New 2-designs from strong difference families

Strong difference families will be used to get: seven 2-designs whose parameter sets were previously in doubt; a strong indication about the existence of 2-(pq,p,1) designs with p∈{13,17} and q a prime power; a better asymptotic bound on prime powers q for which there exists an (Fp×Fq,Fp×{0},k,λ) relative difference family with p a prime power and k∈{p,p+1}.