Stable System Research Articles

The Cambrian collision of the Yangtze Block with Gondwana: Evidence from provenance analyses

The Neoproterozoic to Paleozoic Proto-Tethys Ocean has preserved critical records of Earth’s evolutionary history. The Lower Cambrian detrital strata along the northern margin of the Yangtze Block provide valuable information for gaining insight into the evolution of the Proto-Tethys Ocean, which is important in understanding the collision between the Yangtze Block and the Gondwana assembly. Here, we present comprehensive U-Pb ages and trace elements of zircons from Lower Cambrian detrital strata in the Yangtze Block. Our results revealed prominent age peaks at 600−500 Ma and 1100−800 Ma for detrital zircons in the Cambrian strata. The trace element characteristics of the detrital zircon indicate that the source rocks were mainly intermediate-felsic magmatic suites with minor input from mafic sources. These results suggest that the detrital materials were not only supplied from the interior of the Yangtze Block but also from magmatic sources in the internal orogenic belt of Gondwana. Furthermore, the kernel density estimate plots of detrital zircon U-Pb ages indicate a stable source-sink system in the Yangtze Block during the Early Cambrian. However, our data indicate that the crustal thickness of the Yangtze Block increased significantly since ca. 526 Ma, and the cumulative characteristics of the detrital zircons indicate that the rocks were deposited in a compressional tectonic environment after ca. 526 Ma, in contrast to those during the late Neoproterozoic, which were generally deposited in an extensional tectonic environment. This transition indicates that the initial collision between the Yangtze Block and the Gondwana supercontinent might have occurred at ca. 526 Ma, marking the rapid aggregation of the northern domain of the Gondwana assembly and potentially serving as an important indicator of the closure of the Yangtze-associated Proto-Tethys Ocean. Our findings provide key insights into late Neoproterozoic−early Paleozoic ocean-land evolution.

PD distributed control and stability analysis for DC microgrids with multiple time delays

Distributed control is widely used for coordination of multiple distributed generations (DGs) in a microgrid (MG), but the information transmission in practice is inevitably suffered from time delays, which will deteriorate system performance and even cause system instability. To solve this problem, a proportional-differential (PD) distributed control method for DC MGs is proposed in this paper. Firstly, a small-signal system model considering multiple time delays including measurement delay and communication delay is established. The introduction of time-delayed differential terms results in the system being transformed into a neutral time-delayed system (NTDS). Then, the time delay margin (TDM) under different delayed scenarios is accurately determined by the frequency-domain stability analysis, and the relationship between the TDM and the differential gain is quantified. Compared with the conventional proportional (P-type) distributed control method, the TDM is enhanced effectively. In addition, an indicator is proposed to quantify the enhancement effect of introducing differential terms on TDM. Finally, the effectiveness of the proposed method and the accuracy of the stability analysis are verified by simulation and hardware-in-loop (HIL) tests.

W/O/W Pickering emulsions stabilized by complex modified phycocyanin.

A water-in-oil-in-water (W/O/W) double emulsion can simultaneously load hydrophilic and hydrophobic substances due to its unique two-membrane, three-phase structure. However, thermodynamic instability greatly limits the application of double emulsions in food processing. Further development of Pickering emulsions based on proteins, etc., can improve the stability and loading capacity. It is of great significance to promote their practical application. Herein, we prepared ultrasound pretreatment complex glycation-modified phycocyanin (UMPC) to stabilize a W/O/W Pickering emulsion for the codelivery of vitamin B12 (VB12) and vitamin E (VE). First, an inner water phase and oil phase containing polyglycerin polyricinoleate were homogenized to prepare a W/O emulsion. Subsequently, the W/O emulsion was homogenized with an outer water phase containing UMPC to obtain a W/O/W Pickering emulsion. A gel-like inner phase emulsion with excellent storage and thermal stabilities was obtained under the condition that the W/O emulsion volume ratio was 80% and the UMPC was stabilized by 10 g kg-1. The double emulsion after loading VB12 and VE showed good encapsulation effect during the storage period, the encapsulation rate could reach more than 90%, it also showed excellent protection effect under long-time storage and UV irradiation and the retention rate increased by more than 65%. In addition, the bioavailability of VB12 and VE significantly increased during simulated gastrointestinal digestion and reached 46.02% and 52.43%, respectively. These results indicate that the UMPC-stabilized W/O/W Pickering emulsion is an effective carrier for the codelivery of hydrophilic and hydrophobic bioactive molecules and also provides a means for useful exploration of an efficient and stable emulsion system stabilized by biological macromolecules. © 2024 Society of Chemical Industry.

Analysis of Geometric and Material Parameters in the Modal Stability of Wind Turbine Brakes Using the Complex Eigenvalue Method

Wind energy is a sustainable and forward-thinking investment, harnessing the vast power of the wind to generate electricity. Recent decades have seen significant advancements in floating offshore wind turbines (FOWTs), which hold great potential for expanding offshore wind energy infrastructure. While wind power has grown in popularity, it has raised questions about the operations and maintenance of wind turbines, particularly those located in remote and challenging environments. Offshore wind energy offers optimal wind conditions and construction flexibility, but FOWTs face complex marine conditions, including turbulent forces, wind variations, and unpredictable weather events. Emergency Mechanical Braking (EMB) is commonly used to swiftly stop wind turbines during adverse conditions, but frequent use can lead to structural oscillations, mooring failures, and blade damage. These issues can result in emergency situations, increased downtime, and higher maintenance costs. One significant challenge in understanding wind turbine brake system instability is the cost of experimental studies. To address this, our work introduces an iterative method that establishes correlations between brake component properties (like Young’s modulus and friction coefficient), geometric and operational parameters, and key instability factors such as frequency and intensity. Using finite element analysis and complex eigenvalue analysis, this approach focuses on reducing vibration instability and optimizing braking performance. Our study yielded intriguing results, including the observation that reducing brake pad thickness, whether through design choices or natural wear, decreases total unstable points but shifts instabilities to lower frequencies. Ultimately, our research highlights the importance of various parameters in wind turbine brake system instability.

Applying the LightGBM model and SHAP interpretation to understand the urban land price index and its influencing factors in China

ABSTRACT Investigating the key factors affecting land prices is conducive to establishing targeted market-oriented reforms of the land market and promoting its healthy development. Traditional linear analysis cannot comprehensively compare the importance of feature variables and is unable to analyse the nonlinear influence process of feature variables. Therefore, based on the land transaction dataset from 2011 to 2020 in China, we used machine learning and the Shapley Additive exPlanations method to analyse the importance ranking of factors affecting land prices and analyse the nonlinear influence processes. The government fiscal, industrial development, and financial system indices are determined as the most important factors affecting residential, commercial, and industrial land price indices, respectively, and each exhibits different characteristics. The financial system index exerts the strongest impact on land price indices in large cities, whereas transportation and communication indices are the most dominant in small cities. Moreover, industrial development index is the most important influencing factor in industrial cities, whereas regional economic index exerts the greatest impact in small cities. By employing machine learning methods, we determined nonlinear effects that traditional linear models fail to obtain. Based on the results, we propose policy recommendations for market-oriented reforms on the land market, real-estate policies, and a stable monetary system.

Understanding zinc isotopic signatures in volcanic lakes

Magmatic activity can be monitored through the chemical variations of volcanic lakes. While those lakes can be influenced by direct magmatic input, water-rock interaction processes in hydrothermal system also have a large influence. Disentangling those effects is critical to use crater lakes for volcanic activity monitoring purposes. Zinc is a volatile metal that is easily degassed and can be incorporated into fluid circulation. During degassing, Zn isotopes can be fractionated and can thus be a potential tracer of magmatic input. Here we present a novel approach using stable Zn isotopic systems to understand how dissolution/precipitation processes affect isotopic compositions of volcanic lakes and if they can be used as tracers of magmatic activity. We investigate Zn isotopes expressed as δ66Zn for four volcanic lakes ranging from hyperacidic to neutral waters. Two of them, Kawah Ijen (Indonesia) and Santa Ana (El Salvador) volcanic lakes have been sampled from 2010 to 2012 and 2000–2002, respectively, and show a clear magmatic input with extremely low pH [0.1–1]. Taal (Philippines, pH ≈ 3) and Kelud (Indonesia, pH ≈ 6.5) volcanic lakes were sampled from 2017 to 2019 and 2003–2007 respectively, and are dominated by hydrothermal rather than magmatic inputs. Hyper-acidic lakes show minimal isotopic variation over the investigated time ranges, with δ66Zn values similar to their basalt-andesitic host rocks (0.26 ± 0.08 ‰). In contrast, we observe large δ66Zn fractionation for the Taal waters (0.4 ± 0.01 ‰) compared to their basalt-andesitic host rocks but no δ66Zn temporal variations. Kelud waters show significant δ66Zn (−0.08 ± 0.06 ‰ to 0.43 ± 0.06 ‰) temporal variation. This could be related to an evolution of the lake water chemistry as the sampling period occurred between two increases in lake temperature culminating into a lava dome eruption in 2007. For Taal and Kelud volcanic lakes, enrichment factors (EF) and PHREEQc modelling indicate that Zn is depleted and suggest that Zn could precipitate in the hydrothermal system, hence fractionating Zn isotopes during these precipitation processes. This contrasts to Zn elemental and isotope values from Kawah Ijen and Santa Ana with an EF ≈ 1 suggesting that Zn is derived from host rock dissolution, in agreement with their δ66Zn. These data are still limited and a longer observation is needed in the future to highlight significant geochemical changes in volcanic lakes and their relation to volcanic activity.

Potassium isotope compositions of Mariana arc lavas and their sedimentary input

We apply the stable potassium isotope system (41K/39K) to well-studied Mariana arc lavas, in which inter-island geochemical variability has been interpreted to reflect near constant addition of an aqueous fluid flux, that dominantly samples the subducting mafic oceanic crust and variable amounts of sediment melt addition to the sub-arc mantle wedge. The nature of the sediment component in the Mariana arc lavas remains enigmatic, with a mixture of melts from all subducted sediment lithologies and the altered-mafic oceanic crust seeming likely, but some interpretations point towards a component from melting of the volcaniclastic sediment alone. We present K isotopic data on a set of well-characterised Mariana arc lavas and sediment samples (from Ocean Drilling Program site 801). Our data show that the majority of Mariana arc lavas are isotopically heavy (ẟ41K), by up to ∼0.2 ‰, relative to mid-ocean ridge basalt (MORB), but most of the subducting sediment samples are slightly isotopically lighter than, or indistinguishable from MORB. The volumetrically important volcaniclastic sedimentary unit however is significantly isotopically lighter than MORB, by ∼0.8 ‰, which reflects marine diagenetic processes. Thus, volcaniclastic material significantly influences the bulk sediment K isotope composition. We show that ẟ41K compositions of the Mariana arc lavas can be reproduced by the addition of an aqueous fluid with isotopically heavy K (relative to MORB) and an additional fraction of an incompatible-element-enriched isotopically light melt component. Modelling of K isotopes together with K/La and radiogenic Nd indicate that the melt component is best explained by a mix of melts from bulk sediment and altered-mafic oceanic crust. Our results show that distinctive K isotopic variations in subduction zone inputs and K isotopic fractionation during dehydration reactions makes K a useful tracer of subduction zone processes.

Torsional behaviors of motor rotor of permanent magnet semi-direct drive system for aerial passenger device

Considering the influence of motor shaft torsional damping, the torsional dynamics equations of a permanent magnet semi-direct drive rotor system in an aerial passenger device are derived. The derivation relies on the coupling between the mathematical model and the gear dynamics model of the permanent magnet motor, and the Lagrange–Maxwell equations are used for streamlined analysis. To protect the motor under extreme working conditions, the influence of supercritical Hopf bifurcation caused by different torsional dampings of the motor shaft on the torsional vibration of the motor rotor is investigated. Based on the Hurwitz criterion, the influence of the linear control gain and nonlinear gain of the washout filter on the system bifurcation point and the limit cycle amplitude of the system is analyzed. Then, from the perspective of the system instability and oscillation caused by friction damping change of the drive motor and the complex electromechanical coupling behavior in the permanent magnet semi-direct drive cutting drive system of the aerial passenger device, the system stability domain is defined. The results can be applied to effectively suppress the torsional vibration of the shaft system in the permanent magnet semi-direct drive system of the aerial passenger device, providing a theoretical guidance for stable operation of the system.

Passivity-based adaptive current control loop of cascaded H-bridge multilevel converter for grid-tied photovoltaic system

This paper proposes an algorithm to passivity-based control (PBC) for the current control loop of the cascaded H-bridge converter (CHB) connecting the grid-connected PV system with the space vector modulation (SVM) algorithm using the law of expanding any number of voltage levels. The algorithm SVM in this paper is suitable for CHB converters. It can create a number of high levels of alternating voltage that other methods cannot do. Passivity-based control (PBC) algorithm aims to create a flexible controller that can change its structure or parameters to adapt to changes in the system, ensuring stable system quality, reducing switching losses and gaining energy conversion efficiency. It enhances the capability of accurately delivering power on demand to the grid with the CHB inverter in situations in which the grid demands the mobilization of maximum power from the photovoltaics (PV) system. The simulation results of the 9-level CHB system performed by MATLAB/Simulink software have proved the feasibility of the proposed algorithm.

Design of a cybersecurity defense system based on big data and artificial intelligence

With the development of big data and artificial intelligence technologies, hacker attack techniques and capabilities have continuously improved, and the methods of network attacks have diversified. Without cybersecurity, there is no national security. Therefore, cybersecurity has become a focal point of attention. To comprehensively enhance the network security defense capabilities of computer operating systems, aligning with the rapid development trends of big data and artificial intelligence technologies, this study focuses on constructing an efficient, stable, and practical cybersecurity defense system. This system deeply integrates advanced technologies of big data analysis and artificial intelligence, thoroughly analyzing the current status of network information security in computer operating systems and closely aligning with the practical needs of design and production. The aim is to provide highly valuable reference solutions for the field of cybersecurity defense.

The Effect of Macroprudential Policies on Financial Stability

Purpose: The general objective of the study was to investigate the effect of macroprudential policies on financial stability. Methodology: The study adopted a desktop research methodology. Desk research refers to secondary data or that which can be collected without fieldwork. Desk research is basically involved in collecting data from existing resources hence it is often considered a low cost technique as compared to field research, as the main cost is involved in executive’s time, telephone charges and directories. Thus, the study relied on already published studies, reports and statistics. This secondary data was easily accessed through the online journals and library. Findings: The findings reveal that there exists a contextual and methodological gap relating to the effect of macroprudential policies on financial stability. Preliminary empirical review revealed that macroprudential policies were crucial in mitigating systemic risk and enhancing financial stability. It found that tailored approaches, considering specific economic conditions, were necessary for these policies to be effective. Coordination with other regulatory measures and continuous adaptation to evolving financial landscapes were also essential. The research highlighted the importance of robust regulatory institutions and effective enforcement mechanisms, particularly in emerging markets, to address challenges such as regulatory capture and limited institutional capacity. Overall, the study emphasized the need for a dynamic and adaptable macroprudential regulatory framework to maintain a stable and resilient financial system. Unique Contribution to Theory, Practice and Policy: The Financial Stability Hypothesis, Regulatory Capture Theory and Agency Theory may be used to anchor future studies on macroprudential policies on financial stability. The study recommended adopting a comprehensive macroprudential regulatory framework that integrated various tools to address systemic risk. It suggested enhancing theoretical models to understand the dynamic effects of these tools and their combined impact. Practical recommendations included building strong regulatory institutions, improving data collection, and enhancing international cooperation and information sharing. Policy recommendations emphasized clear and transparent frameworks, regular policy reviews, and considering potential unintended consequences. Engaging with stakeholders to address concerns and ensure balanced regulation was also advised to support sustainable economic growth while maintaining financial stability.

Unveiling the structural and optoelectronic properties of (P, Bi, Sb)-doped GaAs by first- principles calculations

In this work, we investigate the influence of M substitutions (M = P, Bi, and Sb) on the structural, electronic, and optical properties of gallium arsenide, GaM x As1-x for x=0,0.25,0.50,0.75,1.0 using density functional theory (DFT). We have observed that the cubic symmetry of the semiconductors in conserved, and lattice constants show a linear behavior with dopant concentration, according to Vegard’s law. Specifically, the lattice constants increased for Bi and Sb dopants, whilst decreased for P dopants. Furthermore, the bulk modulus decreased with an increase in M-concentration for all M-doped systems. The energy analysis showed that the P-doped system was the most stable system. In terms of the electronic band structure, all M-doped compounds exhibited a direct electronic band gap. The P-doped system showed a wide band gap, while the Sb-doped systems displayed a narrow band gap, both compared to pristine GaAs. The Bi-doped system showed metallic-like behavior. To gain insights into the linear optical properties of the GaM x As1-x compounds, we calculated the real and imaginary parts of the dielectric function, as well as other optical parameters such as the absorption coefficient, refractive index, extinction coefficient, and reflectivity. The results showed that P doping leads to a blue-shift in the optical absorption coefficient, while Bi and Sb doping lead to a red-shift. These findings provide valuable theoretical insights for the potential application of GaM x As1-x semiconductors in photovoltaics and optoelectronic devices.

Factors Affecting Specialty Training Preference Among UK Medical Students (FAST): Protocol for a National Cross-Sectional Survey.

The UK medical education system faces a complex landscape of specialty training choices and heightened competition. The Factors Affecting Specialty Training Preference Among UK Medical Students (FAST) study addresses the need to understand the factors influencing UK medical students' specialty choices, against a backdrop of increasing challenges in health care workforce planning. The primary objectives of the FAST study are to explore UK medical students' preferred specialties and the factors that influence these choices. Secondary objectives are to evaluate students' confidence in securing their chosen specialty, to understand how demographic and academic backgrounds affect their decisions, and to examine how specialty preferences and confidence levels vary across different UK medical schools. A cross-sectional survey design will be used to collect data from UK medical students. The survey, comprising 17 questions, uses Likert scales, multiple-choice formats, and free-text entry to capture nuanced insights into specialty choice factors. The methodology, adapted from the Ascertaining the Career Intentions of UK Medical Students (AIMS) study, incorporates adjustments based on literature review, clinical staff feedback, and pilot group insights. This approach ensures comprehensive and nondirective questioning. Data analysis will include descriptive statistics to establish basic patterns, ANOVA for group comparisons, logistic regression for outcome modeling, and discrete choice models for specialty preference analysis. The study was launched nationally on December 4, 2023. Data collection is anticipated to end on March 1, 2024, with data analysis beginning thereafter. The results are expected to be available later in 2024. The FAST study represents an important step in understanding the factors influencing UK medical students' career pathways. By integrating diverse student perspectives across year groups and medical schools, this study seeks to provide critical insights into the dynamics of specialty, or residency, selection. The findings are anticipated to inform both policy and educational strategies, aiming to align training opportunities with the evolving needs and aspirations of the future medical workforce. Ultimately, the insights gained may guide initiatives to balance specialty distribution, improve career guidance, and improve overall student satisfaction within the National Health Service, contributing to a more stable and effective health care system. DERR1-10.2196/55155.

Bird names as critical communication infrastructure in the contexts of history, language, and culture

Standardized taxonomies and lists of birds were created to improve communication. They are linguistic infrastructure―biodiversity indices and dictionaries―that have been painstakingly built and maintained and that have enhanced regional and global participation in the study and enjoyment of birds. Inclusion of people has been a core objective in creating and maintaining these standardized lists, and dissatisfaction and desires to overwrite objectionable names have been associated with them for nearly two centuries. Suggestions that bird names should be changed are continuous. Today, these suggestions include the view that some bird names must be changed to make them more accurate, inoffensive, and culturally appropriate to further increase diversity and inclusion among ornithologists and bird watchers. The latter, meritorious goal has been largely successful thus far despite many ongoing objections. Historic examples indicate that large-scale name changes, however, are not needed to accomplish major societal goals of inclusion. Some barriers to inclusion likely remain, and some changes are likely needed for English names. Often overlooked or underappreciated in name change discussions are that: 1) standardized names lists have had numerically staggering success in fostering inclusion of diverse participants globally; 2) stability is vital in such systems, and destabilization has exclusionary effects; 3) dissatisfaction with such lists and the names they include has been ongoing since these naming systems began; 4) important flexibilities exist in conjunction with these communication systems that enhance local and regional communication (e.g., alternative names in English and other languages); and 5) cultural values, important as they are, are neither universally shared nor constant, and thus risk bringing divisiveness and instability when used as a central reason for change. Consideration of standardized lists of bird names as communication systems in the fuller context of history, language, and culture will improve our management of these systems and their continued utility in fostering inclusion. With standardized, stable naming systems acting as a skeleton, proactively building outwards, both within and among languages and cultures, offers a positive and productive way to increase inclusion and to improve cultural and biodiversity conservation.

Adaptive control for circulating cooling water system using deep reinforcement learning.

Due to the complex internal working process of circulating cooling water systems, most traditional control methods struggle to achieve stable and precise control. Therefore, this paper presents a novel adaptive control structure for the Twin Delayed Deep Deterministic Policy Gradient algorithm, which is based on a reference trajectory model (TD3-RTM). The structure is based on the Markov decision process of the recirculating cooling water system. Initially, the TD3 algorithm is employed to construct a deep reinforcement learning agent. Subsequently, a state space is selected, and a dense reward function is designed, considering the multivariable characteristics of the recirculating cooling water system. The agent updates its network based on different reward values obtained through interactions with the system, thereby gradually aligning the action values with the optimal policy. The TD3-RTM method introduces a reference trajectory model to accelerate the convergence speed of the agent and reduce oscillations and instability in the control system. Subsequently, simulation experiments were conducted in MATLAB/Simulink. The results show that compared to PID, fuzzy PID, DDPG and TD3, the TD3-RTM method improved the transient time in the flow loop by 6.09s, 5.29s, 0.57s, and 0.77s, respectively, and the Integral of Absolute Error(IAE) indexes decreased by 710.54, 335.1, 135.97, and 89.96, respectively, and the transient time in the temperature loop improved by 25.84s, 13.65s, 15.05s, and 0.81s, and the IAE metrics were reduced by 143.9, 59.13, 31.79, and 1.77, respectively. In addition, the overshooting of the TD3-RTM method in the flow loop was reduced by 17.64, 7.79, and 1.29 per cent, respectively, in comparison with the PID, the fuzzy PID, and the TD3.

Cultures as types and the utility of viable specimens for fungal nomenclature

The debates over the requirement of the International Code of Nomenclature for algae, fungi, and plants (ICNafp) for a viable specimen to represent the name-bearing type material for a species or infraspecific taxon have a long history. Taxonomy of fungi commonly studied as living cultures exemplified by yeasts and moulds, strongly depend on viable reference material. The availability of viable cultures is also particularly useful for several groups of filamentous and dimorphic fungi. While the preservation of metabolically inactive cultures is permitted and recommended by the ICNafp, there is room for improvement. Below, we review the history and current status of cultures as the name-bearing type material under the Code. We also present a roadmap with tasks to be achieved in order to establish a stable nomenclatural system that properly manages taxa typified by viable specimens. Furthermore, we propose setting up rules and defining the nomenclatural status of ex-type cultures under Chapter F, the section of the ICNafp that includes provisions specific to names of fungi.

Magneto-Acoustic Field-Induced Unstable Interface of Magnetic Microswarm.

Research on the interfacial instability of two-phase systems can help in gaining a better understanding of various hydrodynamic instabilities in nature. However, owing to the nonlinear and complex spatiotemporal dynamics of the unstable interface, the instability is challenging to control and suppress. This paper presents a novel interfacial instability of the magnetic microswarm induced by the competition between the destabilizing effect of magnetic field and the stabilizing effect of acoustic field. The physics underlying this novel phenomenon is discussed by analyzing the contributions of the external fields. Unlike previous studies, this study demonstrates that the instability is independent of the interfacial force or diffusion effect and can persist without dissipation over time. The manipulation of the unstable interface is further achieved by adjusting the configuration of the magneto-acoustic system. This approach can be used in thermal encoding metamaterials and has great potential applications in systems where the instability is detrimental.

Fire is associated with forest degradation and economic land concessions, but not land conversion in the rapidly transforming Cambodian landscape

Abstract Cambodia is beset by high deforestation rates and fire frequencies. From 2001–2020, forest cover declined by 34%, and cropland and rubber expanded by 31,401 km2 and 4,530 km2, respectively; meanwhile nearly 8.7 million fires burned 41.6% of the land. Fires may be associated with deliberate land change, stable land management systems, and unplanned forest degradation. We integrated annual land cover and monthly burned area data from 2001–2020 to test three hypotheses. First, if fire is used during land conversion, there would be a detectable pulse in fire activity in the year immediately prior to, and the year of land cover change. Our temporal analysis found statistically elevated burn rates in five of 16 transition tests, however, they were typically <1% outside the predicted range, indicating no practical significance in the association of fire with land cover change. Second, fire prevalence would be lower in land managed for conservation or agricultural production than unclassified or unmanaged land. persistent forest and shrubland burned at significantly higher rates than expected, cropland burned significantly less, burning was almost absent from rubber plantations, and forests in protected areas (PAs) exhibited lower total burn percentages than unclassified land or industrial economic land concessions (ELCs), thus supporting the fire-land management hypothesis. However, total burned area in ELCs was greater than unclassified land for several persistent land cover classes, suggesting that local landowners may prevent fire in commercially valuable private agricultural land, but there may be no such prevention measures in industrial ELCs. Anti-fire policy enforcement in ELCs should be enhanced. Third, forests that converted into (degraded) shrublands would experience increasing fire frequency in the years leading up to transition, a hypothesis we found strong support for through our temporal analysis. Cambodia’s 2013 Law on Fire Prevention and Fire Fighting deputizes the public to enforce its provision, however given that the vast majority of fires occur in persistent forest in state-owned land, collective action problems are likely to hinder its effective implementation.

Synthesis and Characterization of ZnO Quantum Dot-Functionalized Mesoporous Nanocarriers for Controlled Drug Delivery

In this study, ZnO quantum dots (ZnO@QDs) were synthesized and functionalized with 2nd generation poly amido amine (2GPD) using 3-amino-propyl tri-methoxy silane as the initiator core, facilitated by tetramethylammonium hydroxide (TMAH) to enhance stability against oleate coating. Concurrently, a mesoporous substrate with a unique morphology was developed as a drug reservoir for doxorubicin loading. ZnO quantum dots displayed photoluminescence radiation, with dimensions ranging from 5 to 7 nm and exhibiting spherical morphology. The cubic structure of the synthesized mesoporous nanocatalysts was also confirmed. Brunauer-Emmett-Teller analysis indicated a multidimensional porous structure of the nanocarriers, while zeta potential analysis showed a stable system (approximately -9.6 mV). Fourier transform infrared spectroscopy, X-ray diffraction, and energy dispersive spectroscopy corroborated these findings. Drug release studies demonstrated sustained release under acidic conditions (pH 5.5), with an efficiency of approximately 94%. These results highlight the potential applications of this nanosystem for controlled drug delivery, underscoring its practical implications in the field of nanotechnology.

Financial stability and financial inclusion: a non-linear nexus

PurposeThe purposes of the paper are as follows: (1) Analysing the effect of financial inclusion on financial stability. (2) Examining whether financial inclusion non-linearily impacts financial stability. (3) Analysing whether the effect of financial inclusion varies across quantiles of financial stability. (4) Investigating whether dimensions of financial inclusion affect financial stability differently. (5) Examining whether the effect of financial inclusion on financial stability depends on competitiveness of the banking industry.Design/methodology/approachUsing panel data for 19 African countries for the period 2006–2022, we first developed multidimensional index of financial inclusion using two-stage indexing approach. Then employing panel semiparametric regression, we analyse the non-linear nexus between financial stability and financial inclusion. We further employ panel quantile regression to investigate the differential effect of financial inclusion at different quantiles of financial stability. We also employed two-stage least squires, and alternative measurement of financial stability as robustness checks.FindingsEmploying panel semiparametric regression, we demonstrate that the financial inclusion-stability nexus exhibits non-linearity: below (above) threshold level financial inclusion promotes (reduces) financial stability. Employing panel quantile regression, we find that the effect of financial inclusion increases at higher quantiles of financial stability. We further demonstrate that the effect of financial inclusion on financial stability is pronounced in a more competitive bank industry. The findings are robust to two-stage least squares estimation, and alternative measurement of financial stability. The results suggest that keeping a balance between achieving stable and inclusive financial system, and ensuring a competitive banking industry are essential to achieve bank soundness while promoting financial inclusion.Originality/valueThe study incrementally contributes to the literature related to the financial inclusion – stability nexus in four-fold. First, unlike studies that relied on some indicators of financial inclusion, we employed the effect of multidimensional financial inclusion on financial stability and further examined whether or not the effect varies across financial inclusion dimensions. Second, unlike studies that assumed a linear nexus between financial inclusion and stability, employing panel semiparametric regression, we investigated for non-linear relationship between the two. Employing a novel panel quantile estimation approach, we further scrutinised whether the effect of financial inclusion varies across quantiles of financial stability. Third, to our knowledge, our study is the first to examine the effect of multidimensional financial inclusion on bank soundness in Africa.HighlightsWe find a non-linear nexus between financial inclusion and financial stability.Financial inclusion below (above) threshold enhances (reduces) financial stability.The effect of financial inclusion is pronounced at higher quantiles of financial stability.The effect of financial inclusion on financial stability depends on bank competition.The results hold across different dimensions of financial inclusion.