Generation of J0 Bessel Beams with controlled spatial coherence features

An alternative method to generate J0 Bessel beams with controlled spatial partial coherence properties is introduced. Far field diffraction from a discrete number of source points on an annular region is calculated. The average for different diffracted fields produced at several rotation angles is numerically calculated and experimentally detected. Theoretical and experimental results show that for this particular case, J0 Bessel beam is a limit when the number of points tends towards infinity and the associated complex degree of coherence is also a function of the number of points.Comment: 6 pages, 5 figure

Fresnel Incoherent Correlation Holography (FINCH)

Bakalářská práce je zaměřena na teoretické a experimentální aspekty Fresnelovské nekoherentní korelační holografie, která byla navržena teprve nedávno a v odborné literatuře se objevuje pod názvem FINCH. Její hlavní přednost spočívá v možnosti realizace holografické rekonstrukce nekoherentně osvětlených 3D objektů. V metodě FINCH se záznam objektu provádí s využitím metod optické holografie a digitální difraktivní optiky. Rekonstrukce objektu se realizuje numericky pomocí principů známých z digitální holografie. V experimentech se efektivně využívají moderní optoelektronická zařízení známá jako prostorové modulátory světla. Bakalářská práce obsahuje přehled zahrnující popis základních principů metody FINCH, ale vlastní příspěvek práce spočívá v matematickém popisu metody a vytvoření numerického simulačního modelu v prostředí Matlab. Hlavním výsledkem práce je návrh a realizace experimentů umožňujících praktické ověření metody. V bakalářské práci jsou prezentovány výsledky dvou nezávislých experimentů provedených se dvěma rozdílnými typy prostorových modulátorů světla firem HOLOEYE a HAMAMATSU. Experimentální výsledky mají velmi dobrý soulad s teoretickou předpovědí. Bakalářská práce zahrnuje také krátkou diskuzi získaných výsledků, dalších možných výzkumných směrů a aplikací metody FINCH.In the Bachelor's thesis, the recently proposed method known as Fresnel Incoherent Correlation Holography (FINCH) is examined both theoretically and experimentally. Its main advantage consists in a possibility to realize holographic reconstruction of 3D objects illuminated by incoherent light. In FINCH, the object recording is performed applying methods of optical holography and digital diffractive optics. The object reconstruction is realized numerically and utilizes principles of digital holography. In experiments, the modern optoelectronic devices known as Spatial Light Modulators are effectively used. The Bachelor's thesis includes a short review including description of the basic principles of FINCH but its own contribution consists in the mathematical description of the method and creation of the numerical simulation model in Matlab. The main result of the thesis is design and realization of experiments enabling verification of the method. In the Bachelor's thesis, results of two independent experiments realized with different types of Spatial Light Modulators HOLOEYE and HAMAMATSU are presented. An agreement of experimental results with theoretical predictions is very good. A short discussion of the obtained results, further research topics and FINCH applications is also included in the Bachelors's Thesis.

Wide-field common-path incoherent correlation microscopy with a perfect overlapping of interfering beams

Incoherent correlation microscopy is recently discovered technique for digital imaging of three-dimensional objects in a quasimonochromatic spatially incoherent light. Its operation is based on wavefront division carried out by a spatial light modulator and capturing correlation recordings of the observed scene. To achieve image reconstruction, at least a partial overlapping of the signal and reference waves created by the spatial light modulator is necessary. In the known experimental configurations, the overlapping of interfering beams is strongly reduced in off-axis areas of the object and the image can be reconstructed only in a very small portion of the field of view provided by the used microscope objective lens. Here, we propose and successfully demonstrate modified experimental system working with two-component relay optics inserted between the microscope objective and the spatial light modulator and providing full overlapping of correlated beams in all areas of the field of view of the objective lens. The benefits and applicability of the proposed system design are clearly demonstrated on the imaging of the USAF resolution targets

Arabic Handwritten Text Line Dataset

Segmentation of Arabic manuscripts into lines of text and words is an important step to make recognition systems more efficient and accurate. The problem of segmentation into text lines is solved since there are carefully annotated dataset dedicated to this task. However, To the best of our knowledge, there are no dataset annotating the word position of Arabic texts. In this paper, we present a new dataset specifically designed for historical Arabic script in which we annotate position in word level.Comment: TAMARICS'2022 Conference held on December 8-11,2022 at University of Tamenghasset,Algeri

High‐performant all‐organic aqueous sodium‐ion batteries enabled by PTCDA electrodes and a hybrid Na/Mg electrolyte

Aqueous sodium-ion batteries (ASIBs) are aspiring candidates for low environmental impact energy storage, especially when using organic electrodes. In this respect, perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) is a promising anode active material, but it suffers from extensive dissolution in conventional aqueous electrolytes. As a remedy, we here present a novel aqueous electrolyte, which inhibits the PTCDA dissolution and enables their use as all-organic ASIB anodes with high capacity retention and Coulombic efficiencies. Furthermore, the electrolyte is based on two, hence “hybrid”, inexpensive and non-fluorinated Na/Mg-salts, it displays favourable physico-chemical properties and an electrochemical stability window >3 V without resorting to the extreme salt concentrations of water-in-salt electrolytes. Altogether, this paves the way for ASIBs with both relatively high energy densities, inexpensive total cell chemistries, long-term sustainability, and improved safety

Caring for the Terminally Ill: An Interpretation of Time, Existence, and Mortality

In this paper, the first author explores the complexity of caring for palliative care patients approaching end of life in response to the statement nursing is an interpretive practice. A real-life scenario is used to unravel the exploration of time, existence, and mortality. The author proclaims that the question of death remains unanswered, and the call to palliative care nursing requires an extensive examination of one’s own temporality to cultivate an understanding of patients experiences of grief, legacy, and meaning making in the context of terminal illness

Monitoring Polysulfide Solubility and Diffusion in Fluorinated Ether-Based Electrolytes by Operando Raman Spectroscopy

Polysulfide (PS) solubility is a key property of Li-S battery electrolytes for the conversion reaction(s) at the electrolyte-electrode interface. When PSs shuttle between the composite C/S cathode and the lithium metal anode, however, this leads to a continuous loss of active material and thus rapid capacity fading. In order to restrict the shuttle effect, fluorinated ethers have recently been proposed as a remedy; by only sparsely dissolving PSs they physically block the diffusion. We show here how the diffusion of PSs in fluorinated ethers, as monitored by operando Raman spectroscopy, is selective and that only short-chain PS (S42-) are soluble and diffuse. This fundamental observation can be used to further leverage the practical performance of Li-S batteries by novel electrolyte design

High-quality and universal empirical atomic charges for chemoinformatics applications.

BackgroundPartial atomic charges describe the distribution of electron density in a molecule and therefore provide clues to the chemical behaviour of molecules. Recently, these charges have become popular in chemoinformatics, as they are informative descriptors that can be utilised in pharmacophore design, virtual screening, similarity searches etc. Especially conformationally-dependent charges perform very successfully. In particular, their fast and accurate calculation via the Electronegativity Equalization Method (EEM) seems very promising for chemoinformatics applications. Unfortunately, published EEM parameter sets include only parameters for basic atom types and they often miss parameters for halogens, phosphorus, sulphur, triple bonded carbon etc. Therefore their applicability for drug-like molecules is limited.ResultsWe have prepared six EEM parameter sets which enable the user to calculate EEM charges in a quality comparable to quantum mechanics (QM) charges based on the most common charge calculation schemes (i.e., MPA, NPA and AIM) and a robust QM approach (HF/6-311G, B3LYP/6-311G). The calculated EEM parameters exhibited very good quality on a training set ([Formula: see text]) and also on a test set ([Formula: see text]). They are applicable for at least 95 % of molecules in key drug databases (DrugBank, ChEMBL, Pubchem and ZINC) compared to less than 60 % of the molecules from these databases for which currently used EEM parameters are applicable.ConclusionsWe developed EEM parameters enabling the fast calculation of high-quality partial atomic charges for almost all drug-like molecules. In parallel, we provide a software solution for their easy computation (http://ncbr.muni.cz/eem_parameters). It enables the direct application of EEM in chemoinformatics