Description of the US Army small-scale 2-meter rotor test system

A small-scale powered rotor model was designed for use as a research tool in the exploratory testing of rotors and helicopter models. The model, which consists of a 29 hp rotor drive system, a four-blade fully articulated rotor, and a fuselage, was designed to be simple to operate and maintain in wind tunnels of moderate size and complexity. Two six-component strain-gauge balances are used to provide independent measurement of the rotor and fuselage aerodynamic loads. Commercially available standardized hardware and equipment were used to the maximum extent possible, and specialized parts were designed so that they could be fabricated by normal methods without using highly specialized tooling. The model was used in a hover test of three rotors having different planforms and in a forward flight investigation of a 21-percent-scale model of a U.S. Army scout helicopter equipped with a mast-mounted sight

Characteristics of Waterfowl Harvest at Horseshoe Lake, Madison County, Illinois

Division of Wildlife Resources Migratory Bird Section, Periodic Report No. 13Report issued on: April 21, 197

The Suffolk Bank and the Panic of 1837

The Suffolk Bank in Boston is well known as having been the clearinghouse for virtually all the banknotes that circulated in New England between 1836 and 1858. An examination of 19th century bank balance sheets shows that during and after the U.S. banking Panic of 1837, this private commercial bank also provided some services that today are provided by central banks. These include lending reserves to other banks (providing a discount window) and keeping the payments system operating. Because of Suffolk's activities, banks in New England fared better than banks elsewhere during the Panic of 1837. And after the panic, when much of the United States suffered a prolonged economic slowdown, New England fared better than the rest of the country, at least partly because of Suffolk’s central bank-like activities.Bank notes ; Banks and banking - History

Lessons from a laissez-faire payments system: the Suffolk Banking System (1825-58)

A classic example of a privately created interbank payments system was operated by the Suffolk Bank of New England (1825–58). Known as the Suffolk Banking System, it was the nation’s first regionwide net-clearing system for bank notes. While it operated, notes of all New England banks circulated at par throughout the region. Some have concluded from this experience that unfettered competition in the provision of payments services can produce an efficient payments system. But another look at the history of the Suffolk Banking System questions this conclusion. The Suffolk Bank earned extraordinary profits, and note-clearing may have been a natural monopoly. There is no consensus in the literature about whether unfettered operation of markets with natural monopolies produces an efficient allocation of resources. ; Reprinted in Quarterly Review, Fall 2002 (v. 26. no. 4)Suffolk Banking System ; Payment systems

In order to form a more perfect monetary union

Why did states agree to a U.S. Constitution that prohibits them from issuing their own money? This article argues that two common answers to this question—a fear of inflation and a desire to control what money qualifies as legal tender—do not fit the facts. The article proposes a better answer: a desire to form a viable monetary union that both eliminates the variability of exchange rates between various forms of money and avoids the seigniorage problem that otherwise occurs in a fixed exchange rate system. Supporting evidence is offered from three periods of U.S. history: the colonial period (1690–1776), the Revolutionary War (1776–83), and the Confederation period (1783–89). This article is adapted from a chapter prepared for a forthcoming book, Varieties of Monetary Reforms: Lessons and Experiences on the Road to Monetary Union, edited by Pierre Siklos, to be published by Kluwer Academic Publishers.Banks and banking - History ; Money theory

Lessons from a laissez-faire payments system: the Suffolk Banking System, 1825-58

Suffolk Banking System ; Banks and banking - History ; Payment systems ; Banks and banking - New England ; Clearinghouses (Banking)

Influence of rubbing on rotor dynamics, part 1

The results of analytical and experimental research on rotor-to-stationary element rubbing in rotating machines are presented. A characterization of physical phenomena associated with rubbing, as well as a literature survey on the subject of rub is given. The experimental results were obtained from two rubbing rotor rigs: one, which dynamically simulates the space shuttle main engine high pressure fuel turbopump (HPFTP), and the second one, much simpler, a two-mode rotor rig, designed for more generic studies on rotor-to-stator rubbing. Two areas were studied: generic rotor-to-stator rub-related dynamic phenomena affecting rotating machine behavior and applications to the space shuttle HPFTP. An outline of application of dynamic stiffness methodology for identification of rotor/bearing system modal parameters is given. The mathematical model of rotor/bearing/seal system under rub condition is given. The computer program was developed to calculate rotor responses. Compared with experimental results the computed results prove an adequacy of the model

Directionally asymmetric self-assembly of cadmium sulfide nanotubes using porous alumina nanoreactors: Need for chemohydrodynamic instability at the nanoscale

We explore nanoscale hydrodynamical effects on synthesis and self-assembly of cadmium sulfide nanotubes oriented along one direction. These nanotubes are synthesized by horizontal capillary flow of two different chemical reagents from opposite directions through nanochannels of porous anodic alumina which are used primarily as nanoreactors. We show that uneven flow of different chemical precursors is responsible for directionally asymmetric growth of these nanotubes. On the basis of structural observations using scanning electron microscopy, we argue that chemohydrodynamic convective interfacial instability of multicomponent liquid-liquid reactive interface is necessary for sustained nucleation of these CdS nanotubes at the edges of these porous nanochannels over several hours. However, our estimates clearly suggest that classical hydrodynamics cannot account for the occurrence of such instabilities at these small length scales. Therefore, we present a case which necessitates further investigation and understanding of chemohydrodynamic fluid flow through nanoconfined channels in order to explain the occurrence of such interfacial instabilities at nanometer length scales.Comment: 26 pages, 6 figures; http://www.iiserpune.ac.in/researchhighlight