Bubble Burst Research Articles

EXPRESS: Can Experience with International Alliances Help Firms Navigate Jolts? a Study of Resilience Amidst the Dot-Com Bubble Burst

EXPRESS: Can Experience with International Alliances Help Firms Navigate Jolts? a Study of Resilience Amidst the Dot-Com Bubble Burst

Artificial intelligence as a core of the new industrial revolution: prospects and limitations

The purpose of the article is to define prospects and limitations of artificial intelligence as a core of in the new industrial revolution. The definition of the concept of AI in the scientific community remains the subject of heated debate. At the same time, in the regulatory and legal plane, a trend is being formed towards unification of the concept of AI. Based on the analysis conducted and literary sources, the following prospects for AI can be identified on theoretical and practical levels. On theoretical level: (1) alienation of tacit knowledge from the individual (employee and entrepreneur); (2) optimization of the planning system; (3) revision of the socialist-calculation debate; (4) decreasing information asymmetry. On practical level: (1) formation of new products and markets; (2) increasing labor and capital productivity; (3) massive creation of new jobs; (4) optimization of business processes; (5) opportunity for rapid growth for small businesses and startups. Limitations: (1) long-term structural unemployment; (2) inflated expectations from AI and, as a consequence, the possible formation of a speculative bubble in the global stock market; (3) energy consumption of AI; (4) outdated pre-AI corporate culture and regulatory environment. Further improvement of AI (including the transition from AI to AGI) and the expansion of its use can make a significant contribution to solving problems related to economic calculation and minimizing information asymmetry, and therefore optimizing transaction costs in the economy. AI, certainly acting as a locally useful tool at the level of individual enterprises and organizations, causes the acceleration of attracting funds to the stock market, which can lead to the formation of a bubble on global level. If this bubble bursts, expectations about the economic efficiency of AI will be revised, and some AI-related companies will experience significant margin reductions (perhaps losses and bankruptcies). But this, in turn, will initiate the next stage of AI development, will accelerate its transition from the current narrow specialization to the creation of full-fledged general artificial intelligence (artificial general intelligence), which has a greater potential to change the economy at all levels. As a result, AI will become established as the core of the new industrial revolution.

Comparative Analysis Between Japan's Real Estate Economy and China's Real Estate Status

Japan's real estate bubble economy in the 1990s caused a major blow to the Japanese economy, Japan entered the "disappearing 30 years". The causes of Japan's real estate bubble economy and the reasons why the bubble burst are worthy of the world's countries to learn from. 21st century since the rapid development of China's real estate economy, housing prices are growing rapidly. The real estate economy has been overheated in some areas, although the Chinese government has taken relevant measures to cool down, still can't relax the vigilance, people should always pay attention to the overheated areas of real estate prices, land prices. Through the comparison between China and Japan, although the economic structure and development trend are similar when the property overheating phenomenon occurs, the economic development background and international background between the two countries are different, and the governments of the two countries have adopted different strategies to deal with the property overheating phenomenon. So in conclusion, although there are some areas in China where real estate is overheating, China's real estate market will not burst the bubble. In order to prevent China's real estate bubble from bursting and its impact on economic development, China should pay attention to the reasons behind it and make targeted policy adjustments, while also drawing on the lessons learned from other countries to promote the healthy and stable development of the real estate economy.

Analysis of Japan's Real Estate Regulatory Policies and Their Effects

The development of real estate is closely related to China's national economy, and in recent years, China's real estate industry has experienced rapid development and change. With the continuous expansion of the industry's development scale and the increasingly complex market environment, the real estate industry is also facing a series of challenges and problems. Japan also faced the bursting of its real estate bubble in the 1990s. Reviewing the history of the bursting of the real estate bubble in Japan in the 1990s has important research and mirror value for us to clarify the formation and bursting of real estate risks and how to implement appropriate policies. This study analyzes the negative and positive impacts of policies implemented before the bursting of the real estate bubble, and the policies introduced by the Japanese government to address the bursting of the real estate bubble. Based on the results of the analysis of Japan real estate, suggestions are made on the idea of regulating China's real estate industry, the means of regulation and the rhythm of regulation.

Validated Dynamic Stall Simulation of Pitching Low Reynolds Number Airfoils

Deep dynamic stall is one of several complex behaviors that result in extreme variation of the aerodynamic loads on small wind turbine (SWT) blades during unsteady wind conditions. In this study, unsteady Reynolds-averaged Navier–Stokes simulations are performed for two low Reynolds number (Re) airfoils where sinusoidal pitching is applied to replicate the dynamic stall that occurs on rotating SWT blades. The SD 7037 airfoil is simulated at Re=4.1×104 and a pitching reduced frequency of k=0.08, and the S833 airfoil is at Re=1.7×105 and k=0.06. The simulated lift coefficient and dynamic stall timing agree with experimental data, which is attributed to the wall-normal resolution of the mesh and is an advancement from the early prediction of stall seen consistently in previous numerical studies. The accurate prediction of dynamic stall is found to be dependent on the correct simulation of the bursting of the laminar separation bubble (LSB), which initiates the complete separation of the boundary layer and the formation of a leading-edge vortex. The γ−Reθ,t k−ω model combined with the use of a fine mesh at the airfoil leading edge results in an accurate simulation of the bursting LSB and the correct prediction of the deep dynamic stall.

Caring for uncommon bodies: Commoning yoseba through indifferent care and working together

ABSTRACT This study examines the emergence of care as a commoning practice within grassroots movements by focusing on Sōgidan, an activist group supporting rough sleepers in San’ya, Tokyo. San’ya is yoseba (day labor auction market), a historical urban margin turning into a service hub. Produced as cheap, disposable labor in the process of Japanese modernization, Japan’s day laborers were enclaved in yoseba and left without social protection after the economic bubble burst. However, they were not merely victims; they embodied a rebellious subjectivity, actively breaking away from the oppressive society. Despite welfare provisions after the 2000s, many day laborers refused aid and continued to sleep on the streets. Through extensive archival research, ethnographic observation, and in-depth interviews, this paper illuminates how Sōgidan has developed strategies of care to relate to the underclass, the historical others who refuse aid. Sōgidan embodies and carries forward the underclass movement, which uniquely echoed feminist ethics of care. It also initiates the creation of the radical commons, reconfiguring the distance between individuals and collectives, and sharing precariousness differently from capitalist norms. By linking Sōgidan’s practices to feminist ethics of care, this research contributes to opening up new perspectives of care and in(ter)dependence toward the commons.

Scaling-Free Cathodes: Enabling Electrochemical Extraction of High-Purity Nano-CaCO3 and -Mg(OH)2 in Seawater.

For electrochemical application in seawater or brine, continuous scaling on cathodes will form insulation layers, making it nearly impossible to run an electrochemical reaction continuously. Herein, we report our discovery that a cathode consisting of conical nanobundle arrays with hydrophobic surfaces exhibits a unique scaling-free function. The hydrophobic surfaces will be covered with microbubbles created by electrolytic water splitting, which limits scale crystals from standing only on nanotips of conical nanobundles, and the bursting of large bubbles formed by the accumulation of microbubbles will cause a violent disturbance, removing scale crystals automatically from nanotips. Benefiting from the scaling-free properties of the cathode, high-purity nano-CaCO3 (98.9%) and nano-Mg(OH)2 (99.5%) were extracted from seawater. This novel scaling-free cathode is expected to eliminate the inherent limitations of electrochemical technology and open up a new route to seawater mining.

Modeling non-monotonic variation of plume angle with superheat index of flash boiling spray

There is an urgent need for modeling angles and widths of liquid jet with internal phase change, but existing semi-empirical models rely strongly on coefficient fitting and lack a thorough understanding of the additional phase-change physics. In the present work, we proposed a theoretical model to predict the non-monotonic variation of plume angle with the defined superheat index of flash boiling spray. Assuming that the plume angle is determined by the trajectories of tiny droplets in the perimeter of the spray, this model identifies the angle with the inverse tangent of the ratio of the streamwise and crosswise velocities of the tiny droplets. The streamwise velocity is determined by solving a one-dimensional two-phase flow within the channel, and the crosswise velocity is determined by modeling the burst of an equivalent bubble at the exit of the nozzle. Compared with the existing semi-empirical models, this model is free of fitting parameters, and it agrees well with the experimental data from a rectangular microchannel with discrepancies being sufficiently discussed. This model has the potential of being applied to modeling the plume angle of flash boiling sprays with different nozzle geometries in various atomization practices.

Analysis of the Potential Economic Bubble Burst in Indonesia (Case Study on Start-Up Companies)

Analysis of the Potential Economic Bubble Burst in Indonesia (Case Study on Start-Up Companies)

Multiple boundary layer suction slots technique for performance improvement of vertical-axis wind turbines: Conceptual design and parametric analysis

Vertical-axis wind turbines (VAWTs) are gaining attention for urban and offshore applications. However, their development is hindered by suboptimal power performance, primarily attributable to the complex aerodynamic characteristics of the blades. Flow control techniques are expected to regulate the flow on the blade surface and improve blade aerodynamics. In the present study, an effective active flow control technique, multiple boundary layer suction slots (MBLSS), is designed for VAWTs performance improvement. The impact of MBLSS on the aerodynamic performance of VAWTs is examined using high-fidelity computational fluid dynamics simulations. The response surface methodology is employed to identify the relatively optimal configuration of MBLSS. Three key parameters are considered, i.e., number of slots (n), distance between slots (d), and slot length (l), which vary from 2 to 4, 0.025c to 0.125c, and 0.025c to 0.075c, respectively. The results show that MBLSS positively affects the power performance and aerodynamics of VAWTs. Parameter n has the most significant effect on VAWT power performance and the importance of d and l is determined by tip speed ratios (TSRs). Tight and loose slot arrangements are recommended for high and low TSRs, respectively. The relatively optimal configuration (n = 2, d = 0.025c, l = 0.05c) results in a remarkable 31.02% increase in the average net power output of the studied TSRs. The flow control mechanism of MBLSS for VAWT blade boundary layer flow has also been further complemented. MBLSS can prevent the bursting of laminar separation bubbles and avoid the formation of dynamic stall vortices. This increases the blade lift-to-drag ratio and mitigates aerodynamic load fluctuations. The wake profiles of VAWTs with MBLSS are also investigated. This study would add value to the application of active flow control techniques for VAWTs.

Bubble ascent and rupture in mud volcanoes.

Large gas bubbles can reach the surface of pools of mud and lava where they burst, often through the formation and expansion of circular holes. Bursting bubbles release volatiles and generate spatter, and hence play a key role in volcanic degassing and volcanic edifice construction. Here, we study the ascent and rupture of bubbles using a combination of field observations at Pâclele Mici (Romania), laboratory experiments with mud from the Imperial Valley (California, USA), numerical simulations and theoretical models. Numerical simulations predict that bubbles ascend through the mud as elliptical caps that develop a dimple at the apex as they impinge on the free surface. We documented the rupture of bubbles in nature and under laboratory conditions using high-speed video. The bursting of mud bubbles starts with the nucleation of multiple holes, which form at a near-constant rate and in quick succession. The quasi-circular holes rapidly grow and coalesce, and the sheet evolves towards a filamentous structure that finally falls back into the mud pool, sometimes breaking up into droplets. The rate of expansion of holes in the sheet can be explained by a generalization of the Taylor-Culick theory, which is shown to hold independent of the fluid rheology.

Zombie lending, labor hoarding, and local industry growth

After the bursting of real estate bubbles in 1991, Japanese banks continued lending to unviable firms to conceal problem loans. We revisit Japan’s experience and propose a new mechanism via which banks’ loan-evergreening policy undermines allocative efficiency across industries by focusing on construction and real estate loans. Namely, banks’ continuing support for construction and real estate firms encourages labor hoarding in unviable construction projects. Since construction projects predominantly use low-skilled workers, banks’ loan-evergreening policy in these troubled sectors may depress other low-skilled industries. Based on the industry-level data in each of Japan’s 47 prefectures from 1992 to 1996, we document empirical facts consistent with this hypothesis. On average, low-skilled industries experienced disproportionately slower output and employment growth and more sluggish growth in the number of new establishments in prefectures where the share of bank loans to local construction/real estate sectors increased more after construction boom ended.

Direct measurements of sea spray particle fluxes using a high temporal resolution optical particle counter over the coastal ocean

ABSTRACT Sea spray particles play a key role in transferring momentum, heat, and gas across the atmosphere–ocean interface at high wind speeds and represent an important source of cloud condensation nuclei which affect the genesis, chemistry, and radiative properties of marine clouds. Here, we present direct measurements of sea spray particle fluxes obtained using an eddy covariance technique through the use of a newly developed high temporal resolution optical particle counter. With this instrumentation measurements were made over the coastal ocean during a 5-week field campaign conducted at an observation pier from November to December 2021. Our optical particle counter was capable of measuring size spectra at a rate of 10 Hz in 8 channels covering a range of mean radii between 0.3 and 15. The power spectra of particle number density followed the Kolmogorov −2/3 power law. The shape of the cospectrum of the particle number density flux was basically similar to that of the cospectra of the heat and gas fluxes. The measured sea spray particle fluxes at mean wind speeds of up to 21 m s−1 were dominated by an upward flux, which likely represents aerosol production caused by the bursting of bubbles at the ocean surface.

Barricades against Evictions: Coexistence of Short- and Long-term Frames in the Housing Movement on Facebook and Twitter

Social movements fight to change society’s roots and challenge entrenched cultural frameworks. At the same time, however, they must attend to everyday activism and protests that constitute a clear and pragmatic mobilization goal. This article analyzes the case of a movement for decent housing on social media called Platform for Those Affected by Mortgages (PAH). This organization fights to guarantee universal access to housing, a recurrent problem in large cities. It grew in 2010 when the subprime mortgage crisis broke out in the United States. The bursting of the real estate bubble built up at that time had a global impact, pushing other markets. On the one hand, the movement has to change entrenched cognitive frameworks that say property must be bought and its loss is the individual’s responsibility. On the other hand, it must coordinate and try to gather as many people as possible to stop the evictions that occur every day. Twitter seems crucial for daily mobilization in this double logic, while Facebook allows for more complex narratives. The methodology used was a framing analysis of the content published on the organization’s official Facebook and Twitter accounts. Although these should be understood as overlapping layers, the movement is often trapped in a narrative that it does not want. By highlighting specific cases, it leads to an understanding that access to housing does not affect most of society.

A Study on the Asset Management and Taxation Types of the Rich in Japan

The Japanese economy is facing a new phase from a long-term recession over the past 30 years to an annual economic growth of around 2%. With the recovery of the Japanese economy, not only foreigners but also Japanese capital are returning to Japan. Already, the Japanese Composite Stock Price Index has exceeded 39000 points before the bubble burst. Changes in the yen exchange rate are also inducing the inflow of foreign capital into Japan. In this economic trend, investors are paying attention to the Japanese capital market, and in particular, the wealthy in Japan are focusing on the Japanese domestic market to increase their assets. In particular, the Japanese financial market is attracting attention as a relatively safe asset due to the unstable environment at home and abroad. According to this trend, asset management of the wealthy in Japan is also carried out in various ways. Sometimes there are considerable losses due to asset management failures. That is why it has emerged recently to use various tax savings. Companies and individuals show the same behavior. On the contrary, the government sometimes strengthens monitoring in various ways to prevent a decrease in tax revenue. This phenomenon has recently become common in Japan.

The loose monetary policy and the housing bubble

This research paper explores whether loose monetary policy has led to a real estate bubble. The background section of the study introduces the current impact of monetary policy on the real estate market and the importance of the formation and bursting of real estate bubbles. The significance of this research lies in understanding the mechanism by which monetary policy affects the formation of real estate bubbles and providing references for relevant policy formulation.

The crypto-market bubble burst: identifying the risk factors that prohibit cryptocurrency investments

The crypto-market bubble burst: identifying the risk factors that prohibit cryptocurrency investments

Splashing and sealing of an ejecta sheet induced by a cavitation bubble close to a water surface

An ejecta sheet is commonly formed when a cavitation bubble bursts into the air, creating an open cavity. The evolution of the sheet has been studied independently, with limited focus on the interaction between the ejecta sheet and the cavity. This study offers insights into the splashing and sealing of a laser-induced ejecta sheet. An object-distance compensation method is developed to capture clear images of the phenomena both above and below the water surface simultaneously. The ejecta sheet exhibits two patterns: an open splash and a sealed splash. In the case of an open splash, the cavity seals quasistatically, whereas in the case of a sealed splash, the cavity type transitions from shallow sealing to surface sealing as the dimensionless standoff distance γ increases. An axisymmetric model is proposed for analyzing how the ejecta sheet evolves during the sealing process. Since the sealing process is dominated by suction pressure resulting from rapid expansion of the cavity, we obtain the cross-sectional area As of the ejecta sheet as a function of the rates of change of the bubble volume (V̇b) and the sheet cross-sectional area (Ȧinn), and this function is shown to be independent of time. Remarkably, as γ increases, As decreases and increases in the regimes of shallow sealing and surface sealing, respectively. This tendency is induced by the significant difference in V̇b due to the initial state of the cavity. Our findings offer a new understanding of the dynamics of laser-induced ejecta sheets.

Microfluidic controllable production and morphology-independent phase-change heat transfer of boehmite nanofluids

Enhanced boiling heat transfer through nanofluids represents a significant approach to improving the cooling performance of electronic devices. However, the preparation of nanofluids poses challenges regarding production efficiency, morphology control, and structural stability. In addition, the underlying mechanism of flow boiling heat transfer enhancement of nanofluids, particularly changes in vapor behavior, remains a limited understanding. This study presents a facile and straightforward microfluidic strategy for the controllable synthesis of nanofluids toward efficient heat transfer enhancement. The microfluidic flow synthesis approach effectively enhances mixing efficiency at various flow rates, enabling continuous and high-throughput synthesis of boehmite nanofluids with different morphologies. The synthesized nanofluids exhibit long-term stability (>50 days) at room temperature. Both rod- and sphere-shaped nanofluids under equivalent concentrations can significantly improve critical heat flux (CHF) and maximum heat transfer coefficient (HTC) across various operating parameters, but with similar enhancement characteristics. Analysis of the period of bubble growth and burst, bubble size distributions, number of bubbles, and vapor phase fractions reveals that rod- and sphere-shaped nanofluids could shorten the period, enhance surface wetting, increase nucleation sites, and reduce bubble size efficiently and similarly. Furthermore, the effect of the concentration of nanofluid on phase-change heat transfer performance is systematically explored. 0.01 wt% nanofluid behaves the most remarkable enhancement, CHF and maximum HTC are improved by 24 % and 14.4 %, respectively. These findings not only shed new light on the controllable synthesis of functional nanomaterials but also provide important guidelines for the rational design of nanofluids for efficient two-phase cooling of electronic devices.

Empirical Distribution of the U.S. Housing Market during the Great Recession: Nonlinear Scaling Behavior after a Major Crash

This study focuses on the real estate bubble burst in the US housing market during 2007–2008. We analyze the dynamics of the housing market crash and the after-crash sequence during the Great Recession. When a complex system deviates away from its typical path by the occurrence of an extreme event, its behavior is strongly characterized as nonstationary with higher volatility. With the utilization of a robust method, we present the characteristics of the aftershock period and provide useful information about the spatial distribution and the decay process of the aftershock sequence in terms of time. The returns of the housing price indices are well approximated by the empirics of a power law. Although we deal with low-frequency data, a time power-law relaxation pattern is identified. Our findings align with those in geophysics, indicating that the value of the relaxation parameter typically hovers around one and varies across different thresholds.