The Betz theory expresses that no horizontal axis wind turbine can extract more than 16/27 (59.3%) of the kinetic energy of the wind. The factor 16/27 (0.593) is known as the Betz limit. Horizontal Axis wind turbine designers try to improve the power performance to reach the Betz limit. Modern operational wind turbines achieve at peak 75% to 80% of the Betz limit. In 1919, Albert Betz used an a...

Let (Xn)n∈ω be a sequence of uniform spaces such that each space Xn is a closed subspace in Xn+1. We give an explicit description of the topology and uniformity of the direct limit u-lim −→ Xn of the sequence (Xn) in the category of uniform spaces. This description implies that a function f : u-lim −→ Xn → Y to a uniform space Y is continuous if for every n ∈ N the restriction f |Xn is continuo...

Points P1; : : : ; Pn in the unit square de ne a convex n-chain if they are below y = x and, together with P0 = (0; 0) and Pn+1 = (1; 1), they are in convex position. Under uniform probability, we prove an almost sure limit theorem for these chains that uses only probabilistic arguments, and which strengthens similar limit shape statements established by other authors. An interesting feature is...

Points P1, . . . , Pn in the unit square define a convex n-chain if they are below y = x and, together with P0 = (0, 0) and Pn+1 = (1, 1), they are in convex position. Under uniform probability, we prove an almost sure limit theorem for these chains that uses only probabilistic arguments, and which strengthens similar limit shape statements established by other authors. An interesting feature i...

London equity dealers routinely use two trading systems to trade with one another. In one, they trade directly by phone, using the best bid and ask quotes as a basis for negotiation. In the other, they submit and consume anonymous limit-orders in electronic limit-order books. In this paper, we use unique data to examine why dealers might prefer one system over another. We consider the predictio...

We study multivariate generalizations of the q-central limit theorem, a generalization of the classical central limit theorem consistent with nonextensive statistical mechanics. Two types of generalizations are addressed, more precisely the direct and sequential q-central limit theorems are proved. Their relevance to the asymptotic scale invariance of some specially correlated systems is studie...

conclusions the brachial plexus block can be performed at different levels in the same patient to achieve desired results, while employing sound anatomical knowledge and adhering to the maximum safe dose limit of the local anesthetic. case presentation we present the case of a 68-year-old gentleman who had brachial plexus block at supraclavicular and interscalene levels as the sole anesthetic f...

Objective(s):The present study reports the development and validation of a sensitive and rapid extraction method beside high performance liquid chromatographic method for the determination of crocetin in human serum. Materials and Methods:The HPLC method was carried out by using a C18 reversed-phase column and a mobile phase composed of methanol/water/acetic acid (85:14.5:0.5 v/v/v) at the flow...

In this note we comment on a recent publication in this journal by the CERES (NA45) Collaboration [1]. The authors report to have determined an upper limit on the direct photon yield relative to the decay photon yield in S + Au collisions of 14 % and 7 % by two different methods, respectively. We argue that these limits are unsupported by the results and analysis of the CERES data. The systemat...