Search results

Filter

Filetype

Your search for "*" yielded 530292 hits

Impact of coordinate rotation on eddy covariance fluxes at complex sites

The choice of coordinate system to calculate eddy covariance fluxes becomes particularly relevant at complex measurement sites. The traditional way is to perform double rotation (DR) of the coordinate system i.e., to calculate turbulent fluxes in a coordinate system that is aligned with the flow streamlines within the flux averaging period (e.g., Kaimal and Finnigan, 1994). The second approach, th

Identification of principal chemical subsets of biofuel combustion : Ants walking in renewable fire

The work in this thesis was carried out to highlight important chemical pathways in skeletal mechanisms for the three smallest alcohol fuels (methanol, ethanol and npropanol), two representative fuel alkanes n-heptane and n-decane, and finally the biodiesel surrogates, methyl-decanoate, methyl-5-decenoate, and methyl-9-decenoate. This aim was set up to further the efforts of creating Computational

A reduced chemical kinetic reaction mechanism for kerosene-air combustion

Development of a new reduced chemical kinetic reaction mechanism for kerosene-air combustion is presented. The new mechanism uses a modular based development technique and is a further development on previously presented kerosene-air mechanisms. The new mechanism consists of 30 species and 77 irreversible reactions and is developed to accurate reproduce key flame parameters yet being small enough

Gradient acoustic focusing of sub-micron particles for separation of bacteria from blood lysate

Handling of submicron-sized objects is important in many biochemical and biomedical applications, but few methods today can precisely manipulate this range of particles. We present gradient acoustic focusing that enables flow-through particle separation of submicron particles and cells and we apply it for separation of bacteria from blood lysate to facilitate their detection in whole blood for imp

Structural changes induced by electroconvulsive therapy are associated with clinical outcome

Background: Electroconvulsive therapy (ECT) is the most effective treatment option for major depressive disorder, so understanding whether its clinical effect relates to structural brain changes is vital for current and future antidepressant research. Objective: To determine whether clinical response to ECT is related to structural volumetric changes in the brain as measured by structural magnetic

Optimization of energy and directional response of a small 4π silicon dosemeter for quality control of CT/CBCT-units – A 3D CAD, Monte-Carlo, AM approach

A 4π radiation dosemeter for use in medical radiology was designed. It is based on a solid state silicon detector, a sensor wafer, a flex card, a 3D plastic holder and a spherical stainless steel filter with a distribution of holes around the detector. The detector is attached to the wafer using only low Z material. To achieve an energy and directional response which is as uniform as possible for

Luminescence and vacuum ultraviolet excitation spectroscopy of cerium doped Gd3Ga3Al2O12 single crystalline scintillators under synchrotron radiation excitations

Cerium doped Gd3Ga3Al2O12 (GGAG) single crystals as well as GGAG:Ce single crystals co-doped by divalent (Mg2+, Ca2+), trivalent (Sc3+) or tetravalent (Zr4+, Ti4+) ions have been studied by means of the excitation luminescence spectroscopy in vacuum ultraviolet spectral range. Synchrotron radiation from the undulator beam was utilized for the luminescence excitation in the energy range from 4.5 to

QPDAS: Dual Active Set Solver for Mixed Constraint Quadratic Programming

We present a method for solving the general mixed constrained convex quadratic programming problem using an active set method on the dual problem. The approach is similar to existing active set methods, but we present a new way of solving the linear systems arising in the algorithm. There are two main contributions; we present a new way of factorizing the linear systems, and show how iterative ref

Physical Store Development in the Era of Digitalization : Experiential Learning in Collaboration with City Center Management

Purpose of the Study: This study describes a teaching innovation introduced into a retail course assignment. The purpose with the innovation was to increase students’ level of experiential learning by incorporating digital retail and collaborating with stakeholders. Method/Design: A course assignment allows students in the final semester of a Bachelor Program in Retail Management to develop a busi

Simultaneous laser-driven x-ray and two-photon fluorescence imaging of atomizing sprays

In this Letter, we report for the first time, to the best of our knowledge, the possibility of visualizing an atomizing spray by simultaneously recording x-ray absorption and two-photon laser-induced fluorescence imaging. This unique illumination/detection scheme is made possible due to the use of soft x rays emitted from a laser-driven x-ray source. An 800 mJ laser pulse of 38 fs duration is used

Guided web-based treatment program for reducing cannabis use : a randomized controlled trial

BACKGROUND: The aim of this study was to investigate the effects of a web-based treatment program with therapist guidance for adults and adolescents with regular cannabis use from the general population. METHODS: A double blinded randomized controlled trial with a parallel group design was conducted (intervention group n = 151, wait-list control group n = 152). Follow-up 12 weeks from treatment co

Potassium Disturbances and Risk of Ventricular Fibrillation Among Patients With ST-Segment-Elevation Myocardial Infarction

Background Potassium disturbances per se increase the risk of ventricular fibrillation (VF). Whether potassium disturbances in the acute phase of ST-segment-elevation myocardial infarction (STEMI) are associated with VF before primary percutaneous coronary intervention (PPCI) is uncertain. Methods and Results All consecutive STEMI patients were identified in the Eastern Danish Heart Registry from

Midlife physical activity is associated with lower incidence of vascular dementia but not Alzheimer's disease

BACKGROUND: Physical activity might reduce the risk of developing dementia. However, it is still unclear whether the protective effect differs depending on the subtype of dementia. We aimed to investigate if midlife physical activity affects the development of vascular dementia (VaD) and Alzheimer's disease (AD) differently in two large study populations with different designs.METHODS: Using a pro