Відео

I chose cement because it remains a long time, even in rainy weather. So you can make several reflectors one after the other. But I actually also used gypsum (see 8:00 - 9:40) because it can be sanded finer than cement. Perhaps I should have used the term "plaster" instead of "gypsum"; it's probably just a translation error, sorry.

Hello Andy! I used 3.5 liters of resin. In the film description you will find a link to a pdf document. It describes all the details. Greetings Bruno

Thank You

Part 2: ua-cam.com/video/s34NRYzmL6c/v-deo.html Part 3: ua-cam.com/video/cSrxndJZOjE/v-deo.html

In der Filmbeschreibung, oder hier: gotobrasil[at]gmx.ch

Hello Brian! That's a very good idea to test the alu foil with a laser pointer. Sorry I didn't reply sooner, I was traveling and away from my alu foil collection. Today I tested them and noticed big differences. In fact, the thin household foil is the worst, the one I used (self-adhesive, covered with a plastic layer) is the best. A plastic foil generally used for wrapping presents also performed well. Its reverse side is mirror-smooth and colorless. I will test other films when I get the chance, but for now these tips must suffice. Thanks for the tip! There is still room for improvement.

@@brunokagi1090 Thanks for your reply, Bruno. I never expected this! I though it would make a blurry dot. I did more tests and aluminum foil here in Canada, produces a line in one direction and it produces a nice semicircle in the other direction! And I think the reason is because the aluminum has grooves in it (like the roof of a farm shed) and the grooves cause the line in one direction and semicircle in the other direction. Its very interesting but someone should have warned us years ago. I made parabolic dishes a decade ago and I had no idea that aluminum foil was a horrible reflector. I made a bad video about it on my main youtube channel, and I will replace it with a better one soon. I also found research from India, where they tested different coverings. They thought vinyl car wrap was worth the extra cost because it was about twice as good as foil. They also found "mylar" good.

Hello Brian! I have now found a mirror film that reflects quite well and with low loss: It is a self-adhesive film from the German company d-c-fix.com, the film can be ordered online from the manufacturer (www.d-c-fix.com). Article no. F2150013. This film is quite stiff, so it compensates for irregularities in the surface, but must be cut into small pieces before application because it does not adapt to the curvature of the shape. Greetings Bruno

@@brunokagi1090 Thank you Bruno, I'll probably get to ordering it in february, (this is the same Brian, just from my DIY environmental and experimental site.)

Please let me know your ideas! -> gotobrasil@gmx.ch

Why?

Hi Moussa Maadani! I think that this cooker is not suitable for producing electric energy. A better solution would be a trough-shaped mirror that focuses sunlight on a black copper tube. This would turn water into steam, which could be used to produce electricity. But this is something completely different from my cooker with a parabolic mirror.

Hallo Sam! Der Aufwand war tatsächlich beträchtlich. Aber erstens kann man mit der Form Dutzende von Parabolspiegeln herstellen, und zweitens ist es z.B. in der Savanne auch sehr aufwendig, Brennholz fürs Kochen zu suchen, es nach Hause zu schleppen, zu zerkleinern und dann noch beim Verbrennen den giftigen Rauch einzuatmen. Und wenn ich an den Aufwand denke, der für die Erstellung eines elektrischen Kochherds getrieben wird, dann bin ich doch recht zufrieden. Schliesslich zwinge ich niemanden dazu, meinen Vorschlag nachzuahmen. Perfektion ist schwierig zu erreichen, aber wenn Du Verbesserungsvorschläge hast, so bin ich neugierig, sie kennenzulernen!

Guten Tag Herr Hopf! Meine Auftraggeberin war an meiner wissenschaftlichen Erhebung nicht interessiert, daher brach ich die Bekämpfung des Japanknöterichs an diesem Standort nach 4 Jahren ab. Danach habe ich auch nicht mehr besonders auf neue Vorkommen geachtet. Entlang der Aare wird der Japanknöterich, soviel ich weiss, durch Freiwillige periodisch bekämpft. Da die vollkommene Ausrottung dieser Problempflanze aber praktisch unmöglich ist, werden Sie sicher noch Restbestände finden. Auskunft könnte Ihnen ausserdem stadtgruen@bern.ch geben, und auch neo.infoflora.ch/de/index.html zeigt die aktuellen Standorte invasiver Neophyten auf.

Danke für Ihr Lob! Tatsächlich ist der von Ihnen erwähnte Weg sehr schön. Hoffentlich bleibt das Engnis in seiner Mitte bestehen, sonst ist mit mehr Verkehr zu rechnen. Gemäss historischen Karten wurde dieser Weg erst in den den 1940er Jahren gebaut, ist also wahrscheinlich nicht historisch. A propos: Einer der schönsten Wegstrecken St. Margrethens ist meines Erachtens der sog. Bollensteinweg, mit wunderschönen alten Edellaubbäumen; aufgrund seiner Lage könnte er sogar historisch sein (Erschliessung der früheren Rebberge und Verbindung zwischen Leuchen und St. Margrether „Weite“), ist aber erst in jüngster Zeit auf Karten abgebildet.

Very good idea! Thank you!

www.cumaru-pe.com.br/gallery/9cff23c867fd488622032df5cee0c9ca_flector-construction-manual.pdf

On my computer it works perfectly. Try again, please! www.cumaru-pe.com.br/gallery/9cff23c867fd488622032df5cee0c9ca_flector-construction-manual.pdf If you don't succeed, send me an E-Mail, and I will send you the document.

@@brunokagi1090 Thanks, it worked on my computer, so kind of you for quick response.

بكل سرور!

Não recomendo pq a borracha pode queimar. Se não tem este risco, pode tentar.

@@brunokagi1090 Eu vou tentar, pois gosto de cozinhar feijão numa panela de pressão e creio que se eu focar no raio do Sol na parte lateral e não na parte da tampa onde está a borracha, pode dar bom. De qualquer forma, vou tentar fazer esses dois experimentos tanto na parte lateral como na tampa pra ver o resultado. Se não queimar, pode ser uma boa.

coat the epoxy parabolic surface

Normal household alufoil should work. The perfect reflective material does not exist, but the better the reflection, the faster you can cook. If you have a choice between thick and thin aluminum foil, choose the thick one, because it compensates for unevenness of the surface. When sticking, the better reflective side should be visible.

@@brunokagi1090 And what do you think of mirror squares? is it better than aluminum to reflect light?

@@dani45987 Sí, es cierto que los espejos reflejan mejor que el papel de aluminio, pero también tienen desventajas: Las partes del espejo no deben estar en ángulo recto porque se supone que forman una parábola. Como los espejos no son curvos, hay que unir muchas piezas pequeñas y alinear correctamente cada una de ellas con el foco. Por último, los espejos son mucho más caros y pesados que el papel de aluminio.

@@brunokagi1090 Gracias por tus consejos.

Dear Mr. Harsha Vasanthala. You were absolutely right. My homepage was corrupted, but I managed to fix it. The link should work now. Thank you for your advice. Sorry for the inconvenience! I wish you good success!

🙏

In the description of the film you find the link to a pdf-document with all necessary informations.