bluuebunny/crossref_metadata_2025 huggingface dataset:
Teaching Population Panel Management: A Patient Outreach Activity in a Family Medicine Clerkship
Authors: de la Cruz Maria Syl , Cymring Barbara , Padgaonkar Pooja , Langley Jennifer K.
Published: July 2024

Background and Objectives: The delivery of population health education in medical school can be challenging. We developed a patient outreach activity for third-year students to teach them the role of population panel management in primary care.
Methods: The family medicine undergraduate medical education and population health teams collaborated to develop an educational patient outreach toolkit. After an orientation, family medicine clerkship students were assigned to call patients on their faculty adviser’s patient panel to discuss care gaps and identify barriers and potential strategies to improve care. After the experience, students completed reflection questions, which we analyzed.
Results: From February to August 2022, 82 third-year medical students participated in the patient outreach activity during their 6-week clerkship. Of the 1,235 total attempted calls, 24% of the patients scheduled their appointments afterward. After analyzing the reflective student feedback, we identified six main takeaways, which focused on the importance of population health, the identification of barriers to care, positive and negative feelings that students experienced when making calls, student self-identified areas of growth, and the fragmentation/inefficiency of the health care system.
Conclusions: An opportunity exists to continue to teach students about how to communicate with patients about their health and how to address and improve social determinants of health. This curricular activity can be a step toward efforts to align population health and clinical practice and a way for medical students to add value by educating patients.
Figuração e potências da trabalhadora doméstica no cinema brasileiro recente
Authors: Carrière Romane
Published: July 2024

Neste artigo, propomos analisar a figuração da trabalhadora doméstica em três filmes recentes: Trabalhar cansa (2011), realizado pela dupla Juliana Rojas e Marco Dutra, O som ao redor (2012) e Aquarius (2016), ambos realizados por Kleber Mendonça Filho. Esses filmes valem-se de elementos de suspense e/ou sobrenaturais, o que traz consequências na figuração da trabalhadora doméstica. Trazemos a hipótese de que as modalidades utilizadas pelos filmes para representar a trabalhadora doméstica questionam, sob uma nova luz, as dominações e desigualdades sofridas por essa categoria profissional.  Assumimos que esses filmes desfazem a representação convencional da trabalhadora doméstica no cinema, porque ela aparece como uma figura fundamentalmente outra, uma alteridade absoluta que vai escapar ao entendimento tanto dos empregadores, quanto do espectador. Consideramos que o trabalho de historicização efetuado pelos filmes nos convida a pensar a herança do passado colonial e escravista do Brasil que se manifesta no trabalho doméstico, ainda marcado por formas de “colonialidade” (Quijano, 2005). Ao longo deste ensaio, estudaremos o papel subversivo e político da personagem da trabalhadora doméstica que perturba a narrativa dos filmes, desestabiliza as relações com os empregadores, desnaturaliza o trabalho doméstico e nos convida a encarar alguns impensados do trabalho doméstico. Mediante análises fílmicas, mostraremos que essas profissionais se valem de três estratégias para aparecer e ficar na imagem nos filmes: manter distância, ocupar o plano e tornar-se fantasma.
Retrospectiva Sarah Maldoror
Authors: Bergamaschi Novaes Barbara
Published: July 2024

Esta resenha discute a sensação de estranheza e familiaridade vivida por uma brasileira em Lisboa, conectando essa experiência pessoal à obra da cineasta anticolonial Sarah Maldoror (1929-2020). Maldoror é reconhecida como a primeira mulher a dirigir um longa-metragem em um país africano. Neste texto - um híbrido entre crítica, diário de bordo e crônica - abordamos a trajetória de Maldoror, a partir dos filmes vistos na retrospectiva de sua obra na Cinemateca Portuguesa. A resenha oferece breves análises dos seus filmes mais célebres, incluindo “Monangambée” (1969) e “Sambizanga” (1972), como também relatos acerca de seus filmes de mais difícil acesso, tais como Un Masque à Paris (1978) e Un dessert pour Constance (1981). A resenha destaca a parceria entre Maldoror, Aimé Césaire e cineastas da Rive Gauche francesa, e como estas  trocas intelectuais estão patentes em sua fatura fílmica e na sua luta anticolonial. Relaciona-se também a obra de Maldoror com a literatura e o movimento surrealista, ressaltando a sua habilidade de criar jogos com as palavras, transitando entre diferentes saberes e sabores, subvertendo a língua e a cultura do colonizador por meio da própria linguagem cinematográfica.
vAImpir *publication/artifact
Authors: Kenneth Russo
Published: July 2024

vAImpir: AI as a vampiric tool. //publication-artifact//
The vAImpir project (виипир) takes as its starting point AI as an axis of self-reflection: on the one hand, as a tool for content expansion and artistic exploration, and on the other, as a tool that parasites with representations of the historical biases that accumulate in the databases within the framework of the digital humanities, and that in some way describe the current moment, in which the understanding of the world unfolds on a digital interface where authorship is diluted. A reflection-action from diffusion models on the narrow margins that separate the space of reality and the space of fiction. This project is contextually fed by the work Vampir-Cuadecuc (Pere Portabella, 1970).
Virtual education space at ESP classes: challenges and perspectives
Authors: Humeniuk Iryna , Trofymenko Anastasiia , Kruk Alina , Melnyk Iryna
Published: July 2024

Higher education has moved to various online platforms in recent years, with virtual classes established following national norms during the COVID-19 pandemic and wartimes in Ukraine. Early engineering education, namely teaching ESP, is directly related to the development of soft skills like time management, teamwork, creative thinking, and digital literacy as well as practical talents like sketching, computer graphics, mechanism projecting, etc. This study examines qualitative data collected from second-year engineering students at the Higher Educational Institution “Podillia State University”, Ukraine. The paper is based on instructors’ thoughtful observations of instruction in both times of war and the COVID-19 pandemic. The research conclusions offer some important things to think about when assessing the virtual classroom long-term effects on language education and second-year study techniques. The results of this study showed that the use of technology in second-year engineering education, namely the TED Talks application, promoted creative teaching strategies, increased digital literacy, and improved teamwork. Even if online learning achieved its learning goals, there were drawbacks, such as social isolation and low motivation. The study highlights the value of looking at virtual language studios and integrating technology in early engineering education, providing chances for future research and curriculum development. These results are pertinent to educators worldwide who instruct second-year mechanical engineering students in ESP.
Effect of forest stand thinning on tree biomass carbon stock
Authors: Bickovskis Karlis , Samariks Valters , Jansons Aris
Published: July 2024

Forest store significant amount of carbon and carbon stock in living tree biomass is amongst the largest carbon pools in forest ecosystems. Forest management practises, such as thinning, can improve tree growth, and increase carbon sequestration in forest ecosystems, thus be beneficial for achieving climate change mitigation goals. However, information about additional carbon stock increase as a result of thinning in the first 10 years is lacking in hemiboreal region. Therefore, this study investigates the additional carbon stock of the most common tree species (Scots pine, Norway spruce, and Silver birch) on mineral soils in hemiboreal forest of Latvia, focusing on the effects of thinning 5 and 10 years after. The aim of the study was to evaluate the effect of first commercial thinning on gained additional carbon stock of living tree biomass. Our results show, that thinning has a positive effect on additional carbon stock and timely performed thinning is crucial for the best outcome. Performing thinning in a timely manner results in a significantly higher additional carbon stock, as trees exhibit a more pronounced response, with biomass production peaking at younger age. Positive effect of thinning on additional carbon storage decreases with the age. This study provides valuable insights into the nuanced relationships between the tree species, stand age, and the temporal effects of thinning on carbon accumulation. The observed trends underscore the importance of forest management strategies that consider both species-specific traits and stand age for effective climate change mitigation.
Economic efficiency of methods for surveying rural infrastructure: assessment of accuracy, cost and duration
Authors: Openko Ivan , Shevchenko Oleksandr , Stepchuk Yanina , Tykhenko Ruslan , Tykhenko Olha , Horodnycha Anastasiia
Published: July 2024

The study delves into a pivotal realm of rural infrastructure management by scrutinizing the efficacy of diverse building survey methodologies. The assessment encompassed laser scanning, total station surveying, and smartphone-enabled LiDAR, encompassing a meticulous evaluation across key dimensions: accuracy, economic cost, and time efficiency. The overarching objective was to pinpoint the most optimal surveying approach tailored for rural landscapes, considering the delicate equilibrium between cost-effectiveness and precision. The study findings illuminate a multifaceted landscape of trade-offs inherent in these methodologies. The findings revealed that the Total Station method, utilizing the GEOMAX ZOOM 10 (2”), emerged as the most expensive among the building measurement techniques, with a cost of 185.04 euros. However, it demonstrated the highest accuracy with an RMS (Root Mean Square) value of 0.0135 m. In contrast, Laser scanning employing the Leica ScanStation C10 had a cost of 149.85 euros, with an RMS value of 0.0205 m. The Lidar method using the iPhone 13 Pro, while being the third most expensive at 128.48 euros, exhibited a comparatively lower accuracy with an RMS value of 0.1694 m. By navigating the intricate interplay between economic considerations and the imperative for precise infrastructure management, this study endeavours to foster sustainable, efficient, and economically viable approaches in rural infrastructure development. The insights garnered herein endeavour to bridge the gap between precision and financial prudence, fostering a pragmatic balance in survey method selection for rural infrastructure initiatives.
Maize-legume intercropping effect on soil properties and CO2 concentration
Authors: Romaneckas Kestutis , Sinkeviciene Ausra , Svereikaite Austeja , Kimbirauskiene Rasa , Vitulskis Kristijonas , Balandaite Jovita , Ginelevicius Ugnius
Published: July 2024

The EU Greening program requested increasing the area of leguminous crops. The use of legumes as intercrops reduces both wind and water erosion, which has a positive effect on the yield of the main crops. Unfortunately, there is no precise scientific background of legume intercropping technologies in Lithuania. For this reason, a stationary short-term field experiment was started in 2022 at the Experimental Station of the Vytautas Magnus University Agriculture Academy (VMU AA), Lithuania (54º52′ N, 23º49′ E). The experimental soil is a silty loam Planosol (Endohypogleyic-Eutric – Ple-gln-w). The experiment consisted of maize (Zea mays L.) with legume intercrops, with a total of 6 treatments: 1. Inter-row loosening (control 1, K1); 2. Inter-row mulching with weeds (control 2, K2); 3. Faba bean intercropped (LUP); 4. Crimson clover intercropped (PUD); 5. Persian clover intercropped (PED); 6. Blue-flowered alfalfa (MEL) intercropped. Contrary to expectations, the slow development of the intercrops did not halt the physical erosion of the soil caused by the uneven precipitation. During the growing season, soil microstructure particles increased, and structural durability deteriorated. The CO2 concentration in the soil depended more on the amount of precipitation and the type of intercrops, but the highest soil CO2 concentrations at the beginning and the end of the growing season were in the control plots K1 and K2 without intercrops.
Mechanical properties of epoxy and concrete based composite materials reinforced with oil shale ash
Authors: Jafarli Ilgar , Macanovskis Arturs , Gjerlow Eirik , Novakova Iveta , Motlep Riho , Vaisnoras Mindaugas
Published: July 2024

The elastic properties of composites with reinforcing particles are under investigation in this research. Oil shale ash (OSA), produced in Estonia, is a powder and a by-product of the combustion process in generation of electricity at power plants. During previous years many thousands of tons of OSA have been collected. Starting from 2018 in the European Union, oil shale ash is no longer considered as toxic and hazardous waste, this is opening new possibilities for commercial application of OSA in new products and giving it a second life. Recycling and reusing oil shale ash is therefore an important problem for environmental sustainability. The use of this product as a reinforcement for epoxy resin matrix as well as for the concrete matrix in Epoxy/OSA and Concrete/OSA composites was experimentally investigated in this work. Several sets of Epoxy/OSA specimens were experimentally fabricated: Epoxy resin without OSA, Epoxy resin with 10% of oil shale ash by weight and sets of specimens with increasing ratios (10% increase between) of oil shale ash by weight, until a 50% ratio of OSA was reached. The tensile test experiments were conducted with the goal to obtain elastic modulus of the oil shale ash composite material. Tensile tests were realized according to ISO 527-1:2012 and specimens were fabricated according to ISO 527-2:2012 1B standards. Tensile tests were performed, and the experimental results were compared with predictions from analytical approaches. According to the obtained tensile test results and analytical predictions (using the rule of mixture and other approaches), the modulus of elasticity increases in direct proportion with increasing weight fraction of the oil shale ash in the composite material. Finally, samples of concrete with OSA were fabricated and tested until failure. Different amounts (by weight) of cement (0%, 5%, 10%, 15%, and 35%) in the samples were replaced by OSA. The elastic properties of these samples were also experimentally evaluated and compared with theoretical prediction results.
System model of e-services for suburban area management
Authors: Nazarenko Volodymyr , Smolii Victor , Onyshchenko Borys , Misiura Maksym
Published: July 2024

Nowadays, smart cities are a prominent research field with practical implementation. Many prominent economically developed city governments and institutions are working on the implementation of large software, hardware, and IoT systems to help make cities more convenient to manage and comfortable to live in. At the same time, few acknowledge that rural and specific rural suburban areas can benefit from smart system implementation. In this paper the authors present the system model concept of e-services that can be used by local government bodies to manage their settlements. We focus our attention on the case of sub-urban areas for the case study. For data management and system development concept evaluation, the authors have used information from several rural settlements in the Kyiv region (country of Ukraine). The suburban areas management system model is based on the concept of digital e-services, which are often used in the case of smart city and land management solutions. Information systems are vital for effective processing and decision support in the case of large data and complex system management. In addition to information systems rural settlement requires a web portal and notification modules. The presented research work can be used as a substantial foundation for further studies and case implementation for each specific statement, considering local area specifics. In the future, the authors plan to add GIS and land management system modules to the list of e-services, besides researching a way to connect smart city management solutions with the presented suburban areas management digital service.
Changes in electric car energy consumption depending on mass
Authors: Berjoza Dainis , Jurgena Inara , Masek Jiri
Published: July 2024

The use of electric cars has developed rapidly in the last 10 years. The capacity of car batteries has increased. Initially, batteries with a capacity of 16-22 kWh were used, while today the batteries of modern electric cars have at least 3 times more capacity. The main disadvantage of any type of battery is the low specific energy density per kilogram of battery mass. Liquid fuel used in most vehicles today has one of the highest energy densities. This means that a liquid fuel tank with a relatively small mass can store and transport a much larger amount of energy than can be stored in the batteries of an electric car. The research designed and tested an analytical algorithm for calculating the energy consumed, depending on the change in the mass of electric cars. By choosing an electric car with a lighter battery, it is possible to achieve significant savings in reducing environmental pollution. Lower capacity and mass batteries consume less energy and raw material resources. Electric cars equipped with lower mass batteries can achieve more economical operation due to lower energy consumption per kilometre. However, the use of lower-capacity batteries in electric cars is not in line with the current trends in electric cars because car users want to get the same driving range per charge from electric cars as from internal combustion cars. The solution to the use of low-capacity batteries in electric cars can be found by introducing a new infrastructure, such as battery swap stations, inductive charging lanes on roads and other modern infrastructures. The analytical part of the research analysed various impacts of the mass of an electric car on the energy consumed. From the perspective of energy consumed, electric cars with lighter batteries, e.g. a Citroen C-Zero and a Renault Zoe, are more efficient than those examined.
Research on highlight restoration algorithm for sea surface oil spill images
Authors: Yu Wei , Chen Yuqing , Zhou Shitong , Zhou Qianchen
Published: July 2024

With the advancement of digital image processing technology, the restoration of highlight images has become a significant research direction. In the case of oil spill monitoring systems for close monitoring of the sea surface, improper camera shooting positions and the presence of sunlight at a small incident angle can result in highlight areas in the captured images. These highlight regions significantly impact the quality of oil images which also reduces and the detection accuracy of oil spills. Since traditional highlight removal methods cannot be applied to water scenes, this paper proposes a Criminisi-PM highlight restoration algorithm for image enhancement. Firstly, for the improvement of the priority calculation formula, the multiplicative relation between the confidence item and the data item is changed to the addition relation. In this way, even if the confidence term is zero, the impact of data items still exists, which avoids the impact on priority when the confidence is zero, and improves the stability and accuracy of the algorithm. The introduction of the brightness term of the image in the priority calculation formula can focus more on the restoration of pixel points with larger brightness values. Secondly, for the improvement of the matching formula of the best matching block, the pixel gradient and Euclidean distance information are added to consider the features of the image more comprehensively, which makes the matching process more robust, especially in the processing of images with complex texture structures. The proposed algorithm can effectively improve the quality of visible oil spill image by eliminating the influence of the high-light region in the image. Experiments show that the method has a strong anti-interference ability and after removal the image is more natural.
Results of research on factors intensifying hemp trust preparation processes
Authors: Sheichenko Viktor , Koropchenko Serhii , Horbenko Oleksandr , Skoriak Yuliia , Sheichenko Denys
Published: July 2024

The object of the research is technological processes, plant material (stems of industrial hemp), factors that intensify the processes of preparation of the trust. The influence of the stem mass, preliminary destruction of their outer shell by flattening or beating, periodic moistening of the stems every other day on the time of the pulp preparation and the quality of the fiber was systematically investigated. It has been established that the shortest time for preparing the trust is 35 days for flattened and moistened stems every other day at a stacking density of 1 kg.m-1. The noted term is 20% less than with a stacking density of 2 and 3 kg.m-1, 5.7% less than for stems laid out on a film with and without moistening every other day at a stacking density of 1 kg.m-1, 31% less than for stems spread on the film at a density of 2 kg.m-1, and 42.9% less for ones spread at a density of 3 kg.m-1, by 31.4% less than for stems spread out on the rettery with a density of 1 kg.m-1, and by 42.8% at densities of 2 and 3 kg.m-1, respectively. The stem colour indicator, determined with the device during the laying period, changed from the initial value of 45.2 lux for a density of 1 kg.m-1, density of 2 kg.m-1 – 45.4 lux, density of 3 kg.m-1 – 45.7 lux, to values of 21.2 lux, 21.6 and 21.8 lux at the time of raising the trust, respectively. It was established that the produced long fiber corresponded to the 2nd – 3rd grade according to the content of shive (1.2-1.6%), by the content of tow (1.8-2.5%) – 3rd – 4th grade, by the content of hurd (6.5-10.5%) 3rd – 4th grade, respectively. According to the index of breaking load (16.6-25.1 daN), the obtained long fiber corresponded to the 3rd-4th grade. The index of linear density of the produced long fiber in all options for the preparation of hemp trust exceeded the maximum permissible value of 50 Tex, which, along with the complex indicators, made it possible to classify the fiber as non-standard.
Influence of K2ZrF6 and SiO2 on refining ability of flux for manufacturing bimetallic castings
Authors: Aftandiliants Yevhenii , Gnyloskurenko Svyatoslav , Meniailo Helena , Khrychikov Valerii , Lomakin Viktor
Published: July 2024

Bimetallic material is considered as an advanced functional material due to the unique physical and mechanical properties varied over the layers. Formation of bimetallic castings with steel base greatly depends on diffusion coupling with the second material working layer at elevated temperatures. The common technological problem is to remove the oxide films from the solid steel surface while its heating prior pouring melt of the working layer. This work studies the protective refining fluxes matching the selected requirements of good wetting the surfaces of solidified metal, effective protection against oxidation in the working temperature range, easy separation after pouring liquid metal and high refining capacity for oxides. The most effective fluxes based on Na2B4O7 and B2O3 compounds were used. To improve their ability to enhance wetting, work of adhesion and reduce surface decarbonization addition of K2ZrF6 and SiO2 to the flux in the amount of 3-4 wt.% was proposed and investigated. It was established that such additions increased wettability up to 9 and 20%, respectively and reduced the average rate of decarburization in the temperature range from 800 to 1000 °С on 57 and 37%. The complete reduction of iron from scale on the steel surface was observed, while in the case of Na2B4O7 – B2O3 system it achieved 30-40% only. The mechanism explaining such a result is proposed to be due to the prevailing effect of zirconium in protecting the surface of the steel base from the oxidation and decarburization. The important result of the study is the recommendation of optimal flux composition (wt.%): Na2B4O7 – from 60 to 80; B2O3 – from 10 to 30; K2ZrF6 - from 3 to 4; SiO2 from 3 to 4. Thus, such flux could improve the production of steel based bimetallic castings and increase their properties.
Development of method and study of granular fertilizer production process based on sapropel
Authors: Khomych Serhiі , Tsiz Igor , Tarasyuk Victor , Khlopetscyi Roman
Published: July 2024

Considering the prospects of using organic sapropel as a raw material for fertilizers in agriculture, particularly in organic farming, its processing becomes an extremely important step. Traditional organic fertilizers, such as manure, are produced virtually untreated using a fairly simple technology, and their quantity is limited by the number of animals. The quality of sapropel-based fertilizers depends on the content of the organic part, the processing method, and the characteristics of the deposit. An analysis of the existing research has shown that sapropel-based fertilizers can be single-component and multi-component. In addition, the content of organic matter in such fertilizers varies widely. Many studies have been devoted to the production of granular sapropel fertilizers and the processes of forming and drying independent particles of arbitrary size and shape, the formation of large balls and strands by pressing, the formation of particles in the form of plates, cylinders, etc. But, given the design features of bulk fertilizer machines, it is necessary to strive for the formation of granules in the form of a ball. The paper proposes directions for the use of sapropel in the production of single-component and multicomponent granular fertilizers. The design of machines for the production of granular sapropel fertilizers in the form of balls with an equivalent diameter of 2-6 mm is presented. The results of experimental studies on the strength, fractional composition, volume, and unit density of granules produced in laboratory conditions are also presented. The obtained results demonstrate the feasibility of implementing the development in production conditions and suggest directions for improvement.
Regulation of space grid structure stress-strain state
Authors: Sribniak Nataliia , Lutskovskyi Valerii , Tsyhanenko Liudmyla , Halushka Serhii , Tsyhanenko Hennadii , Rohovyi Stanislav
Published: July 2024

By analysing publications and research, it is found that space grid structures, which are spatial rod lattice systems, are characterised by their effective static behaviour. The stress-strain state of construction structures, in particular slabs, can be significantly dependent on a number of factors: the shape of the base cell, the way it rests on the supports (walls, columns), the method of arrangement of support posts, and the thickness of the slab. As a conclusion from the research analysis, it can be stated that the research of one of these factors (force regulators), which affects the material capacity of the structure, is relevant. Finite element models of space grid structures are described, which differ in the arrangement of columns on which the structure is supported. The arrangement of columns is taken in three ways: columns are located at the corners of the slab; columns are located along two parallel sides of the slab; columns are displaced inside the slab 4.5 m on both sides. That is, the method of localization of the columns is the regulator of forces in the slab elements. The variants of column arrangement can be used to determine the most efficient model in terms of static behaviour. Consequently, this most efficient model will also be the least material-intensive, i.e. it will have the lowest possible weight. The most rational (efficient) model from the considered variants was determined. The efficiency was determined by the criterion of more rational stress-strain state. Selection of element cross-sections according to the first and second groups of limit states was carried out. The weight of each model was counted and the model characterised by the lowest material capacity was determined. According to the criterion of material capacity, the most efficient model of the space grid structure is the model No. 3, supported by 4 columns displaced inside the slab by 4.5 m.
Developing a BIM-based technique in the design phase to achieve sustainability in residential building projects
Authors: Shaban Mohamed H. , Ali Hassan Mohammad
Published: July 2024

The building construction industry is one of the industries that contribute most to waste production in the world. Therefore, the efforts of researchers focused on reducing construction waste (CW). The building design stage is a decisive factor in the formation of waste by determining the sizes and dimensions of the elements and the resulting formation of some remains (waste) that may become a resource added to the project resources if this process is planned in advance. The absence of this planning may lead to it becoming waste. In our research, we present a BIM-based model for reducing floor tile construction waste in multi-story residential buildings, which contributes significantly to achieving sustainability standards in construction projects. Tartous housing projects -in the Sheikh Saad complex project were chosen as a case study, which consists of 20 residential towers with 16 floors, each floor containing 8 residential apartments. The Revit program was used to model buildings, and Dynamo to design a technique to reduce CW in the design stage, by comparing different sizes of floor tiles using visual programming techniques. We chose the floor tile size that achieves the lowest value of waste throughout the entire project. High reduction rates were reached, amounting to 96.43% (of the actual waste in the project) compared to the current traditional design, which is a very promising percentage in the field of reducing the formation of construction waste and achieving sustainability standards.
Improving performance of wheeled tractor with gas engine as part of transport machine unit
Authors: Zaharchuk Victor , Zaharchuk Oleh , Tolstushko Mykola , Tolstushko Nataliya
Published: July 2024

Increasing requirements for the environmental performance of agricultural transport vehicles require improvement of their design that will reduce emissions of harmful substances from exhaust gases. A method of estimating fuel efficiency and environmental performance of a wheeled tractor with a gas engine when performing transport works has been developed. A mathematical model of the wheeled tractor movement along the driving cycle has been developed. The mathematical model used the results of experimental studies of a gas engine. Bench tests of a diesel engine that was converted into a spark ignition gas engine for operation on natural gas were performed and they confirmed its operability and showed good operational performance. A wheeled tractor was converted to run on gas fuels using the same technology and elements. Its test results showed that there are certain peculiarities of driving such tractor due to the fact that the diesel tractor engine is equipped with an all-mode crankshaft speed regulator which is not used in a gas engine. A driving cycle was chosen to study the performance of a wheeled tractor when performing transport works. Environmental indicators and fuel consumption of a specific engine, that are used in the mathematical model, are described by polynomial models based on its experimental characteristics. Using the mathematical model of tractor movement during the driving cycle, the appropriate ways of controlling the transmission and gas engine during tractor movement were determined, in particular, the proper order of gear shifting when the tractor is accelerating. The total emissions of harmful substances during the driving cycle of a tractor both with a gas engine and a diesel engine were calculated, which prove the environmental feasibility of using gas fuel. The total toxicity of exhaust gases, reduced to carbon monoxide CO, of a tractor with a gas engine is 1.9 times lower than of a diesel engine.
CH4 and N2O emissions from surface of deciduous tree stems in forests with drained and naturally wet mineral soils
Authors: Petaja Guna , Purvina Dana , Bardule Arta , Zvaigzne Zaiga Anna
Published: July 2024

Deciduous tree stems can become an important source of methane (CH4) and nitrous oxide (N2O) emissions especially in case of flooding or increase of the soil water-table level. So far, studies were mainly implemented in forests with organic soils, while limited information is available about mineral soils. Within this study we estimated the CH4 and N2O fluxes from the stem surface of silver birch, black alder and aspen in 16 study sites (forest stands) with drained and naturally wet mineral soils in Latvia to evaluate the impact of soil moisture conditions. We found that in forest stands with drained mineral soil, the mean CH4 fluxes from the tree stems were 10.2 ± 3.2 µg CH4-C·m-2·h-1 for aspen, 1.3 ± 2.6 µg CH4-C·m-2·h-1 for black alder, 4.5 ± 2.9 µg CH4-C·m-2·h-1 for silver birch. In forest stands with wet mineral soil, CH4 fluxes from the tree stems were higher for all tree species (21.1 ± 5.5 µg CH4-C·m-2·h-1 for aspen, 6.3 ± 2.4 µg CH4-C·m-2·h-1 for black alder, 10.3 ± 2.3 µg CH4-C·m-2·h-1 for silver birch) than in stands with drained soil. Similarly, higher N2O fluxes from the stem surface were found in forest stands with wet mineral soils for aspen and silver birch (4.1 ± 1.5 and 4.0 ± 1.5 µg N2O-N·m-2·h-1, respectively) than in forest stands with drained mineral soil (-0.8 ± 1.4 and 1.9 ± 1.5 µg N2O-N·m-2·h-1, respectively), while N2O fluxes for black alder were similar under drained and wet condition (3.8 ± 1.3 and 3.6 ± 1.3 µg N2O-N·m-2·h-1, respectively). However, high variation in CH4 and N2O fluxes was observed and the difference in mean fluxes between drained and wet conditions was not statistically significant. In general, the study shows that forest drainage can reduce CH4 and N2O fluxes from the surface of tree stems; however, due to the high variation of the fluxes more data are necessary to increase accuracy of projections of the studied greenhouse gases.
Short term effect of clear-felling on greenhouse gas emissions from naturally wet organic and mineral soils
Authors: Upenieks Emils Martins , Duka Martins Vanags , Butlers Aldis , Lazdins Andis
Published: July 2024

Clear-felling, a predominant method for forest regeneration in areas with wet soils, has profound implications for greenhouse gas (GHG) emissions. This technique, by removing the forest cover, exposes the soil to increased sunlight, which can raise soil temperatures and enhance decomposition rates. Consequently, this process can significantly boost the emissions of carbon dioxide (CO2) and nitrous oxide (N2O). The absence of canopy cover also impacts soil moisture due to the decrease in plant transpiration, potentially leading to conditions that promote anaerobic processes in wet soils, thereby increasing methane (CH4) emissions. We monitored soil GHG (CO2, CH4, N2O) emissions in clear-felling sites before and after the harvesting. The study findings reveal a notable increase in CO2 emissions following the harvest, with an average rise of 226 mg CO2·m-2·h-1, representing a 120% increase. The CO2 emissions from mineral and organic soils did not significantly differ. While clear-felling had minimal impact on CH4 emissions from mineral soils, emissions from organic soils saw approximately a sixfold increase. Meanwhile, N2O emissions remained largely unchanged in both soil types post-clear-felling. When converted to CO2 equivalents, the emission results reveal a significant elevation in GHG emissions post-clear-felling, particularly from organic soils which witnessed a near threefold increase, whereas emissions from mineral soils roughly doubled. The study results highlight the implications of even-aged forest management strategies on wet soil GHG emissions.
Case study on effect of rewetting grassland with organic soils on greenhouse gas (GHG) emissions from soil
Authors: Skranda Ilona , Spalva Gints , Bardule Arta , Lazdins Andis
Published: July 2024

Rewetting grasslands with organic soils is an effective environmental strategy aimed at restoring natural water levels, crucial for mitigating GHG emissions. This process involves reintroducing water to previously drained or degraded peatlands, which helps in re-establishing wetland ecosystems. According to results of other studies rewetting slows down the decomposition of organic matter, significantly reducing carbon dioxide (CO2) emissions; however, can increase methane (CH4) emissions. Additionally, it supports biodiversity, enhances water quality, and can create new habitats for wetland species. This practice plays a vital role in climate change mitigation and ecosystem restoration. Our case study is implemented in former grassland near Smiltene, which was rewetted by closing culvert passing P27 road in late 80-ies during reconstruction of the road. Since that time the area is accumulating water from surrounding forests and farmlands. We measured GHG fluxes, groundwater, temperature, and other environmental parameters for two years once per month using the closed chamber method. Two-year measurements result that nearly 20-40 years after rewetting the grassland is still a significant source of GHG emissions – 6.04 tons CO2-C·ha-1·yr-1, 0.62 kg CH4·ha-1·yr-1 and 0.67 kg N2O·ha-1·yr-1. The net emissions from soil equal to 22.87 tons CO2·ha-1·yr-1. This is about twice less than from cropland, but about the same level of emissions as in grassland according to other studies implemented in Latvia. Thus, our study does not provide evidence that rewetting can reduce GHG emissions from organic soil.
Development and application of biodegradable wheat straw and carrageenan composite in agriculture
Authors: Ozolina Sintija , Zaimis Uldis , Kukuskins Andrejs
Published: July 2024

Environmental concerns in the long run have led the public to develop alternative materials that could be used in agriculture. The development and application of carrageenan and wheat straw biodegradable composite in agriculture is the main focus of this study. This composite is crafted to tackle the environmental repercussions linked with traditional agricultural materials. The manufacturing procedure encompasses the extraction and treatment of wheat straw fibres, which are then merged with carrageenan, a naturally occurring polysaccharide sourced from red seaweed Furcellaria Lumbricalis. The resultant bio composite displays encouraging mechanical traits, rendering it suitable for a variety of agricultural applications. The employment of wheat straw not only offers an environmentally conscious substitute but also addresses the predicament of disposing of agricultural waste. Regarding its application, the biodegradable composite can serve as a material for seedling trays. Due to the composite natural propensity to break down over time, long-term environmental pollution is prevented. Additionally, the material biodegradability is improved by its contact with soil microbes, enhancing the overall sustainability of agricultural methods. The outcomes of this study underscore the potential of the biodegradable wheat straw and carrageenan composite as a sustainable substitute for diverse agricultural applications. The development and assimilation of such environmentally friendly materials contribute to the ongoing endeavours to promote sustainable practices in agriculture, addressing both ecological apprehensions and the necessity for pioneering solutions in the field.
Solutions for reducing (minimizing) firefighting truck repairs in EU countries and in Latvia in particular
Authors: Politika Viktorija , Pundure Jelena , Jarvis Marina
Published: July 2024

This research project aims to develop innovative approaches, reducing firefighting truck repairs in the EU countries, focusing on Latvian State Fire and Rescue Service (hereinafter - SFRS). The study comprehensively analyses existing maintenance, repair, and training procedures to identify potential optimization strategies. Employing both qualitative and quantitative methods, the research meticulously evaluates the efficiency of current procedures in maintaining and repairing fire engines, providing a thorough and holistic understanding of existing processes, potential issues, and overall efficiency. Additionally, the study conducts an in-depth analysis of technological innovations to identify and evaluate the potential benefits of improved diagnostic systems, materials, and other technological approaches that could minimize the need for repairs. This aspect includes a comprehensive economic analysis to assess the cost-benefit ratio associated with implementing these innovations. The obtained results offer not only a detailed understanding of existing problems but also propose comprehensive solutions for minimizing fire truck repairs. This valuable information serves as a foundational basis for future improvements in both academic and practical realms, thereby enhancing the safety and efficiency of the fire service in Latvia and other EU countries. This extensive and in-depth research contributes significantly to advancing the field, fostering a proactive and innovative approach to firefighting truck maintenance and repair, ultimately improving the overall effectiveness and resilience of fire services within the European Union. In conclusion, the findings underscore the paramount importance of sustained innovation for the continuous enhancement of firefighting operations and ensuring the safety of communities.
Comparison of fuel consumption in broccoli production
Authors: Strnad Michal , Matyas Libor , Cisler Martin , Novak Petr
Published: July 2024

Broccoli is a highly valued vegetable for its high content of vitamins and health-promoting substances. The heads weight up to 0.7 kilograms and can grow to a diameter of 0.25 meters. Broccoli is a plant that is very demanding on moisture, so it cannot do without irrigation in the dry season. Growing vegetables is generally very labour intensive, but many operations in growing broccoli can already be automated. With broccoli, automation can be used in work operations such as planting and harvesting. This article presents the results of a field experiment comparing the fuel consumption of growing broccoli throughout the entire growing season. The field trial took place in the Czech Republic near the city of Hradec Králové in the 2021 season. Fuel consumption measurements were made at the plot where the stand was established at the beginning of the growing season and at the plot that was planted last. Fuel consumption was measured for each growing operation that was carried out on the plot. The distance of both plots from the farm was similar. The resulting amount of fuel consumed per one hectare of planted area was calculated by dividing the total fuel consumption for a certain cultivation operation by the planted area. Fuel consumption per one hectare of planted area is based on this calculation. The most fuel-intensive growing operation was harvesting broccoli. Harvesting broccoli consumed 35% of the total fuel consumption per hectare. The total fuel consumption for plot 1 was 216.1 litres per hectare, for plot 2 the total consumption was 199.4 litres per hectare. Individual work operations were compared with the norms and did not show statistically significant differences, except for soil preparation with a rotary tiller, where the value is twice as much as the norms.
Development and testing of automated control system for sea buckthorn berry harvesting robot ""Agrobot""
Authors: Stupans Andrejs , Maksimkins Pavels , Senfelds Armands , Ribickis Leonids
Published: July 2024

The paper describes the control system of an autonomous agriculture robot and evaluates its operation using a laboratory stand and a digital environment. AgroBot is an autonomous sea buckthorn berry harvesting robot. It automatically finds the bush branches to harvest, cuts them, and stores them in a box. AgroBot consists of a 3 DOF (Degrees of Freedom) Cartesian mobile platform and a Hyundai HH7 industrial robot arm with 6 DOF. The control system is specifically designed for real-time operation, enabling AgroBot to adapt to dynamic environmental conditions (wind, varying light) that complicate target tracking. The control system consists of two modules operating as two separate programs. The first module is the Computer Vision Module (CVM) which has high-level control of AgroBot operation. It uses feed from cameras to find the cutting spot and sends commands to approach, cut, store, and search. The module is written in Python. The second module is the Robot Control Module (RCM) which receives high-level commands from CVM and manages lower-level control of the Hyundai Controller (HC). RCM calculates the robot trajectory to a target position, communicates with both CVM and HC in parallel threads and handles errors. As HC requires time-critical control, RCM is written in C + + . RCM and CVM are running on one computer communicating via sockets. As the mobile platform hardware is in the development stage and is not available at the moment, the digital twin of the robot is created to test the system’s performance in a simulated environment. The input to the digital twin is the same as for the actual robot. It is the x, y, z position and orientation A, B, C using Euler angles. The digital twin visualization is developed in the Unity game engine. Matlab Robotic Toolbox is used with the Levenberg-Marquardt solver algorithm to calculate inverse kinematics of 9 DOF robot. The paper focuses on the Robot Control Module architecture and control system’s testing.
Analysis of changes in brain model parameters after stroke
Authors: Grigorjeva Olesja , Markovics Zigurds
Published: July 2024

The human brain consists of many structures, or so-called functional areas. Each area participates in the implementation of a certain function of the human organism (senses, vision, movements, thinking, etc.). Of course, these areas are not autonomous and are connected to each other, forming a network of brain connections, often called the connectome. Understanding how connectivity varies across nodes is an important step in analysing a network. These connections are of varying strength and importance and have various other important parameters that describe brain activity and its changes under the influence of external events (e.g. stroke, Alzheimer’s disease, dementia and other neurological diseases). It turns out that functional regions and their connections can be represented as vertices and arcs of a graph, and elements of graph theory can be used to analyse such a model. The number of functional areas for graphing can vary and will depend on how detailed the brain structural model is. Previous studies have created a literature review, resulting in a knowledge base, and identified the consequences of injury or damage to each region resulting in different disfunctions. When the brain is affected by a stroke or any other abnormal neurological condition, the functional areas are damaged and the connections between them are altered. Consequently, the model of the brain - the graph, the parameters of its vertices and arcs - also changes. The purpose of this article is to look at what changes occur in the brain graph in order to use the changed model in future studies in the development of a system for predicting possible stroke consequences.