bluuebunny/crossref_metadata_2025 huggingface dataset:
Fear and Practice Modifications among Nepalese Prosthodontists during COVID-19 Outbreak
Authors: Shrestha A , Mathema SRB , Pathak B , Karna SL
Published: October 2024

Introduction: The COVID-19 pandemic poses significant risks to healthcare professionals, including dental specialists such as prosthodontists. Prosthodontists face unique challenges due to their close contact with patients and the nature of their procedures, which often involve multiple visits and exposure to saliva, blood, and aerosols. This study aims to assess the anxiety and fear experienced by prosthodontists in Nepal and evaluate their knowledge of practice modifications to mitigate COVID-19risks.
Methods: A hospital-based descriptive cross-sectional study was conducted from September 15 to October 15, 2020. Self-administered questionnaires were distributed online to registered prosthodontists in Nepal. The survey included 33 closed-ended questions divided into two sections: socio-demographic characteristics and fear/anxiety assessment, and practice modifications. Responses were collected via Google Forms and analyzed using the Statistical Package for Social Sciences (SPSS version 25).
Results: The study included 73 participants from various provinces and work settings. The majority (90.4%) were within the age group of 30-60 years, with a nearly equal gender distribution. Most prosthodontists (61.6%) expressed fear of transmitting the virus to their families, and 39.7% felt anxious when treating patients with potential COVID-19 symptoms. More than half (54.8%) had not resumed regular prosthodontic practice, although 87.7% provided emergency care. High adherence to safety protocols was noted, although gaps existed in the use of disposable equipment and single-use items.
Conclusions: The findings highlight significant anxiety and fear among prosthodontists in Nepal due to COVID-19, emphasizing the need for continued education and support. Adherence to updated guidelines, enhanced safety protocols and psychological support can help alleviate apprehensions and improve the overall practice environment.
Prosthodontic Management of Flabby Ridge with Modified Impression Technique: A Case Report
Authors: Maskey B , Kandel K , Regmi M
Published: October 2024

Complete denture is a commonly used prosthesis used to replace missing dentition and associated structures in oral cavity. The success of complete denture is dependent on several factors, among which the health of the underlying denture bearing area plays a significant role. Any compromises on the quality of these denture resting areas, be it in the form of inflammation, ulceration, hyperplastic tissue, to name a few, will certainly affect the overall prognosis of the dentures. Compromised quality in the form of flabby ridge is not an uncommon clinical presentation and should always be considered during denture fabrication. Attempts have been made, both surgically and conservatively to accommodate these tissues. This case report describes one of the conservative methods wherein modification in impression making using conventional impression material was undertaken.
Generating Unity and Establishing Connectivity Through Road Construction by Nepali Army
Authors: Yadav Pranav , Adhikari Ruby
Published: October 2024

In the diverse topography of Nepal, the Nepali Army has emerged as a beacon of connectivity through its strategic road construction projects. This abstract delves into the profound impact of these endeavors on unifying communities and enhancing connectivity across the nation. The Nepali Army, cognizant of the pivotal role infrastructure plays in connecting regions, has undertaken ambitious road construction projects. These initiatives transcend mere physical connectivity, serving as bridges that link disparate communities, fostering unity, and promoting economic growth. By navigating challenging terrains and overcoming logistical hurdles, the Nepali Army has woven a network of roads that traverse mountains, valleys, and remote areas, bringing isolated communities into the fold of national development. The construction of roads by the Nepali Army stands as a testament to their commitment to the nation's progress. These roads not only facilitate the movement of goods and services but also serve as conduits for cultural exchange and social integration. They act as lifelines, enabling access to essential services like healthcare and education previously inaccessible to remote populations. Moreover, these roads stimulate economic activities, unlocking the potential of remote areas by connecting them to markets and opportunities, thereby uplifting livelihoods and reducing disparities. Furthermore, the Nepali Army's road construction projects have reinforced national solidarity by promoting inclusivity and interconnectivity among diverse ethnicities and geographies. The collaborative efforts between the army and local communities have not only expedited the construction process but have also cultivated a sense of ownership and unity among the populace. So, the Nepali Army’s endeavors in road construction transcend infrastructure development; they epitomize a unifying force that bridges geographical gaps, fosters socio-economic development, and nurtures a sense of solidarity among the diverse tapestry of Nepal. These roads pave the way towards a more connected, prosperous, and unified nation, imbodying the ethos of progress through connectivity.
Paths for Exploring AI in Applied Linguistics
Authors: Chapelle Carol , Beckett Gulbahar , Ranalli Jim
Published: October 2024

AI-powered technologies have made natural language recognition and generation more accessible than ever before, opening new possibilities for applied linguistics research and practice. Like previous technological advances from word processing and accessible databases for storing texts to computer-mediated communication and automated grammar feedback, Generative AI (GenAI) invites professionals in applied linguistics to imagine new ways of teaching, learning, assessing, and researching language. Unlike previous advances, however, GenAI tools appear to forecast seismic changes in the field.
Integrating AI Tools into Instructed Second Language Acquisition
Authors: Godwin-Jones Robert , O'Neill Errol , Ranalli Jim
Published: October 2024

The public availability of ChatGPT and other AI tools is having a transformative effect on our lives in a variety of domains including education. Many language learners have for some time been avid users of AI-enabled tools such as Google Translate, text editors like Grammarly, or voice assistants. While some uses of AI products in L2 teaching and learning have generally been seen positively, the use of others has been controversial. This chapter addresses issues surrounding the integration of AI tools into instructed SLA (second language acquisition), focusing on machine translation, chatbots, and AI-based tools for written corrective feedback. It suggests that, based on existing research studies and reports on teaching practices using AI tools, L2 instructors should adopt a critical, balanced approach to AI integration in L2 instruction that leverages generative AI’s strengths while taking into account its downsides.
EFL School Teacher’s AI Assessment Literacy: An Exploratory Study
Authors: Xu Hao
Published: October 2024

This study investigates the AI assessment literacy of high school EFL teachers using the Chinese AI-powered chatbot, ERNIE Bot. Interviews and digital protocols revealed a dynamic relationship between teachers’ practical and conceptual knowledge, with both areas mutually reinforcing each other. However, technical knowledge emerged as a potentially independent domain, operating separately from practical and conceptual understandings. This finding underscores the importance of recognizing technical proficiency as a critical component of AI assessment literacy, alongside the interconnectedness of practical and conceptual knowledge.
Artificial Intelligence Shows Human-like Lens Capability in Subjectivity: Evaluating Chinese Pragmatic Capability of GPT-4 via Microsoft Copilot with Direct Prompting
Authors: Su Danjie , Goslar Kevin
Published: October 2024

Communication with humans requires the ability to decode and convey “lenses”—subjective evaluations of reality—because humans make sense of the world through lenses and convey them through language. Can Artificial Intelligence decode and convey subjectivity in lenses? Exploring this uncharted area of pragmatic capability sheds light on AI’s linguistic capabilities. This study provides an initial linguistic evaluation of the pragmatic capability of Large Language Models (LLMs) by evaluating GPT-4 through Microsoft Copilot in expressing, comprehending, and explaining subjective lenses in Chinese, using zero-shot, single-turn direct prompting. We qualitatively evaluated 51,168 AI-generated words using the Nursing-Home Test repeated over six months. Findings indicate that Microsoft Copilot exhibits human-like pragmatic capability in lens-related subjectivity, but specific abilities vary and are prompt sensitive. Production matched “Language-Teacher.” Comprehension matched “High-Schooler.” Knowledge matched “Elementary-Schooler” (pragmalinguistic) and “College-Student” (sociopragmatic) with general prompts and “Language-Teacher” with academic prompts. These findings highlight GPT-4’s potential in language education, emphasizing the importance of prompt design and qualitative linguistic evaluation of AI language
Performance Evaluation of Tourist Destinations: The Case of Vlora Region
Authors: Agaraj (Shehu) Xhiliola , Pulaj (Brakaj) Enida
Published: October 2024

Management of tourist destinations oriented towards sustainable development is necessary for a competitive international market. The impor­tance of the authorities responsible for the management of tourist destina­tions, the coordination of activities, and the orientation of interest groups in the design and implementation of policies towards a common goal are in fo­cus today. Given the role, responsibilities, and importance of the authorities re­sponsible for the management of tourist destination management, the need to evaluate their performance in terms of the management and marketing ini­tiatives of the tourist destination is evident. The purpose of this research is to evaluate the performance of the responsi­ble authorities regarding the performance evaluation indicators. The research methodology is based on the collection of secondary data on the performance indicators, which belong to the last few years. The secondary data collected for each indicator served to complete the ques­tionnaire that evaluates the trend of the performance indicators of the local, regional, and national authorities responsible for the management of the tourist destination. This research provides an understanding of the performance evaluation of the responsible authorities in tourist destination management as well as the im­portance of evaluating performance indicators in the sustainable manage­ment of tourist destinations and taking appropriate measures related to their improvement.
Promoting Gastronomy Tourism in Croatia: Comparing Food and Wine Experiences
Authors: Hanžek Matea , Sušić Gordi
Published: October 2024

At a time when tourism destinations are looking at prospects to expand their offering, it is of significant importance to echo on opportuni­ties these offer for gastronomy tourism development. This paper provides an overview of gastronomy and tourism as an attraction for tourism, beforehand moving on to the case of Croatia, whose geographical position in the South­east of Europe made it one of the ideal locations for gastronomy tourism de­velopments. In attempting to at least partially answer the question of wheth­er Croatia is portrayed and perceived as a destination with a rich gastrono­my tourism offering, this research relies on content and semiotic analysis of the official Croatian National Tourist Board website in order to shed light on the modes in which representations of gastronomy tourism are included in the cur­rent tourism campaign. The research concludes with reflections on the overall importance of gastronomy tourism for the development of Croatia as an allur­ing gastronomy destination and highlights the role meaningful inclusions of representations of gastronomy tourism can play in contributing to strategical­ly desirable shifts in the country’s overall destination image.
Gastronomy Tourism Experiences: A Review and Future Research Agenda
Authors: Laškarin Ažić Marina , Rašan Dora , Mikinac Krešimir
Published: October 2024

This research aims to analyse an extended body of literature on gas­tronomy tourism experiences (GTEs) and propose a future research agenda. To achieve this purpose, a literature review was conducted. The review results im­ply that research in this field had a peak moment before COVID-19, specifical­ly in 2018 and 2019, in North America and Asia. During this period, scholars predominantly applied quantitative methods, focusing on keywords such as service quality, satisfaction, memory, and behavioral intentions to study GTEs. This review suggests new directions for future research in the field of GTE. In particular, researchers should focus on exploring adaptive strategies to exter­nal shocks, value for money, the impact of AI on multisensory experiences, and enhancing authenticity through collaboration with local communities.
Influence of the Binder properties on Silicon Anode for Solid-State Batteries
Authors: Tak Heetae , Ko Yuna , Oh Sungbin , Park Yechan , Park Hyunjung
Published: October 2024

Silicon (Si) has been considered as one of the most promising anode materials because of its high theoretical capacity of 4200 mAh g−1. However, the huge volume change and side reactions upon cycling cause poor cycle performance and limit a use of Si for the commercialization. Recently all solid-state batteries open up new possibilities for an introduction of high capacity electrode materials due to their ability to operate under compression, which can mitigate electrode volume expansion. Herein, we study an effect of multifunctional polymeric binders on silicon anode for all solid-state batteries enabled by a sulfide Li6PS5Cl electrolyte. The Si electrode manufactured by a single rigid polymer shows stable electrochemical properties because of applied external pressure and potential hydrogen bonds between carboxyl groups and Si particles, resulting in a mitigation of a volume change. In addition, an introduction of multifunctional network binders to the Si-based electrode leads to a high discharge capacity of 3000 mAh g−1 and stable cycle performances at room temperature.
O DESAFIO DO ENSINO COLABORATIVO NA ESCOLA INCLUSIVA
Authors: COSTA-RENDERS Elizabete Cristina , COUTINHO Regina Izabel D’Andrea
Published: October 2024

Este artigo apresenta resultados de uma pesquisa que colocou em questão os desafios da inclusão escolar, especialmente, considerando as demandas do ensino colaborativo. A pergunta foi: quais as contribuições do ensino colaborativo para a inclusão escolar? O objetivo geral desta investigação foi identificar e problematizar como tem se dado o ensino colaborativo entre professores especialistas e professores regentes no processo de inclusão escolar. Foi uma pesquisa narrativa, os instrumentos foram cartas pedagógicas e roda de conversa. Os participantes da pesquisa foram quatro professoras regentes e duas professoras especialistas. Os resultados apontaram que ensino colaborativo em sua verdadeira concepção ainda não ocorre na maioria das unidades escolares, no entanto existem diversas ações colaborativas. Apontou-se também que é necessário proporcionar aos profissionais tempo e espaço para estas interações.
FORMAÇÃO DOCENTE NA REDE MUNICIPAL DE ENSINO DE SALVADOR/BA, NO CONTEXTO DA PANDEMIA DE COVID-19
Authors: VASCONCELOS Cristiane Regina Dourado , LEAL Ione Oliveira Jatobá , NOVAES Ivan Luiz , ARAUJO Jomária Alessandra Queiroz de Cerqueira
Published: October 2024

Considerando a importância da formação docente para garantir a oferta de uma educação de qualidade, especialmente em redes públicas de ensino e, em contextos atípicos, como os gerados pela Pandemia de covid-19, realizamos uma pesquisa que objetivou contribuir para que a formação docente pudesse, nestes contextos, ser reconhecida e aprimorada. No desenvolvimento, optamos pelo método qualitativo, revisão de literatura e aplicação de questionário misto. A análise de conteúdo permitiu evidenciar que a maioria dos docentes da Rede Municipal de Salvador não estava habilitada para atuar no ensino remoto e que, mesmo depois de mais de dois anos de pandemia, esta rede não investiu em formações para seus professores. De outro lado, identificamos um movimento auto formativo por parte de muitos docentes. Ademais, constatamos que o modelo de ensino utilizado no período não contemplou o necessário acesso de estudantes e professores a recursos tecnológicos e digitais.
SAPO-34 Zeolites/Polyamide (PA) Mixed-Matrix Membranes with Enhanced CO2/CH4 Separation Performance
Authors: Mondal Barun Kumar , Bisoi Soumendu
Published: October 2024

A novel mixed-matrix membrane (MMM) comprising semi-fluorinated aromatic polyamide (PA) and Submicron SAPO-34 zeolites filler was synthesized and evaluated for gas separation capabilities targeting CH4, N2, O2 and CO2. Mixed-matrix formulations represent a promising strategy to mitigate the permeability-selectivity compromise inherent in polymer membranes by integrating fillers. The properties of the filler are pivotal in dictating the performance of MMMs. MMMs were synthesized with varying weight percentages (0%, 5%, and 10%) of Submicron SAPO-34 zeolites filler incorporated into the semi-fluorinated PA matrix. The MMM incorporating 10 wt% Submicron SAPO-34 displayed CO2 permeability and a selectivity of 44.20 for CO2/CH4 gas pairs, showcasing enhanced CO2/CH4 separation performance credited to the existence of Submicron fillers. SEM imaging confirmed the uniform combination of Submicron SAPO-34 filler into the polyamide matrix. This investigation presents a promising pathway for developing efficient and high-performance separation membranes.
A Brief Review on Recent Rh-Catalyzed C-H Bond Activation in Pyridines and Quinolines
Authors: Paira Rupankar
Published: October 2024

In this short review article, attempts have been made to provide a concise pathway towards the recent advancements of organometallic chemistry, showcasing the broad spectrum of applications of Rh-catalysis in C-H bond activation and the transformative impact it has on society. By exploring these current developments of the last decade and the future opportunities of various sub-disciplines, it can certainly be hoped that the implementation of these works on other pyridine, oxazole, and aza-heterocycle derivatives will instigate further research and collaborative endeavors, fostering a deeper understanding of the limitless potential of rhodium chemistry. The continuous exploration and application of Rh-catalyzed C-H activation promise to revolutionize synthetic methodologies, driving innovation and progress across multiple scientific domains.
Anticancer Activities of 1,3-Diaryltriazene Based Compounds: An Overview
Authors: Roy Sarkar Chhandasi Guha
Published: October 2024

The present article discusses the anticancer and antitumor properties of aliphatic and aromatic triazene compounds and their derivatives. The triazene molecule is an essential tool in organic synthesis, acting as the starting material or the reactive intermediate in various organic transformations. In addition, it possesses interesting biological properties. The most explored biological application of the triazene moiety is its cytotoxic effect. The present review highlights the antineoplastic activities of the triazene molecule in vitro and in vivo, as well as its different derivatives and complexes.
Recent Developments in the Biological Activities of 2- Pyrazoline Derivatives
Authors: Mukherjee Attreyee
Published: October 2024

Pyrazolines, a significant class of heterocyclic compounds, have gathered attention in medicinal chemistry for their diverse biological activities. In recent years, scientists have explored structural modifications, leading to pharmacologically active derivatives incorporated into therapeutic agents. 2-pyrazoline scaffold is found to be present in various important drug molecules e.g antipyrine, phenylbutazone, oxyphenbutazone, ibipinabant, ramiphenazone etc. 2- Pyrazoline derivatives have been reported to possess broad-spectrum biological activities such as antimalarial, antidepressant, antiinflammatory, antitumor, antibacterial, anticancer and also MAO (monoamine oxidase), acetylcholine esterase (AChE), cannabinoid (CB1) etc. inhibitory activities. Pyrazoline based drugs are also used to treat neurodegenerative diseases such as Alzheimer's disease, Perkinson’s disease, psychiatric disorders etc. The variation of substituents in the pyrazoline scaffold has had a tremendous impact on biological activity. It has been shown from different research studies that the electronegativity and steric factor of the substituents present in N-1, C-3 and C-5 positions have a great influence on the biological properties of the compounds. This article will cover numerous biological significances of 2-pyrazoline based compounds in medicinal chemistry and SAR (structure-activity relationship) for the improvement of therapeutic implications.
Effect of tie beams on the behavior of isolated foundation systems
Authors:   Department of Civil Engineering, University of Moratuwa, Sri Lanka, Gunathilaka L.T.D. , De Silva L.I.N.
Published: October 2024

The stability of isolated foundation systems is crucial to the structural integrity and safety of buildings, especially in regions with varying load conditions. Tie beams, widely used to connect isolated footings, play an integral role in this process. However, their impact on bearing capacity and settlement characteristics is often overlooked in standard analyses. This research primarily aimed to explore the influence of tie beams on the settlement characteristics and overall performance of isolated foundation systems. A comprehensive methodology combining both model experiments and finite element analysis (FEA) was employed to achieve these objectives. Initially, two model experiments were conducted using small-scale prototype structures: one with a single isolated footing and another with two footings connected by a tie beam. These experiments aimed to validate the FEA results by comparing the experimental settlement data with the simulated outcomes. Two distinct models of the foundation system were developed, each based on a typical three-story building with 16 isolated footings. This setup was designed to simulate a realistic structural scenario and evaluate the impact of tie beams under varying loading conditions. The footings were loaded with varied loadings in the range of 350 kN to 1300 kN to simulate real-world scenarios. One model included tie beams connecting the footings, while the other omitted them, allowing for a comparative analysis of their effects on settlement and structural integrity. The findings reveal that incorporating tie beams significantly reduces the maximum individual settlement, with a decrease of up to 22 mm (43%). Furthermore, the inclusion of tie beams narrowed the variation in settlement across individual footings, resulting in a more uniform distribution of settlements. Differential settlements were notably reduced, with all values staying under 2 mm, reflecting a 92% reduction compared to the model without tie beams. In conclusion, the inclusion of tie beams significantly reduces both settlements and differential settlements, contributing to a more uniform distribution of loads across isolated foundation systems. While positioning tie beams at the footing level may further reduce settlements, it also increases the forces acting on the tie beams, necessitating higher reinforcement and potentially leading to increased construction costs. The research recommends maintaining tie beams at ground level in general construction practices, except in scenarios where minimizing settlements is critically important. This study underscores the significance of tie beams in enhancing the performance and stability of isolated foundation systems, highlighting their essential role in mitigating settlement-related issues.
Effect of preloading and endplate imperfections in bolted connections: Moment-rotation characteristics through explainable artificial intelligence
Authors:   Department of Civil Engineering, University of Moratuwa, Dharmawansha D.A.S.T. , Herath H.M.S.T.
Published: October 2024

Stainless-steel is a popular engineering material due to its durability, high resistance to corrosion, aesthetic appeal, ease of construction and maintenance, recyclability, and ductility. It is often used in a wide range of structural engineering applications such as frames, buildings and bridges. Across these diverse applications, steel connections are a crucial component as they ensure the unified performance of the structure. This study investigated the effect of bolt preloading, endplate imperfections, and geometric parameters on the connection moment rotation response of extended endplate bolted connections. This study employed a validated numerical model against experimental results from the structural testing laboratory of the University of Moratuwa, further validated against experimental results available in the literature. The validated numerical model was then used to investigate the impact of varying levels of bolt preloading and imperfections on rotational stiffness. The results showed that rotational stiffness increases by 134% with ultimate preloading. Residual deformation from welding causes initial imperfections in bolted endplate connections, with V-shape, C-shape, and W-shape imperfections identified in the literature. This study examines the impact of C-shape and V-shape imperfections on rotational stiffness. The results indicate that V-shape imperfections have minimal influence if the level of imperfection is limited to the criterion of (endplate depth)/300, while C-shape imperfections significantly affect rotational stiffness, even within acceptable limits. A novel explainable machine learning approach was utilized to investigate the influence of geometric parameters on the moment-rotation response of connections. A comprehensive numerical modelling approach (validated using related work) was used to generate data for various input features, such as endplate thickness, bolt diameter, overall section width, overall depth, web thickness, flange thickness, vertical bolt spacing, and horizontal bolt spacing. An artificial neural network (ANN), extreme gradient boosting (XGB), random forest (RF), and k-nearest neighbours (KNN) were employed alongside Shapley additive explanations (SHAP) to interpret the trained models. Analysis shows that endplate thickness strongly governs the moment-rotation behaviour of the bolted endplate connections. Moreover, SHAP explanations align with the generally accepted behaviour of steel extended endplate bolted connections according to EN 1993-1-8.
Influence of number of plies on flexural behaviour of ultra-thin woven composites
Authors:   Department of Civil Engineering, University of Moratuwa, Sri Lanka, Wanasinghe W.M.C.S. , Mallikarachchi H.M.Y.C.
Published: October 2024

Deep space missions necessitate the development of weight-sensitive structures capable of supporting multiple operational configurations. The high strength-to-weight ratio and flexible material properties of woven fibre composites make them ideal for aerospace structures. Epoxy laminates reinforced with carbon fibre are often used in primary and secondary aircraft structures. Woven fibre composites have greater advantages compared to unidirectional fibre lamina. The number of fibres in a yarn and the type of weave determine the material properties. The high curvature experienced by space structures during folding and deployment points out the critical importance of understanding their bending behaviour for optimising future designs. Experimental studies show a significant reduction in the bending stiffness of ultra-thin woven composites when subjected to high curvatures according to the literature. The in-plane properties of woven laminates have been estimated through the development of numerous micromechanical analytical methods. Although in-plane properties can be accurately determined through Classical Lamination Theory (CLT) for thin woven composites, the flexural properties tend to over-predict by 200 – 400%. This paper introduces micro-mechanical models to capture the impact of ply count on the mechanical characteristics of thin woven fibre composites. Accordingly, this study expresses a geometric model with solid elements that simulate the effect of the two waviness with increasing plies in a Representative Unit Cell (RUC) to analyse the bending stiffness reduction near failure. The study focuses on a plain-woven carbon fibre composite having fibres arranged in an in-phase configuration. A finite element pre-processor, TexGen software, is used to generate the representative unit cell geometry. This generated RUC model is then imported into the commercial finite element software Abaqus/Standard to simulate the mechanical behaviour. The numerical results are validated with experimental results obtained from the literature. In addition, the study aims to investigate the behaviour of results derived from CLT under varying numbers of plies. The reduction in bending stiffness between CLT predictions and finite element (FE) simulations across all ply configurations varies from approximately 500% for single-ply laminates to 90% for three-ply laminates while 150% for two-ply laminates, highlighting the efficacy of the CLT approach in accurately predicting bending properties with increasing number of plies. One reason for this deviation is that CLT does not account for the inherent waviness of woven fibre composites, which generally exhibit a sinusoidal wave pattern. This waviness is reduced with an increasing number of plies, leading to a closer alignment between CLT and FE results.
Effect of urban vegetation cover on CO2 reduction in the city
Authors:   Department of Civil Engineering, University of Moratuwa, Sri Lanka, Chanika H.K.P. , Weerasinghe N. , Halwatura R.U.
Published: October 2024

Rising urban carbon dioxide levels have emerged as a critical issue due to their adverse effects on public health and the environment. Trees are a natural and sustainable solution to mitigate urban carbon dioxide (CO2) concentrations, as they absorb CO2 from the atmosphere through photosynthesis. However, the specific relationship between tree density and CO2 concentration within cities is unclear. The main objectives of this research are to determine the relationship between tree density and CO2 concentration reduction in cities and to identify the optimum tree density to reduce the CO2 level in the city to obtain the required CO2 level. For this study, data were collected in the densely urbanized city of Colombo and various urban areas within the Hambantota district. Tree densities and CO2 concentration reduction data were collected from 300 sample plots, each with a fixed size of 50m x 50m, near roads in selected urban areas. When calculating tree density, it is important to calculate canopy volumes of trees. It depends on canopy height, crown diameter and canopy shape. The tree density of the sample plot was calculated by dividing the total canopy volume by the area of the sample plot. A digital portable CO2 meter was used to measure the CO2 level. First the CO2 concentration was measured at the centre of the road and then the CO2 concentration was measured at the centre of the sample plot. The reduction in CO2 level was calculated by the difference between these two readings. By analysing tree densities and CO2 concentration data collected through field data studies, a linear relationship was obtained between tree density and CO2 concentration reduction in urban areas. The plotted line got a R2 value of 0.8806 indicating a well-fitting model. Therefore, this linear plotted line can be described as a reasonable fitted line representing all collected data. Also, the data was classified based on the CO2 concentration in the centre of the road and the behaviour of the CO2 concentration reduction Vs tree density relationship was studied in each range. A linear relationship was obtained in each of those ranges. When all the collected data were classified as residential and non-residential based on the usage of the sample plots, the R2 values obtained from those graphs were higher than the R2 value of the graph drawn without classification. The R2 value of the graph for non-residential areas has increased relative to the value of the graph for residential areas. Accordingly, classifying in this manner led to an increase in the accuracy of the relationship. Using these relationships, the optimum tree density required to obtain the required CO2 reduction in urban areas can be identified. The results of this study will be valuable for policymakers and urban planners looking for ways to improve air quality and create more sustainable urban environments.
Full-field deformation measurement system for early age concrete cracking
Authors:   Department of Civil Engineering, University of Moratuwa, Sri Lanka, Silva K.G.N.S.S. , Gamage E.S. , Mallikarachchi H.M.Y.C.
Published: October 2024

Identification of the risk of early age shrinkage cracks in fresh concrete is essential as they can lead structures to unserviceable conditions. These cracks occur when the shrinkage induced stresses exceed its tensile strength capacity of fresh concrete. In general, the risk of early age shrinkage cracks is evaluated by inspecting the tensile strain development of fresh concrete. Hence measurement of strain distribution of early age concrete is essential. However, measuring displacements and strains in fresh concrete is challenging due to its semi-solid state, which prevents the direct use of contact-based deformation measuring tools. There were several techniques used to measure the deformations of early age concrete. Some studies have used strain gauges attached to the moulds while some measured deformations by attaching strain gauges to posts cast into the concrete. However, deformations of moulds are not the same as that of concrete and semi-solid state of fresh concrete leads to relative movements between posts and accuracy can be compromised. Recent research has processed images, taken at specific time intervals, to calculate the deformation of preidentified targets. This overcame the challenges faced with contact-based methods but suffered from poor resolution and required image corrections. With recent rapid advancements in computer processing units and camera technology, avenues are now available to use machine vision techniques such as Digital Image Correlation (DIC). This study aims to develop an in house DIC based measurement system for evaluating full-field deformation of early-age concrete. An in-house 3D digital image correlation-based system was utilized for this purpose with a direct tensile apparatus, with modifications made to enhance accuracy. Great care was taken during the experiment procedure to distribute the speckle pattern on the semi-solid concrete surface. The modified DIC system was capable of generating full-field deformations and strain distributions of fresh concrete which is after 1 hour from casting. The suitability of the modified system was evaluated through experimental analysis. Physical measurements were obtained using a vernier calliper and the results depict that the developed technique can measure strains with an accuracy of over 94%. The precision of the system can be enhanced by optimizing the distribution of the speckle pattern. It is intended to utilise the developed DIC system to investigate the tensile properties of early-age concrete for different mix proportions.
Utilization of waste plastic HDPE with filler materials (fly ash and bottom ash / ceramic waste) as alternatives to natural coarse aggregates; strength properties
Authors:   Department of Civil Engineering, University of Moratuwa, Sri Lanka, Weerasinghe D.N. , Wickramasinghe D.P.H.K. , Rathnayake R.M.K.M. , Halwatura R.U.
Published: October 2024

The increasing costs of construction materials and the rapid depletion of natural aggregates have highlighted the urgent need for sustainable alternatives in the construction industry. In this context, plastic waste, particularly high-density polyethylene (HDPE), has become a significant environmental challenge due to the global surge in plastic production and disposal. This study investigates the feasibility of using synthetic coarse aggregates derived from post- consumer HDPE plastic waste, combined with various filler materials, as an environmentally friendly substitute for natural aggregates in concrete. The research focuses on developing two types of synthetic aggregates, one consisting of HDPE mixed with fly ash and bottom ash and the other comprising HDPE combined with ceramic waste powder. The synthetic aggregates were created by varying the proportions of HDPE and filler materials, followed by extensive testing of the resulting plastic aggregate cubes for compressive strength and shrinkage. The results revealed that the optimal mix for the first type of aggregate consisted of 60% HDPE, 15% fly ash, and 25% bottom ash, while the second type achieved the best performance with a blend of 80% HDPE and 20% ceramic waste. These compositions demonstrated the highest compressive strength, making them the most effective synthetic aggregate blends for potential use in construction. Subsequent to developing these optimal mixes, concrete cubes of different grades (15, 20, 25, and 30) were cast using both natural aggregates and a full (100%) replacement with the developed plastic aggregates. The findings of the study indicate that concrete made with synthetic plastic aggregates exhibited lower compressive strength and density compared to traditional concrete. However, these materials also resulted in significantly reduced production costs. Notably, replacing conventional natural aggregates with synthetic aggregates in higher- grade concrete mixes led to substantial cost savings, with reductions in production expenses ranging from 20% to 24% per footing in a sample building. The research underscores the potential of incorporating synthetic coarse aggregates made from HDPE plastic waste, along with fly ash, bottom ash, and ceramic waste, as a sustainable and economically viable alternative to natural aggregates in concrete construction. The use of such synthetic aggregates not only addresses environmental concerns related to plastic waste but also offers a cost-effective solution that does not compromise the structural integrity of the concrete. These findings contribute to the growing body of knowledge on sustainable construction practices, presenting a promising pathway for the industry to reduce its environmental footprint while maintaining economic efficiency.
Influence of Processing Conditions on the Properties of High Paraffin Oil and Sediment Composition
Authors: Volkova G. I. , Zubarev D. A.
Published: October 2024

The influence of ultrasonic treatment, a polymer additive, and their combined effect on the structural and rheological properties of high paraffin, low-resin oil and the composition of separated sediments is studied. The oil was processed in the ultrasonic field (with the field intensity of 6 W/cm2, the frequency of 22 kHz, and the time of 1–10 min). The sedimentation process was carried out at an ambient temperature of 30°С and a coldfinger temperature of 5°С. A Brookfield DV-III ULTRA rotary viscometer was used to determine the viscosity-temperature parameters of the oil. Ultrasonic treatment for 1 min and a polymer additive (0.05 wt%) leads to a decrease in the viscosity by a factor of 5 and in pour point by 8°C. The introduction of the additive and the complex effect contribute to changes of the molecular weight distribution of n-alkanes in the sediments, viz. the second distribution maximum shifts to the region of higher molecular weight components and the concentration of n-alkanes ∑С17Н36–С33 Н68 increases.
Transformations of Asphaltenes A1 and A2 During Atmospheric Residue Cracking
Authors: Sviridenko N. N. , Sergeyev N. S. , Urazov Kh. Kh.
Published: October 2024

In this work, various conditions for cracking the atmospheric residue of the Novokuibyshevsk oil refinery are considered and analyzed. The optimal conditions for cracking the atmospheric residue have been established as a temperature of 450°С and a duration of 30 minutes. These conditions result in an additional 51.8 wt % of light fractions due to the destruction of 31.3 wt % of resin-asphaltene components. The study also examines the compaction products formed during cracking. The study analyzed two fractions of asphaltenes (A1 and A2) isolated from liquid cracking products using the method of structural group analysis. It was found that the duration of atmospheric cracking had an impact on the formation of secondary asphaltenes.
Influence of Mineral Components on the Composition of Oil Shale Organic Matter Cracking Products
Authors: Pantilov P. V. , Gorbunova M. V. , Krivtsov E. B.
Published: October 2024

The composition of the oil shale cracking products (OS) from the Kashpirskoe deposit, as well as kerogen isolated from it, has been studied. The influence of OS mineral components on the material balance and cracking products composition is shown. It has been established that the amount of gaseous and solid products in kerogen cracking products decreases, and the yield of liquid products increases. Removal of mineral components from OS leads to an increase in oil content and a decrease in asphaltenes in liquid cracking products, the resin content changes slightly, and the yield of light fractions increases. The peculiarities of the influence of mineral components on the structural-group characteristics of resins and asphaltenes of liquid cracking products have been established. The absence of mineral components leads to enlargement of resin molecules; asphaltene molecules, on the contrary, become more compact.
Study of the Composition and Distribution of Compounds in Oil-Contaminated Peat Soils of the Mamontovskoye Field (Khmao-Yugra)
Authors: Fedorov D. V. , Serebrennikova O. V. , Elchaninova E. A. , Kadychagov P. B.
Published: October 2024

Using the chromatography-mass spectrometry (CMS) method we have studied the changes in the composition of oil compounds in a vertical section of peat soil on the territory of the Mamontovskoye oilfield (KhMAO, Western Siberia) 6, 12 and 18 years after oil pollution. With an increase in the pollution period, the distribution of individual compounds in the surface layer of the soil is largely determined by time-progressing biodegradation reactions. In the underlying layers at a depth of 10–50 cm, the composition and content of oil components indicate the influence of migration processes on their differentiation.
Dwarf Dolly Varden Salvelinus malma (Salmonidae) from Mountain Lakes of the Kamchatka Subnival Belt
Authors: Esin E. V. , Medvedev D. A. , Korostelev N. B. , Markevich G. N.
Published: October 2024

Charrs of the genus Salvelinus (Salmonidae) exhibit diverse patterns of heterochrony throughout their ontogeny, resulting in contrasting intraspecific phenotypic variation. This study focuses on isolated populations of Dolly Varden charr, Salvelinus malma, inhabiting cold-water lakes within the subnival belt on the Kamchatka Peninsula. Our study reveals a previously undescribed trend towards paedomorphosis in these populations. Specialization is associated with inhibition of somatic growth compared to the widely distributed migratory (anadromous and river-lake) Dolly Varden from open water systems. Juvenile charrs from landlocked lakes differ in relatively high muscle fat content. Rates of sexual maturation and morphological differentiation remain similar to those of migratory populations. Paedomorphic trends in skull structure are insignificant and the numbers of meristic serial elements do not decrease. Charrs from landlocked mountain lakes grow to a maximum length of 20 cm reaching an age of eight to nine years, while the median age of spawners is 6.2 years. Migratory charrs have the same lifespan, but spawners are 1.6–2.0 times larger. Dwarfism tends to evolve over a small number of generations, as similar phenotypes have been described in populations from the lakes originated more than 12,000 and 400 years ago.
Locomotor Activity of the Intact and Visually Deprived Senegal Bichir Polypterus senegalus (Cladistia) at Different Water Temperatures
Authors: Kasumyan A. O. , Zdanovich V. V. , Sataeva V. V.
Published: October 2024

For the first time, the locomotor activity of the intact and visually deprived Senegal bichir Polypterus senegalus was assessed at different water temperatures (20, 25, 30 and 34°C). Using the open field method, it was shown that in intact fish, with increasing temperature, locomotor activity increases (most rapidly in the range of 20–25°C) and reaches a maximum at a temperature of 30°C, which can be close to the temperature optimum (or correspond to it) for the Senegal bichir. In visually deprived fish, locomotor activity is maximum at 20°C and decreases monotonically with increasing temperature; all indicators of locomotor activity (frequency of crossing test lines; time spent for the test line crossing; distance covered by the fish, swimming speed) vary in visually deprived fish weaker than in intact ones. The discovered differences in the behavior of intact and visually deprived fish indicate the presence of a functional relationship between vision and locomotor activity in evolutionarily ancient Cladistia.