Special Joint Research Articles

Lunar laser ranging

At the 1990 AGU Spring Meeting in Baltimore, Md., on Tuesday morning, May 29, there will be the special joint Geodesy‐Planetology session Apollo Lunar Laser Ranging and Our Lunar Return. This session of invited papers will focus on and, yes, celebrate lunar laser ranging, which has been made possible by simple laser reflectors of the type first left by Buzz Aldrin on the powdery surface of the Sea of Tranquility. The session has been arranged to recall that on July 20 of this past year we celebrated the twentieth anniversary of the first human landing on the Moon.

Canada's Economic Relations with Southeast Asia: Federal–Provincial Dimensions of Policy

In its reply to the Report of the Special Joint Committee of the Senate and House of Representatives (The Hockin Committee) on Independence and Internationalism (1986), the Government of Canada reiterated its intention to treat the Asia-Pacific as ‘an area of concentration in the National Trade Strategy’ (Canada's International Relations, 1986, p. 60). Within the National Trade Strategy, significant attention is being given to the development of Canada's economic relationship with the countries of Southeast Asia, most notably the ASEAN (Association of Southeast Asian Nations) grouping. The policy mechanisms deployed to promote closer economic and social ties with Southeast Asian countries include those pertaining to international trade and finance, development assistance, transport, immigration and cultural relations.

Discontinuum approach to compaction and subsidence modelling as applied to Ekofisk : Barton, N; Makurat, A; Harvik, L; Vik, G; Bandis, S; Christianson, M; Addis, A Proc BOSS'88, Trondheim, June 1988V1, P129–141. Publ Trondheim: Tapir, 1988

The Ekofisk Centre in the North Sea has undergone unexpected seabed subsidence involving 150 cu km of underlying rock and sediments over an area of 50 sq km. NGI was engaged by the Norwegian Petroleum Directorate to perform independent studies of the factors involved in the subsidence, and of the implications of the compaction. NGI's studies included laboratory tests of the jointed reservoir chalk, numerical continuum modelling using the CONSAX code and discontinuum modelling using UDEC. In the final studies performed a special joint subroutine was incorporated in UDEC do that the effects of compaction on joint apertures and conductivity could be investigated. The studies showed that the steeply dipping conjugate joints in the 300m thick reservoir were probably undergoing shear during the approximately 1-D compaction. Joint shear and dilation were admissible in this uniaxial strain environment, due to shrinkage and pore collapse of the matrix between the joints caused by the 20 MPa drawdown in pore pressure. The 3 km of overburden shale was also modelled as a discontinuum and demonstrated the possibility of shear along bedding planes and sub-vertical jointing. Discontinuum models showed larger ratios of subsidence to compaction than continuum models due to such shear mechanisms.

Analysis of Thermal Stresses in a Ceramic-to-Metal Cylindrical Joint With a Homogeneous Elastic Medium

It is well known that large thermal stresses arise in a ceramic-to-metal joint because of thermal expansion mismatch. Therefore, to avoid fracture of a joint, it has been recommended a joint in which thermal expansion coefficient of a ceramic member is smaller than that of a metal member. The joint is called a “compressive” joint, because it was believed that only compressive stresses occur in the ceramic member. Since ceramic is about ten times as strong in compression as in tension, this joint is considered stronger than a tensile joint. A finite element calculation (FEC), however, has shown that a large tensile stress is generated even in ceramic part of a compressive joint. The aim of this study is to clarify stress distribution in a compressive joint by solving analytically the stress equation of the joint. For convenience, we deal with a special joint in which the elastic constants of the ceramic member are assumed to be the same as those of the metal member. The result of the analysis gives the same stress distribution obtained by FEC, and its value of the tensile stress agrees fairly well with that of FEC.

Nonlinear Seismic Analysis of Arch Dams

A nonlinear finite element procedure for arch dams is described in which the gradual opening and closing of vertical contraction joints and predetermined horizontal cracking planes are considered. A special joint element approximately represents the deformations due to plane sections not remaining plane at each open joint and allows a single shell element discretization in the thickness direction to be used for the dam. Compressive and sliding nonlinearities are not included. Finite element treatments are also used for the water, assumed incompressible, and for the foundation rock, assumed massless, with all degrees of freedom (dof) off the dam condensed out. For efficiency in the computations, the condensed water and foundation matrices are localized in a way which maintains good accuracy. The response of Pacoima Dam to the 1971 San Fernando ground motion recorded on a ridge over one abutment and scaled by two.‐thirds is computed first for water at the intermediate level that existed during the 1971 earthquake and then for full reservoir. In the first analysis, the dam exhibits pronounced opening and separation of the contraction joints, allowing violation of the no‐slip assumption. The presence of a full reservoir greatly increases the dam response, enough to bring some of the other assumptions of the analysis into question. Reducing the ground motion scale to 0.44 with full reservoir drops the response back to a reasonable level, but the contraction joint separations remain.

Double Pipe Ensures Reliable Insulation of Offshore Pipelines

At the beginning of the eighties, the offshore technology relevant to thermally insulated pipelines did not offer a cost-effective and technically challenging solution. Nowadays, the oil industry requires an ever-increasing use of thermally insulated pipelines with improved reliability in the offshore and, more particularly, for the exploitation of arctic fields. The present solution has been developed on the basis of easy handling, conventional laying procedures and long-term integrity criteria adopting a special field joint connector. This type of connector allows the two coaxial pipes to be assembled in a workshop and the individual double pipe sections to be connected in the field by means of a standard butt weld. This paper includes: the presentation of the DPIS (Double Pipe Insulated System) concept, which deals with the structural and thermal insulation aspects relevant to this new system; and a brief description of the first application of the DPIS for a pipeline connecting an unloading terminal for heavy oils to onshore plants.

Introduction to Probability and Mathematical Statistics.

Probability Random Variables and Their Distributions Special Probability Distributions Joint Distributions Properties of Random Variables Functions of Random Variables Limiting Distributions Statistics and Sampling Distributions Point Estimation Sufficiency and Completeness Interval Estimation Test of Hypotheses Contingency Tables and Goodness-of-Fit Nonparametric Methods Regression and Linear Models Reliability and Survival Distributions Answers to Selected Exercises.

Bracing cubic grids—a necessary condition

Bolker and Crapo [4] studied the possibilities of applying diagonal braces to rigidify a special bar and joint framework, the so called one-story building. Apparently, one of their ultimate goals was to solve the more general problem of the cubic grids. Some partial results towards this end were published in Bolker [2], who characterized the circuits of the describing matroid. However, his result is not completely satisfactory from the algorithmic point of view, since one still cannot decide whether a given set of diagonal braces makes the cubic grid rigid. In the present note we give a necessary condition for this, using matroid partition algorithm. This result also enables one to efficiently find a minimal set of braces meeting this condition; even an optimal one with respect to a weight function (say, when the costs of the possible diagonal braces are different). Finally we give an example which shows that the condition is not sufficient.

The Missing Link: Canada's Security Interests and the Central American Crisis

The Central American crisis has occasioned a great deal of discussion in Canada over the past half-decade, and there is no reason to assume that the coming years will see any abatement of the public interest in the region and its problems. If anything, one can foresee an increase in concern over Central American issues and for reasons other than the likely growth in the proportion of the Canadian population with Central American roots or affinities. It is revealing that the Special Joint Committee on Canada's International Relations discovered that more Canadians wanted to talk more often about Central American issues than about problems in any other single region of the world,1 and this notwithstanding Canada's very real and expensive alliance commitments to Western Europe and the United States commitments that presumably should have betokened a vibrant public attentiveness, at least to Western Europe, as a region of Vital' Canadian interest. Yet despite the demonstrably high level of public concern with Central America, the debate within Canada both over the causes and implications of the crisis and over the logic of Can-

接合体の熱応力の解析

It is well known that large thermal stresses arise in a ceramic-metal joint because of thermal expansion mismatch. To avoid fracture of a joint, therefore, a ceramic with a smaller thermal expansion coefficient than metal has been recommended. The joint is called a joint, because it is believed that only compressive stresses arise in the ceramic part. A finite element calculation, however, has shown that a large tensile stress acts even in a ceramic part of a compressive joint. The aim of this study is to clarify stress distribution in a compressive joint by solving analytically the stress equation of the jointWe have dealt with a special joint in which the elastic constants of the ceramic are assumed to be the same as those of the metal, for convenience. The calculated tensile stress agrees fairly well withthat obtained by the finite element method and also the stress distributions by both the methods are more or less the same.

Pre‐insulated pipe mains for district heating

A method developed by co‐operative research in Hungary differs from many other ‘pipe‐in‐the‐pipe’ systems; it uses a special joint to couple the prefabricated insulated pipe sections and includes many sub‐systems which can be built into the pipe casing, such as a separate mains line for high‐temperature media. A built‐in electric indicator precisely locates any possible fault area in service.

Coordinating Control of a Special Joint Structure with More Servos than Degrees of Freedom

Coordinating Control of a Special Joint Structure with More Servos than Degrees of Freedom

Remembering the Monarch

The Quee's influence in Canada is waning, as nearly everyone agrees. Yet a majority of Canadians must regret this decline, because opinion polls have shown that for every one Canadian who wants to abolish the monarchy, two want to preserve it. Canadians, it would appear, have resigned themselves to accepting their countr's gradual transformation into a republic, as though it were part of some larger inevitable process.Many of them, for example, continue to support electorally a political party that, since the days of William Lyon Mackenzie King, has had a policy of dissociating Canada from her British imperial past. In 1972, a special joint parliamentary committee formed by the Trudeau government to study the constitution declared that it “preferred a Canadian as Head of State for Canada.”

An experimental approach to the contact problem between high hardness surface bodies. Single and multi contact

Many engineering and bioengineering applications require a basic knowledge of the contact problem between two bodies of comparable high hardness, or even quasi-rigid bodies contacting in any number of points. Let us mention only some special mechanical joints, cog-wheels, ball or roller bearings presenting very hard contact surfaces, or more generally, problems in the field of Tr ibology or in the field of Biomechanics of jaws (dental occlusion). These problems are characterized by the relative geometry of the two surfaces in contact, by their deformabi l i ty and by the loading system. It is therefore necessary to analyse first the geometrical relationships between the two surfaces and to evaluate the variation of the minute distances created when the bodies are brought together under the action of a loading system.

A Review of Recent Ultraviolet Observations of Close Binaries from Space

The reason for presenting this review at this Joint Meeting, in spite of the fact that there was, a few days ago, a special Joint Discussion on recent UV observations is partially that somehow the general subject of close binaries was overlooked at the Joint Discussion, although unique close binaries, such as cataclysmic binaries and X-ray binaries, were included. There exist a large number of vigorous research projects being carried out with UV telescopes in the field of close binaries. I shall concentrate on IUE results, although other satellite and balloon-borne telescopes have continued to produce interesting UV observations of close binaries.There are a number of active IUE programs on this theme. In the time allocated to this review I shall only be able to present highlights of selected programs in the hope of giving a glimpse of what is going on. The programs on close binaries from the first year of IUE operations include those by P. Conti, M. Hack, J.B. Hutchings, R.H. Koch, Y. Kondo and G.E. McCluskey, M. Plavec, and J. Sahade. In the second year, additional astronomers are also observing close binaries with the IUE.

LYELL AND UNIFORMITARIANISM

The centenary of the death of Sir Charles Lyell (1797‐1875), the most notable earth scientist of the nineteenth century, was celebrated in 1975 by a special joint symposium of the International Union of Geological Sciences and the International Committee on the History of Geological Sciences. Much of what Lyell and his contemporaries regarded as “geology has become intrenched in “physical geography or in “geomorphology,“ so that any valid revaluation of Lyell's work is of as much significance to geographers as to geologists. It is appropriate at this time that his great contribution be recognized, but it is also a suitable occasion to re‐examine some of its limitations.

Introduction to session on the noise of large machines St. Louis, Missouri, 6 November 1974

This is a special joint session sponsored by the Technical Committees on Noise and on Architectural Acoustics. There were six invited papers.

The pectoral anatomy of selected Ostariophysi. I. The Characiniformes.

The muscles and bones of the pectoral fin of Serrasalmus nattereri, the piranha, resemble those of generalized, lower teleosts with specializations related to a body shape adapted for high-speed carnivory; the pectoral fins being highly mobile with strong ligaments to the rays. The presence of two occipital nerves appears primitive, while the emergence of the subclavian artery within the branchial cavity, as in Gasteropelecus sternicla, appears specialized. The muscles and bones of the latter fish, a fresh-water flying fish, are specialized for self-propelled, aerial flight in the fusion of the right and left girdles greatly expanded for insertions of complex appendicular (flight) muscles, and in the consolidation of the rays and radials into one functional unit moving vertically in flight through contraction of vertical, massive ventral flight muscles. The bony pectoral anatomy of Electrophorus electricus, the electric eel, is specialized in having a mobile joint between the primary girdle and the cleithrum, the former being suspended vertically from the cleithrum by ligaments. The proximal radials and rays are very numerous and vertically aligned. The cleithrum is shaped to accommodate the extensive sternohyoid and pharyngocleithral muscles. The sheet-like appendicular muscles extend beyond the special joint and control its movement. The deeper muscles do not cross this joint. The arterial system is specialized in lacking a deep brachial artery.

Canada's Immigration Policy, 1962–74

A number of significant changes have occurred in Canada's immigra? tion policy during the last fifteen years, and increasingly more public and parliamentary interest in immigration has been particularly evident during the past year or so. For example, the regulations specifying the requirements for admission of immigrants were substantially revised in 1962 and 1967 and significantly amended in 1974, responsibility for immigration was transferred in 1966 to a new Department of Manpower and Immigration, and both an Immigration Appeal Board and a Canada Manpower and Immigration Council were established in 1967; more recently, over 5,000 refugees from Uganda and about 1,500 refugees from Chile were admitted to Canada in 1972 and 1974 respectively, and several legislative changes were enacted in 1973 to eliminate not only the provision under which increasing numbers of visitors in Canada were applying for landed-immigrant status, but also the accompanying rapidly growing backlog of appeals against deportation which over the past years had been brought before the Immigration Appeal Board. But possibly of greatest importance, the government in 1973 again promised the intro? duction of a new Immigration Act and, in preparation for this, set up a special Task Force which, among other things, was to identify the policy options that exist; the resulting four volume Green Paper, A Report of the Canadian Immigration and Population Study, was tabled in February, 1975, and a special joint committee of the Senate and the House of Commons was appointed the following month to consider this tabled report and to invite the views of the public on its contents.1

TOTAL ELBOW REPLACEMENT

This is a report of a total elbow low friction arthroplasty consisting of a vitallium humeral component and a high density polyethylene ulnar component equipped with a special snap-lock fit joint. The immediate results in 16 patients are most encouraging.