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Application and validation of a method to assess the energy reduction and environmental impact of renovation alternatives
Full text linkThe renovation of residential stock is one of the most promising areas, in terms of energy reduction, because these buildings are highly inefficient and represent the largest part of the building stock. However, the environmental impact assessment over the life cycle of building renovation is rare. It is more common to develop an assessment for new buildings. This study presents a method that combines the evaluation of the benefits of renovating residential buildings, considering cost, energy and environmental benefits using Life Cycle Assessment (LCA). The method is based on 3 stages of development. First, the database of energy certificates, costs and LCA was analysed. The second step is to develop a workflow in Rhino/Grasshopper/E-Plus to automatically model a residential building and feed the simulation model with the data obtained from the databases. Finally, a simulation campaign was carried out to obtain an optimal renovation package, minimising energy consumption and environmental impact. The research was carried out in a case study in Uddevalla, Sweden. The residential building has different measurements including energy consumption data before and after renovation. This was used to validate the proposed methodology. The validation shows that accurate results are achievable with potential for mass application
Analysis of Swedish school buildings\u27 energy performance certificates with focus on ventilation systems
Full text linkEnergy performance certificates are valuable sources of information about buildings. They are primarily used to assess the buildings\u27 energy performance, however the data included can also be used for building stock description or analysis from different perspectives. School buildings account for a substantial part of the Swedish public building stock and represent a great opportunity for implementation of energy saving strategies. To improve the energy efficiency, it is first important to analyse and understand the current energy use and identify the key factors responsible for most of the energy use. In Sweden, data used for EPC compilation are in most cases real measured data opposite to other European countries where EPC comprises calculated data practices. Therefore, the energy performance value provides a much more realistic representation of the building energy use. This study analyses certain aspects of school buildings\u27 energy performance using data available in EPCs, such as year of construction, floor area, heat supply systems and ventilation system. Comparison with data from some other European countries is also presented. The data which could be included in the certificate to extend the potential of EPC use in other areas, such as evaluation of indoor environmental quality, is also discussed
Using data-driven indoor temperature setpoints in energy simulations of existing buildings: A Swedish case study
Full text linkBuilding energy analyses of large samples or building stocks commonly use National building stock temperature averages in their calculations. However, such averages may not be representative of the conditions in a specific building type and may mask meaningful information found at building or dwelling level. Analysis of indoor temperature data from the Swedish housing stock showed that 25% out of approximately 1000 dwellings were heated at a temperature ≥23\ub0C in wintertime. If indoor temperature management is considered as a potential energy saving measure for the building stock it may be more effective to explore implementation in these specific dwellings, than considering average temperature reduction across the entire building stock. This however would require more detailed input data on indoor temperatures. Would such an approach be worthwhile? To answer this question, two types of Swedish multifamily buildings were simulated with i) business-as-usual scenarios and ii) setpoints based on indoor temperature data from the last Swedish National Survey. The study shows that using data-driven, dwelling-specific indoor temperatures could lead to more effective decision making on indoor temperature management, targeting buildings and dwellings where temperature reduction would most likely cause the least compromise on comfort. Such a strategy however should be complementary to a wider plan of improved energy efficiency measures across the building stock
Scalable and Efficient Pipeline for ML-based Optical Network Monitoring
No full textWe demonstrate a scalable processing of OPM data using ML to detect anomalies in optical services at run time.\ua0A dashboard will show operational SDN controller metrics, raw OPM data, and the ML assessment results
Filamentous fungi display different behavior during spruce bark degradation.
No full textMicrobial degradation of trees is hindered by their outermost tissue, the bark, which is also a material produced in vast amounts annually through debarking in the pulp and paper industry. While the bark is composed of the typical lignocellulose components cellulose, hemicellulose, and lignin, it also contains a large fraction of small molecules referred to as extractive compounds. The extractives are attributed to the strong anti-microbial properties of the bark, but despite their presence, filamentous fungi can frequently be found growing on the outside of fallen trees. How fungi deal with the presence of extractive compounds and polysaccharides while growing on bark is however not known today, and this precludes development of biological valorization methods. \ua0Here, we have followed fungi growing on spruce bark over six months, including white-rot (Dichomitus squalens), brown-rot (Postia placenta), as well as three Ascomycetes (Trichoderma reesei, Penicillium crustosum, Trichoderma sp. B1). The changes in the material were analyzed continuously using a combination of mass-loss determination, GC-MS, HPAEC-PAD, to monitor overall changes as well as detailed changes in extractives, carbohydrates, and lignin. These data enabled a comparison of the growth and substrate metabolism of five different fungi growing on the bark. The fungi exhibited clearly different approaches to the extractive compounds – from simply tolerating them, to detoxification and/or fully metabolizing them. Also carbohydrate analyses revealed significant differences among the fungi, with the brown-rot fungus P.\ua0 placenta displaying the typical hemicellulose first – cellulose second type of degradation pattern. From compositional analyses, D. squalens had the highest mass-loss (30%) and was quickest to reach stationary phase (12 weeks), and was able to significantly modify extractives and polysaccharides, in particular monosaccharides derived from pectin and xylan. Therefore, additional proteomic analyses was performed on D. squalens grown on bark, acetone-extracted bark (i.e. extractive-less), and galactomannan. The results revealed little difference in the proteome composition between acetone-extracted bark and bark, however, were identified. In particular, carbohydrate-active enzymes (CAZymes) related to pectin and xylan degradation were upregulated in the bark samples. \ua0Our results suggest that D. squalens, P. placenta, T. reesei, P. crustosum, Trichoderma sp. B1 have different substrate preferences, in particular, extractives are either degraded or tolerated. Significant changes could also be found in carbohydrate composition revealing pectin degradation. This work forms a basis for an understanding fungal degradation of bark
Automated Methods for the suspension pre-development - Design of a front axle for a long range electric vehicle
No full textWith rising customer expectations and additional requirements stem-ming from the electrification, today’s suspensions need to fulfill an increasing number of requirements: Aerodynamic efficiency targets are stricter, driving properties are defined more specifically and the use of carry-over-parts is grow-ing. Moreover, the package volume has a huge effect on the exterior design as well. This leads to complications in the pre-development process. A typical prob-lem is the sequence of development steps: if a completely new suspension is de-signed, is it more important to optimize the hard points and adjust the part geom-etry accordingly or vice versa? The common approach of a trial-and-error method is time consuming, since the design of a suspension concept takes days of engi-neering work.To meet this dilemma, a new approach is developed. With an automized design method for kinematics and elastokinematics paired with an automatic packaging evaluation, it is possible to create a first feasible solution within minutes. This concept can then be evaluated and improved either in terms of hard points, bush-ing stiffness or packaging. Since a much higher amount of possible suspension designs can be evaluated, the probability to find an adequate solution rises tre-mendously.This approach is demonstrated for an optimized five link suspension for bat-tery-electric vehicles (BEVs). The shape of the suspension volume should be modified in a way, that the height of engine hood can be lowered. Therefore, the aerodynamic behavior has potential to be improved. It is found that the design of an innovative concept solution can be supported by using automated methods
Fluxes in a full-flooded lubricated Tapered Roller Bearing: Particle Image Velocimetry measurements and Computational Fluid Dynamics simulations
Full text linkThe acquisition of complex fluxes inside a Tapered Roller Bearing (TRB) via Particle Image Velocimetry (PIV) is an experimental challenge. This can be successfully performed by exploiting a special test rig having the outer ring manufactured with sapphire. In the present paper, the velocity field in the region between cage, rollers and outer race have been captured via PIV in a fully flooded lubricated TRB. The experimental conditions have been reproduced numerically via Computational Fluid Dynamics (CFD). The comparison of PIV results with CFD ones showed excellent consistency. It has been observed that, in the target domain, the tangential velocity of the lubricant is greater than those of the cage. In addition, in the proximity of the edges of the rollers, squeezing effects due to high gradients of pressure have been recorded. The distribution of flow rates due to the pumping effect in different regions of the TRB have been estimated
New insights into the protein stabilizing effects of trehalose by comparing with sucrose
Full text linkDisaccharides are well known to be efficient stabilizers of proteins, for example in the case of lyophilization or cryopreservation. However, although all disaccharides seem to exhibit bioprotective and stabilizing properties, it is clear that trehalose is generally superior compared to other disaccharides. The aim of this study was to understand this by comparing how the structural and dynamical properties of aqueous trehalose and sucrose solutions influence the protein myoglobin (Mb). The structural studies were based on neutron and X-ray diffraction in combination with empirical potential structure refinement (EPSR) modeling, whereas the dynamical studies were based on quasielastic neutron scattering (QENS) and molecular dynamics (MD) simulations. The results show that the overall differences in the structure and dynamics of the two systems are small, but nevertheless there are some important differences which may explain the superior stabilizing effects of trehalose. It was found that in both systems the protein is preferentially hydrated by water, but that this effect is more pronounced for trehalose, i.e. trehalose forms less hydrogen bonds to the protein surface than sucrose. Furthermore, the rotational motion around dihedrals between the two glucose rings of trehalose is slower than in the case of the dihedrals between the glucose and fructose rings of sucrose. This leads to a less perturbed protein structure in the case of trehalose. The observations indicate that an aqueous environment closest to the protein molecules is beneficial for an efficient bioprotective solution
Monitoring system for an energy storage system
No full textThe present disclosure relates to a monitoring system for an energy storage system, an energy storage system comprising such a monitoring system, a vehicle comprising such an energy storage system and a manufacturing method for such a monitoring system. The monitoring system for an energy storage system comprises a plurality of energy storage cells comprising at least one stretchable electronic unit and a communication element. The stretchable electronic unit is arrangeable at least at one of the energy storage cells. The stretchable electronic unit is configured to generate data based on strain applied on the stretchable electronic unit. The communication element is integrated in the stretchable electronic unit and configured to transfer data generated by the stretchable electronic unit
Exploring the potential of ChatGPT as a supplementary tool for providing orthopaedic information
Full text linkPurpose: To investigate the potential use of large language models (LLMs) in orthopaedics by presenting queries pertinent to anterior cruciate ligament (ACL) surgery to generative pre-trained transformer (ChatGPT, specifically using its GPT-4 model of March 14th 2023). Additionally, this study aimed to evaluate the depth of the LLM’s knowledge and investigate its adaptability to different user groups. It was hypothesized that the ChatGPT would be able to adapt to different target groups due to its strong language understanding and processing capabilities. Methods: ChatGPT was presented with 20 questions and response was requested for two distinct target audiences: patients and non-orthopaedic medical doctors. Two board-certified orthopaedic sports medicine surgeons and two expert orthopaedic sports medicine surgeons independently evaluated the responses generated by ChatGPT. Mean correctness, completeness, and adaptability to the target audiences (patients and non-orthopaedic medical doctors) were determined. A three-point response scale facilitated nuanced assessment. Results: ChatGPT exhibited fair accuracy, with average correctness scores of 1.69 and 1.66 (on a scale from 0, incorrect, 1, partially correct, to 2, correct) for patients and medical doctors, respectively. Three of the 20 questions (15.0%) were deemed incorrect by any of the four orthopaedic sports medicine surgeon assessors. Moreover, overall completeness was calculated to be 1.51 and 1.64 for patients and medical doctors, respectively, while overall adaptiveness was determined to be 1.75 and 1.73 for patients and doctors, respectively. Conclusion: Overall, ChatGPT was successful in generating correct responses in approximately 65% of the cases related to ACL surgery. The findings of this study imply that LLMs offer potential as a supplementary tool for acquiring orthopaedic knowledge. However, although ChatGPT can provide guidance and effectively adapt to diverse target audiences, it cannot supplant the expertise of orthopaedic sports medicine surgeons in diagnostic and treatment planning endeavours due to its limited understanding of orthopaedic domains and its potential for erroneous responses. Level of evidence: V