. I've used a 2 meter sqarred of table to concentrate light on 2 botles of 2 L. The result gived me lot of satisfaction ! I almost boiled water ! If I'd have used different material for bottels like copper (insted of plastic) I could boil .... 4L in 30 - 50 minutes. (you can't boil water in plastic botles or even glass botlers!!! )

The result of all this is good in the country side or when your are on a trip --
- 70L - 100L per sunny day with may first project
- an ECOLOGICAL way to heat water (NO CO2 emission, no money, no nothing !!!)
- think a little of how much money you need to pay to heat 70L-100L of water (using gas, electricity or fossil fuels like coal)
- and it's lot of fun !

And the total result ( I mean with the first amator project and with the second professional project ) is more 100L per day of HOT water !!!
I want say how much money you can save with both projects -- but you can do it too !!!

The aluminium foil can be "bouth" with 3ron (1$) pe 5 meter squared.
The steel table of 2 meter squared (1 mm thickness) is about 20ron (~6.5 $).
The BROWN botles (I repeat again,again and again: BROWN) sealed as Bear botles !
The botles I all ready have on hand so no money for them.

So every thing is : 23 ron (~7$) fir both projects .... and assuming that all the summer,the begining of automn and the end of spring (5 months) you can to heat water for washing purposes ...
The mirrors require minor revisions every year...
Comparing with gas which is 30(~10$) ron per 9L and other prices .... you say what does this mean !!!

Have fun with your own project --- !!!

Now lets take a look to energy values for heating water ...
The formula used to calculate the energy for temperature change is : Q = m * c * dT
m = mass [kg]
c = specific heat of material
dT = Tfinal - Tinitial = change in temperature
Specific heat for water called "c" its about 4200 J/(kg*K)
For instance to heat 1kg (~1L) water from 0'C to 100'C requires:
Q = 1kg * 4200 J/(kg*K) * ((100+273)-(0+273))
Q = 4200 * 100 = 4.2e5 Jules = 116 WattsHour = 0.116 KWh (KiloWattsHour)

So you need 0.116 KWh to heat 1kg of water from 0'C to 100'C (this is like boiling ~1L of water in the winter)
But if you need water for other purposes you will not need to boil it ...
We can assume during spring/summer/automn the initial temperature of water is 15'C
It's final temperature is almost 65'C
So in this conditions : Q = 1 * 4200 * (65-15) = 210000 J = 58.(3) Wh = 0.058(3) KWh
But for 10 L of water => : Q = 583.(3) Wh = 0.58(3) KWh
...
Now back to my projects ...
Heating 100Liters from 15'C to 45'C requires (air temperature: 27..33'C):
Q = 100 * 4200 * (45-15) = 12600000Jules = 3500 Wh = 3.5 KWh
And it will take all day ... I mean all the time that sun is still shining ...
Assuming 6-7hours need to heat 100L to 45'C => Solar panels provide : 538 Wh each hour and a total of 3.5KWh for 6h30min
If I would've use this every day for 120 days => 3.5 KWh * 120days = 420KWh totaly
Need more water ? Or it's supose to be more hot ? Add up more Solar Panels ...:)

Let's how much "wood" we would've need for this (and also how much petrol) !
In order to compute this will use : Q = m * C
For wood C = 15000 KJ = 4.1667 KWh
For petrol C = 45980 KJ = 12.7222 KWh
So to boil 1kg water (0'C to 100'C) we need 0.116 KWh => m=Q/C =>
m=0.116 KWh / 15000 KJ= 0.116 KWh / 4.1(6) KWh = 0.027 Kg = 27grams :) (wishfull thing ... because of the inefficency of the "heaters")
For 10kg => 0.270 Kg
For 100Kg => 2.7 kg
But we need to include the heater efficiency :( ... which may vary .. 5..30%)...
So for 5% eff :

1 kg => 0.027 * 100/5= 0.54 kg ..

10 kg => 0.27 * 100/5 = 5.4 Kg ..

100 kg => 2.7 * 100/5 = 54 Kg ...
For 25% eff

1 kg => 0.027 * 100/25= 0.108 kg ..

10 kg => 0.27 * 100/25 = 1.08 Kg ..

100 kg => 2.7 * 100/25 = 10.8 Kg ...

Now lets see petrol but briefly...
100% eff =>

to boil 1KG water => 0.116 KWH / 12.7KWH = 9.08 grams of petrol

to boil 10KG water => 1.16 KWH / 12.7KWH = 90.8 grams of petrol

to boil 100KG water => 11.6 KWH / 12.7KWH = 0.908 kg of petrol
for 5% eff =>

to boil 1KG water => (100/5) * 0.116 KWH / 12.7KWH = 0.1816 kg of petrol

to boil 10KG water => (100/5) * 1.16 KWH / 12.7KWH = 1.816 kg of petrol

to boil 100KG water => (100/5) * 11.6 KWH / 12.7KWH = 18.16 kg of petrol
for 25% eff =>

to boil 1KG water => (100/25) * 0.116 KWH / 12.7KWH = 0.03632 kg of petrol

to boil 10KG water => (100/25) * 1.16 KWH / 12.7KWH = 0.3632 kg of petrol

to boil 100KG water => (100/25) * 11.6 KWH / 12.7KWH = 3.632 kg of petrol

By comparison, heating water directly from sun AND heating water using electricity from photovoltaics cells =>

solar heater cost : 2mp stailess steal + aluminium foil + brown botles + stuff=> 10$

photovoltaics cells that can produce 3.5KWH each day => 500W photovoltaic cells (assuming 550$/100W) => 2750$
So the winner is : SOLAR HEATER ...
But the solar heater can only be used in the spring/summer/automn and only during bright sunny days ...
while the photovoltaic cells can produce electricy which can be used for many other purposes
(and there will be no problem with heating water in the winter -during sunny days of course)...
Note: you will need also a power inverter that can provide more than 500W (like 1KW) and a heating
device

Now, after seeing first and second project you might think thats all ! No, no and NO ! There is third project too !
The third project come to me while I was trying to find a cheap solution for photovoltaic panels BUT I wouldn't have enough courage without www.thegreenpower.com, and without Mike, and without MIT teachers, and without many others.
Everyone knows photovoltaic panels .... Unfortunatly they aren't quite cheap ... They generally cost as much as they produce for 20-25 years (even if only energy produced by them in 4 years is envolved but there are many taxes to be added to the price and silicon wafers are pricey too)
One solution to cut down the costs is to use additional mirrors with normal panels ! This can be applied to any kind of panels as long as you don't heat them to much because they will "blow" if their temperature increases to much ! And also hi temperatures decreasses theit efficiancy .... But , yess !!!! there is a but ! In the winter it's cold so no problem with temperature ! And also in the winter there's not so much light from the sun so additional mirror may be used to make panels function like in summer time and even better !

There is a lot to talk about this and because of this I will resume my self to showing you pictures and telling you how I did !
For more details please see this page under development

Two cells connected in series : V=0.58x2 =1.16 Volts and I=0.330 Ampers. No additional mirrors.

Bulb is lighting too low.... not enough energy....

Same 2 cells with additional 30x23 cm semi-parabolic mirror ! (with 60-80% percent efficency)

Bulb is lighting much better with additional mirror reflecting light on cell ! (3Volts mini-bulb)

Cells but no mirror !

MP3 is working at the limit ... It's stopping after few seconds (10-30sec)....

Cells with mirror give now more energy !

MP3 works fine and almost all the time ! (except when cells get to hi in temperature)

IMPORTANT NOTE about the next table:

The open-circuit voltage (Volts) is the potential measured under no-load (that means no consumer-device is attached to it); No-load is equivalent with infinity resistance (or very high any way).

The short-circuit current (Amperes) is the current measured under short-circut; short cirtcuit is equivalent with a 0 (zero) load resistance (or very low any way).

This values will NOT BE EXPECTED TO BE MEASURED under a load resistance (that means adding up a consumer). Each device has a specific resistance. Depending on it, energy will be taken by the consumer.
SO, for devices with high resistance like 50 ohms/100 ohms (and higher values [greater than 50ohms]) the energy consumed is less than the one that can be provided by the solar cell so you can expect to values closed to OPEN-CIRCUIT VOLTAGE and for a curent equal with : I = Voc / R
BUT, for devices with low resistance ("heavy" consumers) NONE of the values are to be expected, except that : Vdevice < Voc --and-- Idevice < Isc --and- Vdevice/Idevice=Rdevice
ALSO, depending on the impurity doping concentration used for the fotovoltaic cell jonctions, the direct current (Id) will be greater or small for voltages close to Voc.(for high doping values this current can be neglicted (like 1.0e19 #atoms/cm3 on each jonction) but for devices with a jonction doped less than 5.0e18 #atoms/cm3 things change a lot, and this current can not be neglected any more.
Also high concentration reduces losses because of direct current but they decrease the depletion region yielding to lower current produced :( ...
Because of this using mirrors will increase the power available, but, depending on the doping level, under a load-resistance you will not gain the same 100% more energy but values as small as 20% better.
For more details please see the diagram/table for the same PHOTOVOLTAIC cells under variable load-resistance(s)

Comparison of open-circuit voltage(V) and short-cirtcuit current (I) when not using mirrors and when using mirrors
Digital Multimeter (error=0.8-1%)
			No mirror		Mirror(s)
Date	Time	Weather	V [Volts]	I [mA]	V [Volts]	I [mA]	P2/P1	%	Mirror(s) size
03.12.09	09:40:00	rain	0,686	3,020	0,736	3,910	1,389	38,90%	23x30cm
03.12.09	09:40:00	rain	0,820	6,150	0,880	8,780	1,532	53,00%	23x30cm
03.12.09	09:45:00	rain	0,834	6,290	0,883	8,220	1,369	53,00%	23x30cm
03.12.09	09:50:00	rain	0,888	10,000	0,932	14,000	1,460	46,00%	23x30cm
03.12.09	09:50:00	rain	0,929	11,000	0,968	15,000	1,427	42,70%	23x30cm
03.12.09	10:34:00	rain	0,829	7,070	0,877	9,250	1,389	38,90%	23x30cm
03.12.09	12:50:00	cloudy,semi-sun	1,090	47,000	1,112	60,000	1,300	30,00%	23x30cm
03.12.09	12:50:00	cloudy,semi-sun	1,058	35,600	1,082	46,200	1,327	32,70%	23x30cm
03.12.09	12:52:00	cloudy,semi-sun	1,065	38,000	1,092	48,100	1,298	29,78%	23x30cm
04.12.09	09:50:00	cloudy,semi-sun	0,799	5,520	0,842	7,020	0,000	0,00%	23x30cm
04.12.09	09:50:00	cloudy,semi-sun	0,807	0,000	0,853	0,000	0,000	0,00%	23x30cm
05.12.09	09:07:00	cloudy	0,880	9,210	0,923	12,020	1,368	36,80%	23x30cm
05.12.09	09:08:00	cloudy	0,894	9,846	0,936	13,120	1,390	39,30%	23x30cm
05.12.09	09:09:00	cloudy	0,902	10,000	0,948	13,700	1,330	33,20%	23x30cm
05.12.09	09:33:00	cloudy	0,907	10,630	0,947	14,070	1,380	38,00%	23x30cm
07.12.09	08:50:00	Sun !	1,102	64,500	1,137	98,000	1,554	55,35%	23x30cm
07.12.09	08:55:00	Sun !	1,114	78,300	1,150	158,000	2,083	108,00%	23x30cm
07.12.09	09:00:00	Sun !	1,138	110,300	1,180	220,000	2,068	106,80%	23x30cm
07.12.09	09:05:00	Sun !	1,116	120,000	1,170	230,000	2,009	100,94%	23x30cm
07.12.09	09:10:00	Sun !	1,123	140,000	1,175	290,000	2,167	116,73%	23x30cm
07.12.09	09:17:00	Sun !	1,188	150,000	1,233	320,000	2,214	121,41%	23x30cm
07.12.09	11:15:00	Sun !	1,166	300,000	1,202	620,000	2,130	113,00%	23x30cm
07.12.09	11:19:00	Sun !	1,120	300,000	1,166	640,000	2,220	122,00%	23x30cm
07.12.09	11:20:00	Sun !	1,122	320,000	1,166	650,000	2,115	111,46%	23x30cm
07.12.09	11:25:00	Sun !	1,122	320,000	1,167	690,000	2,243	124,27%	23x30cm
07.12.09	11:30:00	Sun !	1,125	310,000	1,170	730,000	2,449	144,90%	23x30cm
07.12.09	11:40:00	Sun !	1,182	320,000	1,200	670,000	2,164	116,46%	23x30cm
07.12.09	11:50:00	Sun !	1,182	330,000	1,222	720,000	2,250	125,57%	23x30cm
21.12.09	8:53:00	Sun !	1,175	130,000	1,221	230,000	1,933	93,3%	23x30cm
21.12.09	10:30:00	Sun !	1,180	310,000	1,222	600,000	2,0009	100,09%	23x30cm
21.12.09	10:30:00	Sun !	1,201	350,000	1,231	670,000	1,96688	96,688%	23x30cm
21.12.09	11:36:00	Sun !	1,170	360,000	1,210	720,000	2,06837	106,83%	23x30cm
21.12.09	11:46:00	Sun !	1,180	360,000	1,212	710,000	2,0257	102,57%	23x30cm
21.12.09	13:30:00	Sun !	1,180	350,000	1,222	770,000	2,2783	127,83%	23x30cm

Mini bulb : 3Volts
MP3 Player designed for 1.2 Mini Batery AAA (920mAh)
Solar Cells: 2 cells of 0.58V , 330mA in series, giving total power of = 0.3828Watts BUT wth mirror P average~= 0.84216W
PS: don't forget to cool the cells in the hot summer days using water (stick cells to some water pipes and let water pass slowly through pipes !)

The cells, the mirror and the multimeter
Cloudy day - the cells and the meassured potential (mV)	Cloudy day - the cells and the meassured intensity (mA)	Cloudy day - the cells and the mirror
Cells and multimeter	Cells and mirror	Old part of a CPU cooler (used to cool cells)
SUNNY DAY - no mirror; potential in miliVolts	SUNNY DAY - no mirror; current intensity in Amperes
SUNNY DAY - MIRROR; potential in miliVolts	SUNNY DAY - MIRROR; current intensity in Amperes

Now the diagram for potential/current under a load resistance (consumers of different powers)
Short example:
The improved version of this 2xcells is a 4xcells array.
With no-mirror :

open-circuit potential is : 2.2 .. 2.3 Volts

short-circuit current is : 0.3 .. 0.4 Amperes
With a load resistance of 6.7 Ohms (a small bulb) the following values are measured :

parallel potential : 1.5 .. 1.7 Volts

series current : 0.27 .. 0.29 Amperes

With mirror I've got :

open-circuit potential is : 2.3.. 2.4 Volts

short-circuit current is : 0.5 .. 0.7 Amperes
With the same load resistance of 6.7 ohms (small bulb) the following values are measured :

parallel potential : 1.8 .. 2 Volts

series current : 0.29 .. 0.31 Amperes

From this we can compute the benefit of using mirrors :
1) in case of no consumer : 74%..82% more energy
2) in case of the 6.7 ohm consumer : 20%..25%..28% more energy
Transfer ration :
1) in case of no-mirror (PowerAtDevice/PowerAtCell) : 53%
2) in case of mirror (PowerAtDevice/PowerAtCell) : 36.9% , but the device gets 25% more energy
Also more power is available for the photovoltaic cells but not all the surplus(excess) is usable (because of the reasons that I already told you)
The cells are rated by the producer as (on the back): "0.5V 0.33A" and each is about 5cm*2.5cm(and they are 4 in series) - this is the size of the silicon wafer -

Advice : When buying photovaltaic cells ask for MAXIMAL POWER POINT which is the maximum energy you can get under a load-resistance (they won't tell you anything about the mirrors or about maximal-power when using mirrors).
Don't simply relay on the OpenCircuit Voltage and ShortCircuit Current ... Be carefull to ask for MAXIMAL-POWER POINT under a load-resistance... (this is just an advice)

Trick to measure direct-current of photovoltaic cell
Also, there's a little trick for detecting Id(direct-current) of the device !

1) Take one cell - name it cell1

2) Connect wires to it - cell1

3) Put it somewhere where is completly dark - like in a box or coverd by something

4) Take another cell of the same type - name it cell2

5) Connect wires to it - cell2

6) Shine light on cell2.

7) Measure open-voltage current of cell2 (call it Voc)

8) Measure short-circuit current of cell2 (call it Isc)

9) Now, measure open-voltage of cell1 (that one in the box). It should be 0 (zero) or allmost zero...

10) Connect cell2's positive wire to cell1's positive wire. Do the same with the negative wires

11) Measure parallel voltage (connect your voltmeter to the wires)(call it Vd)

12) Now disconnect negative wire (or positive wire, but only one). Connect your ampermeter in series with disconnected wires. Take care of polarity.
Measure direct-current (call it Id).

13) And finally you've got the numbers ! Id will tell you how much current is lost from Isc due to direct-conduction.
Also you can compute how much potential is lost because of direct-conduction by substracting from Voc, Vd.
So lost potential Vlost=Voc-Vd.
To compute power lost due to direct-conduction simple do : Plost = Vd * Id

I used this method and I found out that :
while Voc = 0.579V and Isc = 0.15A
Vd = 0.559V and Id = 0.05A..0.065A (or sometimes 0.03A)
So : Vlost = 0.579-0.559 = 0.020V (20mV)
And Plost= 0.559*0.05 = 0.02795W
If we would've use a load (like a bulb) this is what it would happen :
e.g. Vdev=0.5V Idev=0.29A
Id=0.05A => Itotal=0.29+0.05=0.34A
We could have : = 0.5*0.34 W but we lost [15%] so we have 0.50*0.29W !

REMARK: This is a simple way to estimation, but may contain a little error ... Because there are other effects which should be counted on ... (like : when shining light on the device the quasi-neutral-reqion (QNR) get's more conductive [that good !], Light => more carriers => carrier lifetime affected; light => potential => depletion region shortens => current/potential saturates; etc

Here are also my first mesurements using an analog device ...
Data in the next table are too unprecise, but it's good to see them ...

Comparison of power production when not using mirrors and when using mirrors
Analog Multimeter (low precission, error=10-30%)
			No mirror			Mirror(s)
Date	Time	Weather	I (mA)	R	V (Volts)	I (mA)	R	V (Volts)	P2/P1	Mirror(s) size
15.11.09	12:10:00	Cloudy, cold (no sun)	20	70		28	78		1,7	20x30
15.11.09	12:10:00	Cloudy, cold (no sun)	28	78		32	79			same
15.11.09	14:55:00	rain,cold	5	59		7	59			same
15.11.09	15:35:00	rain,cold	4	55		6	59			same
16.11.09	07:46:00	cold,cloudy	2		0,55	3		0,65	1,77	23x30, new foil
16.11.09	08:07:00	cold,cloudy	4		0,7	6		0,75	1,6	same
16.11.09	08:25:00	cold,cloudy	6		0,75	8		0,83	1,47	same
16.11.09	09:25:00	cold,cloudy	20		1,1	23		1,1
16.11.09	12:05:00	cold,cloudy	18		1,1	21		1,15
16.11.09	12:22:00	cold,cloudy	18		1,1	24		1,15
17.11.09	09:52:00	cold,cloudy	14		1	19		1,1
17.11.09	15:36:00	cold,cloudy	4		0,7	5,5		0,74
18.11.09	07:32:00	SUNNY MORNING	4,5		0,8	6,5		0,85
18.11.09	08:14:00	Sun !	225		1,3	much more than 260		1,3
18.11.09	all day	Sun !	at least 330		1,3	much more than 330		1,3
			bulb doesn't light			bulb lights
			MP3 Player not working too much			MP3 is working all the time !

Mini bulb : 3V
MP3 Player: 1.5 Mini Batery AAA
Solar Cells: 2 cells of 0.56V , 330mA in series !

*) I have used 2 cells in series, rated as: V=0.5V (infact they are 0.56 V), I=0.330A. So because they where in series total voltage should be V=1V and I=0.330A.
*) mini bulb spec. : 3V ???mA

Cells no mirror : I = 0.012mA !	Cells - same position - with mirror : I = 0.042mA	Cells - same position - with mirror : I = 0.042mA
Cells no miror - but a better position : I = 0.028 - 0.032mA	Cells - better - with mirror : I = 0.038 - 0.043mA	Cells - better - with mirror : I = 0.038 - 0.043mA

The Universal Declaration Of Human Right
Art. 26:(1) Everyone has the right to education. Education shall be free, at least in the fundamental stages. Elementary education shall be compulsory. Technical and professional education shall be made generally available and higher education shall be equally accesible to all on the basis of merit. (2) Education shall be directed to the full development of the human personality and to the strengthening of respect for human rights and fundamental freedoms. It shall promote understanding, tolerance and friendship among all nations, racial or religious groups, and shall further the activities of the United Nations for the maintenance of peace. (3) Parents have prior right to chose the kind of education that shall be given to their children. Art. 27:(1) Everyone has the right freely to participate in the cultural life of the community, to enjoy the arts and to share in scientific advancement and its benefits. (2) Everyone has the right to the protection of the moral and material interest resulting from any scientific, literary or artistic production of which he is the author.

The fourth project is comming soon with inspiration and help from :
Intel's IA32/64 Arhitecture Books (free downloadble books :))

MIT Open Courses, especialy from :
Mr. Anant Argwal's 6.002 : Anant Agarwal and Jeffrey Lang, course materials for 6.002 Circuits and Electronics, Spring 2007. MIT OpenCourseWare (http://ocw.mit.edu/), Massachusetts Institute of Technology. Downloaded on [1/6/2009]

Mr. (Prof. Paul Gray, Dr. Charles Rohrs, Prof. Alan Willsky, Prof. Joel Voldman and Prof. Victor Zue)'s 6.003 : Signals and Systems

Mr. (Prof. Steve Ward, Prof. Chris Terman and Gill Pratt)'s 6.004 : Computation Structures

Mr. (Prof. Clifton Fonstad Jr., Prof. Akintunde Akinwande and Prof. Michael Perrott)'s 6.012 : Electronic Devices and Circuits

Mr. (Prof. David Staelin, Prof. Erich Ippen, Prof. Jin Au Kong, Prof. James Melcher and Prof. Markus Zahn)'s 6.013 : Electromagnetics and Applications

Mr. (Prof. Albert Meyer and Prof. Ronitt Rubinfeld)'s 6.042 : Mathematics for Computer Science

Mr. (Prof. Erik Demaine and Prof. Charles Leiserson)'s 6.046 : Introduction to Alghorithms

Mr. (Prof. Anantha Chandrakasan and Prof. Donald E. Troxel)'s 6.111 : Introduction to Digital Systems Laboratory

Mr. (Prof. Martin Schmidt, Dr. Robert O'Handley and Susan R)'s 6.152 : Micro/Nano Processing Technology

Mr. (Prof. Markus Zahn)'s 6.641 : Electromagnetic Fields, Forces and Motion

Mr. (Prof. Carol Livermore and Prof. Joel Voldman)'s 6.777 : Design and Fabrication of Microelectromechanical Devices

Mr. (Prof. Max Tegmark)'s 8.033: Relativity

Mr. (Prof. Darrell Irvine and Prof. Nicola Marzari)' 3.012 : Fundamental's of Material Science

Mr. (Prof. David Perreault)'s 6.334 : Power Electronics

Mr. (Prof. Jesus del Alamo)'s 6.720 : Integrated Microelectronic Devices

Mr. (Prof. Robert Guy Griffin and Prof. Troy Van Voorhis)'s 5.61 : Physical Chemistry

Mr. (Prof. Vladan Vuletic)'s 8.04 : Quantum Physics I

[a big thanks to] Mr. (Prof. Prof. Saman Amarasinghe and Prof. Martin Rinard)'s 6.035 : Computer Language Engineering

Mr. (Prof. Frdz?do Durand and Prof. Barbara Cutler)'s 6.837 : Computer Graphics

Mr. ()'s 6.0?? : Networks and security ??

Mr. ()'s 6.0?? : Java ??

[a big thanks to] Mr. ()'s 6.0?? : Laser Demonstrations

(Facultatea de Inginerie Electrica, Politehnica Buc, Ro)
Mrs. (Prof. Gabriela Cone)'s course : "Electricitate si magnetism"
Mr. (Prof. Nicolae Puscas)'s course : "Fizica - Note de curs"

Theachers and stuff from International Computer High School of Bucharest

Big thanks to Albert Einstein ,Maxwell, Luis de Broglie, Faraday, Ampere, Kirchoff, Volta, Newton, Bill Gates ....

Wikipedia's articles

Many fans and amators : Mike D., A big thanks to all of you

Mr. (Mark Mitchell, Jeffrey Oldham and and Alex Samuel)'s free book: Advanced Linux Programming

Related articles:
The best site to learn how to build your own mirrored solar panels
Mirrored 3 MegaWatt Salar array According to them the price of solar panels is reduced 6 times. (from 3$/watt to 50cents/watt and further more to 32cents/watt)
Mirrored Solar Panelss
The Best Electric Scooters of 2008
"Home" made electric cars [--I can't find any more that video ... please be patient]

Usefull stuff:
() Original idea from the game: Ri_Li*, integrated in Linux Mandriva 2008.1 DVD (Game written by: Dominique Roux-Serret
A text database with advanced properties of chemical elements. It contains: name, Z, A, r.c, r.a, r.i, r.i2, V.a, E.ion, electronegativity, T.vap, T.fus, cond.el, cond.temp, T.specific, electonical configuration, density, T.melt, T.liquefaction ,T.critical, specifc q rap., solub. in H20, magnetic suscept., hardness, ctristalin structure, T.boiling, ionization potential, normal oxidation potential, conduct.el, conduct.temp, color, oxidation states, clarck