Sökresultat

Filtyp

Din sökning på "*" gav 529815 sökträffar

Cylinder Pressure Based Method for In-Cycle Pilot Misre Detection

For the reduction of emissions and combustion noise in an internal combustion diesel engine, multiple injections are normally used. A pilot injection reduces the ignition delay of the main injection and hence the combustion noise. However, normal variations of the operating conditions, component tolerances, and aging may result in the lack of combustion i.e. pilot misfire. The result is a lower in

Compton-thick active galactic nuclei from the 7 Ms observation in the Chandra Deep Field South

We present the X-ray spectroscopic study of the Compton-thick (CT) active galactic nuclei (AGN) population within the Chandra Deep Field South (CDF-S) by using the deepest X-ray observation to date, the Chandra 7 Ms observation of the CDF-S. We combined an optimized version of our automated selection technique and a Bayesian Monte Carlo Markov chains (MCMC) spectral fitting procedure, to develop a

Sweden: Non-binding Rules against the Pandemic – Formalism, Pragmatism and Some Legal Realism

Swedish measures to fight the spread of COVID-19 differ from the strategies used in other comparable countries. In contrast to the lockdown approach that has been applied in many European countries, the Swedish strategy has been based to a substantial extent on individuals taking responsibility under non-binding recommendations. This contribution explores the Swedish strategy from a constitutional

Stochastic Set-Point Optimization for In-Cycle Closed-Loop Combustion Control Operation

The constrained indicated efficiency optimization of the set-point reference for in-cycle closed-loop combustion regulators is investigated in this article. Closed-loop combustion control is able to reduce the stochastic cyclic variations of the combustion by the adjustment of multiple-injections, a pilot and main injection in this work. The set-point is determined by the demand on engine load, bu

Primary care physicians’ knowledge, attitudes and concerns about bariatric surgery and the association with referral patterns : a Swedish survey study

Background: Obesity prevalence is increasing globally. Bariatric surgery is an effective treatment for severe and complex obesity resulting in significant and sustained weight loss. In Sweden, most bariatric surgery patients are referred by primary care physicians. We aimed to explore barriers for physicians to refer patients with severe and complex obesity for bariatric surgery. Methods: A questi

In Search of Search (& its Engines)

Research notes & miscellany from a research group focused on the intersection between media & information literacies and search, search engines, and search-adjacent recommender systems. Based at Lund University’s Pufendorf Institute for Advanced Studies.

The ghost of the king: Traces of 'Royal Majesty' in the Swedish constitution of 1974

The 1974 Instrument of Government forms the core of Swedish constitutional law. It replaced its partly defunct predecessor of 1809 and scrapped the separation of powers between King and Riksdag that characterised the previous constitutional system. By abolishing the formal power of the King in Council (Kungl. Maj:t, “Royal Majesty”), it aimed at establishing a modern written constitution, which la

Clinical validation of a commercially available deep learning software for synthetic CT generation for brain

Background: Most studies on synthetic computed tomography (sCT) generation for brain rely on in-house developed methods. They often focus on performance rather than clinical feasibility. Therefore, the aim of this work was to validate sCT images generated using a commercially available software, based on a convolutional neural network (CNN) algorithm, to enable MRI-only treatment planning for the

Internal Combustion Engine Cylinder Volume Trace Deviation

Heat release analysis is a widely used cylinder pressure-based method for evaluating combustion in engine development, and it is also being investigated as a means to control engine combustion. Heat release analysis has been shown to be sensitive to errors in the calculated cylinder volume, but despite this one of the most common assumptions is that the cylinder volume is nominal and can be calcul

Experience of using video support by prehospital emergency care physician in ambulance care - an interview study with prehospital emergency nurses in Sweden

Introduction: When in need of emergency care and ambulance services, the ambulance nurse is often the first point of contact for the patient with healthcare. This role requires comprehensive knowledge of the ambulance nurse to be able to assign the right level of care and, if necessary, to provide self-care advice for patients with no further conveyance to hospital. Recently, an application was de

Modular Design and Integration of In-Cycle Closed-Loop Combustion Controllers for a Wide-Range of Operating Conditions

This paper investigates how multiple in-cycle closed-loop combustion controllers can be integrated for a seamless operation under a wide-range of operating conditions. The stochastic cyclic variations of the combustion can be successfully compensated by the adjustment of the fuel injection pulses within the same cycle. The feedback information and controllability obtained relies on the different o

Quantication of FPGA Requirements for Closed-Loop Combustion Control Implementation

This paper investigates the quantification of FPGA resources for the implementation of closed-loop combustion control algorithms. Specifically, the study focuses on methods for their in-cycle execution and control of the combustion in real-time. A National Instruments Xilinx Virtex-5 platform was used for the quantification of the resources.Closed-loop combustion control obtains feedback from fast

Acoustic focusing of beads and cells in hydrogel droplets

The generation of hydrogel droplets using droplet microfluidics has emerged as a powerful tool with many applications in biology and medicine. Here, a microfluidic system to control the position of particles (beads or astrocyte cells) in hydrogel droplets using bulk acoustic standing waves is presented. The chip consisted of a droplet generator and a 380 µm wide acoustic focusing channel. Droplets

Efficiency Optimization by In-Cycle Closed-Loop Combustion Control

This paper is a comprehensive review of in-cycle closed-loop combustion controllers to achieve higher indicated efficiencies. Closed-loop combustion control reduces the effect of external disturbances and system uncertainties, which permit tighter safety margins and robust operation with a reduced calibration effort. The paper combines different components of previous investigations by the authors

Projections of thermal growing season indices over China under global warming of 1.5 °C and 2.0 °C

Global warming may prolong and intensify the thermal growing season of vegetation. It is not yet clear how the Paris Agreement's long-term temperature goals will affect the thermal growing season of vegetation, particularly crops, in China. Based on the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) datasets and the Global Gridded Crop Model Intercomparison (GGCMI) phase 1 dataset, w

Laminar burning velocities of propionic acid + air flames : Experimental, modeling and data consistency study

Laminar burning velocities of propionic acid + air flames have been determined using the heat flux method at atmospheric pressure and initial gas mixture temperature of 348 K over the range of equivalence ratios 0.7–1.3. The detailed kinetic model of the authors was extended by the reactions of propionic acid and its intermediates. Attention has been paid to the proper description of the formation

Design and Optimization of In-Cycle Closed-Loop Combustion Control with Multiple Injections

Ett samhälle med ökande behov av transporttjänster och stort behov av minskade växthusgasutsläpp måste bryta sitt beroende av fossila bränslen. Introduktionen av alternativa, elektrifierade, fordonsdrivlinor kräver tekniska lösningar och långsiktiga ekonomiska investeringar som inte finns än. Samtidigt ökar efterfrågan på förbränningsmotorbaserade drivlinor, eftersom de på ett tillförlitligt och eWith the increasing demand of transportation, biofuels play a fundamental role in the transition to sustainable powertrains. For the increased uncertainty of biofuel combustion properties, advanced combustion control systems have the potential to operate the engine with high flexibility while maintaining a high efficiency and robustness. For that purpose, this thesis investigates the analysis, des

Encapsulation of Lactobacillus reuteri in W1/O/W2 double emulsions : Formulation, storage and in vitro gastro-intestinal digestion stability

Encapsulation of Lactobacillus reuteri in the internal aqueous phase of W1/O/W2 emulsions was investigated. Microstructure of the emulsions was evaluated using a particle size analyzer and light microscopy. The encapsulation properties were evaluated in terms of encapsulation efficiency (EE) for freshly prepared samples and encapsulation stability (ES) during storage and in vitro digestion and the

Spatiotemporal changes of terrestrial water storage and possible causes in the closed Qaidam Basin, China using GRACE and GRACE Follow-On data

Terrestrial water storage (TWS) is a crucial indicator of regional water balance and water resources changes. Due to limited hydrological observations, we combined the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) products using the Long Short-Term Memory (LSTM) neural network to monitor the TWS changes from April 2002 to March 2020 over the closed Qaidam Basin in

Distributed adaptive stabilization

In this paper we consider distributed adaptive stabilization for uncertain multivariable linear systems with a time-varying diagonal matrix gain. We show that uncertain multivariable linear systems are stabilizable by diagonal matrix high gains if the system matrix is an H-matrix with positive diagonal entries. Based on matrix measure and stability theory for diagonally dominant systems, we consid