Showing papers on "Boom published in 1987"

Nigeria During and After the Oil Boom: A Policy Comparison with Indonesia

Abstract: Nigeria and Indonesia provide an interesting contrast with regard to performance and policy during and after the oil boom. Roughly a decade after the first oil shock, Nigeria is faced with several economic problems including a serious decline in its agricultural sector and a deteriorating external debt situation. While some decline in the nonoil traded goods sector reflects efficient adjustment to the oil boom, policy with regard to public expenditure, exchange rates, pricing, and the trade regime could exacerbate such decline and impede readjustment as the boom subsides. The links between oil prices, deficits, inflation, and real exchange rate appreciation are analyzed and Nigerian and Indonesian fiscal and exchange rate and agricultural and foreign borrowing strategies are compared. It is concluded that with the exception of cuts in the deficit since 1984, Nigerian policy following the boom has not been conducive to adjustment to the current period of low oil prices and high real interest rates. Corrective measures and policy options are discussed.

The Political Economy of Central America since 1920

Abstract: In this book Victor Bulmer-Thomas uses his previously unpublished estimates of the national accounts to explore economic and social development in the five Central American republics from 1920. He examines in detail variations in economic policy between countries which help to account for differences in performance. The major political developments are woven into the analysis and linked to changes in internal and external conditions. Growth under liberal oligarchic rule in the 1920s, heavily dependent on exports of coffee and bananas, was accompanied by modest reform programmes. The 1929 depression, which hit the region hard, undermined most of the reforms and ushered in a period of dictatorial rule in all republics except Costa Rica. The Second World War, particularly after the entry of the United States, at first strengthened the dictatorships, but ultimately produced challenges to rule by authoritarian caudillos. The social upheavals accompanying the post-war export-led boom forced governments in each republic to address the question of economic, social and political reform.

Consequences of a commodity boom in a controlled economy : accumulation and redistribution in Kenya 1975-83

Abstract: The economic theory of "Dutch disease" is extended and applied to the 1976-79 coffee boom in Kenya in this article. When a commodity boom is perceived as temporary, a large fraction will tend to be saved out of transient income. The spending effect of the boom is supplemented by relative price changes resulting from capital stock increases. In the presence of foreign exchange and import controls, the benefits of a sudden export price increase may be transferred intersectorally. Using a general equilibrium model, it is estimated that in Kenya the benefits of the boom were largely transferred from coffee growers to urban groups.

System for the protection of an aerial device having a pivotable boom

Abstract: A mobile aerial device, which also has deployable outriggers, has sensors for the outrigger-supported weight, sensors for boom azimuth, elevation and extension, and sensors for other boom conditions. An on-board digital computer is programmed with load tables for the device. The various sensor signals and load table data are computer-processed to determine the approach of tipping or overload conditions. When operating near a dangerous obstacle which it is desired to avoid, the boom is initially caused to assume certain preparatory positions relative to the obstacle and data are computer-generated which extrapolate from these positions a region in space which represents a prohibitively close approach of the boom to the obstacle. The foregoing information is used to alert the operator to the approach of a dangerous condition and also to prevent the crane from performing movements which could cause tipping or which would encroach upon the prohibited region.

Control handle arrangement for aerial bucket lift

Abstract: In an aerial lift having a lower boom, an upper boom, and a personnel carrier bucket attached to the upper boom, with the upper boom having an overcenter capability, wherein the upper boom can pivot from a folded position in a non-overcenter zone of operation past a center position and into an overcenter zone of operation, there is provided a control handle arrangement with first and second handles having control movements such that, when the operator is correctly positioned, the direction the bucket moves corresponds to the direction the respective handle moves for all zones of operation.

Inter-War House Building, Cheap Money and Building Societies: The Housing Boom Revisited

Abstract: (1987). Inter-War House Building, Cheap Money and Building Societies: The Housing Boom Revisited. Business History: Vol. 29, No. 3, pp. 325-345.

Control system for a crane

Abstract: The invention relates to a system for controlling the boom of a hydraulic crane, in particular, the crane being provided with at least one load sensor on the basis of which the speed of the boom is controlled so that the greatest permissible speed of the boom increases with decreasing load and correspondingly decreases with increasing load. The drawback of the known systems is that they do not in a satisfactory way consider the dynamic loads the crane is subjected to, wherefore their control properties are unsatisfactory. The problem is eliminated according to the invention so that in order to reduce the dynamic stresses exerted on the crane, the oil flow of the hydraulic actuating means is controlled by directly adjusting the movements of the valves of the actuating means on the basis of a speed instruction of the boom and of a load signal and by filtering such speed instructions which indicate valve movement speeds exceeding a predetermined value.

Pedestal crane and method of assembling and erecting it

Abstract: A method of installing a boom on the top of a high vertical tower comprising vertically positioning a first tower section and securing the tower section to a base; installing a plurality of additional tower sections in consecutive order on top of the first tower section and securing the adjoining sections together until a tower is erected having a desired height; a boom having a base section, at least one extendable section and a load lifting end; releasably attaching the boom in vertical position to and along side the tower as it is erected with the boom load lifting end at the bottom; jumping the boom vertically upwardly by alternately extending and retracting various boom sections as the tower sections are installed; positioning the boom base end adjacent the boom turret, tilting the boom turret into close contact with the boom base end and joining the turret to the boom base end by a horizontal boom footpin; releasing the boom lifting end from the tower; tilting the turret into contact with the adapter upper portion top end and releasably securing the turret to the adapter; and attaching apparatus to the boom for pivoting the boom vertically about the horizontal boom footpin.

Extendable boom for belt-conveyor

Abstract: A gravel delivery truck is disclosed, which carries a moving belt conveyor, on a boom that can swing over the delivery site. The boom is foldable for stowage on the truck. The boom includes a foldable extension, hinged to the main length of the boom. For stowage, the extension is doubled over the main length, and the main length is placed lengthwise, behind the driver's cab, down one side of the truck, and over the rear wheels. The folded-over extension fits into the space ahead of the rear wheels, underneath the main length. The layout of the hinge joint is such that, during folding of the boom, the total length of the run of the belt remains the same. The belt can be kept running, and delivering, at all angles of fold of the boom, and even while the boom is being folded.

Retractable aircraft hoist

Abstract: A hoist is provided for an aircraft, such as a helicopter or VTOL, capable of hovering flight and has a boom pivotally connected to the structural frame of the aircraft for movement between retracted and extended positions. A cable powered by a winch is engaged with the boom and is used with the extended boom for conventional hoisting operations. The arrangement of the cable guide pulleys relative to the pivot axis of the boom and the operation of the winch control system is such that the cable and winch are additionally usable to effect movement of the boom between its retracted and extended positions thereby eliminating the need for a separate boom extending and retracting motor.

Floating Debris Control: A Literature Review

Abstract: : Floating debris can have an extremely harmful effect on certain hydraulic structures such as flood control works and navigation facilities and is consequently an important concern in maintenance and repair activities. This report assembles information found in published sources about equipment and methods used to control floating debris. Also included is an appendix on booms, their functions in the water transportation of pulpwood, and results of laboratory tests of various boom designs which was previously published by the Pulp and Paper Research Institute of Canada and which contains much useful information applicable to booms for control of floating debris.

Redeployable high temperature oil boom

Abstract: A redeployable, high temperature oil containment boom which allows for the in-situ burning of spilled or leaked oil during offshore oil spill cleanup operations is disclosed. The boom can be used for precautionary fire containment during non-burn oil spill cleanups and can be easily recovered and redeployed.

Crossed log-periodic dipole antenna and method of making same

Abstract: A crossed log-periodic dipole antenna having a unique feedline/boom structure providing improved antenna performance The antenna is assembled from a pair of orthogonally displaced log-periodic antennas each having a pair of half-dipole structures, each structure having a half-dipole assembly and a central feed boom The half-dipole assembly comprises a single sheet of conducting material formed to provide a central boom portion and a plurality of half-dipole elements projecting radially from opposite sides of the boom The boom portion has a reduced thickness, a shape which complements that of the outer surface of the boom, and is press-fitted against and bonded to the boom exterior to form an integrated rigid unit This configuration minimizes the force required to connect each half-dipole assembly with the adjacent boom, decreases the offset distance between the two dipole halves of each antenna, and reduces the electrical shadowing effect of the booms on the antennas The invention also comprehends a method of making such an antenna

Backhoe boom cylinder bleed circuit

Abstract: A bleed circuit for a backhoe boom cylinder which minimizes cylinder pressure during over-center movement of the boom while permitting the maintenance of sufficient cylinder pressure during other boom operations. The boom cylinder is provided with a retract port, a head end port, and a small bleed port with a bleed line connecting the bleed and head end ports. As the boom cylinder crosses over-center, the fluid pressure in the retract side of the boom cylinder may be transmitted from the rod end to the head end of the cylinder thereby reducing cylinder pressure and improving the over-center controlability of the boom.

Mainsail reefing and furling device and method

Abstract: A method and device for gathering a mainsail in a cavity within the boom as the sail is being lowered. The boom has a plurality of engaged rollers which draw in or let out the sail by tractive forces.

Knock-down boom for pick-up truck

Abstract: A knock-down boom is removably installed on a pick-up truck so as to be manually raised or lowered for moving a load either onto or off the truck. The boom can be readily disassembled in a few minutes by separating the legs forming the boom and storing them in a convenient compact area. A jib can also be mounted on the outer end of the boom for extending its overall length.

Material handling vehicle for use in a mine

Abstract: A self-propelled vehicle maneuverable in an underground mine includes an elongated body having a forward end portion with a boom assembly mounted thereon. The boom assembly includes a pair of boom members that are telescopically arranged to vary the overall length of the boom. A material handling device is secured to the end portion of the boom assembly and is operable to perform various material handling operations in the mine. A support arrangement secures the boom assembly to the front of the vehicle. A pair of double acting piston cylinder assemblies are mounted on the mobile body and are connected to the support arrangement for laterally swinging the boom assembly relative to the elongated body. The boom assembly is also connected to the support arrangement for upward and downward pivotal movement independently of the lateral swinging movement by operation of a pair of pivoting cylinders. The pair of pivoting cylinders are positioned laterally of a longitudinal axis of the boom assembly and are connected to the support arrangement and to the sides of the boom assembly. With this arrangement the boom assembly is extensible and movable laterally and vertically to position the material handling device at a preselected position relative to the vehicle.

Folding, articulated, square truss

Abstract: A larger, stronger deployable boom was developed to handle the requirements of larger, heavier payloads in space. The main components of the boom and its deployer are described and their functions explained. Desirable features of the boom are identified and physical properties are reported.

Tree delimber equipped with an articulated boom

Abstract: An improved boom construction having a base, a first straight boom slidably mounted on the base, and a second, hinged boom pivotally mounted at one end to the base and at its other end to the front end of the first boom. Power jacks are provided for operating the second boom to move its other end toward or away from its one end so as to slide the first boom relative to the base. The improved boom construction is preferably employed on a tree delimber with a tree delimbing unit mounted on the front end of the first boom, and tree gripping unit mounted on the base beneath the first boom. A rotating reel is advantageously provided on the base above the first boom for simultaneously winding and unwinding flexible feed and return hydraulic lines extending over the top of the boom, and connected to the delimbing unit, as the first boom slides.

Property cycles in Dublin - the anatomy of boom and slump in the industrial and office property sectors

Abstract: The property development process is the means by which built space is created to accom­ modate the variety of urban functions. The paper examines the existence of boom-slump cycles in the industrial and office property development sectors and their relationship to Irish macroeconomic trends. The consequences of boom and slump are examined with respect to the construction sector and in relation to Dublin's built environment.

Boom for a vehicle including folding linkage between boom parts

Abstract: A boom H for a vehicle A which carries a working implement K to enable operations to be carried out such as excavation or loading, comprises first (11) and second (10) parts, the first part (11) carrying the working implement (K) and the second part (14) being mounted on a body (B) of the vehicle, the first and second parts being connected together for relative pivotal movement about a generally horizontal axis (A 1), a fluid operated actuating means (18) acting between the first (11) and second (10) boom parts to effect relative pivotal movement at least in one sense of rotation, characterized in that the fluid operated actuating means (18) comprises two relatively movable members (20,23) which operate in tension, one member (20) being pivotally secured to one of the boom parts (14) and the other member (23) being connected via a flexible linkage (24) to the other boom part (11) to enable the two boom parts to be relatively pivoted to include a smaller angle between them than would be possible with a rigid linkage with an actuating means (18) operating in tension.

On Resource Booms and Busts: Some Aspects of the Dutch Disease in Six Developing Economies

Abstract: This paper examines changes in national product and net welfare over resource boom and bust cycles in six developing economies: Chile, Zaire, Zambia, Indonesia, Mexico, and Nigeria. The authors find that changes in the terms of trade account for over 25 to 33 percent of the changes in net welfare, that capital movements usually act procyclically, and that a fall in the growth rate of real product accompanies the end of the resource boom. They also examine changes in the government's share in output over the resource cycle and the pro- or anti-cyclical nature of real outputs and price movements in the "lagging sectors" of the economy.

Controller for power shovel

Abstract: PURPOSE:To permit the combined point between the second boom and an arm to move to desired directions by providing a means to designate the moving direction of the combined point between the second boom and the arm and a means to control a boom cylinder on the basis of the designation CONSTITUTION:The attitude and slewing angles of the first boom, the second boom, arm, and the upper slewing body of a power shovel are detected by potensiometers 6-9, and the turning angle of the base of the arm is also detected by a potensiometer 10 Signals corresponding to the operating amounts of levers 15 and 16 and a pedal 17 are put in a controller 28 On the basis of the outputs of these potensiometers 6-10, 27, 32, and 33, switching valves 21, 24, 29, and 37 and operating valves 22, 26, 31, 35, and 39 are through servo valves 34, 40, 43, and 44 by the controller 28 The first and second boom cylinders 11 and 12 are controlled so that the combined point between the second boom and the arm is moved to a desired direction

Tooling support apparatus with linear boom

Abstract: A tooling support apparatus in which a linear tooling boom has one end adapted to support a tooling member and its opposite end connected to a scissors-lift apparatus for adjusting the height and horizontal position of the tooling boom