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Soil Quality Index as a Predictor of Maize–Wheat System Productivity Under Long-Term Nutrient Management
No full textThe long-term effects of integrated nutrient management (INM) on crop performance and soil health—particularly within sub-humid environments—remain insufficiently explored. This research aimed to quantify the relationship between the soil quality index (SQI) and overall system productivity. The SQI represents a numerical indicator of soil functioning and its biological and chemical integrity, while system productivity reflects the economic yield generated by the cropping system. A long-term experiment initiated in 1972 formed the foundation for this study, which was conducted from 2019 to 2021 and included eleven nutrient management treatments. These comprised the following treatments: inorganic fertilizers alone (100% NPK, 150% NPK, 100% NP, 100% N, and 100% NPK without sulfur); combinations of organic and inorganic inputs (50% NPK + FYM and 100% NPK + FYM); lime with inorganic fertilizers (100% NPK + lime); zinc with inorganics (100% NPK + Zn); hand weeding with inorganics (100% NPK + HW); an unfertilized control. The study was implemented in a maize–wheat rotation under the sub-humid climatic conditions of Palampur, Himachal Pradesh, India. System productivity was estimated using wheat grain equivalent yield, and SQI values were generated from selected soil properties. These indicators—along with the sustainable yield index (SYI)—were applied to assess the effectiveness of each treatment. The results showed that the 100% NPK + FYM combination produced the highest SQI, followed by 100% NPK + lime, whereas the 100% N treatment yielded the lowest value. Overall, the findings highlight the crucial role of adopting sustainable nutrient management practices to maintain soil quality and optimize productivity in sub-humid agricultural systems.Funder: King Saud University (ORF-2026-958); Indian Council of Agricultural Research;Full text license: CC BY</p
Core training: exercise selection and motivational factors in gym-training individuals with and without low back pain - a descriptive pilot study
No full textBakgrund: Ländryggssmärta är vanligt förekommande och har följder som smärta, nedsatt rörlighet, mindre delaktighet, psykologiska, sociala påföljder och försämrad arbetsförmåga. Bålkapacitet är viktigt för funktion och förebygga ländryggssmärta. Träning av bål kan utföras i många variationer, högbelastad, lågbelastad, neuromuskulär kontroll och stabilisering. Open chain träning ger möjligheten att träna mer specifikt. Closed chain skapar förutsättningar för att träna med tyngre belastning, fler muskler och leder. Delaktigheten för patienter i beslutsprocessen (val av övningar m.m.) påverkar motivation och följsamhet. Både stabiliserande och konventionell träning har visat sig effektiv för ländryggssmärta, däremot finns det begränsad kunskap kring specifika träningsval (open eller closed chain). Syfte: Undersöka vilken typ av bålträning open- eller close chain som utförs av personer med respektive utan ländryggssmärta, samt att belysa motivationsfaktorer bakom deras val. Metod: 35 individer från utvalda sociala medier och ett lokalt gym genomförde en enkät om ländryggsbesvär och träningsvanor. Resultat: Vanligaste träningsformen var enbart open chain övningar eller en kombination av open och closed chain. Estetiska skäl drev främst påbörjan av bålträning medan förbättrad prestation/förebyggande motiverade fortsatt bålträning. Det förekom mellan gruppers skillnad för deltagare med smärta och utan smärta avseende övningsval och motivationsfaktorer. Konklusion: Individer utan smärta föredrar främst open chain övningar samtidigt som individer med smärta väljer en kombination eller att avstå från bålträning. Motivationsfaktorerna varierar sig över tid, egna erfarenheter avgör träningsval. Background: Low back pain (LBP) is prevalent, resulting in pain and reduced mobility, participation, psychological and social implications, as well as impaired ability to work. Core capacity is vital for function and LBP prevention. Core training has various variations, including high-load, low-load, neuromuscular control, and stabilization exercises. Open chain exercises offer the opportunity for specific training, closed chain exercises facilitate heavier loads involving multiple muscles and joints. Patient participation in the decision-making process (e.g., exercise selection) influences motivation and adherence. Both stabilizing and conventional training is effective for LBP however, knowledge regarding specific exercise choices (open versus closed chain) remains limited. Aim: To investigate which type of core training open or closed chain is performed by individuals with and without LBP, and to highlight the motivational factors underlying their choices. Method: 35 individuals recruited from selected social media and a local gym completed a questionnaire regarding LBP and training habits. Result: The most common form of training were solely open chain exercises or a combination of open and closed. Aesthetic reasons were the primary drivers for initiating core training, whereas improved performance and injury prevention motivated continued training. Differences were observed between participants with and without pain regarding exercise selection and motivational factors. Conclusion: Pain-free individuals prefer open chain exercises, while individuals with pain choose a combination of exercises or refrain from core training altogether. Motivational factors vary over time, and personal experiences determine exercise selection
Autonomous Offroad Vehicle Real-Time Multi-Physics Digital Twin: Modeling and Validation
No full textThe use of physical vehicles and environments during vehicle research and development is highly resource-intensive, particularly for autonomous vehicles. Recently, digital models are therefore increasingly used instead, which require high levels of fidelity and validity. While the two aforementioned qualities are often lacking, an absence of versatility for multi-purpose use is even more prevalent in current digital models. In response to these challenges, this work presents a novel real-time multi-physics digital twin of an offroad vehicle with high levels of fidelity and validity, both regarding the vehicle dynamics and hydraulics, as well as regarding the visual representation of the environment and the exteroceptive sensor emulation. The versatility of the digital twin enables its usage for vehicle development tasks concerning mechanical components and driveline, as well as for visual machine learning tasks, such as generation of auto-annotated visual training data. Development of control algorithms leveraging both visual input and mechanical systems is also enabled. Furthermore, the real-time capability allows for Hardware-in-the-Loop and Vehicle-in-the-Loop simulation. The modeling, calibration, and real-world validation of the digital twin is presented, with an emphasis on the vehicle dynamics and hydraulics. The shown validity enables advancements in the development of autonomous offroad vehicles.Full text license: CC BY 4.0;</p
Constructing Inclusion in the Child Group : Preschool Teachers’ Adaptations and Their Impact on Interaction in Preschool
No full textStudiens syfte var att synliggöra hur förskollärares anpassningar för barn i behov av särskilt stöd, konstruerar inkludering mellan det enskilda barnet och barngruppen. Begreppet inkludering är komplext, och nämns inte i förskolans läroplan över huvud taget. Tidigare forskning pekar på att barn i behov av särskilt stöd upplevs beröva de andra barnen på förskollärarnas tid och resurser. När det enskilda barnet upplevs ta något från de andra skapas en klyfta mellan barnet och barngruppen, då de upplever en orättvisa gentemot barnet. För att få fram hur förskollärare arbetar med inkludering har studiens teoretiska utgångspunkt varit socialkonstruktionsim samt det relationella och det kategoriska perspektivet. Genom semistrukturerade intervjuer med fyra förskollärare framkom det att förskollärarna arbetar medvetet med inkludering för alla barn, samtidigt som utmaningar uppstår. Utifrån olika anpassningar arbetar de för att motverka exkludering för det enskilda barnet, samtidigt som de genom varierande strategier även tar hänsyn till barngruppens uttryck om orättvisor. Detta menar förskollärarna även i sin tur leder till ett förbättrat samspel sett till hela barngruppen. Slutsatsen i denna studie visade därför att förskollärarna har en avgörande roll i konstruktionen av barns identitet och positionering i relation till inkludering. Anpassningarna som förskollärarna skapar påverkar barnens uppfattningar om varandra, vilket i sin tur påverkar hur inkludering konstrueras och därmed även samspelet mellan barnen.
Unified Approach to Industrial Information
No full textIndustry 4.0, has significantly altered industrial processes by integrating advanced technologies such as Cyber-Physical Systems, Internet of Things (IoT), cloud computing and AI. Despite these advancements, the industry is facing challenges with achieving effective communication and interoperability. Through the wide variety of advances that has been made, an upstream of different heterogeneous data sources and protocols have emerged, even when studying a specific domain such as the industrial sector. It has led to fragmented interoperability and somewhat unreliable information exchange. This thesis presents research that explores the potential of ontologies and semantic modeling to address some of these challenges by providing explicit descriptions of concepts and their relationships, thereby enhancing a shared understanding and vocabulary, improving interoperability and stakeholder communication. Furthermore, efforts are made to enable system communication through OPC UA and the Arrowhead framework, to enable seamless interoperability. Despite the possible benefits of ontologies, challenges such as the need for experience and expertise in ontology development is required to created and maintain their reliability. Introducing the Industrial Data Ontology (IDO) as an industrial upper ontology, a newly adopted ISO standard, enables a higher level of knowledge abstraction. IDO describes industrial assets and processes throughout their lifecycle. The findings underscore the transformative potential of semantic models, ontologies, and seamless interoperability to enhance the quality of industrial information exchange and a more sustainable and reliable process. Future directions include exploring the integration of real-time data with semantic benefits, enhancing business transaction process, and implement semantic explicitness to a Service-Oriented Architecture (SOA) such as the Arrowhead framework
On Cone Penetration Tests in Tailings : The need for a calibration chamber
No full textTailings is a fine-grained granular mine waste, typically with particle sizes in the range of sands to silts. Conventionally, tailings are hydraulically deposited into impoundments surrounded by tailings dams. The safety against dam failure must be ensured, as a failure can result in catastrophic consequences. In recent times, catastrophic tailings dam failures of upstream constructed dams have reported static (or flow) liquefaction in tailings as a failure mechanism. Static liquefaction can betriggered in saturated and loose silty sandy soils, generating a nearly complete strength loss in the soil. Undoubtedly, static liquefaction is a critical failure mode to investigate in the design of tailings dams, especially for cases where the dam stability relies on strength of the deposited tailings. In engineering practice, the primary focus for failure modes involving static liquefaction is to identify if the tailings are saturated and loose. If so, the tailings are considered to have liquefaction potential and it is common to assume that static liquefaction will occur independently of any triggering event. Thus, low strength values corresponding to a case of “liquefied” soil strength is used in the stability assessments and such scenarios typically governs the tailings dam design. The most challenging part of the liquefaction potential assessment is to investigate if the tailings are loose, which in this context refers to “looser” than its critical state at the current stress level indicated by contractive behaviour during shearing. Assessment of tailings state (i.e. loose or dense) is thereby crucial and engineering practice relies on in-situ testing, since undisturbed sampling in sandy soils is challenging. The Cone Penetration Test (CPT) is today the most used in-situ test for liquefaction assessments in sandy soils, including tailings deposits. However, existing CPT related interpretation methods were mainly developed based on natural clean sands and CPT conducted in calibration chambers. Using these interpretation methods on the CPT response in a loose silty-sandy tailings is thereby outside the original context in which the methods were derived. Concludingly, there are uncertainties in CPT interpretation of tailings state which become uncertainties inherent in the tailings dam design. In this thesis the usage of CPT for assessing the tailings state is further discussed, from physical measured CPT data, like cone tip resistance or pore pressure development during penetration, to interpreted parameters used in static liquefaction assessments. CPT as well as static liquefaction is highlighted from a perspective in close connection to the framework of Critical State Soil Mechanics. Uncertainties in the CPT interpretations in tailings are highlighted, with focus on deviating characteristics between tailings and natural sands that motivates the need for CPT calibration chamber testing on tailings. As part of the ongoing research a new calibration chamber has been designed and developed at LTU. The chamber is in detail presented in this thesis. In the chamber a sample with 0,6 m diameter and 1 m height can be prepared. Sample saturation and consolidation to desired conditions are conducted in the chamber prior to pushing a CPT. Details on how the CPT calibration chamber testing will be utilized in forthcoming research are presented in the thesis. Loose (contractive) silty sandy tailings will initially be tested to investigate the relation between tailings state and CPT data. In addition, other possibly relations between conditions for static liquefaction potential in tailings and CPT data are also of interest in the upcoming research
Hydraulic Analysis of River Regulation to Assess Ecological, Social and Economic Impacts
No full textHydropower is one of the main pillars of the industrial transition and a more sustainable future. A global reinforcement of renewable energy sources is required to face climate change and meet international goals and agreements. The phase-out of fossil fuels in the heavy industry and other sectors will result in a largely increased electricity demand. Among the intermittent renewable sources, hydropower can act as a regulation capacity, besides other energy storage solutions. In the deregulated electricity market hydropower reservoirs can be flexibly used to match production and demand. In the Nordic Countries, where hydropower provides 56 % of the electricity, this can already be seen on a daily basis. While hydropower can be seen as a low-emission and relatively clean energy source it nevertheless has adverse effects on the ecological and social river system. The effects can be related to different phases of a hydropower project and different parts of the river system. The construction of the dam, filling of the reservoir, operation of the hydropower plant, and decommissioning all have various effects on the environment around, upstream and downstream of the dam and reservoir as well as the communities close to the river. The indicated increased flexibility in hydropower production leads to increasing and new pressures on the river system. The conflicting interests of renewable energy production and environmental protection are reflected in legislation and goals on different levels of governance. On the one hand, the EU biodiversity and water framework directives advocate the maintenance and restoration of healthy surface water bodies and the protection of ecological species. On the other hand, the EU renewable energy directive stresses the necessity of clean energy production. In Sweden, a national process for relicensing of the existing hydropower plants and assessment of their ecological impact was decided in 2020. The evaluation of effects and assessment of potential measures requires knowledge and a trade-off between energy production and environmental goals. This work aims to contribute to a more funded decision-making on sustainable hydropower. For this purpose, the ecological, social, and economic impacts of hydropower are investigated. The future need for more flexible energy production will further alter the natural flow of rivers. Therefore, the research focuses on the effects of river regulation and concentrates on the reaches downstream of hydropower plants. The possibilities of hydraulic models as predictive tools in impact assessment are investigated. In a first step, the effects of river regulation on the downstream river system and the possibility of evaluating these effects with hydraulic models are investigated. The literature reveals numerous effects of flow alteration on the river ecosystem. Furthermore, socio-economic effects could be observed as a direct implication of the flow alteration or a consequence of ecological effects. Combining the evaluation of ecological effects with hydraulic modeling is state-of-the-art. However, a majority of ecohydraulic studies concentrate on fish habitat and only a limited number of hydraulic studies include social or economic effects. This reveals a necessity for further research on socio-hydraulic modeling, more diverse ecohydraulic studies, and the comparability of ecological and socio-economic interests to develop holistic evaluation approaches and inform founded trade-offs and decision-making. In a second step, a restoration project was hydraulically analyzed as a case study. In 2021 the minimum flow into the 70-km-long bypassed reach of river Juktån (Västerbotten, Sweden) was seasonally adapted. The former discharge was mostly changing between constant winter and summer discharges. The new discharge scheme is imitating natural conditions with a significant spring peak while maintaining the annual discharge volume of 12 % of the natural flow. Additionally, morphological measures were taken. Both measures were intended to enhance and restore the state of the river ecosystem. The hydraulic effects of the measures were investigated with hydraulic 2d-simulations. The seasonal flow adaption led to more diverse hydraulic conditions with an increased water level variation and a larger maximum inundation area. Flow velocities relatively doubled for the highest discharge case but remained in a low range. These more varying conditions will benefit the ecosystem and especially the riparian components. The results show that seasonal flow alteration can be a useful measure to improve the hydraulic conditions in bypassed reaches at low costs. The morphological changes in a different river stretch were less effective according to the hydraulic models. In a further step, the effect of the seasonal flow restoration on the potential riparian vegetation in river Juktån was analyzed. The riparian ecosystem is seen as an important connection between terrestrial and aquatic ecosystems with naturally high biodiversity. Based on the results from the hydraulic simulations and ecological data on the inundation tolerance of riparian vegetation the states before and after restoration were compared. As a reference, the potential vegetation for larger annual discharge volumes up to natural flow was modeled. The results show that the seasonal flow alteration will diversify the riparian vegetation and strongly increase the extent of the riparian zone. When increasing the total annual discharge volume into the bypassed reach towards a natural flow scenario the total riparian vegetation area will grow steadily. The certain vegetation zones behave indeed diverse. While the willow shrubs region reaches its maximum extent at full natural flow, the graminoid zone and riparian forest peak at 50 % respectively 70 % of the natural flow.
Generalization of Oberlack's definition of the MILD combustion regime
No full textThe Oberlack definition of the MILD combustion limit for premixed systems was derived under the assumption of lean combustion and a one-step reaction. In this study, a generalization of this definition is presented by removing the lean combustion assumption, which leads to a more comprehensive relation between the Damköhler number and temperature, defining the so-called S-curve. The transition of the S-curve to a monotonic function, indicating MILD conditions in the generalized formulation, reveals a dependency on the kinetic parameters of the reaction (reaction orders) and the equivalence ratio. Unlike the previous definition, the proposed solution applies across a broader range of conditions, from rich to lean mixtures, incorporating variations in combustion conditions and the reactivity of the analyzed system. Analytical solutions are not available due to the strong non-linearity of the model; therefore, the results are obtained numerically and are presented as plots and approximation functions, all valid in a wide range of parameter values and applicable to various fuels. The proposed methodology is adaptable to different parameter ranges if needed. Finally, two practical examples, based on hydrogen and methane, illustrate the findings. The results show that reaction orders and the equivalence ratio significantly influence the limit curve defining the MILD combustion regime, with dependencies on the combustion conditions and the chosen fuel.Validerad;2025;Nivå 2;2025-08-18 (u1);Full text license: CC BY 4.0;Funder: National Science Centre, Poland (grant No. 2020/39/B/ST8/02494)</p
Technology advancements in future waste biorefineries: Focus on low carbon fuels and renewable chemicals
No full textTransitioning from fossil fuels to renewable energy sources is essential for combating climate change and minimizing greenhouse gas emissions. Innovative biorefineries are at the forefront of this shift, designed for enhanced productivity and carbon neutrality. These facilities can extract low-carbon fuels and biobased materials from renewable feedstocks, presenting opportunities for diverse product development and low-carbon outputs. Recent advancements in acidogenic and methanogenic biorefineries showcase their potential to produce valuable compounds, including carboxylates, alcohols, and biopolymers while generating fuels like hydrogen and methane. This article explores biorefineries extracting low-carbon fuels and biobased materials from renewable feedstocks, emphasizing advancements in renewable fuel and chemical production. It focuses on acidogenic and methanogenic biorefineries, highlighting synergies in extracting and utilizing compounds such as carboxylates, alcohols, and biopolymers. Additionally, it addresses the production of hydrogen, methane, bioelectricity, and bio-ammonium, emphasising their role in carbon farming and the associated challenges in optimizing these processes for sustainable energy solutions. Validerad;2025;Nivå 2;2025-08-07 (u8);Funder: JSPS KAKENHI (24K11471); Iwatani Foundation for the Promotion of Science and Engineering, Japan;Full text license: CC BY-NC-ND</p
Enhancing Tunnel Fire Safety in Design and Operation: Computational Modeling and Risk Mitigation Strategies for Passenger and Goods Carrier
No full textRoad tunnels need a robust risk management strategy being critical component of modern transportation network. Change in vehicle types with intrinsic hazard source change due to evolution of power sources (H2, EV etc.), tunnels must evolve into intelligent infrastructures to safeguard lives through robust engineering and proactive risk governance mechanism. The risk profile within a road tunnel fluctuates instantaneously based on the types and volumes of vehicles present. Traditional design-stage risk assessments, often grounded in conservative assumptions, fall short in managing such dynamic infrastructure. Advancements in high-performance computing and computer vision technology, a real-time tunnel risk estimation can be achieved. This necessitates a robust methodology for continuous risk quantification, enabling proactive monitoring and timely intervention to manage risk. The primary objective of this research work was to develop dynamic risk estimation framework for road tunnels, forming the basis for a smart tunnel Risk Monitor that evaluates real-time risk based on vehicle types, traffic volume, and hazard potential. Applied to the Bhatan tunnel under simplified traffic assumptions and simulated traffic flow conditions, to derive a correlation between overtaking and severe accident collision probability. The methodology models event progression using an event tree and estimates risk every second over a one-year period. The framework demonstrates scalability across diverse tunnel configurations, vehicle categories, and traffic volumes. As secondary objective, it provided the method to derive the URCL, the Upper Risk Control Limit and ARTL, the Acceptable Risk Threshold Limit for effective risk management of a tunnel and demonstrated the evaluation using the estimated one-year risk profile for Bhatan tunnel. Further, it recommended administrative actions and restrictions that can be initiated triggered once instantaneous risk reaches the URCL and stopped with the restoration of ARTL. Computational fluid dynamics (CFD) simulations were used to estimate peak heat release rates (HRR), aligning closely with results from the Runehamar tunnel fire experiment involving heavy goods vehicles (~200 MW). Simulations were extended to five vehicle categories viz. cars, SUVs, six and ten-wheeler trucks and buses with certain substitute material fire properties like n-heptane as engine oil and mixture of polyvinyl chloride (PVC) & urethane as burnable materials in all vehicles. The observed peak HRR values exceeded significantly for cars, SUV/LMVs (~25 MW vs ~ 5 MW) and bus (~ 200 MW vs ~ 20 MW) those suggested by some of the widely adopted international guidelines. This study therefore proposes revised HRR benchmarks for individual passenger and freight vehicles, intended for use in tunnel design-stage safety and risk assessments. This study introduced and applied a potential two-vehicle collision scenario weighted methodology to estimate the design fire load or peak heat release rate (HRR) for road tunnels. The approach was implemented for five reference vehicle categories in Bhatan to estimate the design basis peak HRR at 81 MW, offering a refined framework for evaluating fire severity under realistic multi-vehicle conditions. This study established the groundwork for the development of a Tunnel Risk Monitoring and Management System (TRMMS) for a smart tunnel. Integrating the proposed risk estimation framework with computer vision and deep learning for vehicle classification, hazard assessment, and speed detection can enable intelligent, real-time risk monitoring