Mimeo Circular 10

Alaska's Extension Service was fortunate in again obtaining the services of Dr. George D. Scarseth, Director of Research for the American Farm Research Association. His task during the 1956 growing season was to review the fertility status of potato fields and to diagnose the potato malady that has reduced yields in recent years. Having familiarized himself with the symptoms during the 1955 season, he came back to Alaska in August of this year to study in greater detail the onslaught of this malady and to help interpret the results of studies designed to: explore basic causes and possible corrective measures. Dr. Scarseth's report is here reproduced in full for the guidance of farmers and agencies dealing with food production in Alaska.In cooperation with UNITED STATES DEPARTMENT OF AGRICULTUR

Convenience in the mutual fund industry

Abstract I examine the role of convenience in the mutual fund industry. I find that investors pay more for relatively convenient funds, and that the flows to convenient funds are less responsive to performance. These findings suggest that investors do not evaluate mutual funds independently, but rather that investors select a primary fund, likely based on beliefs about managerial ability, and then select funds which are relatively convenient to this primary fund. Highlights ► I find that investors pay a significant premium to invest in convenient mutual funds. ► I find that the flows to convenient funds are indifferent to fund performance. ► These results demonstrate the importance of convenience to mutual fund investors. ► They suggest that investors choose a primary fund and then funds that are convenient

Metallic composites as high-temperature fasteners

Metallic composities can be fabricated in one-step process in which mixture is directionally solidified. Phase-reinforced eutectic alloys have superior high-temperature mechanical properties

Interpretation of Light Scattering Spectra in Terms of Particle Displacements

Quasi-elastic light scattering spectroscopy of dilute solutions of diffusing mesoscopic probe particles is regularly used to examine the dynamics of the fluid through which the probe particles are moving. For probes in a simple liquid, the light scattering spectrum is a simple exponential; the field correlation function $g^{(1)}_{P}(q,\tau)$ of the scattering particles is related to their mean-square displacements $\bar{X^{2}} \equiv < (\Delta x(\tau))^{2}>$ during $\tau$ via $g^{(1)}(q,\tau) = \exp(- {1/2} q^{2} \bar{X^{2}})$. However, historical demonstrations of this expression refer only to ideal Brownian particles in simple liquids, and show that if the form is correct then it is also true that $g^{(1)}(q,\tau) = \exp(- \Gamma \tau)$, a pure exponential in $\tau$. In general, $g^{(1)}_{P}(q,\tau)$ is not a single exponential in time. $g^{(1)}_{P}(q,\tau)$ reflects not only the mean-square particle displacements but also all higher-order mean displacement moments $\bar{X^{2n}}$. A correct general form for $g^{(1)}(q,\tau)$, replacing the generally-incorrect $\exp(- {1/2} q^{2} \bar{X^{2}})$, is obtained. A simple experimental diagnostic determining when the field correlation function gives the mean-square displacements is identified, namely $g^{(1)}(q,\tau)$ reveals $\bar{X^{2}}$ if $g^{(1)}(q,\tau)$ is exponential in $\tau$.Comment: Now 19 pages, no figures, accepted by Journal of Chemical Physics Revision: Add New Section V Spectrum of a Bidisperse System giving a concrete example of issues raised, and did minor rewrite