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vribeiro1

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  • Sorry for insisting, but biodiesel is a mixture of esters and not triglycerides - in your insctructable you show how to change the physical properties of the oil by mixing it with solvents so it will work in a diesel engine.This is not a question of point of views, its a fact... See more here: http://biodiesel.org/what-is-biodiesel/biodiesel-...Some search at the pubmed site can also lead you to several scientific articles that say the exact same thing as the site. The process could not involve transesterification, but the ester must be there.

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  • although interesting, you can’t call this biodiesel... not without the transesterificaton process...

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  • Hello!Thank you so much for your answer! I have made several experiences and have now some spectrometers with red and blue light, and another one with RGB.When I was investigating the wavelengths I've come across the data sheets of the LEDs with an emission percentage versus wavelength. Is this what you mean by the spectral efficiency curve?Being the absorbance calculated as a logarithm of intensities, even if there is an efficiency influencing my raw data, it should not change my end result, given that the value is the same for Io and I. Or... I am making a really ugly mistake somewhere... And it may be this, because I'm using the measured resistance as Intensity to make the calculations...Hope I am not being too much boring to you, but could you give me some references where I could see…

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    Hello!Thank you so much for your answer! I have made several experiences and have now some spectrometers with red and blue light, and another one with RGB.When I was investigating the wavelengths I've come across the data sheets of the LEDs with an emission percentage versus wavelength. Is this what you mean by the spectral efficiency curve?Being the absorbance calculated as a logarithm of intensities, even if there is an efficiency influencing my raw data, it should not change my end result, given that the value is the same for Io and I. Or... I am making a really ugly mistake somewhere... And it may be this, because I'm using the measured resistance as Intensity to make the calculations...Hope I am not being too much boring to you, but could you give me some references where I could see how to make this models of the nonlinear function for light irradiance? I guess I have a lot to learn and work before I put my spectrometers to work...Thank you again very much for your time and thoughts.Have a nice week!Best regards,Vasco

    Usually no one answers me but here it goes anyway...First of all, amazing instructable! I really wish to make one (or several) of this just for the fun of it.I have a question... I've been searching for ir for a while now. I am trying to make a fixed wavelength spectrometer with a LED and a LDR. The simplest way to do so may be using a multimeter to read the LDR, for example, although I use an Arduíno interfaced with a software I made so I don't have to register all the values and make thousands of calculations... I can use it to calculate concentrations when comparing the absorbances of my samples with standards, of known concentrations. But, the molar extinction coefficients of the compounds I'm studying are not the same as I would get in a normal laboratory spectrometer (I have …

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    Usually no one answers me but here it goes anyway...First of all, amazing instructable! I really wish to make one (or several) of this just for the fun of it.I have a question... I've been searching for ir for a while now. I am trying to make a fixed wavelength spectrometer with a LED and a LDR. The simplest way to do so may be using a multimeter to read the LDR, for example, although I use an Arduíno interfaced with a software I made so I don't have to register all the values and make thousands of calculations... I can use it to calculate concentrations when comparing the absorbances of my samples with standards, of known concentrations. But, the molar extinction coefficients of the compounds I'm studying are not the same as I would get in a normal laboratory spectrometer (I have access to them, so I can even compare results with the same standards in the two equipments).I'm happy with the results but quite distressed about this molar extinction diferences. Can anyone help me or have any idea why this happens?Thank you! ;)

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  • First... This is amazing! And it resembles very closely to the insides of an expensive spectrometer from a lab.I have a question. I've been searching for ir for a while now... I am trying to make a fixed wavelength spectrometer with a LED and a LDR. The simplest way to do so may be using a multimeter to read the LDR, for example, although I use an Arduíno interfaced with a software I made so I don't have to register all the values and make thousands of calculations... I can use it to calculate concentrations when comparing the absorbances of my samples with standards, of known concentrations. But, the molar extinction coefficients of the compounds I'm studying are not the same as I would get in a normal laboratory spectrometer (I have access to them, so I can even compare results w…

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    First... This is amazing! And it resembles very closely to the insides of an expensive spectrometer from a lab.I have a question. I've been searching for ir for a while now... I am trying to make a fixed wavelength spectrometer with a LED and a LDR. The simplest way to do so may be using a multimeter to read the LDR, for example, although I use an Arduíno interfaced with a software I made so I don't have to register all the values and make thousands of calculations... I can use it to calculate concentrations when comparing the absorbances of my samples with standards, of known concentrations. But, the molar extinction coefficients of the compounds I'm studying are not the same as I would get in a normal laboratory spectrometer (I have access to them, so I can even compare results with the same standards in the two equipments).I'm happy with the results but quite distressed about this molar extinction diferences. Can anyone help me or have any idea why this happens?Thank you! ;)

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  • I have a question... I've been searching for ir for a while now. I am trying to make a fixed wavelength spectrometer with a LED and a LDR. The simplest way to do so may be using a multimeter to read the LDR, for example, although I use an Arduíno interfaced with a software I made so I don't have to register all the values and make thousands of calculations... I can use it to calculate concentrations when comparing the absorbances of my samples with standards, of known concentrations. But, the molar extinction coefficients of the compounds I'm studying are not the same as I would get in a normal laboratory spectrometer (I have access to them, so I can even compare results with the same standards in the two equipments).I'm happy with the results but quite distressed about this molar …

    see more »

    I have a question... I've been searching for ir for a while now. I am trying to make a fixed wavelength spectrometer with a LED and a LDR. The simplest way to do so may be using a multimeter to read the LDR, for example, although I use an Arduíno interfaced with a software I made so I don't have to register all the values and make thousands of calculations... I can use it to calculate concentrations when comparing the absorbances of my samples with standards, of known concentrations. But, the molar extinction coefficients of the compounds I'm studying are not the same as I would get in a normal laboratory spectrometer (I have access to them, so I can even compare results with the same standards in the two equipments).I'm happy with the results but quite distressed about this molar extinction diferences. Can anyone help me or have any idea why this happens?Thank you! ;)

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  • In the arduino ide go to tools>port and select the right choice... ;)

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  • This is an amazing project that I will test out really soon.I only wished to know one thing, is hexane available to the general public? I'm a chemist, of course I could get some, but I'm interested in making projects that anyone could do.Thanks for the instructable!

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