Books on the topic 'Aggregati stabili'

Characteristically, surfactants in aqueous solution adsorb at interfaces and form aggregates (micelles of various shapes and sizes, microemulsion droplets, and lyotropic liquid crystalline phases). This book is about the behaviour of surfactants in solution, at interfaces, and in colloidal dispersions. Adsorption at liquid/fluid and solid/liquid interfaces, and ways of characterizing the adsorbed surfactant films, are explained. Surfactant aggregation in systems containing only an aqueous phase and in systems with comparable volumes of water and nonpolar oil are each considered. In the latter case, the surfactant distribution between oil and water and the behaviour of the resulting Winsor systems are central to surfactant science and to an understanding of the formation of emulsions and microemulsions. Surfactant layers on particle or droplet surfaces can confer stability on dispersions including emulsions, foams, and particulate dispersions. The stability is dependent on the surface forces between droplet or particle surfaces and the way in which they change with particle separation. Surface forces are also implicated in wetting processes and thin liquid film formation and stability. The rheology of adsorbed films on liquids and of bulk colloidal dispersions is covered in two chapters. Like surfactant molecules, small solid particles can adsorb at liquid/fluid interfaces and the final two chapters focus on particle adsorption, the behaviour of adsorbed particle films and the stabilization of Pickering emulsions.

This article discusses time-series methods such as simple time-series regressions, ARIMA models, vector autoregression (VAR) models, and unit root and error correction models (ECM). It specifically presents a brief history of time-series analysis before moving to a review of the basic time-series model. It then describes the stationary models in univariate and multivariate analyses. The nonstationary models of each type are addressed. In addition, various issues regarding the analysis of time series including data aggregation and temporal stability are considered. Before concluding, the article briefly reports the time-series techniques in the context of panel data. In general, time-series analysis can help improve the understanding of the political world.

Abstract: The chapter introduces the specific indicators of uncertainty in the national campaign context, which include economic volatility, technology shock (with the invention of new mass communication devices, including radio, television, cable television, and the Internet), dramatic national events such as US involvement in major international conflicts, and federal expansion of the franchise. The more change in each indicator, the greater the increase in uncertainty. The increase in uncertainty produces a decrease in nonvoting. Conversely, the more stable the indicator, the less uncertainty and the more likely nonvoting increases. The chapter tests an aggregate model across the full time frame from 1920 through 2012 for presidential and midterm House elections. The results show that relative to such personal factors as age and education, measures of economic volatility, new communication technology, and visible national events decrease nonvoting in both presidential and midterm House elections.

This book identifies 88 Soviet intelligence officers who defected from 1924 to 1954 and provides an aggregate analysis of their information to uncover Soviet strategic priorities and concerns. When intelligence officers defect, they take with them privileged information and often communicate it to the receiving state, and thereby they open a window into a closed national security decision making system. The book provides the most comprehensive list of Soviet intelligence officer defectors compiled to date representing a variety of specializations. Through the information they provided in now-declassified debriefings, documents they brought with them, and post-defection publications and public appearances, this book shows the evolution of Soviet threat perceptions and the development of the "main enemy" concept in the Soviet national security system. It also shows fluctuations in the Soviet recruitment and vetting of personnel for sensitive national security positions, corresponding with fluctuations in the stability of the Soviet government. The shifting motivations of these officers also reveals the pressures that they were experiencing at the time, leading to their choice to break with the Soviet Union.

The platelet is a small (2–4 µm in diameter), discoid, anucleate cell that circulates in the blood. In health, it plays a vital role in haemostasis, and in disease it contributes to disorders of bleeding and thrombosis. Platelets are produced from the surface of megakaryocytes in the bone marrow, under tight homeostatic control regulated by the cytokine thrombopoietin. Platelets have a lifespan of approximately 7–10 days, and usually circulate in the blood stream in a quiescent state. Intact, undamaged vessel walls help to maintain platelets in this inactive state by releasing nitric oxide, which acts both to dilate the vessel wall and to inhibit platelet adhesion, activation, and aggregation. After trauma to the blood vessel wall, platelets are activated and, acting in concert with the endothelium and coagulation factors, form a stable clot. This chapter addresses platelet structure and function, and the response of platelets to vessel injury.

The book takes a political-culture perspective on the struggle between democracy and autocracy by examining how these regimes fare in the eyes of their citizens. Taking a globally comparative approach, it studies both the levels as well as the individual- and system-level sources of political support in democracies and autocracies worldwide. The book develops an explanatory model of regime support which includes both individual- and system-level determinants and specifies not only the general causal mechanisms and pathways through which these determinants affect regime support but also spells out how these effects might vary between the two types of regimes. It empirically tests its propositions using multi-level structural equation modeling and a comprehensive dataset that combines recent public-opinion data from six cross-national survey projects with aggregate data from various sources for more than one hundred democracies and autocracies. It finds that both the levels and individual-level sources of regime support are the same in democracies and autocracies, but that the way in which system-level context factors affect regime support differs between the two types of regimes. The results enhance our understanding of what determines citizen support for fundamentally different regimes, help assessing the present and future stability of democracies and autocracies, and provide clear policy implications to those interested in strengthening support for democracy and/or fostering democratic change in autocracies.

"Nella lunga vita di molti contratti, possono verificarsi eventi imprevisti che incrinano l’equilibrio, soprattutto economico, delle reciproche prestazioni. Il discorso intorno al diritto-dovere di rinegoziare gli accordi esposti a sopravvenienze è ormai un tema classico del diritto civile, che rispunta ciclicamente in occasione di eventi di rilevanza mondiale capaci di compromettere la tenuta di innumerevoli contratti in corso. La pandemia di COVID-19 è solo l’ultimo esempio in ordine di tempo. Questa ricerca si propone di individuare il miglior approccio giuseconomico per affrontare il dilemma della rinegoziazione, in prospettiva strutturale, cercando di coniugare le soluzioni proposte dagli interpreti del diritto civile con i contributi di analisi economica del diritto, nella prospettiva della riforma del codice civile italiano e della progressiva armonizzazione del diritto privato europeo e internazionale. In questo percorso, l’individuazione di una regola di default stabile e duratura per un contesto mutevole e multiforme è forse la contraddizione in termini che più vale la pena affrontare. Matteo de Pamphilis, dopo la laurea in Giurisprudenza e il conseguimento del dottorato di ricerca in Diritto civile nell’Università di Bologna, collabora con la stessa Alma Mater come professore a contratto e tutor didattico in materie privatistiche. Negli ultimi anni è stato docente degli insegnamenti in lingua inglese Planning and public intervention in the lifestyle and health sector e Public and private action for the development of services nel corso di laurea magistrale in Wellness culture: sport, health and tourism. È socio aggregato dell’Associazione Civilisti Italiani e svolge la professione di avvocato nel Foro di Bologna, prevalentemente nel settore civile, commerciale e concorsuale."

Osteoarthritis (OA) is the commonest condition to affect synovial joints, but although any synovial joint can be affected, most studies of pathology relate to large joints (knees and hips). OA involves the whole joint and pathological alterations typically occur in all joint tissues. Established OA is characterized by a mixture of tissue loss and new tissue production resulting in focal loss of articular hyaline cartilage together with bone remodelling and osteophyte formation. Articular cartilage may show increased thickness in the earliest stages of OA with increased numbers of hypertrophic chondrocytes, followed by progressive decline in matrix components, thickness, and chondrocyte number. Surface fibrillation and vertical clefts become evident in mid- to end-stage OA and eventual complete loss of cartilage can occur, predominantly in maximum load-bearing regions, with subsequent eburnation and furrowing of bone. Bone remodelling may lead to alteration of bone shape and variable trabecular thickness in subchondral bone, whilst subchondral microfractures may result in localized osteonecrosis, fibrosis, and ‘cysts’. Endochondral ossification of new fibrocartilage produced predominantly at the joint margin produces characteristic bony osteophytes. The synovium shows areas of hyperplasia with varying amounts of lymphocyte aggregates and inclusion of osteochondral ‘loose’ bodies, and the outer fibrous capsule thickens to help stabilize the compromised joint. Synovial fluid increases in volume but decreases in viscosity. Periarticular changes include type II muscle atrophy and enthesophytes.

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Politics. Please check back later for the full article.Narrowly understood, social choice theory is a specialized branch of applied logic and mathematics that analyzes abstract objects called preference aggregation functions, social welfare functions, and social choice functions. But more broadly, social choice theory identifies, analyzes, and evaluates rules that may be used to make collective decisions. So understood, social choice is a subfield of the social sciences that examines what may be called “voting rules” of various sorts. While social choice theory typically assumes a finite set of alternatives over which voter preferences are unrestricted, the spatial model of social choice assumes that policy alternatives can be represented by points in a space of one or more dimensions, and that voters have preferences that are plausibly shaped by this spatial structure.Social choice theory has considerable relevance for the study of legislative (as well as electoral) institutions. The concepts and tools of social choice theory make possible formal descriptions of legislative institutions such as bicameralism, parliamentary voting procedures, effects of decision rules (e.g., supramajority vs. simple majority rule and executive veto rules), sincere vs. strategic voting by legislators, agenda control, and other parliamentary maneuvers. Spatial models of social choice further enrich this analysis and raise additional questions regarding policy stability and change. Spatial models are used increasingly to guide empirical research on legislative institutions and processes.

Abstract Trafficking Data argues that the movement of human data across borders for political and financial gain is disenfranchising consumers, eroding national autonomy, and destabilizing sovereignty. Focusing on the United States and China, it traces how US government leadership failures, Silicon Valley’s disruption fetish, and Wall Street’s addiction to growth have yielded an unprecedented opportunity for Chinese firms to gather data in the United States and quietly send it back to China and, by extension, to the Chinese government. Such “data trafficking,” as the book names this insidious phenomenon, is enabled by the competing governance models of the world’s two largest economies: mass government data aggregation in China and impenetrable corporate data management policies in the United States. China is stepping up its data trafficking efforts through national regulations, soft power persuasion, and tech investment, extending the scope of state control over domestic and international data and tech infrastructure, and thereby expanding its global influence. The United States, by contrast, is retreating from participation in foreign alliances, international organizations, and the systemic regulation of the tech industry—practices with the potential to counter data trafficking. Confronting data trafficking as the defining international competition of the twenty-first century, this book advocates for an alternative future of data stabilization. To stem data trafficking and stabilize data flows, it shows, policymakers can synthesize tools from across the private sector, public sector, multinational organizations, and consumers to protect users, secure national sovereignty, and establish valuable international standards.

Despite decades of scholarly attention to conflict and cooperation processes in international politics, rigorous, comparative, large-N analyses of these questions at the region level are difficult to find in the literature. Although this relative absence may stem in part from the difficulties related to the theoretical conceptualization or methodological operationalization of regions, it certainly is not for lack of interesting variation in terms of conflict and cooperation processes across regions. Between this variation and recent contributions toward a dynamic identification of regions, comparative analysis of conflict and cooperation outcomes at the region level are primed for exploration and increasingly salient as recent political elections in the United States (Trump election) and the United Kingdom (Brexit) have demonstrated a willingness on the part of policymakers to scale back efforts toward global interdependence.Turning attention to a region level unit of analysis, however, does not require abandoning decades of scholarship at the state or dyad levels. Indeed, much of this work may be viewed as informing or complementary to comparative regional analyses. In particular, regional propensity for cooperation or conflict is likely to be conditioned by a number of prominent explanations of these phenomena at state and dyad levels, which may usefully be conceived in their regional aggregates as so-called regional fault lines or baseline conditions. These include the presence of major and/or regional powers, interstate rivalries, unresolved territorial claims, civil wars, regime similarity, trade relationships, and common membership in intergovernmental organizations.Of these baseline conditions, the impact of major and regional powers on regional patterns of cooperation and conflict is notable for both its theoretical and practical implications. Power transition theory, hegemonic stability theory, hierarchical theory, and long cycle theory all suggest major—and to a lesser extent regional—powers will seek to establish order within areas under their influence; alternatively, the overwhelming capabilities these states bring to a region arguably act as a deterrent inhibiting conflict. Empirical analysis reveals—irrespective of the causal mechanism at hand—regions characterized by the presence of a major or regional power experience less conflict. Moving forward, future research should work to test the two plausible causal mechanisms for this finding—order building versus deterrence—to determine the true nature of hierarchy’s pacifying influence.

Hard coal mining is characterised by features that pose numerous challenges to its current operations and cause strategic and operational problems in planning its development. The most important of these include the high capital intensity of mining investment projects and the dynamically changing environment in which the sector operates, while the long-term role of the sector is dependent on factors originating at both national and international level. At the same time, the conditions for coal mining are deteriorating, the resources more readily available in active mines are being exhausted, mining depths are increasing, temperature levels in pits are rising, transport routes for staff and materials are getting longer, effective working time is decreasing, natural hazards are increasing, and seams with an increasing content of waste rock are being mined. The mining industry is currently in a very difficult situation, both in technical (mining) and economic terms. It cannot be ignored, however, that the difficult financial situation of Polish mining companies is largely exacerbated by their high operating costs. The cost of obtaining coal and its price are two key elements that determine the level of efficiency of Polish mines. This situation could be improved by streamlining the planning processes. This would involve striving for production planning that is as predictable as possible and, on the other hand, economically efficient. In this respect, it is helpful to plan the production from operating longwalls with full awareness of the complexity of geological and mining conditions and the resulting economic consequences. The constraints on increasing the efficiency of the mining process are due to the technical potential of the mining process, organisational factors and, above all, geological and mining conditions. The main objective of the monograph is to identify relations between geological and mining parameters and the level of longwall mining costs, and their daily output. In view of the above, it was assumed that it was possible to present the relationship between the costs of longwall mining and the daily coal output from a longwall as a function of onerous geological and mining factors. The monograph presents two models of onerous geological and mining conditions, including natural hazards, deposit (seam) parameters, mining (technical) parameters and environmental factors. The models were used to calculate two onerousness indicators, Wue and WUt, which synthetically define the level of impact of onerous geological and mining conditions on the mining process in relation to: —— operating costs at longwall faces – indicator WUe, —— daily longwall mining output – indicator WUt. In the next research step, the analysis of direct relationships of selected geological and mining factors with longwall costs and the mining output level was conducted. For this purpose, two statistical models were built for the following dependent variables: unit operating cost (Model 1) and daily longwall mining output (Model 2). The models served two additional sub-objectives: interpretation of the influence of independent variables on dependent variables and point forecasting. The models were also used for forecasting purposes. Statistical models were built on the basis of historical production results of selected seven Polish mines. On the basis of variability of geological and mining conditions at 120 longwalls, the influence of individual parameters on longwall mining between 2010 and 2019 was determined. The identified relationships made it possible to formulate numerical forecast of unit production cost and daily longwall mining output in relation to the level of expected onerousness. The projection period was assumed to be 2020–2030. On this basis, an opinion was formulated on the forecast of the expected unit production costs and the output of the 259 longwalls planned to be mined at these mines. A procedure scheme was developed using the following methods: 1) Analytic Hierarchy Process (AHP) – mathematical multi-criteria decision-making method, 2) comparative multivariate analysis, 3) regression analysis, 4) Monte Carlo simulation. The utilitarian purpose of the monograph is to provide the research community with the concept of building models that can be used to solve real decision-making problems during longwall planning in hard coal mines. The layout of the monograph, consisting of an introduction, eight main sections and a conclusion, follows the objectives set out above. Section One presents the methodology used to assess the impact of onerous geological and mining conditions on the mining process. Multi-Criteria Decision Analysis (MCDA) is reviewed and basic definitions used in the following part of the paper are introduced. The section includes a description of AHP which was used in the presented analysis. Individual factors resulting from natural hazards, from the geological structure of the deposit (seam), from limitations caused by technical requirements, from the impact of mining on the environment, which affect the mining process, are described exhaustively in Section Two. Sections Three and Four present the construction of two hierarchical models of geological and mining conditions onerousness: the first in the context of extraction costs and the second in relation to daily longwall mining. The procedure for valuing the importance of their components by a group of experts (pairwise comparison of criteria and sub-criteria on the basis of Saaty’s 9-point comparison scale) is presented. The AHP method is very sensitive to even small changes in the value of the comparison matrix. In order to determine the stability of the valuation of both onerousness models, a sensitivity analysis was carried out, which is described in detail in Section Five. Section Six is devoted to the issue of constructing aggregate indices, WUe and WUt, which synthetically measure the impact of onerous geological and mining conditions on the mining process in individual longwalls and allow for a linear ordering of longwalls according to increasing levels of onerousness. Section Seven opens the research part of the work, which analyses the results of the developed models and indicators in individual mines. A detailed analysis is presented of the assessment of the impact of onerous mining conditions on mining costs in selected seams of the analysed mines, and in the case of the impact of onerous mining on daily longwall mining output, the variability of this process in individual fields (lots) of the mines is characterised. Section Eight presents the regression equations for the dependence of the costs and level of extraction on the aggregated onerousness indicators, WUe and WUt. The regression models f(KJC_N) and f(W) developed in this way are used to forecast the unit mining costs and daily output of the designed longwalls in the context of diversified geological and mining conditions. The use of regression models is of great practical importance. It makes it possible to approximate unit costs and daily output for newly designed longwall workings. The use of this knowledge may significantly improve the quality of planning processes and the effectiveness of the mining process.