Might you be able to get a good handle on this essay in Spanish (since Portuguse is close to Spanish) proposing that the secret name of Ra is "NTR", the Egyptian word for God, which the author connects to Physis and Natura?
About the Egyptian origin of the term nature and its relation with naturalistic medicine
Francisco Tomás Verdú Vicente writes in the journal MEDICINA NATURISTA, 2011; Vol. 5 - N.º 2: 80-81
Abstract:The term nature comes from the word Egyptian ntr and it means God. Later on the Greeks identified the divine thing with the goddess of the nature Isis creating the term Phisis and later the Romans denominated Nature.
The notion expressed by nutar as substantive and nutra as adjective or verb should be looked for in the Coptic Nout, which in the Biblical tradition corresponds to the Greek Dynamis (energy), ischis (strength), ischiros (strong), and and ischiron(protection). This form of neter means strong and protection.
I wrote about this a bit on the OO thread on understanding the meaning of the name "NTR".
This is relevant to Egyptian monotheism, because NTR is the name for the concept of a "god" in ancient Egyptian. They would simply refer to the single godhead or "the god" as "NTR". And this makes me interested in what this "NTR" means.
Here are some citations on the topic that propose that the meaning was related to the Latin "Natura":
Land of Osiris
By Stephen S. Mahler
First translated by early Egyptologists after Champollion as God or Goddess, this meaning [of NTR] has since been challenged. R A Schwaller de Lubicz was one of the first to question this translation in the early 1950's, choosing rather to define Neter as principle" and/or "attribute", as a divine aspect of the whole, not in the sense we use the word Deity. The Greeks [sic, no, it must be the Latins] derived their word Nature from Neter, therefore equating the Divine with the natural as the Khemitians taught them. The ancient Khemitians knew every principle or attribute of Nature was also divine, of God - all interconnected and interrelated to the whole, the source.
Religion and the Order of Nature
By Seyyed Hossein Nasr (Professor of Islamic Studies at George Washington University) (Oxford University Press)
...there are basic principles concerning the order of nature that continue through these transformations, such as the identification of cosmic elements with real divinities possessing a personal existence. Most important of these principles for the understanding of the order of nature is the Neter , which has received many interpretations, some even equating it with the Hebrew Wl. The Neter is a principle conveyed by a sign, the hieroglyph being itself called Medu-Neteru. It is the Idea of which a material object is the crystallization.
The order of nature is the reflection of the order that belongs to the realm of the principles or Neteru, which man also carries within his being as a consequence of his central position in the cosmic order. 'Every natural type is a revelation of one of the natures and abstract functions that rule the world, a verb of the divine language —that is, the entities or fully realized Principles (Neteru).
I think it is not really a far fetched idea that certain Latin or Greek words could have a common root with an Egyptian one. Take for example the word "Natron":
Natron deposits in the Era Kohor crater in the Tibesti Mountains, Chad
Natron is a naturally occurring mixture of sodium carbonate decahydrate (Na2CO3·10H2O, a kind of soda ash) and about 17% sodium bicarbonate (also called baking soda, NaHCO3) along with small quantities of sodium chloride and sodium sulfate.
The English word natron is a French cognate derived from the Spanish natrón through Greek νίτρον nitron. This derives from the Ancient Egyptian word nṯry 'natron'. Natron refers to Wadi El Natrun or Natron Valley in Egypt, from which natron was mined by the ancient Egyptians for use in burial rites.