From crisis to normal science, and back again: Coming full “Kuhn cycle” in the career of Warren B. Hamilton

ABSTRACT In this paper, I use Thomas S. Kuhn’s model of scientific change to frame a brief, broad-brushed biographical sketch of the career of Warren B. Hamilton. I argue that Hamilton’s career can usefully be interpreted as encompassing a full “Kuhn cycle,” from a period of crisis in his early work, to one of normal science in midcareer, and back to something resembling crisis in his later research. Hamilton entered the field around mid-twentieth century when earth science can plausibly be described as being in a period of crisis. The then dominant fixist paradigm was facing an increasing number of difficulties, an alternative mobilist paradigm was being developed, and Hamilton played an important role in its development. The formulation of plate tectonics in the 1960s saw the overthrow of the fixist paradigm. This inaugurated a new phase of normal science as scientists worked within the new paradigm, refining it and applying it to different regions and various geological phenomena. Hamilton’s midcareer work fits largely into this category. Later, as the details of the plate-tectonic model became articulated more fully, and several of what Hamilton perceived as weakly supported conjectures became incorporated into the paradigm, problems began again to accumulate, and earth science, in Hamilton’s estimation, entered a new period of crisis. Radically new frameworks were now required, and Hamilton’s later work was dedicated principally to developing and articulating these frameworks and to criticizing mainstream views.

Microstructures and High-Temperature Properties of Sm-Modified Mg-4Al-4RE Alloy

The effect of Sm on the microstructure and tensile properties of Mg-4Al-4 (La, Ce) alloy was studied. The Mg-4Al-4 (La, Ce) alloy was mainly composed of α-Mg and Al11(La, Ce)3. With the addition of Sm, a new phase of Al2(La, Ce, Sm) was revealed in the alloy. The results showed that at room temperature (RT), after Sm addition, the ultimate tensile stress and the elongation decreased, while the yield stress increased slightly; the elongation increased with the Sm addition and the yield stress was basically the same, but the ultimate tensile stress decreased at an elevated temperature of 150 °C. The change in the mechanical properties of the alloy was mainly related to the change in microstructure and phase. With the increase in Sm content, the volume fraction of Al2(La, Ce, Sm) phase increased and the Al11(La, Ce)3 eutectic volume fraction decreased significantly, which led to a change in the mechanical properties of the alloy. The 1 wt.%Sm-addition alloy exhibited greater elongation than the Sm-free alloys.

Dynamic corrosion mechanical properties of magnesium alloys with Erbium in the chloride ions environment

The X-ray diffraction (XRD), scanning electron microscope (SEM), weight loss corrosion rate, corrosion residual strength (CRS), and slow strain rate tensile (SSRT) methods were used to study the effects of the addition of rare earth Erbium (Er) on the dynamic corrosion mechanical properties of the AM50 magnesium alloy. The results show that after Er was added, a new phase of Al3Er appeared and the microstructure was refined. The corrosion resistance of rare earth Er addition to the alloy was 0.5% > 1.5% > 1.0% > 0. Furthermore, the corrosion rates decreased in 432 h. The CRS results within 168 h show that the strength after an addition of 0.5% Er was the highest and the decline rate was the smallest. According to the shape of the tensile curve of CRS and the morphology of the tensile fracture, the addition of rare earth Er did not change the fracture form of the alloy, which remained as quasi-cleavage.

Alternative Futures for the Digital Transformation: A Macro-Level Schumpeterian Perspective

This paper develops and deploys a theoretical framework for assessing the prospects of a cluster of technologies driving what is often called the digital transformation. There is considerable uncertainty regarding this transformation’s future trajectory, and to understand and bound that uncertainty, we build on Schumpeter’s macro-level theory of economy-wide, technological revolutions and on the work of several scholars who have extended that theory. In this perspective, such revolutions’ trajectories are shaped primarily by the interaction of changes within and between three spheres—technology, organization, and public policy. We enrich this account by identifying the critical problems and the collective choices among competing solutions to those problems that together shape the trajectory of each revolution. We argue that the digital transformation represents a new phase in the wider arc of the information and communication technology revolution—a phase promising much wider deployment—and that the trajectory of this deployment depends on collective choices to be made in the organization and public policy spheres. Combining in a 2 × 2 matrix the two main alternative solutions on offer in each of these two spheres, we identify four scenarios for the future trajectory of the digital transformation: digital authoritarianism, digital oligarchy, digital localism, and digital democracy. We discuss how these scenarios can help us trace and understand the future trajectory of the digital transformation.

The Constitutional and Legal Organization of the Supreme Constitutional Court in the Iraqi State for the Year 2005

The constitutional system in Iraq after the overthrow of the previous regime in 2003 witnessed major fundamental changes, which marked the end of a historical era, the advent of the beginning of a new phase of political and constitutional history, and the adoption of the federal (federal) system as a form of the new Iraqi state, where Iraq transformed from a simple state to a complex state. With the adoption of the democratic parliamentary system based on the principle of separation of powers and respect for the constitution by emphasizing the principle of the supremacy of the constitution as a system for the work of state authorities and the management of its various constitutional institutions. If the constitutional distribution of competencies between the federal authorities is one of the essential characteristics of the federal systems, then one of the important features in the design of any federalism and its effective operation is to ensure the rule of law and the constitution as the source of powers, and in contrast, one of the authorities infringes on the powers of the other, which leads to a constitutional imbalance in the federalism And the matter that leads to its disintegration and its end, and in order to preserve this constitutional system, it is necessary to establish a supreme judicial body to ensure respect for the application of the constitutional principles of this system and not to be violated. The federal system is characterized by the presence of a Supreme Constitutional Court that works to monitor the constitutionality of laws and chapters In disputes between the central regions, it has the authority to interpret the Iraqi federal constitution, especially the interpretation of the constitutional rules related to the distribution of constitutional powers between the regions and the federal government. Which is one of the thorny issues in the countries of the union, and on this basis in Iraq the foregoing was the establishment of the Federal Supreme Court, which was granted by the constitution judicial and political competencies in order to exercise its role in preserving the union and the balance of powers within it while preserving the constitution and safeguarding its principles.

Commodities trade, river transport and colonialism: The Brahmaputra river valley in the nineteenth century

The article seeks to show how Assam’s riverine environment, and its natural resources, generated and inflected a process of commercialisation in the nineteenth century. Historically, present-day Assam was connected to the rest of the world through the Brahmaputra river and its tributaries. In the early decades of colonial rule, plants such as caoutchouc and tea were discovered in the valley. These developments, together with transportation networks built with state and private capital, heralded a new phase of commerce in the region. A rich scholarship in South Asian history has shown how the river played a crucial role in the economic changes in different regions. The article belongs in that scholarship but stresses the role of the river as an artery of transportation rather than as an agricultural resource. The river system facilitated Assam’s closer integration with the world economy and the colonial regime.

The Expansion of Life

The story of life tells of relentless expansion from obscure beginnings to smother the earth in organized biochemistry. First came the prokaryotes, Bacteria and Archaea, followed some two billion years later by eukaryotic microbes. The latter pattern of organization underpins the rise of multicellular organisms, and their spectacular proliferation over the past 600 million years. There have been no fundamentally new kinds of organisms since, but the rise of mind culminating in humanity may signal a new phase in life’s history. Life has expanded in both quantity and quality, a gyre of mounting size, complexity, and functional capacity; in some elusive sense evolution is progressive. Multicellularity, the key invention, is not singular but happened multiple times in several eukaryotic lineages. The proliferation of higher organisms was probably enabled by increased energy flow, and dependent on the increase in atmospheric oxygen. It is studded with innovations in structure, physiology, and behavior, whose origin is a recurrent theme in evolutionary biology. Novelty is rooted in mutational events at the gene level, supplemented by the acquisition of genes from the outside by both gene transfer and symbiosis, and possibly by other avenues. Chance events were scrutinized and culled by natural selection. There appears to be no intrinsic progressive drive, but natural selection generally favors the more functional and better organized.

Drug-Induced Phase Separation in Polyelectrolyte Microgels

Polyelectrolyte microgels may undergo volume phase transition upon loading and the release of amphiphilic molecules, a process important in drug delivery. The new phase is “born” in the outermost gel layers, whereby it grows inward as a shell with a sharp boundary to the “mother” phase (core). The swelling and collapse transitions have previously been studied with microgels in large solution volumes, where they go to completion. Our hypothesis is that the boundary between core and shell is stabilized by thermodynamic factors, and thus that collapsed and swollen phases should be able to also coexist at equilibrium. We investigated the interaction between sodium polyacrylate (PA) microgel networks (diameter: 400–850 µm) and the amphiphilic drug amitriptyline hydrochloride (AMT) in the presence of NaCl/phosphate buffer of ionic strength (I) 10 and 155 mM. We used a specially constructed microscopy cell and micromanipulators to study the size and internal morphology of single microgels equilibrated in small liquid volumes of AMT solution. To probe the distribution of AMT micelles we used the fluorescent probe rhodamine B. The amount of AMT in the microgel was determined by a spectrophotometric technique. In separate experiments we studied the binding of AMT and the distribution between different microgels in a suspension. We found that collapsed, AMT-rich, and swollen AMT-lean phases coexisted in equilibrium or as long-lived metastable states at intermediate drug loading levels. In single microgels at I = 10 mM, the collapsed phase formed after loading deviated from the core-shell configuration by forming either discrete domains near the gel boundary or a calotte shaped domain. At I = 155 mM, single microgels, initially fully collapsed, displayed a swollen shell and a collapsed core after partial release of the AMT load. Suspensions displayed a bimodal distribution of swollen and collapsed microgels. The results support the hypothesis that the boundary between collapsed and swollen phases in the same microgel is stabilized by thermodynamic factors.