This paper deals with unbounded solutions to a class of chemotaxis systems. In particular, for a rather general attraction–repulsion model, with nonlinear productions, diffusion, sensitivities, and logistic term, we detect Lebesgue spaces where given unbounded solutions also blow up in the corresponding norms of those spaces; subsequently, estimates for the blow‐up time are established. Finally, for a simplified version of the model, some blow‐up criteria are proved.More precisely, we analyze a zero‐flux chemotaxis system essentially described as The problem is formulated in a bounded and smooth domain Ω of , with , for some , , , and with . A sufficiently regular initial data is also fixed.Under specific relations involving the above parameters, one of these always requiring some largeness conditions on , we prove that any given solution to (), blowing up at some finite time becomes also unbounded in ‐norm, for all ; we give lower bounds T (depending on ) of for the aforementioned solutions in some ‐norm, being ; whenever , we establish sufficient conditions on the parameters ensuring that for some u0 solutions to () effectively are unbounded at some finite time. Within the context of blow‐up phenomena connected to problem (), this research partially improves the analysis in Wang et al. (J Math Anal Appl. 2023;518(1):126679) and, moreover, contributes to enrich the level of knowledge on the topic.

Since the early 2000s Arabic has become an increasingly popular language at academic level across Europe and North America, with high numbers of students enrolling on a variety of programmes offering Modern Standard Arabic – as well as local varieties of Arabic, commonly known as ‘āmmiyya – as the target language (Dickins and Watson 2006, 108; Ryding 2006, 13; Mohamed 2021b, 59). The increasingly high demand for this language has resulted in unprecedented progress in the variety of learning materials available for both teachers and learners. Such developments have largely taken place in the United States, where most textbooks such as the Al-Kitaab series are designed and printed. This paper employs decolonisation and post-colonial theory to look at the ideological implications of the political agendas implicit in popular and widely adopted textbooks and their proposed content for teaching Arabic as a foreign language. Relevant examples from the Al-Kitaab series – one of the most successful and widely adopted textbooks at university level in the UK – show the role of Arabic language teaching materials in perpetuating patterns of European and North American cultural hegemony, making the case for rethinking Arabic language teaching at academic level.

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