Dispersion Values Research Articles

Evaluation of the changes in electrocardiographic ventricular repolarization parameters after COVID-19 recovery in hemodialysis patients.

Coronavirus disease-2019 (COVID-19) has cardiac manifestations. Data about electrocardiogram (ECG) changes after COVID-19 recovery is limited in hemodialysis patients. We aimed to investigate the changes in ventricular repolarization parameters after COVID-19 recovery in hemodialysis patients. Fifty-five hemodialysis patients who recovered from COVID-19 infection were included. QT interval, Tp-e interval, corrected QT (QTc), QTc dispersion, and Tp-e dispersion values were determined on the patients' ECGs, taken before COVID-19 and at least 1 month after recovery. The patients' data before COVID-19 infection and after recovery were compared. It was found that longest QTc (QTcmax) and QTc dispersion values after recovery were prolonged compared with pre-infection period (427 ± 28 ms vs. 455 ± 26 ms, p = 0.000 and 39 ± 16 ms vs. 65 ± 20 ms, p = 0.000). In our hemodialysis patients, ventricular repolarization parameters increased after COVİD-19 recovery. In hemodialysis patients, already predisposed to arrhythmic deaths, arrhythmia risk after COVİD-19 recovery may become more pronounced.

Women misjudge men’s physical characteristics based on vocal cues

ABSTRACT Voice is an important biological cue, which may reveal a significant amount of information about an individual. Particularly in males, it plays a crucial role in processes like male competition or sexual selection. Additionally, voice can provide a cue for body size assessment. This study investigates the relationship between male voice characteristics and physical features (assessed by women) and determines the accuracy of these assessments. Three groups of female judges assessed 60 male voices (20 different voices per group) across seven categories of male physical features: height, body fat, musculature, body shape, hirsuteness, age and strength. Recordings of five vowels and sentence and number of anthropometric measurements were made for each of the studied men. Intra- and extragroup agreement of assessments of men’s physical characteristics was demonstrated. Men with lower fundamental frequency (F0 ) and lower formant dispersion (Df ) values were perceived as being heavier, older, stronger and more likely to have chest hair. However, across all the analysed fields of assessment, no accuracy was registered between estimates and men’s actual physical characteristics. These findings suggest that females were guided by stereotypes in their assessment of men’s appearance from voice alone. We propose the size exaggeration hypothesis as an explanation of this phenomenon

Invasion dynamics of Ponto‐Caspian amphipods leads to changes in invertebrate community structure and function

AbstractBiological invasions remain one of the most pressing threats to biodiversity globally, with unprecedented rates of establishment that are unlikely to abate in the future. As such the occurrence of multiple interacting invasive non‐native species (INNS) is becoming more common. Despite this, much of the research on the interaction of multiple INNS is conducted within laboratory settings, with field studies remaining rare or being conducted as one‐off sampling. There is therefore a deficit of knowledge pertaining to the natural population trajectories of multiple INNS and the wider ecological implications for the structure and function of the native communities. Here we present multiple years of data collected from a reservoir in the United Kingdom, which has undergone invasion by three congener non‐native amphipods. We initially observed the coexistence of Dikerogammarus haemobaphes with Crangonyx pseudogracilis under habitat segregation in the reservoir. However, the following year saw complete displacement of C. pseudogracilis and reduced abundances of D. haemobaphes once the more competitive Dikerogammarus villosus established abundant populations in the reservoir. D. villosus exhibited strong effects for the structure and function of the wider macroinvertebrate community composition in addition to driving reductions in taxa and functional richness. Gastropoda taxa appeared to be unaffected by the invasion dynamics. Significant increases in functional divergence (and less so functional dispersion) values were also observed following D. villosus establishment, with this response metric possibly representing an important tool in detecting stress from biological invasions that we urge scientists to test more extensively. In contrast to D. villosus, D. haemobaphes implications for the wider ecological community appeared to be limited. Importantly, we observed evidence to suggest the presence of boom–bust cycles with the explosion of D. villosus leading to a dramatic drop in their abundances the following year. We believe that the wider ecological implications of their abundant populations were so great that resources were not sufficient within the reservoir to support their abundant populations, leading to the observed population collapses. We call for further studies that investigate the population trajectories and wider ecological implications of multiple non‐native species in field settings to further our limited knowledge base.

Effect of Earthquake Preparation on Changes in Meteorological Characteristics (Based on the Example of the 2003 Chuya Earthquake)

In this paper, we analyze the effect of the preparation of the Chuya earthquake on September 27,2003, the strongest event in the Altai-Sayan folded region for the entire instrumental period of seismologicalobservations, on meteorological characteristics (temperature, relative humidity, atmospheric chemicalpotential correction, latent heat of evaporation, and the mean and dispersion values of these data) and theirspectral characteristics in the Gorny Altai region. The meteorological and spectral characteristics are shownto change for a certain time before the main shock. The spectral characteristics distinctly change both duringthe preparation of the main shock and during the aftershock process.

Facile access to redox responsive self-healing coating materials via living cationic block copolymerization of styrene and 2-chloroethyl vinyl ether

Poly(alkyl vinyl ether)-based functional copolymers have wide applications in many high-tech areas. However, their synthesis is still challenging which limits their applications. This article describes the synthesis of an unprecedented redox-responsive polystyrene-block-poly(2-thioethyl vinyl ether) (PSt-b-PTEVE) diblock copolymers via sequential “water tolerant” cationic polymerization of St and CEVE, followed by post-polymerization transformation of the pendant -CH2CH2Cl functionalities of PCEVE segment to -CH2CH2SH functionalities. The initiating system enabled controlled cationic polymerization of styrene (St), yielding well-defined PSt (at least up to 22500 g/mol) with relatively low dispersity (Đ ≤ 1.36) and polystyrene-block-poly(2-chloroethyl vinyl ether) (PSt-b-PCEVE) diblock copolymers with acceptable dispersity values (Đ ≤ 1.38) thereof, demonstrating high chain-end fidelity. The controlled character of the cationic polymerization reaction was confirmed by linear kinetic plots, linear increase of Mns (with low Đs) and synthesis of PSts of changing Mns simply by varying initial [St]0/[Initiator]0 feed ratio. The synthesized PSt-b-PTEVE diblock copolymers exhibited redox responsivity and self-healing behaviour. The self-healing property of the PSt-b-PTEVE diblock copolymer was studied by optical microscopy. For this, first, a mechanical cut was introduced in the cross-linked PSt-b-PTEVE thin films and then images were taken at regular intervals to investigate the healing. These promising PSt-b-PTEVE diblock copolymers might have potential applications in many emerging areas, including functional coating.

Fast, Multiple-Use Optical Biosensor for Point-of-Care Glucose Detection with Mobile Devices Based on Bienzyme Cascade Supported on Polyamide 6 Microparticles.

Non-invasive glucose determination provides major advantages in health monitoring and protection. It enables widespread point-of-care testing, which is affordable, sensitive, specific, rapid and equipment-free. This work reports on the development and analytical performance of a colorimetric biosensor in detecting glucose in human urine. Highly porous polyamide microparticles were synthesized as the support for the glucose oxidase (GOx) and horseradish peroxidase (HRP) dyad, which was immobilized randomly or consecutively-first HRP and then GOx. The latter system was superior, as GH@PA-C showed much higher activity than the random system, and it was used to prepare the biosensor, along with the 3,3',5,5'-tetramethylbenzidine chromogen. When in contact with urine, the biosensor displayed a strict linear correlation between the color difference and the glucose concentration in urine in the range of 0.01-3.0 mM, as established by the CIELab image processing algorithm and UV-VIS measurements. The biosensor acted in 20 s and had a detection limit of 30.7 µM in urine, high operational activity at pH = 4-8 and unchanged detection performance after 30 days of storage. Its unique feature is the possibility of multiple consecutive uses without the serious deterioration of the recovery and dispersion values. These characteristics can open the way for new routines in non-invasive personal diabetes detection.

Effect of Fiber Bundle Morphology on Fiber Dispersion for Long Fiber-Reinforced Thermoplastics.

Understanding the mechanics of fiber attrition during the extrusion process is highly important in predicting the strength of long fiber-reinforced thermoplastic composites. However, little work has been done to investigate the mechanics of fiber dispersion and its effects on fiber attrition. This study aims at investigating fiber dispersion in simple shear flows for long fiber-reinforced thermoplastic pellets. Depending on the fabrication process, fiber bundles display distinct levels of compaction within the pellets. Studies have shown that morphological differences can lead to differences in dispersion mechanics; therefore, using a Couette rheometer and a sliding plate rheometer, coated and pultruded pellets were subjected to simple shear deformation, and the amount of dispersion was quantified. Additionally, a new image-based analysis method is presented in this study to measure fiber dispersion for a multi-pellet-filled system. Results from the single-pellet dispersion study showed a small amount of correlation between the dimensionless morphological parameter and the dispersion measurement. Pultruded and coated pellets were both found to have similar dispersion rates in a multi-pellet system. However, pultruded pellets were found to have a higher dispersion value at all levels when compared with coated pellets in both dispersion studies.

Coherent qubit measurement in cavity-transmon quantum systems

A measurement of the time between quantum jumps implies the capability to measure the next jump. During the time between jumps the quantum system is not evolving in a closed or unitary manner. While the wave function maintains phase coherence it evolves according to a non-Hermitian effective Hamiltonian. So under null measurement the timing of the next quantum jump can change by very many orders of magnitude when compared to rates obtained by multiplying lifetimes with occupation probabilities obtained via unitary transformation. The theory developed in 1987 for atomic fluorescence is here extended to transitions in transmon qubits. These systems differ from atoms in that they are read out with a harmonic cavity whose resonance is determined by the state of the qubit. We extend our analysis of atomic fluorescence to this infinite level system by treating the cavity as a quantum system. We find that next photon statistics is highly nonexponential and when implemented will enable faster readout, such as on timescales shorter than the decay time of the cavity. Commonly used heterodyne measurements are applied on timescales longer than the cavity lifetime. The overlap between the next photon theory and the theory of heterodyne measurement which are described according to the stochastic Schr\"odinger equation is elucidated. In the limit of large dispersion the intrinsic error for next jump detection, at short time, tends to zero. Whereas for short-time dyne detection the error remains finite for all values of dispersion.

Optimization of Dispersions in GeO2-doped Photonic Crystal Fibers with Square Lattice

Germanium doped photonic crystal fibers with differences in the layers' air hole diameters in the cladding are presented to obtain flat dispersion, small effective mode area, and low attenuation property for supercontinuum generation applications. The flatness and small value of the dispersion depend on the lattice geometry when the fibers have the same germanium doping concentration. The dispersion of the square lattice fibers is a flatter and smaller value at the pump wavelength than the circular lattice fibers. Square lattice fibers with Ʌ = 0.9 µm, d1/Ʌ = 0.4 and Ʌ = 1.0 µm, d1/Ʌ = 0.45 are proposed for supercontinuum generation which has anomalous and all-normal dispersion, respectively. Their small dispersion values of 0.449 ps /nm.km and −1.096 ps/nm.km are suitable for broad spectrum supercontinuum generation. The small effective mode area and low attenuation of the two fibers of 3.221 µm2, 2.361 µm2 and 1.805×10−7 dB/m, 1.322×10−15 dB/m, respectively are favorable conditions for choosing a laser pump sources with low peak power. The proposed fibers can be new supercontinuum generation source replacing traditional glass core fibers.

Internal Kinematics and Structure of the Bulge Globular Cluster NGC 6569 ∗ ∗ Based on observations collected at the European Southern Observatory, Cerro Paranal (Chile), in the context of the ESO-VLT Multi-Instrument Kinematic Survey (MIKiS survey) under Large Programmes 106.21N5 (PI: Ferraro), 195.D-0750 (PI: Ferraro), 193.D-0232 (PI: Ferraro). This publication makes use of data products from the Two Micron All

In the context of a project aimed at characterizing the properties of star clusters in the Galactic bulge, here we present the determination of the internal kinematics and structure of the massive globular cluster NGC 6569. The kinematics has been studied by means of an unprecedented spectroscopic data set acquired in the context of the ESO-VLT Multi-Instrument Kinematic Survey of Galactic globular clusters, combining the observations from four different spectrographs. We measured the line-of-sight velocity of a sample of almost 1300 stars distributed between ∼0.″8 and 770″ from the cluster center. From a subsample of high-quality measures, we determined the velocity dispersion profile of the system over its entire radial extension (from ∼5″ to ∼200″ from the center), finding the characteristic behavior usually observed in globular clusters, with a constant inner plateau and a declining trend at larger radii. The projected density profile of the cluster has been obtained from resolved star counts, by combining high-resolution photometric data in the center, and the Gaia EDR3 catalog radially extended out to for a proper sampling of the Galactic field background. The two profiles are properly reproduced by the same King model, from which we estimated updated values of the central velocity dispersion, main structural parameters (such as the King concentration, the core, half mass, and tidal radii), total mass, and relaxation times. Our analysis also reveals a hint of ordered rotation in an intermediate region of the cluster (40″ < r < 90″, corresponding to 2r c < r < 4.5r c ), but additional data are required to properly assess this possibility.

A beamline to control longitudinal phase space whilst transporting laser wakefield accelerated electrons to an undulator

Laser wakefield accelerators (LWFAs) can produce high-energy electron bunches in short distances. Successfully coupling these sources with undulators has the potential to form an LWFA-driven free-electron laser (FEL), providing high-intensity short-wavelength radiation. Electron bunches produced from LWFAs have a correlated distribution in longitudinal phase space: a chirp. However, both LWFAs and FELs have strict parameter requirements. The bunch chirp created using ideal LWFA parameters may not suit the FEL; for example, a chirp can reduce the high peak current required for free-electron lasing. We, therefore, design a flexible beamline that can accept either positively or negatively chirped LWFA bunches and adjust the chirp during transport to an undulator. We have used the accelerator design program MAD8 to design a beamline in stages, and to track particle bunches. The final beamline design can produce ambidirectional values of longitudinal dispersion (R_{56}): we demonstrate values of + 0.20 mm, 0.00 mm and − 0.22 mm. Positive or negative values of R_{56} apply a shear forward or backward in the longitudinal phase space of the electron bunch, which provides control of the bunch chirp. This chirp control during the bunch transport gives an additional free parameter and marks a new approach to matching future LWFA-driven FELs.

Robust estimation of distribution algorithms via fitness landscape analysis for optimal low-thrust orbital maneuvers

One particular kind of evolutionary algorithms known as Estimation of Distribution Algorithms (EDAs) has gained the attention of the aerospace industry for its ability to solve nonlinear and complicated problems, particularly in the optimization of space trajectories during on-orbit operations of satellites. This article describes an effective method for optimizing the trajectory of a spacecraft using an evolutionary approach based on EDAs, incorporated with fitness landscape analysis (FLA). The approach utilizes flexible operators that are paired with seeding and selection mechanisms of EDAs. Initially, the orbit transfer problem is mathematically modeled and the objectives and constraints are identified. The landscape feature of the search space is analyzed via the dispersion metric to measure the modality and ruggedness of the search domain. The obtained information are used as feedback in developing adaptive operators for truncation factor and constraints separation threshold of the employed EDA. A framework for spacecraft trajectory optimization has been presented where the dispersion value for a space mission is estimated using a k-nearest neighbors (k-NN) algorithm. The suggested method is used to solve several problems related to low-thrust orbit transfer of satellites in Earth’s orbit. Results demonstrate that the suggested framework for trajectory design and optimization of space transfers is effective enough to offer fuel-efficient and energy-efficient maneuvers for different thrust levels of the propulsion system. Moreover, the performance of the proposed approach is evaluated against non-adaptive EDA and other advanced evolutionary algorithms. The obtained results certify that the proposed adaptive evolutionary approach is superior in identifying feasible minimum-fuel and minimum-energy transfer trajectories.

Identifying Optimal Cell Size for Geodiversity Quantitative Assessment with Richness, Diversity and Evenness Indices

The importance of quantitatively assessing the spatial patterns of geodiversity, and their intrinsic relationship with biodiversity and the ecosystem services provided to society, has been signalized by several authors, due to the relevance of this information in territorial management, the planning of environmental and conservation strategies. Within geodiversity method assessments, the grid system is the most widely used GIS spatial approach to calculate a geodiversity index. Preferred for its simplicity, it implies the fundamental decision of choosing the scale of the analysis, defined by the selection of cell size, determinant for the accuracy and correctness of the final maps. Although this topic has been occasionally approached by some authors within geodiversity assessments, there is no formal procedure for cell size selection. This is a key issue, and, in the scope of the present work, an empirical procedure to select optimal cell size(s) was tested on the national scale in Portugal, in lithology and geomorphology datasets. The quantitative method based on geodiversity indices was applied, using richness, diversity and evenness indices, in a hexagonal analytical grid, through eight cell dimensions. Several descriptive statistical parameters were analyzed, with particular emphasis on dispersion statistical measures. Optimal cell size corresponded to the minimum cell size, once dispersion values were significatively reduced or stabilized, and distributions from evenness and diversity indices were closer to symmetry, which provided more accurate results and higher spatial differentiation, although the final decision should always consider the main purposes of the analysis.

Temporal changes of QT dispersion in patients with acute ischemic stroke

Aim: Ischemic stroke is a significant cause of morbidity and mortality and can lead to fatal arrhythmias even in the absence of underlying cardiac pathology. The objective of this study was to investigate the impact of acute ischemic stroke on QT dispersion and its temporal changes over time. Methods: A total of 124 patients with acute ischemic stroke who did not receive any reperfusion treatment were included in the study. Corrected QT dispersion (QTcd) values were obtained from 12-lead surface electrocardiograms taken within the first 12 hours and after 48 hours of stroke onset. These values were compared with those of 93 age and sex-matched control subjects. The effects of diabetes and lesion lateralization on QT dispersion were also analyzed. Stroke patients whose lesions were clearly localized to either the right or left hemisphere were divided into two subgroups. The change in QT dispersion overtime during the follow-up period was also determined. Results: The study included 124 patients with acute ischemic stroke (54 females and 70 males) with a mean age of 67±11 years, as well as a control group of 93 subjects (49 females and 44 males) with a mean age of 69±8 years. The QTcd values of the stroke group were significantly longer than the control group in the first 12 hours of symptom onset. However, after 48 hours, the QTcd values of the stroke group decreased and the difference between the two groups was not statistically significant. The presence of diabetes mellitus caused a more significant increase in QT dispersion, and after 48 hours, the QTcd values of diabetic stroke patients were still significantly longer. The QTcd values of patients with left hemispheric lesions were significantly longer than those of patients with right hemispheric lesions, and this difference persisted after 48 hours. Conclusion: This study found that QT dispersion increases during the first few hours of ischemic stroke and decreases during the treatment period. This increase is more obvious and lasts longer in stroke patients with diabetes and left hemispheric lesions. The results suggest that QT dispersion may be a useful prognostic indicator for patients with acute ischemic stroke.

Influence of MWCNT’s waviness and aggregation factors on wave dispersion response of MWCNT-strengthened nanocomposite curved beam

This article focuses on the impact of waviness and aggregation of nanofillers on wave dispersion behavior of the nanocomposite curved beam strengthened with multi-walled carbon nanotubes (MWCNTs). In fact, the aggregation phenomenon is an inevitable subject in the manufacturing process of strengthened nanocomposite materials. Furthermore, in reality, usage of straight nanoreinforcements is almost impossible. So, MWCNTs can be wavy. These noted topics can significantly affect mechanical behavior of reinforced nanocomposite structures. In the current investigation, aggregation and waviness factors are accounted for through a modified Halpin-Tsai micromechanical homogenization model. The relations of kinetic and kinematic of MWCNTs-reinforced nanocomposite curved beam are expressed by employing Euler-Bernoulli beam theory. The governing equations are obtained by using Hamiltonian approach. The obtained equations are solved via an analytical solution to attain the wave dispersion values. The precision of the obtained outcomes is verified by the reported outcomes in the literature. Finally, the impacts of various important parameters such as aggregation and waviness factor, wave number and opening angles are examined.

ECG Changes in Patients with Amitriptyline Intoxication; P, QT, QTC, T and PR Wave Dispersion: A Retrospective Study

Objective: Amitriptyline intoxication is a life-threatening condition as it can cause cardiac arrhythmias. This study aims to examine the ECG changes in patients with amitriptyline intoxications who were admitted to the emergency department and to compare the P-wave, T-wave, QT, QTC, and PR dispersions with healthy controls.&#x0D; Material and Methods: The sample of the current retrospective study consists of only 46 patients with amitriptyline intoxication and 65 healthy controls. The 12-channel ECG recordings of the participants were evaluated by two experienced cardiologists. P wave, T wave, QT, QTC, and PR distance, minimum, maximum, and dispersion values were measured. The obtained data were recorded on the data set and subjected to statistical analysis.&#x0D; Results: There was no significant difference in sociodemographic variables between patients with amitriptyline intoxication and the control group. The main symptoms of the patients were as follows: 28.3% (n=13) lethargy, 32.6% (n=15) nausea-vomiting, 21.7% (n=10) unconsciousness, and 17.4% (n=8) other. According to the analysis of amitriptyline intoxication and ECG parameters of healthy controls, P-wave, T-wave, QT, QTC, and PR dispersion were higher in the intoxication group than in the healthy controls (p0.05). The patient group had a higher heart rate than the control group (p=0.026).&#x0D; Conclusion: The current study found that P-wave, T-wave, QT, QTC, and PR dispersion were higher in the amitriptyline intoxication group than in the control group, which is thought to play a role in cardiac arrhythmias. Clinicians should be on alert for any ECG changes in these cases.

Suggesting A Stochastic Measurement Tool for Determining Crime and Safety Indexes: Evidence from Turkey

Crime is a phenomenon that disrupts the welfare and structure of society and has become an important problem in both developed and developing countries. In recent years, in parallel with the increasing rate of urbanization all over the world, there has also been a serious increase in crime rates. With the increase in crime rate, fear of crime has emerged among individual members of society. Fear of crime is the degree of anxiety an individual feels about the deterioration of the social structure. This degree of anxiety is expressed by crime and safety indexes today. In this study, a new measurement tool is proposed in order to eliminate the effects such as emotional preference, decision-making difficulty, etc. For this purpose, the Stochastic Multi-Criteria Acceptability Analysis-TRI (SMAA-TRI) method, in which the measurement can be made with interval and dispersed values, and the probability theory can be reflected as an effect on the decision analysis, has been utilized to measure the crime and safety indexes, determined by online survey up to now, because of the fact that the experts/participants had difficulties in expressing their preferences clearly during their evaluations. It was found that the index values obtained in the study are consistent with the results of the surveys conducted with thousands of people and that the SMAA-TRI method can be effectively used in determining the crime/safety indexes.

Analysis of a photonic crystal fiber with ellipse air-holes for supporting 82 orbital angular momentum modes

We proposed a photonic crystal fiber (PCF) with ellipse air holes and high refractive index ring-core, which can stably support 82 orbital angular momentum states from the wavelength of 1.25–1.65 μm. The modes’ average confinement loss keeps as low as 10−9 dB m−1. In addition, the effective refractive index separation (Δn eff) between HE m +1,1 and EH m −1,1 (m = 2–21) is up to 10−3, which makes the mode degeneracy to LP mode can be almost neglected. The dispersion curves of low order eigenmodes are low and flat, especially at the wavelength of 1.4 μm the minimum absolute value of chromatic dispersion for HE1,1 mode is as low as 0.246 ps (nm·km)−1. Furthermore, we also analyze the effect of ellipticity change on the cladding air holes, which instructively show the favorable fault tolerance of confinement loss and dispersion. The proposed PCF structure will be a potential candidate for high-capacity optical fiber communications.

Photonic generation of dual-band dual-chirp waveforms with anti-dispersion transmission.

A photonic approach for generating dual-band dual-chirp waveforms with the capability of anti-dispersion transmission is proposed. In this approach, an integrated dual-drive dual-parallel Mach-Zehnder modulator (DD-DPMZM) is adopted to realize single-sideband modulation of a RF input and double-sideband modulation of baseband signal-chirped RF signals. By properly presetting the central frequencies of the RF input and the bias voltages of DD-DPMZM, dual-band dual-chirp waveforms with anti-dispersion transmission can be achieved after photoelectronic conversion. A complete theoretical analysis of the operation principle is presented. Full experimental verification of the generation and anti-dispersion transmission of dual-chirp waveforms centered at 2.5 and 7.5GHz as well as 2 and 6GHz over two dispersion compensating modules with dispersion values equivalent to 120km or 100km standard single-mode fiber is successfully carried out. The proposed system features a simple architecture, excellent reconfigurability, and immunity to dispersion-induced power fading, which are highly desired in distributed multi-band radar networks with optical-fiber-based transmission.

Extracting Group Velocity Dispersion values using quantum-mimic Optical Coherence Tomography and Machine Learning

Quantum-mimic Optical Coherence Tomography (Qm-OCT) images are cluttered with artefacts - parasitic peaks which emerge as a by-product of the algorithm used in this method. However, the shape and behaviour of an artefact are uniquely related to Group Velocity Dispersion (GVD) of the layer this artefact corresponds to and consequently, the GVD values can be inferred by carefully analysing them. Since for multi-layered objects the number of artefacts is too high to enable layer-specific analysis, we employ a solution based on Machine Learning. We train a neural network with Qm-OCT data as an input and dispersion profiles, i.e. depth distribution of GVD within an A-scan, as an output. By accounting for noise during training, we process experimental data and estimate the GVD values of BK7 and sapphire as well as provide a qualitative GVD value distribution in a grape and cucumber. Compared to other GVD-retrieving methods, our solution does not require user input, automatically provides dispersion values for all the visualised layers and is scalable. We analyse the factors affecting the accuracy of determining GVD: noise in the experimental data as well as general physical limitations of the detection of GVD-induced changes, and suggest possible solutions.