Small Scale Research Articles

Constraints on self-interaction cross-sections of dark matter in universal bound states from direct detection

Abstract$$\varLambda $$ Λ -Cold Dark Matter ($$\varLambda $$ Λ CDM) has been successful at explaining the large-scale structures in the universe but faces severe issues on smaller scales when compared to observations. Introducing self-interactions between dark matter particles claims to provide a solution to the small-scale issues in the $$\varLambda $$ Λ CDM simulations while being consistent with the observations at large scales. The existence of the energy region in which these self-interactions between dark matter particles come close to saturating the S-wave unitarity bound can result in the formation of dark matter bound states called darkonium. In this scenario, all the low energy scattering properties are determined by a single parameter, the inverse scattering length $$\gamma $$ γ . In this work, we set bounds on $$\gamma $$ γ by studying the impact of darkonium on the observations at direct detection experiments using data from CRESST-III and XENON1T. The exclusion limits on $$\gamma $$ γ are then subsequently converted to exclusion limits on the self-interaction cross-section and compared with the constraints from astrophysics and N-body simulations.

Dynamic Changes of Air Particle Pollutants and Scale Regulation of Forest Landscape in a Typical High-Latitude City

Particulate pollutants, particularly PM2.5 and PM10, pose serious threats to human health and environmental quality. Therefore, effectively mitigating and reducing the concentrations of these pollutants is crucial for human survival and development. In this study, we analyzed the distribution characteristics of air particulate pollutants in a typical high-latitude city, extracted urban forest areas from high-resolution remote sensing images, and examined the changing characteristics of PM concentration and the relationship between landscape pattern indexes and PM at different scales. The results showed that the concentrations of PM2.5 and PM10 were highest in winter and lowest in summer. At the small scales of 0.5 km × 0.5 km to 1.5 km × 1.5 km, PM concentration decreased with the decrease in PARA (Perimeter–Area Ratio). At the mesoscales of 2 km × 2 km to 2.5 km × 2.5 km, both PARA and CIRCLE (Related Circumscribing Circle) were highly significant (p < 0.001) correlated with PM concentration. At the large scales of 3 km × 3 km to 4 km × 4 km, PARA and PAFRAC (Perimeter–Area Fractal Dimension) were positively correlated with PM concentration. Our study indicates that reducing the complexity of forest patches in small-scale planning can help mitigate particulate air pollution. In the medium scale of urban forest planning, the more regular the forest patch shape and the more similar the patch shape to the strip, the better PM can be alleviated, while in large-scale planning, increasing the forest area and making the patches more normalized and simplified can reduce PM concentration. Moreover, reducing the complexity of forest patches can significantly mitigate PM pollution at all scales. The results of this research provide theoretical support and guidance for improving air quality in urban forest planning at different scales.

Development of Learning Models to Enhance Students’ Creative Thinking: A Systematic Literature Review

Creative thinking is an essential component in education that drives innovation, problem-solving, and the development of students’ critical thinking skills. This study aims to review various learning models designed to enhance students’ creative thinking abilities through a systematic literature review (SLR). Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework, this research identifies, screens, and evaluates relevant articles from the Scopus database, resulting in eight studies that meet the inclusion criteria. The results indicate that, following innovative learning models such as play-based activities, digital-based virtual classrooms (VCLE), basic movement through play approaches, and project-based mathematics learning are effective in improving creativity, problem-solving, collaboration, and student learning motivation. The integration of technology, STEAM approaches, and creative game design also show positive effects in enhancing students’ creative thinking skills. The higher distribution of research at the tertiary education level highlights the need for greater focus on other educational levels, particularly secondary education, to ensure the benefits of learning innovation are evenly distributed. These findings provide practical implications for educators and policymakers, emphasizing the importance of using innovative teaching methods, integrated technology, and the role of teachers as facilitators to develop a conducive learning environment for student creativity. The study also identifies several limitations, including small trial scales and short research durations, indicating the need for further research with larger scales and longer durations. By continually exploring and developing effective learning models, it is expected that students can achieve their maximum potential in dynamic and diverse learning environments.

Effects of Artisanal Mining on Land Degradation in Zamfara North-West, Nigeria

This paper analyzed the effects of artisanal mining on land degradation. It took critical look on both legal and illegal mining activities in the study areas and their level of devastated effects on land texture and structure over space. The method implored is both probability and non-probability approaches. The purposive targeted populations for the study were licensed and unlicensed small scale gold mining operators in the study areas, with a sample population of 100 person, and types of data used is both primary and secondary sources. Data was analyzed using descriptive statistic and frequency chart that indicated major challenges was illiteracy 31% and lack of coordination among miners 23%, major effect of land degradation was water pollution and deforestation had 30% and 23% respectively, and effects of artisanal mining on land degradation was degradation of arable land had 20% and exposing the soil to wind and chemical had 18%. It had a serious implication on ecosystem. The paper concluded that artisanal mining of mineral ores had caused serious damages on the land resources both soil and rivers. Therefore, to ensure sustainability in mining activities and to secure a quality environment, the following recommendations are hereby suggested, Educating local miners on the dangers of open cast mining and grinding of gold ore using the same grinder for grains to be consumed and Policy makers should avoid politicizing vital issues that will threaten peace and security of people in Zamfara and its environs.

Exploring global citizenship education for preservice early childhood teachers in South Korea: critical reflections on transformative pedagogy through journal writing

AbstractThis study aims to reveal how the “Global Citizenship Education (GCE) for Preservice Early Childhood Teachers” course offered at a teacher education program in South Korea fosters critical reflection in preservice early childhood teachers. Of the 21 preservice early childhood teachers who registered for this course, 11 agreed to participate in the research. The participants were asked to submit journals after each class, and the researchers analyzed the content of the participants' journals, focusing on the aspects of key concepts, inquiry, and change. Participants’ journal entries reevaluate the notion of child-centered education, critique institutional biases, and offer a clarifying perspective on the limitations of “equality” in achieving happiness for all. Participants also critically analyzed anthropocentric perspectives and behaviors, exploring how their thinking, being, feeling, and acting were shaped. By illuminating the possibility of providing opportunities to encourage GCE and critical reflection, albeit on a small scale, this study is expected to encourage teacher educators to implement GCE for preservice teachers.

“There Is No Law for Me in England”: An Indian Grocer’s Struggle for Economic and Geographical Space, and Agency in Oxford (1888–1896)

The Oxford Times ran a headline in May 1896 that stated in bold capitals ‘STRANGE DEATH OF A HINDOO’, detailing the circumstances of the death of Baboo Mookhi Singh, who, it seems, was the first (known) Indian grocer in Oxford. While today, the pioneering research by Rozina Visram related to the presence of Asians in Britain, that of Antoinette Burton in the late-Victorian period, or Michael Fisher’s work on counterflows to colonialism, is not new, the majority of research regarding the presence of Indians in the British Isles is either scant for this period of time, or related to ayahs and lascars, or to poets, intellectuals, and aristocrats, with considerable research also related to the Indian military. The majority of times, that research has also focused solely on London. The originality of this research paper provides material heretofore undocumented related to an early settler in Oxford from India (1880s–1890s): Baboo Mookhi Singh (1867–1893), Oxford’s first grocer, and tea importer from India. He originated from Benaras (Varanasi) and arrived in Britain, where he set up a business in the centre of Oxford. However, what he encountered there was name-calling, verbal as well as physical harassment, and ultimately his death in strange circumstances. He seemingly came alone, although his import business, which boasted the best tea not only in Oxford, but in the whole country, was run by the ‘Singh Brothers’ (his brother remaining in India). While Singh most certainly travelled via the Suez Canal to Britain, the country to which he was travelling would have been both familiar and unfamiliar to him. However, due to the lack of resources available, all too often common people, such as Singh, have been neglected. In this article, newspaper reports and material from the numerous trials (mostly initiated by Singh against the local people and his immediate neighbours) are brought together, as well as the coroner’s reports, and the police notes to determine Singh’s struggle for recognition, and his attempt at resistance. This paper documents his struggle for cultural/geographic space, to redress the imbalance of power, and gain agency. Despite his attempts at resilience, he did, in the end, die. However, Singh was a pioneer in a struggle for power, a stand for resistance, and how the law perceived him, in his difference, changing the community around him, albeit on a small scale. It is a telling story that resurfaces an early Indian settler in Britain, his alterity in Victorian society, and the latter’s attitudes towards race. It steps outside of the traditional image of the empire at home, in Britain, in everyday life.

Stochastic Super-resolution of Cosmological Simulations with Denoising Diffusion Models

In recent years, deep learning models have been successfully employed for augmenting low-resolution cosmological simulations with small-scale information, a task known as “super-resolution”. So far, these cosmological super-resolution models have relied on generative adversarial networks (GANs), which can achieve highly realistic results, but suffer from various shortcomings (e.g. low sample diversity). We introduce denoising diffusion models as a powerful generative model for super-resolving cosmic large-scale structure predictions (as a first proof-of-concept in two dimensions). To obtain accurate results down to small scales, we develop a new “filter-boosted” training approach that redistributes the importance of different scales in the pixel-wise training objective. We demonstrate that our model not only produces convincing super-resolution images and power spectra consistent at the percent level, but is also able to reproduce the diversity of small-scale features consistent with a given low-resolution simulation. This enables uncertainty quantification for the generated small-scale features, which is critical for the usefulness of such super-resolution models as a viable surrogate model for cosmic structure formation.

An Air-Stable, Single-Component Iridium Precatalyst for the Borylation of C-H Bonds on Large to Miniaturized Scales.

The functionalization of C-H bonds enables the modification of complex molecules, often with the intention of forming compound libraries. The borylation of aryl C-H bonds is a widely used class of C-H bond functionalization, and conventional catalyst systems for the borylation of C-H bonds consist of an iridium source and an N,N-ligand, in conjunction with pinacolborane, to form the active iridium(III) tris(boryl) catalyst. These multicomponent catalyst systems complicate borylation reactions at large and small scales, due to the air sensitivity of the most common iridium precursor [Ir(cod)OMe]2, and, particularly on small scale, the challenges associated with dispensing multiple components with differing solubilities or that are air-sensitive. We describe the discovery of an air-stable, single-component iridium precatalyst, [(tmphen)Ir(coe)2Cl], that generates the same active iridium(III) tris(boryl) catalyst and reacts with higher turnovers, comparable selectivity, and similar scope to those of known catalyst systems for the borylation of aryl and heteroaryl C-H bonds. We show how the development of this precatalyst enables reactions to be run on submicromole scale in a high-throughput experimentation format in conjunction with ChemBead technology, and with a second diversification step that illustrates the potential to diversify structures by chemical sequences involving catalytic reactions, including C-H bond functionalizations, on submicromole scales in the same reaction vessel.

Targeted Drug Delivery: From Chemistry to Robotics at Small Scales

The limited bioavailability, susceptibility to degradation, and adverse side effects of novel drugs often hinder their effective administration. Nanoparticles, with customizable properties and small size, have emerged as potential carriers, though their delivery efficiency remains low. With their ability to navigate fluid environments, micro- and nanorobots offer promising solutions to improve the delivery and retention of drugs at targeted tissues. The design and composition of these motile devices, often inspired by natural locomotion mechanisms, are currently being refined for improved biocompatibility, adaptability, and collective task performance. Recent research has focused on loading these devices with therapeutic agents and evaluating their efficacy in living organisms. While chemotherapy has been predominant, micro- and nanorobots also show significant potential for biological and physical therapies, and hybrid methods combining multiple therapies have demonstrated synergistic benefits. This review identifies major challenges, including the need for application-specific solutions, standardized performance evaluation methods, and the integration of engineering with pharmacology.

Temperature anisotropy instabilities driven by intermittent velocity shears in the solar wind

Where and under what conditions the transfer of energy between electromagnetic fields and particles takes place in the solar wind remains an open question. We investigate the conditions that promote the growth of kinetic instabilities predicted by linear theory to infer how turbulence and temperature-anisotropy-driven instabilities are interrelated. Using a large dataset from Solar Orbiter, we introduce the radial rate of strain, a novel measure computed from single-spacecraft data, which we interpret as a proxy for the double-adiabatic strain rate. The solar wind exhibits high absolute values of the radial rate of strain at locations with large temperature anisotropy. We measure the kurtosis and skewness of the radial rate of strain from the statistical moments to show that it is non-Gaussian for unstable intervals and increasingly intermittent at smaller scales with a power-law scaling. We conclude that the velocity field fluctuations in the solar wind contribute to the presence of temperature anisotropy sufficient to create potentially unstable conditions.

Seasonal distribution of cetaceans in the European Atlantic and Mediterranean waters

As apex predators, cetaceans play an essential ecological role in marine ecosystems. Fluctuations in the abundance of these top predators linked to human activities can have detrimental consequences for the entire ecosystem. Cetaceans face numerous anthropogenic threats that can have both short and long-term effects. To ensure their conservation, it is necessary to identify changes in seasonal distributions at small and large scales. We aimed to model the seasonal distribution of the most abundant cetacean species in the European Atlantic waters and the Mediterranean Sea by assembling datasets collected over 16 years of surveys using a standardised line-transect protocol. Data were homogenised, detection functions fitted and effective strip widths estimated. We extracted environmental variables integrated over the water column, which we transformed using a principal component analysis (PCA). The dimensions of the PCA were then integrated as explanatory variables in a generalised additive model, taking seasonal and spatial effects into account to predict the seasonal cetacean distribution. We were able to highlight changes in the spatial distribution and/or density of cetaceans throughout the year at a large scale, considering environmental extrapolation areas to predict where environmental variables were sampled during the surveys. For minke (Balaenoptera acutorostrata) and fin (B. physalus) whales, densities varied over the seasons but not the distribution, suggesting a seasonal migration outside the survey areas. For common dolphins (Delphinus delphis), bottlenose dolphins (Tursiops truncatus) and harbour porpoises (Phocoena phocoena), densities varied little but distributions did over the seasons. Finally, pilot whales (Globicephala spp), Risso’s (Grampus griseus) and striped (Stenella coeruleoalba) dolphins showed little seasonal variation in their distribution. Using monthly dynamic environmental variables at depth and PCA dimensions in habitat models, we produced maps of the seasonal distribution of cetaceans in the Mediterranean Sea and the European Atlantic waters to help fill gaps in our knowledge of cetacean distribution.

EMPLOYEE MOTIVATION AND PERFORMANCE ACROSS SMALL AND MEDIUM SCALE ENTERPRISES IN NIGERIA

Objective: The small and medium scale enterprises remain vital to many countries, contributing to job creation and economic growth. The study aims to determine how the motivational strategies affect performance of employees in SMEs sector in Nigeria. Method: We employ structural equation modelling (SEM) to depict the direct relationship between job satisfaction and employee’s salary, on one hand as well as between job satisfaction and job security on the other. Result and Discussion: The outcome finds that job security has a positive but insignificant relationship with job satisfaction and that job security has a positive and significant relationship with job satisfaction in the Nigerian SMEs sector. Implications: The implication of the finding is that although job security may not be central to the likely psychological well-being of the sector’s employees, employees’ pay motivates them to be satisfied with their job in the SMEs sector. Originality/Value: The value of the article lies in its focus on providing insight into factors that such as pay of employee and job security can motivate a psychological balance for job satisfaction. Recommendations: We recommend that the SMEs improve their current human resource policies relating to staff incentive schemes and employee performance as it will help to increase employee’s performance.

Livelihood Impacts of Micro-Hydro Electricity Project of Rural People of Nepal

Micro-Hydropower (MHP) is generally defined as a decentralized small scale water power plant that generate electricity power up to 100kw and server nearby householders thoughts a local grid for power generation up to 100kw. This study analyzes the livelihood impacts of the micro-hydro electricity projects of the rural people on Taplejung district of Nepal. There are twelve micro hydroelectricity projects constructed as well as they generated and supply the electricity power of the local people without connected in national grid of the NEA. Primary data were used for the study for the information and descriptive statistics were used for data analysis. To measure livelihood impacts of the project, different indicators like housing and sanitation condition, electricity used, industrial situation, agro-product pricing and wage rate of the labour had been used. The completion of the different MHPs in the sample area shows the result that the MHPs had positive impacts upon the surrounding community people’s income and living standard, which shows the positive impacts on their livelihood in the Taplejung district. The result encourages the different stages of governance as well as other investors for the implementation of the micro-hydroelectricity project in the situation of the Nepalese context.

Effective visualization of the AI-based road selection results for small scale maps design

Effective visualization of the AI-based road selection results for small scale maps design

Rural public investment and wage inequality under small‐scale agriculture modernization

Increasing rural public investment is crucial for sustainable rural development and can be an effective approach for reducing inequality. However, wage inequality has increased in some developing countries (e.g., China) after increasing fiscal support. This study explores how rural public investment influences skilled‐unskilled wage inequality by incorporating agricultural modernization in small‐scale agriculture. Agricultural modernization refers to introducing modern non‐agricultural intermediate inputs in agriculture. Owing to the small scale of agriculture, an intermediate sector, the agricultural producer service sector, is required to facilitate this process. We establish a three‐sector general equilibrium model with a two‐layer vertical production structure and investigate the effects of increased public investment in rural areas on the wage inequality between skilled and unskilled labour. The theoretical results show that while more rural public investment raises the wages of both skilled and unskilled labour, it also increases wage inequality. Overall, this study explains why inequality widens as rural public investment increases.

Downscaling MODIS evapotranspiration into finer resolution using machine learning approach on a small scale, Ribb watershed, Ethiopia.

By monitoring evapotranspiration (ET), the exchange of water and energy between the soil, plants, and the atmosphere can be controlled. Routine estimations of ET on a daily, monthly, and seasonal basis can give relevant information on small-scale agricultural practices, such as the Ribb watershed in Ethiopia. However, MODIS sensors have recently given high temporal resolution ET products across large areas, but their low spatial resolution limits its application on a local scale. The primary goal of the study was to downscale the MODIS ET (1km) product to a finer spatial resolution at the watershed level. The model's 12 predictor variables (NDVI, EVI, LAI, FVC, SAVI, NDMI, NDWI, Albedo, emissivity, LST, and DEM: slope and elevation) were produced using the random forest (RF) algorithm using Sentinel-2 (S-2) 20m and Landsat-8 (L-8) 30m. The RF regression model was used to assess the relationship between predicted variables and downscaled MODIS ET. The FAO-PM ET model, developed from meteorological stations, was validated by and RMSE for three seasons (rainy, post-rainy, and dry) in 2022. The results were in good agreement with MODIS ET, with an RMSE of 0.22 for S-2 and 0.28 for L-8. In the FAO-PM ET model, the downscaled result showed greater spatial details and better agreement with gage station readings ( and ). Thus, considering the effectiveness and simplicity of machine learning techniques, our study demonstrated the potential for ET downscaling. Furthermore, the study suggests integrating spatiotemporal time series data to reach higher resolution.

Operational Challenges of Small Scale Enterprises in Namakkal District

The research work examined the operational problems those hinder the efficacy and productivity of the SSEs in the jurisdiction of Namakkal District. This scientific investigation is of an empirical nature and it is based on the data that was personally gathered by following a schedule of interviews. Through formal conversation with the business owners of SSEs every attempt has been made to determine the accuracy of the material that has been gathered. In order to accomplish the goals of the research, a field survey was carried out in order to collect primary data. For the purpose of selecting samples, the type of sampling known as simple random sampling was used. The samples that were selected were comprised of business owners of SSEs from the Namakkal District. In each step of the selection process, the lottery method was used as a simple random sampling methodology. The sample size of the study was fixed to be 147 based on the statistical tools that were used in the study. The collected main data that was obtained from the sample small scale units was performed as part of the analysis of the data. The data have been categorised, and cross tabulation has been performed in accordance with the various attributes of the variables. The study has used confirmatory factor analysis using the AMOS software to analyse the challenges faced by the SSE in Namakkal District. The SSEs operating in the study area are highly impacted by the challenges of skilled labor source and lack of appropriate infrastructure to operate their business which has to be resolved by stakeholders involved in policy making.

A microhistory of architecture historical imagination and the Bauhaus

ABSTRACT In this paper, we develop the notion of historical imagination as a methodological practice in microhistory. The relevance of microhistory for organization research goes beyond the focus on the small scale, as its methods involve tracing the sources that allow us to reconstruct lived experience. We use the Bauhaus School as a case study to illustrate how microhistorical methods and historical imagination can reconstruct the perception and impact of a novel design aesthetic in their historical context. Here we draw on ego-documents as key to historical imagination and define a related type of source, alter-documents, that report on how others are experienced by the self. By bringing historical imagination to microhistory, we introduce methodological rigor and reflexivity to the approach. Our study also contributes to a better understanding of the methodological practice of narrative construction through historical imagination and demonstrates its usefulness for understanding the aesthetic experience of architecture and space in the past.

Lower Energy Consumption in Multi-CPU Cell-Free Massive MIMO Systems

Under the ideal assumption of deploying only one central processing unit (CPU) in the entire system, cell-free (CF) systems can achieve significant macro-diversity gain, thereby providing uniformly reliable service to each user equipment (UE). However, due to limitations in system scalability and the feasibility of strict phase synchronization, CF systems require a multi-CPU setup and perform coherent transmission at a smaller scale. Moreover, conventional CF systems typically operate in time-division duplex (TDD) mode and utilize statistical channel state information (CSI) for downlink (DL) decoding, but the channel hardening effect is not significant. These factors reduce downlink spectral efficiency (SE) and increase DL transmission time, leading to higher energy consumption in CF systems. To address these issues, we introduce downlink channel estimation (DLCE) in multi-CPU CF systems and derive the approximate achievable DL SE. To reduce DL pilot overhead, we propose an uplink–pilot-reuse-constrained DL pilot allocation principle. Based on this principle, we develop a farthest distance pilot allocation (FDPA) algorithm to mitigate pilot contamination. In addition, leveraging the characteristics of the heuristic distributed power allocation algorithm, we propose two access point (AP) clustering algorithms: one based on CSI (BCSI) and the other based on coherent group size (BCGS). Simulation results indicate that the introduction of DLCE significantly improves DL SE in multi-CPU CF massive MIMO systems, while the proposed FDPA algorithm further enhances DL SE. The BCSI and BCGS algorithms also effectively improve DL SE and help reduce energy consumption. By combining DLCE, the FDPA algorithm, and the proposed AP clustering algorithms, the energy consumption of multi-CPU CF systems can be significantly reduced.

Flight initiation distance differs among eumelanin‐based color morphs in feral pigeons

AbstractOrganisms facing anthropogenic activities usually exhibit phenotypic responses assumed to enhance coping with disturbance. These responses include a decreasing degree of reaction toward potentially risky situations (“behavioral tolerance”) with increasing disturbance. Though melanin is associated with many phenotypic traits, including pigmentation and behavior, the potential relationship between behavioral tolerance and melanin has never been explored. Such relationship may potentially result from either direct association between melanin and behavior (e.g., genetic correlation) or indirectly through a coloration‐dependent behavior‐modulating factor (e.g., differential predation or human preferences in cities toward color morphs). Feral pigeons (Columba livia) represent an ideal biological system to test for these hypotheses, due to their presence in cities worldwide, their considerable variation in eumelanin‐based coloration, ranging from white to black plumage, and their close proximity to humans. We measured Flight Initiation Distance (FID, classically used for behavioral tolerance assessment) of feral pigeons of 4 different eumelanin‐based color morphs in sites differing in their urbanization rate and pedestrian traffic within the restricted scale of a city center (Paris). Urbanization rate and pedestrian traffic had no effect on FID, maybe because of the small spatial scale considered. FID varied with eumelanin‐based coloration: white pigeons had lower FID (104.6 cm; i.e., higher behavioral tolerance) than darker morphs (232.3 cm for Blue bar, 184.4 cm for T‐pattern & Checker, and 181.8 cm for Spread color morphs). Though the exact underlying causes remain to be identified, we propose different possible mechanisms for this relationship that remain to be investigated in future work.