X-ray tomography for fully-3D time-resolved reconstruction of bubbling fluidized beds

A new X-ray computed tomography technique for the purpose of imaging fluidized beds is presented. It consists of an experimental set-up with three stationary X-ray source and flat panel detector pairs, a geometric calibration and data processing workflow, and an image reconstruction algorithm. The technique enables sparse-angular tomographic...

Tuning Nanopores in Tubular Ceramic Nanofiltration Membranes with Atmospheric-Pressure Atomic Layer Deposition: Prospects for Pressure-Based In-Line Monitoring of Pore Narrowing

Atomic layer deposition (ALD) is known for its unparalleled control over layer thickness and 3D conformality and could be the future technique of choice to tailor the pore size of ceramic nanofiltration membranes. However, a major challenge in tuning and functionalizing a multichannel ceramic membrane is posed by its large internal pore...

The interaction of parallel and inclined planar rarefied sonic plumes—From free molecular to continuum regime

The interaction between rarefied vapor plumes can cause shocks and consequently distinct peaks in mass flux which produce undesirable non-uniformities. To evaluate the impact of shock formation, we study pairs of interacting planar plumes, varying the degree of rarefaction and general geometric parameters, namely, the nozzle-separation...

Automatic correction of nonlinear damping effects in HAADF–STEM tomography for nanomaterials of discrete compositions

HAADF-STEM tomography is a common technique for characterizing the three-dimensional morphology of nanomaterials. In conventional tomographic reconstruction algorithms, the image intensity is assumed to be a linear projection of a physical property of the specimen. However, this assumption of linearity is not completely valid due to the...

Optimizing Experimental Parameters for the Projection Requirement in HAADF-STEM Tomography

Tomographic reconstruction algorithms offer a means by which a tilt-series of transmission images can be combined to yield a three dimensional model of the specimen. Conventional reconstruction algorithms assume that the measured signal is a linear projection of some property, typically the density, of the material. Here we report the use of...

Total variation minimization approach in in-line x-ray phase-contrast tomography

The reconstruction problem in in-line X-ray Phase-Contrast Tomography is usually approached by solving two independent linearized sub-problems: phase retrieval and tomographic reconstruction. Both problems are often ill-posed and require the use of regularization techniques that lead to artifacts in the reconstructed image. We present a novel...

Phase retrieval in in-line x-ray phase contrast imaging based on total variation minimization

State-of-the-art techniques for phase retrieval in propagation based X-ray phase-contrast imaging are aiming to solve an underdetermined linear system of equations. They commonly employ Tikhonov regularization – an L2-norm regularized deconvolution scheme – despite some of its limitations. We present a novel approach to phase retrieval based on...

Concept selection for a planetary reflection-seismology system with multiple end-user requirements and mission constraints

A study was performed to determine the feasibility of reflection seismology for planetary geology taking into account present-day technology advances. An approach based on end-user requirements was applied to assure the scientific usefulness of the results. Thirty applications of a seismic-reflection system for space applications were determined...

Motion tracking-enhanced MART for tomographic PIV

A novel technique to increase the accuracy of multiplicative algebraic reconstruction technique (MART) reconstruction from tomographic particle image velocimetry (PIV) recordings at higher seeding density than currently possible is presented. The motion tracking enhancement (MTE) method is based on the combined utilization of images from two or...

Reflection seismology systems for planetary geology: A feasibility study

A feasibility study is conducted to determine whether reflection seismology systems can be used for planetary geology research. The focus is on systems with up to 20,000 seismic detectors, such as used today in Earth geological research and energy companies. The study follows a top-down systems engineering end-user approach starting with the...

Do facilities matter?: The influence of facility satisfaction on perceived labour productivity of office employee

Purpose: Companies spend a lot of money to provide facilities such as a nice, effective and efficient building, well designed ergonomic furniture, sophisticated IT, cleaning services, catering, and safety services. Both from a theoretical perspective as well as from a managerial point of view, it is important to know if and how strongly...

Effecten van facilitybeleving op de gepercipieerde arbeidsproductiviteit

In dit rapport wordt verslag uitgebracht van een onderzoek naar de invloed van facilitybeleving op de gepercipieerde arbeidsproductiviteit, op zichzelf en in verhouding tot de invloed hierop van tevredenheid over de organisatie, tevredenheid over het werk en de invloed van persoons- en functiekenmerken. Gaat een hogere tevredenheid over de...

Invloed van facilitybeleving op arbeidsproductiviteit (2)

De arbeidsproductiviteit op kantoor wordt door veel factoren beïnvloed. Voor aanbieders van facilitaire diensten is vooral het effect van de facilitaire voorzieningen interessant. Op initiatief van Facilicom Services Group. hebben het Center for People and Buildings in Delft (CfPB) en onderzoeks- en adviesgroep Dialogic uit Utrecht een onderzoek...