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Feedback Control in Swedish Multi-Family Buildings for Lower Energy Demand and Assured Indoor Temperature—Measurements and Interviews
Get PDFEurope needs to save energy, and lowered indoor temperature is frequently promoted as part of the solution. To facilitate this, heating control systems with feedback from indoor temperature sensors are often required to avoid thermal discomfort and achieve long-term temperature reductions. This article describes a measurement- and interview-based study on feedback control where 107 Swedish multifamily buildings were analysed. The obtained results show that buildings with lowered indoor temperatures had reduced annual heating demand by 4 kWh/m2 and a reduced indoor temperature of 0.4 \ub0C. There were, however, significant individual differences and even buildings with increased indoor temperatures, which harmed the energy savings. Temperature fluctuation was most often significantly reduced, but the impact on heating power demand during cold weather was, on average, only 2%. An interview with different actors indicated higher energy savings, possibly due to their stock’s original room temperature levels. Several interviewees also mentioned other advantages of temperature mapping. Most of the results obtained in this study were in line with several previous investigations. The study’s novelty lies in the large number of investigated buildings with mature commercial heat control technology, including PI-control for adjusting supply temperature, indoor temperature sensors in almost every apartment and a parallel analysis of additional affected parameters
Glycoproteome remodeling and organelle-specific N-glycosylation accompany neutrophil granulopoiesis
Get PDFNeutrophils store microbicidal glycoproteins in cytosolic granules to fight intruding pathogens, but their granule distribution and formation mechanism(s) during granulopoiesis remain unmapped. Herein, we comprehensively profile the neutrophil N-glycoproteome with spatiotemporal resolution by analyzing four key types of intracellular organelles isolated from blood-derived neutrophils and during their maturation from bone marrow–derived progenitors using a glycomics-guided glycoproteomics approach. Interestingly, the organelles of resting neutrophils exhibited distinctive glycophenotypes including, most strikingly, highly truncated N-glycans low in α2,6-sialylation and Lewis fucosylation decorating a diverse set of microbicidal proteins (e.g., myeloperoxidase, azurocidin, neutrophil elastase) in the azurophilic granules. Excitingly, proteomics and transcriptomics data from discrete myeloid progenitor stages revealed that profound glycoproteome remodeling underpins the promyelocytic-to-metamyelocyte transition and that the glycophenotypic differences are driven primarily by dynamic changes in protein expression and less by changes within the glycosylation machinery. Notable exceptions were the oligosaccharyltransferase subunits responsible for initiation of N-glycoprotein biosynthesis that were strongly expressed in early myeloid progenitors correlating with relatively high levels of glycosylation of the microbicidal proteins in the azurophilic granules. Our study provides spatiotemporal insights into the complex neutrophil N-glycoproteome featuring intriguing organelle-specific N-glycosylation patterns formed by dynamic glycoproteome remodeling during the early maturation stages of the myeloid progenitors
Over-the-Air Noise Figure Measurement in a Reverberation Chamber for Low-Noise Devices
No full textMeasuring the noise figure (NF) of highly-integrated wireless devices can be a challenging task. This paper shows that the reverberation-chamber-noise-figure (RCN) method can be used to determine this characteristic of a device with an NF below 4 dB at sub-GHz frequencies. This is a significantly lower NF and operating frequency as compared to the device used for the original RCN method. The lower NF is measured using the simplified RCN method, which has an improved uncertainty over the original RCN method. To accommodate for the operating frequency below 1 GHz, a larger reverberation chamber is used. An uncertainty analysis shows that the NF could be estimated within 0.52 dB uncertainty and the gain within 0.91 dB
Using guaiacol as a capping agent in the hydrothermal depolymerisation of kraft lignin
Get PDFThe depolymerisation of softwood kraft lignin was investigated, under hydrothermal conditions at 290 \ub0C and 250 bar, with guaiacol in the reactor feed to evaluate its impact on the formation of char and on the molecular weights of the products. The effect of residence time was investigated in the time span 1-12 min. Lignin is depolymerised during the process and guaiacol is both formed and consumed during the reaction, with clearly noticeable changes as early as in the first minute of reaction. Although the addition of guaiacol in the reactor feed causes a reduction in the weight average molecular weight of the products, the yield of char increases. Longer residence times result in repolymerisation of the reaction products as well as a further increase in the yield of monoaromatic components and char
Unsteady RANS and IDDES studies on a telescopic crescent-shaped wingsail
Get PDFOver the years, several research projects have evaluated different concepts for wind-assisted propulsion, generally concluding that it can lead to significant fuel savings. The time-averaged propulsive performance of a single rigid wingsail has been analysed in previous studies. However, the unsteady characteristics of the external loads which may induce structural vibration are also important to be considered. In this study, full-scale simulations, with both unsteady RANS and IDDES methods, are performed to analyze the flow field. The paper\u27s analysis includes flow separation and vortex shedding, the development and dissipation of wake vortices, and the lift reduction due to tip vortices. It also studies the telescopic function of the wingsail by analyzing sails with different heights and wind conditions. The paper concludes that the unsteady RANS and IDDES simulations make similar predictions for time-averaged loads but disagree on the unsteady characteristics. The IDDES simulations indicate more complex vortex-shedding phenomena
FlexiGrid Tools for Real-Life Demonstrations of Local Energy System Concepts at Chalmers Campus Testbed
No full textThe ongoing transition in the energy system is accompanied by various challenges such as congestion and voltage violations in electricity distribution networks. Suggested solutions to these challenges are, among others, local energy and flexibility markets, new tariff designs, and centralized control. Simulation and demonstration of such solutions often require a broad chain of tools that need to be automated. The aim of this paper is to present a simulation and demonstration platform integrating several of the required tool and their deployment at the Chalmers Campus test bed. The developed tools include PV and load forecasting, congestion forecasting, energy management system, model predictive control algorithms, and local energy and flexibility markets. The tools are integrated using a common and reusable platform called LESOOP for simulation and demonstration. Demonstration examples of PV and load forecasts, congestion forecasts, model predictive control, and energy management systems are presented and results are discussed. The paper contributes to a more successful transition of the energy system by sharing experiences and provides better understanding of the tool functionalities at the Chalmers campus test-bed. The identified gaps and gained knowledge from the real-life demonstrations at the test-bed can be valuable to projects and researchers aiming to develop a test-bed
Influence of railway wheel tread damage on wheel–rail impact loads and the durability of wheelsets
No full textDynamic wheel–rail contact forces induced by a severe form of wheel tread damage have been measured by a wheel impact load detector during full-scale field tests at different vehicle speeds. Based on laser scanning, the measured three-dimensional damage geometry is employed in simulations of dynamic vehicle–track interaction to calibrate and verify a simulation model. The relation between the magnitude of the impact load and various operational parameters, such as vehicle speed, lateral position of wheel–rail contact, track stiffness and position of impact within a sleeper bay, is investigated. The calibrated model is later employed in simulations featuring other forms of tread damage; their effects on impact load and subsequent fatigue impact on bearings, wheel webs and subsurface initiated rolling contact fatigue of the wheel tread are assessed. The results quantify the effects of wheel tread defects and are valuable in a shift towards condition-based maintenance of running gear, and for general assessment of the severity of different types of railway wheel tread damage
Problem decomposition: the key to Agile sprints in Design Research
Get PDFIn design research, parallelization and anticipation of tasks are crucial to having an effective impact on industry and society. In practice, however, parallelization and anticipation are difficult due to high inter-dependency among research problems and design supports. This paper proposes a framework to use the Design Structure Matrix combined with Axiomatic Design to isolate research problems and their design supports. This modular independence is an important building block to plan for quick and parallel agile design research "sprints". The application of the approach is illustrated through two practical examples. The results highlight the importance to control a limited number of interfaces to work "agile" in design research without wasteful rework
Nutritional metabolomics: Recent developments and future needs
Get PDFMetabolomics has rapidly been adopted as one of the key methods in nutrition research. This review focuses on the recent developments and updates in the field, including the analytical methodologies that encompass improved instrument sensitivity, sampling techniques and data integration (multiomics). Metabolomics has advanced the discovery and validation of dietary biomarkers and their implementation in health research. Metabolomics has come to play an important role in the understanding of the role of small molecules resulting from the diet–microbiota interactions when gut microbiota research has shifted towards improving the understanding of the activity and functionality of gut microbiota rather than composition alone. Currently, metabolomics plays an emerging role in precision nutrition and the recent developments therein are discussed
The extremely sharp transition between molecular and ionized gas in the Horsehead nebula
Get PDFMassive stars can determine the evolution of molecular clouds by eroding and photo-evaporating their surfaces with strong ultraviolet (UV) radiation fields. Moreover, UV radiation is relevant in setting the thermal gas pressure in star-forming clouds, whose influence can extend across various spatial scales, from the rims of molecular clouds to entire star-forming galaxies. Probing the fundamental structure of nearby molecular clouds is therefore crucial to understand how massive stars shape their surrounding medium and how fast molecular clouds are destroyed, specifically at their UV-illuminated edges, where models predict an intermediate zone of neutral atomic gas between the molecular cloud and the surrounding ionized gas whose size is directly related to the exposed physical conditions. We present the highest angular resolution (0.≥ 5, corresponding to 207 au) and velocity-resolved images of the molecular gas emission in the Horsehead nebula, using CO J = 3- 2 and HCO+ J = 4- 3 observations with the Atacama Large Millimeter/submillimeter Array (ALMA). We find that CO and HCO+ are present at the edge of the cloud, very close to the ionization (H+/H) and dissociation fronts (H/H2), suggesting a very thin layer of neutral atomic gas (<650 au) and a small amount of CO-dark gas (AV = 0.006- 0.26 mag) for stellar UV illumination conditions typical of molecular clouds in the Milky Way. The new ALMA observations reveal a web of molecular gas filaments with an estimated thermal gas pressure of Pth = (2.3 - 4.0) - 106 K cm- 3, and the presence of a steep density gradient at the cloud edge that can be well explained by stationary isobaric photo-dissociation region (PDR) models with pressures consistent with our estimations. However, in the H≥ \uafII region and PDR interface, we find Pth,PDR > Pth,H≥ \uafII suggesting the gas is slightly compressed. Therefore, dynamical effects cannot be completely ruled out and even higher angular observations will be needed to unveil their role