A Steiner quadruple system of order v is a set X of cardinality v, and a set Q, of 4-subsets of X, called blocks, with the property that every 3-subset of X is contained in a unique block. A Steiner quadruple system is resolvable if Q can be partitioned into parallel classes (partitions of X). A necessary condition for the existence of a resolvable Steiner quadruple system is that v = 4 or 8 (m...

We study a quadruple of interrelated subexponential subsystems of arithmetic WKL 0 , RCA 0 , IΔ0, and ΔRA1, which complement the similarly related quadruple WKL0, RCA0, IΣ1, and PRA studied by Simpson, and the quadruple WKL 0 , RCA 0 , IΔ0(exp), and EFA studied by Simpson and Smith. We then explore the space of subexponential arithmetic theories between IΔ0 and IΔ0(exp). We introduce and study ...

. The Quadruple Tank system has been used to illustrate both traditional and advanced multivariable control strategies and can be utilized as an educational tool in teaching advanced multivariable control techniques and provide interesting challenges in the control design. The main feature of the Quadruple Tank System is the flexibility in positioning one of its multivariable zeros on either ha...

According to the Maastricht VI consensus, triple therapy (PPI + clarithromycin amoxicillin) and bismuth-based quadruple bismuth tetracycline metronidazole) are considered may be proscribed empirically as first-line regimens in regions with low resistance rates (<15%). In high (> 15%), well unknown this antibacterial agent, it is recommended use classical drugs main choice without (“simult...