Concept Of Durability Research Articles

Report: Extreme Wind and Salt Influence on Adriatic Bridges

This paper presents an overview of maintenance and repair of some large Croatian arch bridges built in a marine environment, characterised by strong winds. The performance in service of older bridges cannot be deemed satisfactory. Structural defects were found at an early age and hence cannot be blamed primarily on the environment, but are attributed also to conceptual design and errors and negligence on site. Therefore, new bridges are being designed and built utilizing new durability concepts.

Axioms For Building and Repairing Durable Concrete Structures

The durability of concrete structures can be defined as their ability to sustain the serviceability for which they were designed. Today’s practicing engineer pays particular attention to the types of deterioration that could threaten preserving the designed function of a structure. The complexities involved in current designs, and the proliferation of new materials, services, and hygenic requirements make the design engineer’s job demanding. Basic to the concept of durability is a commitment to quality assurance that involves testing and inspection to ensure the following: • Proper materials are selected for the job at hand, • The concrete is properly proportioned, mixed, handled, placed, and cured, and • The structure is appropriately designed to meet the demands of the service environment.

LOOKING AT THE POLITICS–ADMINISTRATION DICHOTOMY FROM THE OTHER DIRECTION: PARTICIPANT OBSERVATION BY A STATE SENATOR

The politics–administration dichotomy has been a durable concept in political science and public administration. Many effective critiques of the doctrine, first suggested by Woodrow Wilson in 1887, have not diminished the longevity of the approach it suggests for policy making in government. Yet, most of the literature has been written from the point of view of either academics or public administration practitioners. Little has been presented from the point of the view of the other participants in the dichotomy, the elected officials. Based on participant observation in the Wisconsin Legislature from 1977 to 1989, the author reviews how the politicians with whom he served behaved regarding their relations with administrators. He suggests that elected officials make decisions based on political rationality rather than a comprehensive norm defining their relationship with administrators. The political decision making he observed implicitly viewed administrators as subordinate to politicians rather than equal partners, roughly comparable to the discredited original meaning of the politics–administration dichotomy.

Probabilistic Durability Analysis in Advanced Engineering Design

Expedience of probabilistic durability concepts and approaches in advanced engineering design of building materials, structural members and systems is considered. Target margin values of structural safety and serviceability indices are analyzed and their draft values are presented. Analytical methods of the cumulative coefficient of correlation and the limit transient action effect for calculation of reliability indices are given. Analysis can be used for probabilistic durability assessment of carrying and enclosure metal, reinforced concrete, wood, plastic, masonry both homogeneous and sandwich or composite structures and some kinds of equipments. Analysis models can be applied in other engineering fields.

Resistencia duradera de plantas a las enfermedades

Resistance in the context of disease resistance in plants, is the ability of the host to stop the growth of the pathogen. In other words, genetic resistance is the mechanism by which retards or suppresses plant their tissue invasion by the pathogenic potential. It is complementary to and opposite susceptibility virulence , which is the sum of qualities that make a plant host to serve as a pathogen. Susceptibility and resistance are inversely proportional. Since the discovery of the heritability of rust resistance in wheat by Farrer in 1898 and that resistance to yellow rust obeys the laws of Mendel by Biffen in 1905 , an extensive search was initiated for obtaining durable resistance plant pathogens. Initial expectations of durability based on the assumption of slow evolution of the pathogen in the process by introducing overcome resistance genes in the plant were, however, dramatically removed by the rapid adaptation of new pathogenic variants . Years later, the concept of gene - by -gene in 1944 was firmly established by the Ustilago maydis Oort systems - wheat and flower on Melampsora lini - flax. The discovery of resistance to pathogens encouraged plant breeders to extend the search to the point that breeding for resistance to pathogens became one of the most successful measures in the process control plant diseases . The practice of obtaining resistance by introducing higher ( or qualitative ) genes in plants has become the most popular tool in breeding programs for its specificity , relative ease of recognition and manipulation. This type of resistance is durable until a new strain of the pathogen for which the incorporated gene confers resistance is set , in which case a new gene is introduced , provided when available. Repeating the process from time to time , new varieties with different genes replace those that have succumbed susceptible. Because of the limitations encountered , new strategies to increase the durability of resistance have been proposed. But in terms of durability as the type of interactions between host and pathogen are so varied, probably no model will serve to establish a single strategy. Durable resistance is understood as the resistance that remains effective after several years of use in large areas. The review presented here is intended to summarize the discoveries made to help visualize the magnitude of host-pathogen interactions , while a discussion of the different terms used to relate the concept of durability with the procedures for obtaining resistance Lead durable plant disease

Unimprovable Allocations in Economies with Incomplete Information

The paper considers an exchange economy with incomplete information in which agents can retrade goods until all gains from trade are exhausted. Unimprovable allocations are defined to be those allocations from which agents would not wish to deviate either by retrading goods or by revealing further information. The concept of unimprovability is then used to analyze a lemons market and an adverse selection insurance market in which agents can renegotiate after information has been revealed. Finally, unimprovability is compared to different concepts of efficiency and to the concept of durability. Journal of Economic Literature Classification Number: D82.

Financing Transport Infrastructure: The Effects of Institutional Durability in French and American Policymaking

This article compares the finance of transportation infrastructure in France and the United States in order to test the concept of institutional durability as an intervening variable that can account for different patterns of industrial development. Institutional durability is defined as the degree to which the fiscal norms and principles established in agreements between government, industry, and financial investors go on to exert influence over subsequent attempts to reorder the allocation of collective economic burdens and benefits. Two historical episodes of infrastructure development, mid‐19th century railroad construction and the creation of inter‐city highways between the First and Second World Wars, will be evaluated to identify and differentiate the effect of institutional durability upon American and French transportation policy.French infrastructure finance is shown to exhibit a limited institutional durability which has facilitated the historical adjustment of both rail and road infrastructure along convergent fiscal terms. US infrastructure development is seen to possess a much greater institutional durability which has encouraged the divergence of fiscal arrangements set up at different periods of time. The resulting accumulation of incompatible and often competitive arrangements appears to have locked the US into conflicting means of transport development that make a fiscally coherent transportation policy very difficult to achieve. No such institutional obstacle emerges in French transport policy where the terms of macroeconomic decision‐making are seen to be integrated.

The Rhetorical Voice of Psychoanalysis

The rhetorical voice of psychoanalysis has a long history and has only recently come to be seen as a special feature of the theory. Its beginnings can be found in Freud's earliest pleadings for the usefulness of metaphor and analogy, although he felt that they were largely provisional and would eventually be replaced by more durable concepts. We have begun to see problems in replacing the central metaphors; the rhetorical base of psychoanalysis may be more enduring than we thought. While our metaphors may never provide epistemic access to the stuff of the mind, they can and do point to specific clinical encounters. Ways must be found to expand our rhetorical treasure chest and develop language even better suited to our concepts and observations.

The Rhetorical Voice of Psychoanalysis

The rhetorical voice of psychoanalysis has a long history and has only recently come to be seen as a special feature of the theory. Its beginnings can be found in Freud's earliest pleadings for the usefulness of metaphor and analogy, although he felt that they were largely provisional and would eventually be replaced by more durable concepts. We have begun to see problems in replacing the central metaphors; the rhetorical base of psychoanalysis may be more enduring than we thought. While our metaphors may never provide epistemic access to the stuff of the mind, they can and do point to specific clinical encounters. Ways must be found to expand our rhetorical treasure chest and develop language even better suited to our concepts and observations.

Parliamentary Executive-Legislative Relations and the Implications of Cabinet Stability: "Ballast" and "Energy" in Macroeconomic Policy

OR NEARLY nine decades there has been a common assumption among Anglo-American students of comparative government that the frequent collapse of incumbent cabinet governments undermines the policy-making capacity of public authority. This viewpoint has been echoed recently by Dodd (1976) and Powell (1981) who have cautioned that cabinet instability and/or the emergence of minority governments may undermine executive authority and policy-making momentum. Others, such as Schmidt (1983) and Harmel and Robertson (1986) have built upon this tradition, offering preliminary evidence that the frequent demise of the incumbent cabinet government may weaken public confidence in democracy and the institutions of parliamentary systems. Yet, the student looking for more systematic empirical analysis of the linkage between cabinet stability and the effect on policy output will be hard-pressed to locate an adequate sample (Dodd 1984). The present analysis is conceived as a first step toward a more systematic analysis of the direct linkages between cabinet durability or instability and public policy. Nonetheless, the findings here do buttress the general contours of the theoretical framework of the presumed association. In so doing, these findings underscore the importance of pursuing the task of building the concept of cabinet durability into broader analyses of decision-making and the role of public authority in contemporary parliamentary democracies.

Comments on Miller and on Kleidon

Both Allan W. Kleidon's and Merton H. Miller's papers (in this issue) are organized around list of anomalies or puzzles that seem to be challenging efficient markets paradigm. They both are referring to Kuhn model of revolutions. Maybe something as dramatic as a is in store for us. That does not mean, however, that would lead to (as Kleidon attributes to critics of market efficiency like me) the abandonment of assumptions of rational expectations in favor of mass psychology (p. S497). Obviously efficient markets theory does capture an element of truth. For example, when important concrete information about future earnings potential of a corporation becomes public, of course price of stock in that company tends to jump immediately. Thus, a prediction of efficient markets theory is borne out. This is so even if there is also another component to movements in price of stock of that company, a component not explainable by any fundamental information. It might even be that, in stocks in which important concrete information does not become available, price movements may be dominated primarily by changes in fashions or attitudes of investors. Even in this case, there are still senses in which conventional efficient markets models may be regarded as quite useful. The models will be durable concepts in finance from now on. I tend to view study of behavioral extensions of these efficient markets models as leading in a sense to enhancement of efficient markets models. I could teach efficient markets models to my students with much more relish if I could describe them as extreme special cases to consider before moving to more realistic models. These models would look so much more appealing as first approximations to more complicated and more accurate theories, rather than as only models that profession has to offer. Perhaps what we need is not something so dramatic as a scientific revolution so much as a little softening of dogmatic adherence to

Impact of the Terms of Trade on the U.S. Trade Balance: A Reexamination

The right conclusion could be that there is a strong connection between the spectral components with specified periods. A possible economic interpretation could identify a strong long-term (in the sense of the specified periods) connection between both series. But that would still not allow us to say anything concerning the size and direction of the time delay between the two series. For such an analysis we would have to, at least, consider the phase angles between the components. Because of the ambivalent meaning of the phase angle (in relation to the direction and number of periods) the final answer could come only from the time domain analysis. However, the fact that only spectral components with longer periods, i.e., smaller frequencies, show coherency suggests something else: In order to influence the balance of trade the changes in the terms of trade should be durable enough. Mathematical formalization of this concept of durability would therefore be helpful. I would propose that further research be done in this respect.

The reduction in degree of allosteric and other complex rate equations using sylvester's dialytic method of elimination

1. (1) For all enzyme mechanisms there exists the possibility of reduction in degree of the steady-state rate equation when numerator and denominator are not relatively prime. 2. (2) For some mechanisms, this would occur under specific experimental conditions or at certain special rate constant values resulting in a reduced set of possible curve shapes. 3. (3) In realistic allosteric mechanisms, the introduction of catalytic rate constants may, in some circumstances, increase the number of nodes involving substrate addition leading to an artificially inflated degree. 4. (4) The algebraic theory necessary to study this problem is presented in a form appropriate to the routine testing of rate equations and all functions up to degree 4 : 4 are analysed using Sylvester's Dialytic method of elimination. 5. (5) Formulae are presented that give necessary and sufficient conditions for the reduction of y (n:n+r)= ∑ 1 n λ 1x 1 ∑ 0 n+r β 1x i to the proper, irreducible form y( n : n + r n − k : n + r − k )= ∑ 1 n−k a ix 1 ∑ 0 n+r−k b ix i for n > k thus allowing the routine testing of calculated high degree rate equations for a reduced spectrum of curve profiles. 6. (6) The conditions resulting in reduction in degree are shown to be related to the inequalities dictating curve shape in many instances. 7. (7) It is proved that all n : n rate equations give the same 1 : 1 function on full reduction and this is referred to as the theoretical parent hyperbola defined by y n : n 1 : 1 = λ 1β nx (λ nβ 0+λ 1β nx) 8. (8) All curves given by n : n rate equations can be characterized by reference to a unique 1 : 1 function called the experimental parent hyperbola. This is defined by y = x/[( solβ n α n ) + ( solβ n α n )x] where ( β 0/ α 1) and ( solβ n α n ) are experimentally determined parameters. The possible use of this concept in the study of allosterism and complex kinetics in general is explored. The discovery that an increasing number of enzymes deviate from Michaelis-Menten kinetics makes a thorough understanding of high degree rate equations a matter of some concern. Although at the present time there is considerable controversy over the precise interpretation of non-hyperbolic steady-state kinetics, there is, fortunately, resulting from the studies of King & Altman (1956), Wong & Hanes (1962), Vol'kenstein & Gol'shtein (1965) and others, a unifying reliable theory upon which theoretical studies can be based except for polymerizing systems. This should prove a durable concept and is now formulated explicitly.

The Effects of Advance Organizer, Sequence of Instruction, and Post Organizer on the Learning and Retention of a Taxonomy of Concepts

The present study examined instructional conditions that underly the learning and retention of a group of three related concepts represented in a taxonomy of behaviour management concepts. A total of 225 students in fifth and sixth form classes read instructional material on the first day of the study and were assessed on the second and eighth days. Both advance and post organizers were found to facilitate the learning and retention of the superordinate-coordinate-subordinate relationships among the concepts. Whereas an organizer did not facilitate the initial learning of the individual concepts, both an advance and post organizer significantly affected the retention of the concepts. The sequence in which the concepts were taught did not influence learning or retention. It was concluded that the internal organization of information is an extremely important condition for durable concept learning.

The evolution of modern cardiology.

PERSPECTIVES IN BIOLOGY AND MEDICINE Volume 12 · Number 1 · Autumn 196S THE EVOLUTION OF MODERN CARDIOLOGY WERNER FORSSMANN* Revolutionary discoveries never occur like isolated comets; only for the superficial observer do they burst forth with the radiant splendor ofa nova. Whoever traces them seriously always finds that, like a new star, they stem from a long period ofdevelopment and in them one can recognizethe spiritual influence ofthepast, springing up fromunknown sources. All discoveries—like famous men of old and their achievements—are inseparably bound to the spiritual development ofhumanity and, in their particular field, they form part ofan endless chain. In order to understand their origin and evaluate them, one must plunge deeply into thepastand study thehistory ofscience. This should beviewed in relation to history in general and especially to thehistory ofcivilization. Like everything else in life, scientific progress is governed by strict laws, and oral and written tradition is the starting and finishing point. These principles are handed down, unchanged, as fundamental knowledge until someone with a revolutionary spirit and critical mind challenges their static condition and discovers errors which he can no longer tolerate. The effort to fill the gaps in the conventional trend ofthought and to insure its continuity leads the critical mind into theoretical speculations which always run in diametrically opposed directions. The conservative scientist tries to uphold tradition at anyprice, while the progressive scientist tries to expound, in a dynamic and revolutionary way, new, clear, and durable concepts. This struggle between conservative and revolutionary * Evangelisches Krankenhaus, Düsseldorf, Fürstenwall 91, Federal Republic ofGermany. Permission to republish this essay, which appeared in Reflections on Biologic Research, has been granted by Warren H. Green, Publishers. thinking represents a problem for every generation, often leading to severe conflicts that are fought with the bitterest animosity, becoming keener the longer the conservative period lasts. Hatred and enmity increase mainly because the conservative side, forced more and more to take the defensive, tries to stifle the enemy with moral rather than scientific arguments. Here lies the crux ofthe problem which the following generation always forgets, or else it fails to grasp fully the import ofthese personal or general conflicts, which endanger the material and spiritual existence ofthe liberal scientist. In no way does his life bear the traces ofromantic ecstasy which is often portrayed in cheap and popular literature. On the contrary, it is hard and it becomes lonelier as he cuts himselfofffrom a life ofconformity. It requires courage, energy and also an enormous strength to bear the ups and downs oflife. At the beginning of his career, the young scientist is hardly aware of these difficulties. Overwhelmed by thejoy ofthe fresh line ofresearch and above all ofthe broad horizons which openup before him, he is filled with tremendous happiness. He is willing to devote his life and the work which is still in his mind to all humanity as a mother carries her child who is conceived in love. But all too soon he will be brought back from his enthusiastic state to reality. He realizes that, except for a few who are capable offollowing his train ofthought, his contemporaries are either indifferent to him or consider him an outsider. His ideas are not understood and are branded devious and worthless. In this way, he doesnotplay the imaginary role ofa pioneer, but rather—in the eyes ofthe inert and thoughtless conservative mass—he bears the mark ofan intruder who wants to change the existing conventional ways. Here he stands at the crossroads: he can choose whether to give up his plans and return contrite to the bosom of society or, ifhe is so obsessed by his ideas, to suffer loneliness and the heartlessness of others—all of which he must endure without help. With the latter decision, he brings upon himselfprivation and a mental burden ofwhich nobody can relieve him. Even later recognition or fame cannot eliminate the scars which he acquired during his struggle. Fewhave the good fortune after self-denial and personal renunciation, enmities, and humiliations, to achieve recognition and the crown ofglory from a grateful younger generation , and even this is no consolation for what the scientist has been through. Actually, every true scientist and...