Cruise Report 72-S-8: Crab

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A general aerodynamic approach to the problem of decaying or growing vibrations of thin, flexible wings with supersonic leading and trailing edges and no side edges

Indicial aerodynamic influence coefficients were evaluated from potential theory for a thin, flexible wing with supersonic leading and trailing edges only. The analysis is based on the use of small surface areas in which the downwash is assumed uniform. Within this limitation, the results are exact except for the restriction of linearized theory. The areas are not restricted either to square boxes or Mach boxes. A given area may be any rectangle or square which may or may not be cut by the Mach forecone, and any area can be used anywhere in the forecone without loss of accuracy

Exceptional SW Geometry from ALE Fibrations

We show that the genus 34 Seiberg-Witten curve underlying $N=2$ Yang-Mills theory with gauge group $E_6$ yields physically equivalent results to the manifold obtained by fibration of the $E_6$ ALE singularity. This reconciles a puzzle raised by $N=2$ string duality

Quartic Gauge Couplings from K3 Geometry

We show how certain F^4 couplings in eight dimensions can be computed using the mirror map and K3 data. They perfectly match with the corresponding heterotic one-loop couplings, and therefore this amounts to a successful test of the conjectured duality between the heterotic string on T^2 and F-theory on K3. The underlying quantum geometry appears to be a 5-fold, consisting of a hyperk"ahler 4-fold fibered over a IP^1 base. The natural candidate for this fiber is the symmetric product Sym^2(K3). We are lead to this structure by analyzing the implications of higher powers of E_2 in the relevant Borcherds counting functions, and in particular the appropriate generalizations of the Picard-Fuchs equations for the K3.Comment: 32 p, harvmac; One footnote on page 11 extended; results unchanged; Version subm. to ATM

Prepotentials from Symmetric Products

We investigate the prepotential that describes certain F^4 couplings in eight dimensional string compactifications, and show how they can be computed from the solutions of inhomogenous differential equations. These appear to have the form of the Picard-Fuchs equations of a fibration of Sym^2(K3) over P^1. Our findings give support to the conjecture that the relevant geometry which underlies these couplings is given by a five-fold.Comment: 19p, harvmac; One sign in eq. (A.2) change

Mechanism of deuteron breakup by 42-MeV alpha particles

Coincidence measurements of absolute cross sections for breakup of deuterons by 42 MeV alpha particle

Study of the odd strontium isotopes with stripping and pickup reactions

Odd strontium isotopes induced by deuterons with stripping and pickup reaction

Ocean shrimp report 1976 season

Statewide Pacific ocean shrimp, Pandalus jordani, landings totaled 3,400,191 lb, down from the 1975 record catch of 4,992,233 lb but well above the 10-year (1966-1975) mean of 2.6 million lb. Landings from Areas A (Eureka-Crescent City) and B-1 (Fort Bragg) were 2.7 and 0.7 million lb, respectively. Only negligible amounts were landed in Areas B-2 (Bodega Bay) and C (Avila-Morro Bay). In Areas A and B-1 catch per hour trawled by single-rig vessels ranged from 294 to 1,803 lb while catch per hour by double-rig vessels ranged from 431 to 3,428 lb. Two-year-old (1974 year class) shrimp dominated the catches during the first part of the season, but 1-year-old (1975 year class) shrimp dominated the catches from August to October. The outlook for the 1977 season in Areas A, B-1 and B-2 is good because of the strong showing of the 1975 year class. (15pp.