256 research outputs found
Double facades a more sustainable solution than a optimal single facade
Facade parameters influence the energy flows coming through the facade, in order to optimize the indoor environment for the comfort of the individual building occupant with minimal energy use. How can the facade make optimal use of the free incoming energy flows to maximize the comfort level of the individual building occupant at minimal energy use? The type of façade described as a second skin façade is characterised by a single glass layer on the outside and an isolated façade layer on the inside, which often includes an insulated glass layer. The application of the single glass layer as a second skin around the insulated layer results in an air cavity between these two layers. The property that distinguishes a second skin façade from other DSF is that it relies on natural ventilation of the cavity, in comparison to other facades which use mechanical systems to induce the airflow. The advantage of merely using natural ventilation in the façade cavity is the lower energy consumption. However, it also results in some unresolved issues which require further attention. This project is concerned with the behaviour of a highly complex shaped second skin facade on a Dutch office building, and the thermal comfort impact on the building user. During 3 weeks different measurements were done to determine the main characteristics of the glass and the facade. These measurements were related to earlier measurements done by other buildings with a second skin facade. A key difference between a second skin facade, as well as other climate facades, and more traditional opaque facades is its dynamic behaviour
Double facades a more sustainable solution than a optimal single facade
Facade parameters influence the energy flows coming through the facade, in order to optimize the indoor environment for the comfort of the individual building occupant with minimal energy use. How can the facade make optimal use of the free incoming energy flows to maximize the comfort level of the individual building occupant at minimal energy use? The type of façade described as a second skin façade is characterised by a single glass layer on the outside and an isolated façade layer on the inside, which often includes an insulated glass layer. The application of the single glass layer as a second skin around the insulated layer results in an air cavity between these two layers. The property that distinguishes a second skin façade from other DSF is that it relies on natural ventilation of the cavity, in comparison to other facades which use mechanical systems to induce the airflow. The advantage of merely using natural ventilation in the façade cavity is the lower energy consumption. However, it also results in some unresolved issues which require further attention. This project is concerned with the behaviour of a highly complex shaped second skin facade on a Dutch office building, and the thermal comfort impact on the building user. During 3 weeks different measurements were done to determine the main characteristics of the glass and the facade. These measurements were related to earlier measurements done by other buildings with a second skin facade. A key difference between a second skin facade, as well as other climate facades, and more traditional opaque facades is its dynamic behaviour
Exploiting lens aberrations to create electron vortex beams
A model for a new electron vortex beam production method is proposed and
experimentally demonstrated. The technique calls on the controlled manipulation
of the degrees of freedom of the lens aberrations to achieve a helical phase
front. These degrees of freedom are accessible by using the corrector lenses of
a transmission electron microscope. The vortex beam is produced through a
particular alignment of these lenses into a specifically designed astigmatic
state and applying an annular aperture in the condensor plane. Experimental
results are found to be in good agreement with simulations.Comment: 5 pages, 4 figure
Magnetic monopole field exposed by electrons
Magnetic monopoles have provided a rich field of study, leading to a wide
area of research in particle physics, solid state physics, ultra-cold gases,
superconductors, cosmology, and gauge theory. So far, no true magnetic
monopoles were found experimentally. Using the Aharonov-Bohm effect, one of the
central results of quantum physics, shows however, that an effective monopole
field can be produced. Understanding the effects of such a monopole field on
its surroundings is crucial to its observation and provides a better grasp of
fundamental physical theory. We realize the diffraction of fast electrons at a
magnetic monopole field generated by a nanoscopic magnetized ferromagnetic
needle. Previous studies have been limited to theoretical semiclassical optical
calculations of the motion of electrons in such a monopole field. Solid state
systems like the recently studied 'spin ice' provide a constrained system to
study similar fields, but make it impossible to separate the monopole from the
material. Free space diffraction helps to understand the dynamics of the
electron-monopole system without the complexity of a solid state system. The
use of a simple object such as a magnetized needle will allow various areas of
physics to use the general dynamical effects of monopole fields without
requiring a monopole particle or specific solids which have internal
monopole-like properties. The experiment performed here shows that even without
a true magnetic monopole particle, the theoretical background on monopoles
serves as a basis for experiments and can be applied to efficiently create
electron vortices. Various predictions about angular momentum and general field
effects can readily be studied using the available equipment. This realization
provides insights for the scientific community on how to detect magnetic
monopoles in high energy collisions, cosmological processes, or novel
materials.Comment: 5 pages, 3 figures + 7 pages of supplementary information, 8 figure
Met zodebemesting verdubbelt stikstofwerking uit drijfmest
Uit detailproeven is naar voren gekomen dat de hoeveelheid werkzame stikstof uit drijfmest, in vergelijking met bovengrondse aanwending, bij zodebemesting ongeveer wordt verdubbeld
Духовне життя українців-галичан часів ІІ Речі Посполитої
У статті висвітлюється суспільно-політичне становище в Західній Україні міжвоєнного періоду, дається оцінка тогочасним українським релігійним течіям, які проявлялися, з одно-
го боку, у подальшому розмежуванні сил, а з іншого, – у їх консолідації на ґрунті духовності за допомогою Греко-католицької церкви. Протистояння полонізації та асиміляції викристалізовувало в менталітеті українців-галичан духовність, яка згуртовувала мільйонні селянські
маси.The article analyses social and political life in Western Ukraine within the inter-war period. Ukrainian religious
movements of the period are being evaluated. The author concludes that on the one hand those movements resulted
in separation of forces, but on the other hand they caused consolidation of efforts on the basis of Greek Catholic
religious principles. The opposition of expansion and assimilation have molded spiritual basis of the Galician Ukrainian
mentality that have joined millions of rural citizens together
Theory and applications of free-electron vortex states
Both classical and quantum waves can form vortices: with helical phase fronts
and azimuthal current densities. These features determine the intrinsic orbital
angular momentum carried by localized vortex states. In the past 25 years,
optical vortex beams have become an inherent part of modern optics, with many
remarkable achievements and applications. In the past decade, it has been
realized and demonstrated that such vortex beams or wavepackets can also appear
in free electron waves, in particular, in electron microscopy. Interest in
free-electron vortex states quickly spread over different areas of physics:
from basic aspects of quantum mechanics, via applications for fine probing of
matter (including individual atoms), to high-energy particle collision and
radiation processes. Here we provide a comprehensive review of theoretical and
experimental studies in this emerging field of research. We describe the main
properties of electron vortex states, experimental achievements and possible
applications within transmission electron microscopy, as well as the possible
role of vortex electrons in relativistic and high-energy processes. We aim to
provide a balanced description including a pedagogical introduction, solid
theoretical basis, and a wide range of practical details. Special attention is
paid to translate theoretical insights into suggestions for future experiments,
in electron microscopy and beyond, in any situation where free electrons occur.Comment: 87 pages, 34 figure
Bronchoscopic treatment of intraluminal typical carcinoid: A pilot study
AbstractObjective: The curative potential of various bronchoscopic treatments such as Nd:YAG laser, photodynamic therapy, and brachytherapy for the treatment of intraluminal tumor has been reported previously. Bronchoscopic treatment can be used to treat small intraluminal tumor with curative intent, such as in patients with roentgenologically occult squamous cell cancer. In a retrospective study, we showed that bronchoscopic treatment provided excellent local control with surgical proof of cure in 6 of 11 patients with intraluminal typical bronchial carcinoid. Methods: In a prospective study, 19 patients (8 women and 11 men) with resectable intraluminal typical bronchial carcinoid have undergone bronchoscopic treatment under general anesthesia. Median age was 44 years (range, 20-74 years). If tumor persisted after 2 bronchoscopic treatment sessions, surgery was performed within 4 months after the treatment. Results: Bronchoscopic treatment was able to completely eradicate tumor in 14 of the 19 patients (complete response rate 73%, 95% CI: 49%-91%). Median follow-up of these patients is 29 months (range, 8-62 months). One patient had severe cicatricial stenosis after bronchoscopic treatment, and sleeve lobectomy was necessary. No residual carcinoid was found in the resected specimen. In the remaining 5 patients, bronchoscopic treatment did not result in a complete response and radical surgical resection was performed afterward with confirmation of residual carcinoid in the resected specimen. Median follow-up of the surgical group is 34 months (range, 12-62 months). Conclusions: Current data suggest that bronchoscopic treatment may be an effective alternative to surgical resection in a subgroup of patients with resectable intraluminal typical bronchial carcinoid. It alleviated the necessity of surgical resection in 68% (95% CI: 43%-87%) of the patients. (J Thorac Cardiovasc Surg 1998;116:402-6
Mechanisms of Peptide Oxidation by Hydroxyl Radicals: Insight at the Molecular Scale
Molecular dynamics (MD) simulations were performed to provide atomic scale insight in the initial interaction between hydroxyl radicals (OH) and peptide systems in solution. These OH radicals are representative reactive oxygen species produced by cold atmospheric plasmas. The use of plasma for biomedical applications is gaining increasing interest, but the fundamental mechanisms behind the plasma modifications still remain largely elusive. This study helps to gain more insight in the underlying mechanisms of plasma medicine but is also more generally applicable to peptide oxidation, of interest for other applications. Combining both reactive and nonreactive MD simulations, we are able to elucidate the reactivity of the amino acids inside the peptide systems and their effect on their structure up to 1 μs. Additionally, experiments were performed, treating the simulated peptides with a plasma jet. The computational results presented here correlate well with the obtained experimental data and highlight the importance of the chemical environment for the reactivity of the individual amino acids, so that specific amino acids are attacked in higher numbers than expected. Furthermore, the long time scale simulations suggest that a single oxidation has an effect on the 3D conformation due to an increase in hydrophilicity and intra- and intermolecular interactions
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