Are the following situations considered unlawful seclusion (khalwa muharramah): a doctor being with a female student in a closed room to discuss a scientific research, with the possibility of anyone entering; and a man and a woman working alone in a remote laboratory, with the possibility of other workers entering at any time?

Unlawful seclusion (al-khalwa (definition) al-muharramah) is when a man is alone with a non-mahram (definition) woman, without a third person present, in a way that conceals them from view. The Prophetic hadiths have warned against this, among them the saying of the Prophet, peace and blessings be upon him: "No man should be alone with a woman unless there is a mahram with her," and "Behold, no man is alone with a woman but the third of them is Satan." This is forbidden even if it occurs during prayer or at work, and it includes a woman being alone with a non-mahram man in a car, an elevator, or with a doctor or a teacher. There is no difference in the prohibition between seclusion during prayer or otherwise, except in cases of necessity, such as rescuing a woman stranded on the road. It is permissible for a man to be alone with a woman in the presence of people, provided that their persons are not concealed from them, and they cannot hear their conversation.