Extreme Cases Research Articles

EFFECTS OF ENVIRONMENTAL DEGRADATION ON URBAN DEVELOPMENT IN ENUGU STATE

This study investigated the effects of environmental degradation on urban development in Enugu State. It was guided by two specific objectives and two corresponding research questions and hypotheses. The study adopted a descriptive survey design. The population comprises staff of the Nigeria Environmental Standard and Regulations Enforcement Agency (NESREA) and residents of Enugu metropolis, numbering 820,030, out of which a sample size of 400 was obtained. A self-structured 5-Likert scaled questionnaire was used for data collection. Mean statistics was used for analysing the responses to the research questions while a one-sampled t-test was used for testing the hypotheses. It was found that environmental degradation has a significant negative effect on the social infrastructure/amenities and economic activities in urban centres in Enugu State. It was specifically revealed that environmental hazards such as erosion, flood, industrial and domestic wastes in urban centres destroy residential and commercial buildings, economic crops, strain scarce finances, affect school and hospital structures and cause other social problems; that healthcare centres and personnel are likely to be affected as well, even alternative medicine sources are usually destroyed by environmental degradation and ultimately human lives are lost outright in extreme cases. The study recommended among others that in-depth mass awareness should be adopted while a healthy and safe development pattern should be continually done to discourage indiscriminate housing developments that block drainages and natural waterways. Also, proper waste management mechanisms by residents should be enforced to mitigate the spate of indiscriminate refuse dumps, which often block water channels and canals.

Mixed phase anatase nanosheets/brookite nanorods TiO2 photocatalysts for enhanced gas phase CO2 photoreduction and H2 production

CO2 photoreduction and H2 photocatalytic production reactions have been studied on different TiO2 polymorphs (anatase and brookite) engineered with specific nanocrystal shape. Anatase TiO2 materials of nanosheet morphology and brookite TiO2 of nanorod morphology were developed via a hydrothermal synthesis process. Mixed-phase anatase/brookite TiO2 materials of the above extreme cases were also developed, controlling the phase composition. The materials were fully characterized by a variety of techniques including structural, morphological, textural and electronic properties characterization. N2 physisorption analysis and CO2 adsorption isotherms have shown that minimum amount of brookite phase (i.e. ca. 7 wt%) in the final material improved the textural properties and the CO2 uptake ability. Electron paramagnetic spectroscopy (EPR) provided evidences for improvements in the formation and availability of photogenerated electrons in the mixed-phase materials. CO2 photoreduction was increased by ca. 220% in the optimized mixed-phase anatase/brookite TiO2. Photocatalytic H2 production rates were also improved by ca. 140%. The results in the present study have shown that the TiO2 phase as well as the amount of each TiO2 polymorph plays vital role in photocatalytic efficiency and that the photocatalytic improvement depends greatly on the specific reactions. The new insights provided herein would be of interest for studied focusing on materials shape engineering and phase composition and their effect on activity.

Use of a novel magnetically actuated compression system to study the temporal dynamics of axial and lateral strain in human osteochondral plugs

The high water content of articular cartilage allows this biphasic tissue to withstand large compressive loads through fluid pressurization. The system presented here, termed the “MagnaSquish”, provides new capabilities for quantifying the effect of rehydration on cartilage behavior during cyclic loading. An imbalanced rate of fluid exudation during load and fluid re-entry during recovery can lead to the accumulation of strain during successive loading cycles - a phenomenon known as ratcheting. Typical experimental systems for cartilage biomechanics use continuous contact between the platen and sample, which may affect tissue rehydration by compressing the top layer of cartilage and slowing fluid re-entry. To address this limitation, we developed a magnetically actuated device that provides full lift-off of the platen in between loading cycles. We investigated strain accumulation in cadaveric human osteochondral plugs during 750 loading cycles, with two dimensional profiles of the cartilage captured at 30 frames per second throughout loading and 10 min of additional free swelling recovery. Axial and lateral strain measurements were extracted from the tissue profiles using a UNet-based deep learning algorithm to circumvent manual tracing. We observed increased axial strain accumulation with shorter inter-cycle recovery, with static loading serving as the extreme case of zero recovery. The loading waveform during the 750 cycles dictated the pace of the recovery during the extended free swelling period, as shorter inter-cycle recovery led to more persistent axial strain accumulation for up to five minutes. This work showcases the importance of fluid re-entry in resisting strain accumulation during cyclical compression.

Page curves for accelerating black holes

The island paradigm for the fine-grained entropy of Hawking radiation is applied to eternal charged accelerating black holes. In the absence of the island, the entanglement entropy grows linearly and divergent at late times, while once the island outside the event horizon is taken into account, the unitary Page curve is reproduced naturally. The impact of the charge and the acceleration on Page curves is investigated at late times. For the Page time and the scrambling time, they both increase as the acceleration increases, while decreasing as the charge increases. In particular, neutral black holes have the largest Page time and scrambling time. It is worth noting that the Page time and the scrambling time is divergent at the extremal case, which implies that islands may be related to the causal structure of spacetime.

Design and Development of RF Window for Gyro-TWT

In this paper, the electrical design of an RF quartz window for a Ka-band Gyro-TWT amplifier has been carried out using CST microwave studio. The return loss (S11) and insertion loss (S12) of the RF quartz window have been −35.3 dB and −0.02 dB, respectively. The thermal design of the RF quartz window for Gyro-TWT during extreme cases of operation, i.e. at saturation has been carried out using ANSYS software and as discussed in the paper. The temperature 368 K on the disc of the RF window for Gyro-TWT has been obtained. The RF quartz window for the Ka-band Gyro-TWT amplifier has been developed. The cold characterization of the RF quartz window for the Ka-band Gyro-TWT amplifier has also been carried out using a Vector Network Analyzer. A good agreement between simulation and measurement has been obtained.

Estimating Geomagnetically Induced Currents in High‐Voltage Power Lines for the Territory of Kazakhstan

AbstractExtreme solar events, such as powerful solar flares are accompanied by the release of strong solar disturbances, such as coronal mass ejections (CMEs). The impact of CMEs on the Earth's magnetosphere causes geomagnetic storms, which trigger geomagnetic effects measurable in the ionosphere, upper atmosphere, and on and in the ground. During extreme cases, rapidly changing geomagnetic fields generate intense geomagnetically induced currents (GICs), which can cause dramatic effects on man‐made technological systems, including transmission lines and pipelines. In countries with large territories such as Kazakhstan, long power lines contribute to high values of induced currents during periods of extreme geoeffective solar events. It is of interest to estimate the values of GICs in an extensive network of power lines on the territory of Kazakhstan. However, there are no estimations of induced currents in power lines in Kazakhstan, and most estimation techniques are made difficult because of absence of field measurements of Earth conductivity. This study aims to model geoelectric fields on the surface of the Earth for Kazakhstan and to estimate the values of the GICs in 500 kV power lines. This study also compares between two methods for calculating induced voltages in power lines: one based on linear paths and the other based on curvilinear paths between substations of transmission power lines.

Insights into the copper HiPIMS discharge: deposition rate and ionised flux fraction

The influence of pulse length, working gas pressure, and peak discharge current density on the deposition rate and ionised flux fraction in high power impulse magnetron sputtering discharges of copper is investigated experimentally using a charge-selective (electrically biasable) magnetically shielded quartz crystal microbalance (or ionmeter). The large explored parameter space covers both common process conditions and extreme cases. The measured ionised flux fraction for copper is found to be in the range from ≈10% to 80%, and to increase with increasing peak discharge current density up to a maximum at , before abruptly falling off at even higher current density values. Low working gas pressure is shown to be beneficial in terms of both ionised flux fraction and deposition rate fraction. For example, decreasing the working gas pressure from 1.0 Pa to 0.5 Pa leads on average to an increase of the ionised flux fraction by percentage points (pp) and of the deposition rate fraction by taking into account all the investigated pulse lengths.

Estimation of Spatial Snowpack Properties in a Snow-Avalanche Release Area: An Extreme Case on Mt. Nodanishoji, Japan, in 2021

An extreme dry-slab snow avalanche occurred on January 10, 2021, at Mt. Nodanishoji, Gifu, Japan, during a heavy snowfall. The avalanche ran down a horizontal distance of approximately 2,800 m and damaged trees and infrastructures. This was estimated to be the second largest recorded avalanche in Japan. However, physical snowpack properties and their vertical profiles and spatial distribution, which caused the avalanche, were not addressed in the release area immediately following the avalanche, mainly due to unsafe and lousy weather conditions. Based on a snow depth distribution observed by an unmanned aerial vehicle and a numerical snowpack simulation in the avalanche release area, the spatial distributions of the mechanical snowpack stability and slab mass and their temporal evolution were estimated in this study. The procedure was validated by comparing the calculation results with the observed snowpit and spatial snow depth data. The results indicated that two heavy snowfall events, approximately 3 and 10 days before the avalanche onset, generated two different weak layers made of precipitation particles and associated slabs above the weak layers. The older weak layer was only generated on the northward slope due to its low temperature, whereas the newer layer was predominant over the avalanche release area. The procedure employed in this study is expected to be applied to other avalanche cases in the future.

Supernova Remnants in the Irregular Galaxy NGC 4449

The nearby irregular galaxy NGC 4449 has a star formation rate of ∼0.4M ☉ yr−1 and should host of order 70 supernova remnants (SNRs) younger than 20,000 yr, a typical age for SNRs expanding into an interstellar medium (ISM) with a density of 1 cm−3 to reach the radiative phase. We have carried out an optical imaging and spectroscopic survey in an attempt to identify these SNRs. This task is challenging because diffuse gas with elevated ratios of [S ii]:Hα is omnipresent in NGC 4449, causing confusion when using this common diagnostic for SNRs. Using narrowband interference-filter images, we first identified 49 objects that have elevated [S ii]:Hα ratios compared to nearby H ii regions. Using Gemini-N and GMOS, we then obtained high-resolution spectra of 30 of these SNR candidates, 25 of which have [S ii]:Hα ratios greater than 0.5. Of these, 15 nebulae are almost certainly SNRs, based on a combination of characteristics: higher [O i]:Hα ratios and broader line widths than observed from H ii regions. The remainder are good candidates as well, but need additional confirmation. Surprisingly, despite having superior imaging and spectroscopic data sets to examine, we are unable to confirm most of the candidates suggested by Leonidaki et al. While NGC 4449 is likely an extreme case because of the high surface brightness and elevated [S ii]:Hα ratio of diffuse gas, it highlights the need for sensitive high-resolution optical spectroscopy, or high spatial resolution radio or X-ray observations that can ensure accurate SNR identifications in external galaxies.

The Dilemma of Compliance: Roles and Rules in Schizophrenia, Censorship, and Life

Abstract: The paper concerns the essential and permanent place of roles and rules in human life, or what I call ‘the dilemma of compliance.’ The paper begins with previous scholarship warning therapists and psychologists about the danger of unknowingly reinforcing violent and toxic social expectations. A distinction is drawn between conformity and compliance, with the former standing for rote and mindless following of rules, and the latter a self-conscious and flexible way of relating to rules and roles. The paper argues that following rules and filling roles is unavoidable, and, consequently, a human life is always a double-life, divided between pre-existing, generic roles, and our private and unique way of relating to those roles. The crucial difficulty is learning to comply with rules and roles rather than merely conforming to them. Two extreme cases are examined to develop this problem of rules, roles, and living a double-life: schizophrenia and censorship. It is argued that schizophrenia and censorship are cases in which the place of rules and roles become overbearing and urgent. Finally, the paper argues that attention to the dilemma of compliance highlights the significance of trauma-informed care, as trauma is often connected to how one fits or does not fit into a social milieu constituted by roles, rules, and expectations. The arguments are developed primarily in historical, philosophical, and clinical terms.

Stigma, The Horrors of the Past: How Covid-19 Shaped Our Social Story?

In December 2019, a cluster of pneumonia cases emerged in Wuhan, China, eventually linked to the discovery of a novel coronavirus. On March 11, 2020, the World Health Organization (WHO) declared COVID-19 a pandemic. This declaration triggered anxiety, fear, and depression among many people. However, the lack of knowledge and the spread of rumours about this new virus also gave rise to social stigma. Frontline healthcare workers, individuals who contracted and recovered from COVID-19, as well as migrants, were particularly affected by this social stigma. Many of them experienced heightened levels of anxiety, fear, and guilt as a result. These feelings often led to symptoms of burnout and depression, and in some extreme cases, even suicidal attempts. In this article, we delve into the various dimensions of social stigma that emerged during the COVID-19 pandemic in India as well as worldwide. Conclusion: Societies that faced stigmatization were more vulnerable and had a greater risk of COVID-19 infection. Social stigma has detrimental effects on both mental and physical health, particularly affecting younger individuals, which could potentially hinder the productivity and economic growth of future generations and the nation as a whole. Providing support, be it social, financial, or mental, to one another, plays a critical role in mitigating stigma. To fully grasp the enduring consequences of social stigma on mental health, future studies should investigate this aspect using prospective research designs.

Immediate Lymphatic Reconstruction Using a Handheld Fluorescence Imaging Device.

Immediate lymphatic reconstruction (ILR) has traditionally required a fluorescent-capable microscope to identify lymphatic channels used to create a lymphaticovenous bypass (LVB). Herein, a new alternative method is described, identifying lymphatic channels using a commercially available handheld fluorescence imaging device. This was a single-center study of consecutive patients who underwent ILR over a 1-year period at a tertiary medical center. Intradermal injection of fluorescent indocyanine green dye was performed intraoperatively after axillary or inguinal lymphadenectomy. A handheld fluorescent imaging device (SPY-PHI, Stryker) rather than a fluorescent-capable microscope was used to identify transected lymphatic channels. Data regarding preoperative, intraoperative, and outcome variables were collected and analyzed. The handheld fluorescent imaging device was successfully able to identify transected lymphatic channels in all cases (n = 15). A nonfluorescent-capable microscope was used to construct the LVB in 14 cases. Loupes were used in one case. In 13 cases, ILR was unilateral. In two cases, bilateral ILR was performed in the lower extremities. All upper extremity cases were secondary to breast cancer (n = 7). Lower extremity cases (n = 8) included extramammary Paget disease of the penis, ovarian cancer, vulvar squamous cell carcinoma, squamous cell carcinoma of unknown origin, soft tissue sarcomas, cutaneous melanoma, and porocarcinoma. ILR, using indocyanine green injection with a handheld fluorescent imaging device, is both safe and effective. This method for intraoperative identification of lymphatic channels was successful, and LVB creation was completed in all cases. This approach makes ILR feasible when a fluorescent-capable microscope is unavailable, broadening access to more patients.

Rapid detection of landslides mechanisms and assessment of their geometry and dimensions by means of a drone survey (UAV) after the 2023 Turkey-Syria earthquake

The 2023 Turkey-Syria earthquakes (Mw=7.7 and Mw=7.6, respectively) had serious impact on human lives, infrastructure and buildings. Unfortunately, more than 15 million people have been affected and current estimation of financial loss exceeds 35 billion dollars. Furthermore, more than 550 Mw>4 aftershocks have been recorded since the catastrophic events of February 6th 2023. Such emergency situations require rapid actions for assessing the failure mechanism and scale of problematic landslides since immediate decisions should be taken in most extreme cases. Recent advances in technology allows the application of relatively simple methods for such emergency engineering estimation – a good example is the use of drones (UAV) which are easily available on market nowadays. Drone videos allow the subsequent measurement of important parameters of landslides, such as length, width, depth, failure plane inclination and volume of displaced soil. The presented paper demonstrates three case studies which are based on drone video recordings: two landslides (Islahiye and Tepehan, respectively) and a rockfall (Idili).

J0107a: A Barred Spiral Dusty Star-forming Galaxy at z = 2.467

Dusty star-forming galaxies (DSFGs) are among the most massive and active star-forming galaxies during the cosmic noon. Theoretical studies have proposed various formation mechanisms of DSFGs, including major merger-driven starbursts and secular star-forming disks. Here, we report J0107a, a bright (∼8 mJy at observed-frame 888 μm) DSFG at z = 2.467 that appears to be a gas-rich massive disk and might be an extreme case of the secular disk scenario. J0107a has a stellar mass M ⋆ ∼ 5 × 1011 M ⊙, molecular gas mass M mol ≳ 1011 M ⊙, and a star formation rate of ∼500M ⊙ yr−1. J0107a does not have a gas-rich companion. The rest-frame 1.28 μm JWST NIRCam image of J0107a shows a grand-design spiral with a prominent stellar bar extending ∼15 kpc. The Atacama Large Millimeter/submillimeter Array Band 7 continuum map reveals that the dust emission originates from both the central starburst and the stellar bar. 3D disk modeling of the CO(4–3) emission line indicates a dynamically cold disk with rotation-to-dispersion ratio . The results suggest a bright DSFG may have a nonmerger origin, and its vigorous star formation may be triggered by the bar and/or rapid gas inflow.

Heterogeneous GNN-RL-Based Task Offloading for UAV-Aided Smart Agriculture

Having unmanned aerial vehicles (UAVs) with edge computing capability hover over smart farmlands supports Internet of Things (IoT) devices with low processing capacity and power to accomplish their deadline-sensitive tasks efficiently and economically. In this work, we propose a graph neural network-based reinforcement learning solution to optimize the task offloading from these IoT devices to the UAVs. We conduct evaluations to show that our approach reduces task deadline violations while also increasing the mission time of the UAVs by optimizing their battery usage. Moreover, the proposed solution has increased robustness to network topology changes and is able to adapt to extreme cases, such as the failure of a UAV.

Coverage Increase at THz Frequencies: A Cooperative Rate-Splitting Approach

Numerous studies claim that terahertz (THz) communication will be an essential piece of sixth-generation wireless communication systems. Its promising potential also comes with major challenges, in particular the reduced coverage due to harsh propagation loss, hardware constraints, and blockage vulnerability. To increase the coverage of THz communication, we revisit cooperative communication. We propose a new type of cooperative rate-splitting (CRS) called extraction-based CRS (eCRS). Furthermore, we explore two extreme cases of eCRS, namely, identical eCRS and distinct eCRS. To enable the proposed eCRS framework, we design a novel THz cooperative channel model by considering unique characteristics of THz communication. Through mathematical derivations and convex optimization techniques considering the THz cooperative channel model, we derive local optimal solutions for the two cases of eCRS and a global optimal closed form solution for a specific scenario. Finally, we propose a novel channel estimation technique that not only specifies the channel value, but also the time delay of the channel from each cooperating user equipment to fully utilize the THz cooperative channel. In simulation results, we verify the validity of the two cases of our proposed framework and channel estimation technique.

Uncovering Hidden Massive Black Hole Companions with Tidal Disruption Events

Dynamical perturbations from supermassive black hole (SMBH) binaries can increase the rates of tidal disruption events (TDEs). However, most previous work focuses on TDEs from the heavier black hole in the SMBH binary (SMBHB) system. In this work, we focus on the lighter black holes in SMBHB systems and show that they can experience a similarly dramatic increase in their TDE rate due to perturbations from a more massive companion. While the increase in TDEs around the more massive black hole is mostly due to chaotic orbital perturbations, we find that, around the smaller black hole, the eccentric Kozai–Lidov mechanism is dominant and capable of producing a comparably large number of TDEs. In this scenario, the mass derived from the light curve and spectra of TDEs caused by the lighter SMBH companion is expected to be significantly smaller than the SMBH mass estimated from galaxy scaling relations, which are dominated by the more massive companion. This apparent inconsistency can help find SMBHB candidates that are not currently accreting as active galactic nuclei and that are at separations too small for them to be resolved as two distinct sources. In the most extreme cases, these TDEs provide us with the exciting opportunity to study SMBHBs in galaxies where the primary SMBH is too massive to disrupt Sun-like stars.

The Initiatives for Enforcing the Quality Assurance Standards in Fostering Universities’ Compliance in Tanzania

The world university system currently emphasizes strict compliance with established quality assurance standards for enhancing graduates' quality and academic capabilities. In that vein, compliance with university quality assurance standards across the globe requires critical consideration of the adequate and correct application of initiatives for enforcing such standards. Similar to other countries, Tanzania has some initiatives for enforcing its universities’ quality assurance standards. Despite the application of such initiatives, the country is witnessing low to extreme non-compliance cases each year. This study examined the application of initiatives for enforcing quality assurance standards in fostering universities' compliance in Tanzania. It was informed by the qualitative approach and adopting a case study design. Interviews, documentary analysis, and focus group discussion were data collection methods applied in the four universities involving 46 respondents that were purposively chosen. The data analysis was done through a content analysis approach. The analysis revealed that both technical and administrative enforcement initiatives were found to be applied in universities. The technical initiatives are monitoring and evaluation for teaching, examination moderation and strict invigilation, independent examination, self-assessment and academic audits, and accreditation, while administrative ones are improving quality assurance staff motivation and capacity, promoting quality assurance stakeholders’ involvement, and establishing an effective quality assurance leadership system. In applying such initiatives, the deficiencies (i.e., incorrect and inadequate applications), strengths, differences and similarities were found across the involved universities. Besides, very unsatisfactory applications of enforcement initiatives were found in private universities compared to public ones. Due to such unsatisfactory applications, non-compliance cases at various university stakeholders' levels exist in those universities. This study concludes that the existing university non-compliance cases in Tanzania are attributed to the existing inadequate and incorrect application of enforcement initiatives. It recommends that there is a need for the Tanzania Commission for Universities to issue more detailed guidelines to harmonize the application of some enforcement initiatives that have attracted different application practices across universities. Besides, the Tanzania Commission for Universities and university quality assurance agencies must take the strongest punitive measures against non-complying individuals and universities to discourage such behavior.

Hausdorff dimension method reduces the error of box counting

The Hausdorff dimension of an object is a topological measure of the size of its covering properties. To compute the Hausdorff dimension of an object, this report reviews the method of box counting, a method of gathering data for analyzing complex patterns by breaking a dataset, object, image, etc. into smaller and smaller pieces, typically "box"-shaped, and analyzing the pieces at each smaller scale. However, in this process, errors are always generated because of the extreme cases in which boxes are just covered with a small corner of the pattern but still should be counted. As a result, the number of boxes counted becomes larger than usual resulting in inaccurate results. In order to reduce the error in the final result, this report applies an improvement to this method to reduce the errors in the result and provides the example of Koch snowflake, and also examines the effect of the improvement.

Multi‐Level Governance Feedback and Health Care in Italy in the Aftermath of Covid‐19

At the crossroads of EU studies and public policy analysis, a vast literature identifies global crises as one of the main triggers of change. The present article provides a test of this hypothesis in the case of health care in the aftermath of the pandemic crisis that hit Europe between 2020 and 2022. We use Italy as an extreme case, where both the magnitude of the Covid-19 outbreak and the effect of the pre-existent domestic cost-cutting strategy potentially opened a large window of opportunity for change. Through the lenses of historical institutionalism, we aim to shed light on policy change in multi-level health governance systems. Evidence collected through semi-structured interviews, triangulated with secondary sources, proves that the governance of health care in Italy has experienced no paradigmatic change. We show that “governance feedbacks” have reinforced pre-existing dynamics and inhibited more radical forms of change.