Search results for "Image"

Cultural Heritage and the Image of Chemistry

2009

Assessment of a single-acquisition imaging sequence for oxygen-sensitive (3)He-MRI.

2001

MRI of the lungs using hyperpolarized helium-3 (3He) allows the determination of intrapulmonary oxygen partial pressures (pO2). The need to separate competing processes of signal loss has hitherto required two different imaging series during two different breathing maneuvers. In this work, a new imaging strategy to measure pO2 by a single series of consecutive scans is presented. The feasibility of the method is demonstrated in three healthy human volunteers. Maps and histograms of intrapulmonary pO2 are calculated. Changes in the oxygen concentration of the inhaled gas mixture are well reproduced in the histograms. Monte Carlo (MC) simulations of the temporal evolution of 3He hyperpolariza…

Dynamics of Colloidal Hard Spheres in Thin Aqueous Suspension Layers—Particle Tracking by Digital Image Processing and Brownian Dynamics Computer Sim…

1993

Abstract A new experimentally simple technique is introduced for studying dynamical properties of hard sphere colloids in thin aqueous suspension layers by light-microscopy observation supported by computer-aided digital image processing. The thickness of the layers of the colloidal samples confined between two smooth glass plates is accurately adjusted by monodisperse "spacer" spheres which are larger than the diffusing spheres. Tracking of single particles in concentrated phases is accomplished using fluorescence light microscopy where a few dyed particles are mixed with the undyed colloidal spheres of the same size. First results are presented for the self-diffusion coefficient—(i) in ve…

Time-of-flight photoemission electron microscopy – a new way to chemical surface analysis

2001

Abstract The time structure of synchrotron radiation at BESSY I (Berlin) was utilised to operate a photoemission electron microscope in the time-of-flight mode. The electrons that are emitted from the sample surface with different energies are dispersed in a drift tube subsequent to the imaging optics. Two ways of fast image detection have been explored, a fast gated intensified CCD camera (800 ps gate time) and a special counting electronics in combination with a 3D (x,y,t)-resolving delay line detector ( time resolution ps). The latter device has a lateral resolution of about 50 μm in the image plane being equivalent to 1000 pixels along the image diagonal. An energy resolution of 400 meV…

Vertical and lateral drift corrections of scanning probe microscopy images

2010

A procedure is presented for image correction of scanning probe microscopy data that is distorted by linear thermal drift. The procedure is based on common ideas for drift correction, which the authors combine to a comprehensive step-by-step description of how to measure drift velocities in all three dimensions and how to correct the images using these velocities. The presented method does not require any knowledge about size or shape of the imaged structures. Thus, it is applicable to any type of scanning probe microscopy image, including images lacking periodic structures. Besides providing a simple, ready-to-use description of lateral and vertical drift correction, they derive all formul…

The Brand "Made in China" as a Part of the Growth of the China's Competitive Advantage

2016

In the eyes of consumers, each product has some kind of origin (its country, region, and continent). The image of the place of origin influences the assessment of products and brands (brand image) they come from. Traditionally, consumers extrapolate the characteristics of the country and its inhabitants on the characteristics of the product. Chinese products are very common and they can be purchased almost anywhere. The consumer does not have to take any special efforts to acquire products “made in China”. Many of these products do not have specific characteristics that allow them to be considered as the unique. Products, whose names indicate the place of origin, are witnessing an increasin…

Comparison of MODIS and Landsat-8 retrievals of Chlorophyll-a and water temperature over Lake Titicaca

2016

Chlorophyll-a concentration ([Chl-a]) and Lake Surface Temperature (LST) were retrieved in Lake Titicaca (Peru-Bolivia) using MODIS and Landsat-8 images. The lake was chosen as a case-study for evaluating the feasibility of Landsat-8 images for [Chl-a] and LST monitoring in oligotrophic and mesotrophic water bodies. The big size of the lake and its spatial and temporal variability, allowed the comparison of MODIS and Landsat-8 products for a wide range of [Chl-a] and LST. The atmospheric correction of the images was facilitated by the very high altitude of the lake. MODIS images were processed with standard ocean color algorithms whereas for Landsat-8, specific algorithms were tested and va…

On the measurement of bubble size distribution in gas–liquid contactors via light sheet and image analysis

2010

Abstract Particle image velocimetry techniques coupled with advanced image processing tools are receiving an increasing interest for measuring flow quantities and local bubble-size distributions in gas–liquid mechanically agitated vessels. When trying to analyze image information the problem arises that bubble sizes are generally underestimated, due to the fact that the laser sheet used for lighting the system randomly cuts bubbles over non-diametrical planes, leading to an apparent bubble size distribution even in the ideal case of single sized bubbles. Clearly in the case of bubbles with a size distribution the experimental information obtained is affected by the superposition of effects.…

Automatic detection of large dense-core vesicles in secretory cells and statistical analysis of their intracellular distribution.

2010

Analyzing the morphological appearance and the spatial distribution of large dense-core vesicles (granules) in the cell cytoplasm is central to the understanding of regulated exocytosis. This paper is concerned with the automatic detection of granules and the statistical analysis of their spatial locations in different cell groups. We model the locations of granules of a given cell as a realization of a finite spatial point process and the point patterns associated with the cell groups as replicated point patterns of different spatial point processes. First, an algorithm to segment the granules using electron microscopy images is proposed. Second, the relative locations of the granules with…

Cerebral Dynamics during the Observation of Point-Light Displays Depicting Postural Adjustments

2017

Objective: As highly social creatures, human beings rely part of their skills of identifying, interpreting, and predicting the actions of others on the ability of perceiving biological motion. In the present study, we aim to investigate the electroencephalographic (EEG) cerebral dynamics involved in the coding of postural control and examine whether upright stance would be codified through the activation of the temporal-parietal cortical network classically enrolled in the coding of biological motion. Design: We registered the EEG activity of 12 volunteers while they passively watched point light displays (PLD) depicting quiet stable (QB) and an unstable (UB) postural situations and their r…