Search results for "microscopic"
showing 10 items of 177 documents
Modeling, evaluation, and scale on artificial pedestrians: a literature review
2017
Modeling pedestrian dynamics and their implementation in a computer are challenging and important issues in the knowledge areas of transportation and computer simulation. The aim of this article is to provide a bibliographic outlook so that the reader may have quick access to the most relevant works related to this problem. We have used three main axes to organize the article's contents: pedestrian models, validation techniques, and multiscale approaches. The backbone of this work is the classification of existing pedestrian models; we have organized the works in the literature under five categories, according to the techniques used for implementing the operational level in each pedestrian …
Synthetic Aperture Lensless Digital Holographic Microscopy (SALDHM) for Superresolved Biological Imaging
2013
Lensless digital holographic microscopy (LDHM) relates with the capability to achieve microscopic imaging working without lenses in the regime of holography. LDHM uses an extremely simplified setup and provides micron-range lateral and depth resolutions in three-dimensional (3D) imaging. Typically, LDHM uses a pinhole to provide spherical divergent illumination over the sample. Then, two different basic schemes are usually adopted for providing holographic recording. The first one assumes the interference between two in-line waves since diffraction by the sample can be considered as a perturbation of the reference wave. The second scheme uses an external reference beam in an off-line config…
Microscopic theory for the light-induced anomalous Hall effect in graphene
2019
We employ a quantum Liouville equation with relaxation to model the recently observed anomalous Hall effect in graphene irradiated by an ultrafast pulse of circularly polarized light. In the weak-field regime, we demonstrate that the Hall effect originates from an asymmetric population of photocarriers in the Dirac bands. By contrast, in the strong-field regime, the system is driven into a non-equilibrium steady state that is well-described by topologically non-trivial Floquet-Bloch bands. Here, the anomalous Hall current originates from the combination of a population imbalance in these dressed bands together with a smaller anomalous velocity contribution arising from their Berry curvature…
Die digitiformen Sensillen auf dem Maxillarpalpus von Coleoptera
1980
The digitiform sensilla on the distal segment of the maxillar palps ofAgabus bipustulatus (L.) andHydrobius fuscipes (L.) were investigated by electron microscopic methods. Each sensillum is innervated by a single bipolar sensory cell. The sensilla ofHydrobius are associated with three enveloping cells, which enclose an inner and outer receptor lymph cavity. A single enveloping cell only is found in the completely differentiated sensilla ofAgabus. These sensilla do not form an outer lymph cavity. The area beneath the hair base is filled by the distal process of the enveloping cell and by extensions of epidermal cells. Only one extra-cellular space exists, which seems to be homologous to an …
Microscopical anatomy of the involution of the branchial bars of amphibia [Abinieku žaunu kātu involūcijas mikroskopiskā anatomija]
1936
Teksts angļu valodā, kopsavilkums latviešu valodā.
Elektronenmikroskopische Untersuchungen zur Capillarhyper�mie in der stimulierten Goldhamsterschilddr�se
1966
Untersuchungen an 32 kalte- bzw. thyreotropinaktivierten Goldhamsterschilddrusen unter Vergleich mit den Glanduale thyreoideae 8 normaktiver Tiere ergaben: 1. Mit einsetzender Kolloidmobilisation werden oberhalb der lichtoptisch erkennbaren Basalmembran der Follikel gelegene, intraepitheliale Capillaren entfaltet. 2. Am Endothel dieser intraepithelialen Capillaren treten hierbei breitere Poren auf, die jedoch durch ein Diaphragma verschlossen bleiben (Endothelfenster). Anscheinend erfolgt ferner ein cytopemptischer Transport von Material aus dem erweiterten periendothelialen Spalt in Richtung Saftestrom. 3. In der Nachbarschaft aktivierter Thyreocyten, insbesondere wenn letztere Anzeichen e…
Advances in detection of fastidious bacteria: From microscopic observation to molecular biosensors
2019
Abstract Identification of pathogens and diagnosis of infections are important health challenges, especially in the case of fastidious bacteria which are those difficult-to-grow. A fastidious organism is any organism that has a complex nutritional requirement. Additionally, a fastidious microorganism will only grow when specific nutrients are included in the culture medium. These bacteria can cause serious diseases whose detection and monitoring is critical in many cases. The oldest detection methods are based on simple microscopy observation and staining, after culture on selective growth media, but often do not provide a clear answer. Some new molecular approaches, such as DNA-based seque…
Prenatal Ultrastructural Diagnosis in the Neuronal ceroid-lipofuscinoses
1994
Summary The neuronal ceroid-lipofuscinose (NCL) are autosomal-recessive disorders in childhood of unknown enzymatic origin. They can be recognized by the presence of abnormal lipopigments identified by electron microscopy. Based on the study of circulating lymphocytes, individual clinical subtypes of NCL can be correlated. Prenatal diagnosis of NCL with the electron microscope is now feasible for the infantile (Finnish) from (INCL) and late-infantile form (LINCL). INCL-specific granular lipopigments are present in endothelial cells of biopsied chorion stroma vessels of homozygously affected fetuses. In LINCL, disease-typical curvilinear bodies can be identified in uncultured amniotic fluid …
Twin axial vortices generated by Fibonacci lenses.
2013
Optical vortex beams, generated by Diffractive Optical Elements (DOEs), are capable of creating optical traps and other multifunctional micromanipulators for very specific tasks in the microscopic scale. Using the Fibonacci sequence, we have discovered a new family of DOEs that inherently behave as bifocal vortex lenses, and where the ratio of the two focal distances approaches the golden mean. The disctintive optical properties of these Fibonacci vortex lenses are experimentally demonstrated. We believe that the versatility and potential scalability of these lenses may allow for new applications in micro and nanophotonics.
The microscopic theory of diffusion-controlled defect aggregation
1998
Abstract The kinetics of diffusion-controlled aggregation of primary Frenkel defects ( F and H centers) in irradiated CaF 2 crystals is theoretically studied. Microscopic theory is based on the discrete-lattice formalism for the single defect densities (concentrations) and the coupled joint densities of similar and dissimilar defects treated in terms of the Kirkwood superposition approximation. Conditions and dynamics of the efficient F center aggregation during crystal heating after irradiation are analyzed.