116 research outputs found

    IRREGULARITIES IN THE YRAST LINE OF 156Er

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    The variation of the moment of inertia vs the rotational frequency has been investigated at high spin values using the141Pr(19F, 4nγ) 156Er reaction. In addition to the backbending at I = 12 ħ, a second one has been found at I = 26 ħ. Calculations performed by the Warsaw group with the HFB cranking model suggest a probable neutron effect

    Understanding and measuring child welfare outcomes

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    The new Children\u27s and Family Services Reviews (CFSR) process focuses on the effectiveness of services to children and families by measuring client outcomes. This article reviews the research literature related to child welfare outcomes in order to provide a context for federal accountability efforts. It also summarizes the 2001 federal mandate to hold states accountable for child welfare outcomes and describes California\u27s response to this mandate. Implications of the outcomes literature review and measurement problems in the CFSR process suggest CSFR measures do not always capture meaningful outcomes. Recommendations for change are made

    Shape coexistence, evolution and the parallel proton-neutron core breaking in 15568Er87 studied with the help of the BaF2 4π-detection system

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    A discrete γ-ray study of 155Er has been performed. A level scheme up to spin 85/2 has been established and interpreted using the deformed Woods-Saxon cranking approximation, taking into account pairing forces. Interpretation in terms of shape coexistence, band termination and breaking of the (Z=64, N=82) core is proposed

    A history of civil engineering

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    Derived from the Latin "ingenium," which means natural capacity or invention, the word "engine" provides a clue as to the origin of the title "engineer." Ingenium, engine, military engine, and military engineer follow each other logically when the assault and defense of early mailed cities is considered. It is lively that the word "engineer" was derived from "engine" in much the same manner that "musketeer" was derived from "musket," for the early duties of the military engineer were largely concerned with making and operating engines of war such as catapults, battering rams, and the like. It naturally fell his lot to devise defenses against these weapons as well, so we find the engineer branching out into the building of fortifications and other works to resist or aid siege. In time the engineer's job came to include all types of construction, such as roads and bridges, needed to facilitate the movements of an army. In every case his primary task as an engineer was to contrive or to build something, and that function has continued to this day. The very root of the word, "ingenium," indicates the engineer's mission in society; it is to do, to act, or to make. The aim of the scientist is to know, but the aim of the engineer is to do by applying science to his work. This application of science has resulted in a more efficient utilisation of materials and has given rise to the oft-quoted definition of engineering as "the art of doing with one dollar which any bungler can do with two after a fashion." The first man on record to call himself a "civil" engineer was the eighteenth century Englishman John Smeaton, who sought to distinguish his civilian construction work from that of the military engineer. Just what constituted civil engineering remained a rather indefinite concept until the profession was defined in the charter granted in 1828 to the Institution of Civil Engineers at London as: "andmdash;the art of directing the great sources of power in nature for the use and convenience of man, as the means of production and of traffic in states, both for external and internal trade, as applied in the construction of roads, bridges, aqueducts, canals, river navigation and docks for internal intercourse and exchange, and in the construction of ports, harbours, moles, breakwaters and lighthouses, and in the art of navigation by artificial power for the purposes of commerce, and in t^e construction and application of machinery, and in the drainage of cities and towns." The term "civil" engineer gradually became restricted to those who concerned themselves chiefly with works of a static nature such as roads and tunnels, while those who concerned themselves primarily with the operation of moving machinery adopted the designation "mechanical" engineer. In time other specialties came to be recognized, and new branches such as "chemical" and "electrical" engineering were born. A century after the granting of the 1828 charter civil engineering had become only one of the many branches of the engineering profession and had changed somewhat in the fields it covered. Engineering had come to be defined as the "professional and systematic application of science to the efficient utilization of natural resources to produce wealth." The subfields of civil engineering officially adopted in 1929 by the California State board of Highway Engineering examiners included the following: "highways, bridges, water supply, inland waterways, harbors, drainage, irrigation, water power, flood control, municipal improvements, railroads, tunnels, airports, airways, purification of water, sewage, refuse disposal, foundations, framed and homogeneous, structures, building, city and regional planning, valuation and appraisals, and surveying (other than land surveying)." In other ages and in other civilisations the engineer was known by other namesandnbsp;andndash; as a sage, architect, philosopher, or wise manandnbsp;andndash; but his function was essentially that of his modern counterpart. Regardless of what he called himself or what other duties he performed in the past, we shall try to trace the engineer and his works from earliest times to the present. In a sense, the of engineering is a story of mankind, for no less than law and government has technology been a mark of the civilised world. The archaeological and historical evidence thus far is too meager to permit us to deal at length on the progress of civil, engineering in moat of the civilizations which have previously flourished. The work of many of the civilizations, as for instance the Andean, has been here omittedandnbsp;andndash; even though some evidence is availableandnbsp;andndash; for it seems to bear little or no relationship to the main thread of this history. Relatively little space, then, has been assigned to the history of civil engineering elsewhere than in the Hellenic and Western world, for our main task is to trace the traditions of the profession which have culminated in the civil engineering of the twentieth century. Perhaps the clearest way to present the history of this profession is to review briefly the development of engineering as a whole through every age and then go back and develop each section of the profession in the following order: materials and building construction, roads, bridges, canals, tunnels, surveying, water supply, sewerage, Hydraulic and coastal works, and railroads. According to present evidence, the first traces of what might be called civil engineering appeared in Egypt commencing somewhere around 3000 B.C. Surveying, hydraulic works, and building construction made up the bulk of Egyptian engineering, but it is doubtful whether these had any direct effect on the works of succeeding or contemporary civilizations. The most significant thing about Egyptian engineering is that here, for the first time, we have evidence of man building to a plan instead of haphazardly and using mathematics to ensure the results desired. This contribution is slight when compared with the works of modern civil engineering but gigantic when compared to the works of primitive man. The next people of importance to this study were the Greeks, whose main contributions to civil engineering were theoretical rather than practice, for they did much to develop the mathematics and geometry which later became so important in engineering. This emphasis of theoretical over practical was due in part to the attitude of the philosophers who led Greek thought; it was due in greater measure to the country's geography or to be more precise, its topographyandnbsp;andndash; which in turn shaped its political and economic life. The construction of vast public works, consistent with the technology of the time, could not be justified from an administrative or commercial standpoint, and so they were never brought into being. With the emergence of Rome as the dominant power in the world, civil engineering reached a peak it did not again achieve until the nineteenth century. Parts of the old Roman roads still survive to this day, and this permanence and solidity which manifested itself in their roads was a characteristic which extended throughout all of their engineering endeavors. Aqueducts, bridges, tunnels, canals, and all forms of hydraulic works fall within the scope of the Roman engineers during the time of the republic and later under the emperors. In the Roman structures we find definite evidence of the use of mathematics and geometry in their lay-out and construction. Closer inspection reveals that they were over-designedandnbsp;andndash; by modern standards at leastandnbsp;andndash; a further indication that they were derived more from rule-of-thumb methods than from basic scientific principles. As Rome was on the ascendancy engineering was alternately an effect and cause of strong government, but when the government began to break down technology could not save it. The engineers did not at first lose their skill and know-how, they simply lost the funds to maintain the works they had built. Thus, along with, the other hall-marks of an advanced civilization, the art of civil engineering slowly died among the crumbling ruins of the Roman empire in the fifth century. Following the fall of Rome, a flicker of learning and engineering skill was kept alive in the Arab world, but little new was added. The importance of the Arabic civilization rests in the fact it served as the "funnel" into which the knowledge of Greece, the Near East, and to some extent India and even China passed. Here it was absorbed and passed on to the Western world of the Middle Ages. A revival in Western engineering, crude though it was, was initiated in the medieval monasteries. In the twelfth century we find pious monks in Italy, France, and England taking up the task of building bridges and other works modeled after Roman remains. Monastery water supply and drainage systems also began to appear about this time as did the great Gothic cathedrals which still excite our admiration. The later Middle Ages were also marked by the construction of irrigation and drainage canals in both Holland and Italy, and for generations Dutch and Italian engineers were regarded as supreme in all types of hydraulic work. In time, the ecclesiastics passed their knowledge and skills to the laity in the great period of enlightenment which followed. Except in the field of architecture and building construction, the Renaissance was more a time of ideas than of action insofar as it affected the engineering profession. The new pattern of thought engendered by the Renaissance bore fruit in the brilliant scientific speculations of the philosophers of the seventeenth centuryandnbsp;andndash; a century marked by the contributions of some of the brightest names in science, namely Gilbert, Kepler, Hooke, Torricelli, Pascal, Boyle, Huygens, and Newton. In the strictest sense, these philosophers were not engineers, but their findings helped to establish a theoretical base for the art of scientific engineering which was was to follow. The seventeenth century philosophers were followedandnbsp;andndash; in England especiallyandnbsp;andndash; by the "practical" men of the eighteenth century who made a start in translating scientific theory into practice. Early in the nineteenth century modern civil engineering began. Barge canals, which had been the main civil engineering ventures of the eighteenth century, gave way to the railroads shortly after the opening of the Liverpool and Manchester Railway in 1830. As had the canals which preceded them, the new railroads brought about increased improvements in bridge and tunnel construction. A more scientific approach to road-making also was manifested early in the century, and harbor and waterfront construction kept abreast of other developments in the profession. Large cities, spawned by the Industrial Revolution, soon found their water supplies inadequate, both as to quality and quantity, and here again the skill of the engineer was brought into play for the good of the community. In like manner, stream pollution in industrial areas toward the latter part of the century brought about the need for sewerage reform, a problem which was essentially solved as the century drew to a close. The commercial development of Portland cement and stool was another factor of great importance during this period for a whole new field of design and construction was now opened. It was not until the twentieth century, however, that the great possibilities of these materials came to be realized. New problems in engineering were ushered in with the twentieth century as the automobile and airplane entered the transportation field, but, as had been the case oaf ore, the profession proved flexible enough to meet successfully the new challenges. The rapid changes brought about in the nineteenth century naturally raise a question as to when the emphasis in engineering design shifted from calculations based on rule of thumb to those based on truly scientific principles. Actually, the time when this shift in emphasis became significant did not coincide with the beginningandnbsp;andndash; according to our definitionandnbsp;andndash; of modern civil engineering. We associate the beginning of modern civil engineering with the name of Telford and with the incorporation of Great Britain's Institution of Civil Engineers in 1828andnbsp;andndash; the time when civil engineering came to be formally recognized as a profession both by its members and by the outside world. At the time of its recognition as a profession, engineering still had most of its roots of design in "practical" rather than in scientific principles. By the middle of the nineteenth century, however, the shift to the scientific emphasis in design had become apparent. Squire Whipple's first treatise on stresses in trusses (1847) and De Sazilly's analysis of dam design (1853) marked the beginning of truly rational and scientific design in engineering. From this time forward, design passed out of the hands of the "practical" man into the hands of those with scientific training, and progress leaped forward at an astounding pace during the latter half of the nineteenth century. In glancing over the progress of civil engineering we find that in every case of outstanding achievement the same factors have been in evidence. First of all, topography has been favorable in Initial instances, tough enough to evoke a response but gentle enough to be overcome. Aided by their increased confidence and guided by their past experience, engineers from a country with such topography have been able to go into areas of increasing topographical difficulty and master conditions which would have been impossible to master had they attempted to lay the foundations of their skill there. The effect of climate has been similar. Practically all engineering knowledge has originated with people from temperate climates who have neither bean all but overwhelmed by arctic blasts nor enervated by tropic heat. Another decisive factor has been wealth, both In the form of workable materials and in the form of financial backing. The first depends on nature, but the second may stem from government or private enterprise. Regardless of the source of the financial backing, however, government must be regarded as another factor, for only under relatively stable political organizations has true engineering progress been made. Commercial benefits have provided much of the incentive in engineering, out a great measure of credit must also be given to those men of public spirit who have, with no thought of financial gain, labored to make this a better world in which to live. The combination of all these factors has encouraged engineering development where the need of rational thought has been firmly planted. From thought hat come knowledge, and from knowledge, powerandnbsp;andndash; power of man over his environment. In the final analysis, the effect of the engineer on his environment and the effect of the environment on the engineer cannot be separated. One has continually acted and reacted on the other until cause and effect are hopelessly intermingled. One fact emerges clear, however; the engineer has played a leading role not only in changing the face of the earth but in shaping the destiny of nations and of men as well.</p

    Utilization of n

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