Miracle-dz/UniFAR-FTUs huggingface dataset:
Direct numerical simulation of two-particle relative diffusion in isotropic turbulence

The relative diffusion of fluid particle pairs in statistically stationary isotropic turbulence is studied by direct numerical simulation, at a Taylor‐scale Reynolds number of about 90. The growth of two‐particle separation exhibits asymptotic stages at small and large diffusion times. Through the two‐particle separation, particle–pair velocity correlations are closely related to the Eulerian spatial structure of the turbulence. At large times, the square of the separation distance has a chi‐square probability distribution. At the moderate Reynolds number of the simulations, for this asymptotic distribution to be reached before the particles begin to move independently of each other, the initial separation must be small compared to the Kolmogorov scale. In an inertial frame moving with the initial particle velocities, the velocity increments of two fluid particles become uncorrelated only if their initial velocities are uncorrelated, which requires their initial separation be large compared to the integra.
Successful implementation of Medical Education Faculty Development Project at Saint George University of Beirut in the immediate post triple blow to Beirut

Background The aim of this study is to explore the efficacy of the Faculty Development Program (FDP) implemented at the Saint George University of Beirut-Faculty of Medicine (SGUB FM) under exceptional circumstances as the triple blow to Beirut. Methods The Faculty Development, directed towards a cohort of 35 faculty members, is composed of two major components: methodology of teaching and techniques of assessment. The Kirkpatrick’s assessment model, in combination with a specifically designed psychological questionnaire, were chosen to assess the effectiveness of the faculty development initiative. Results Results of the different questionnaires were interpreted individually, then through the lens of the psychological questionnaire. A majority of faculty (55%) were significantly affected psychologically by Beirut’s triple blow and 77% of all participants found the workshops to be of excellent quality (Kirkpatrick’s Level I). Moreover, Kirkpatrick’s level II results yielded a 76% mean percentage of correct answers to post-workshops MCQs and a significant improvement in the mean results of the self-assessment questionnaires, administered before and after each workshop. Results also show that the more a trainee is psychologically affected, the less he/she performs as evidenced by a decrease in the satisfaction rate as well as in the score of the cognitive MCQs and of the self-assessment questionnaires. Conclusions This study was able to highlight that significant learning can occur amidst exceptional circumstances like the Beirut triple blow and administration should invest in professional growth to retain its faculty.
Location of the source of magnetospheric energetic particle bursts by multispacecraft observations

During a magnetic substorm on October 16, 1973 a number of magnetospheric bursts of energetic particles were observed simultaneously by IMP-6 and IMP-7 in the magnetotail (at X/sub SM/approximately-greater-than-32 R/sub e/, Y/sub SM/approximately-greater-than1.2 R/sub e/ and Z/sub SM/SMapprox. =- 4.7 R/sub e/) while the two spacecraft were separated by only approx.1 R/sub e/ along the X/sub sM/ axis (deltaX/sub SM/approx. =1Re, deltaY/sub SM/=deltaZ/sub Sm/approx. = R/sub e/). Detailed anisotropy measurements of 210 and 290 keV protons by the JHU/APL instruments on both spacecraft provide for the first time an indication of the location of the ''source'' of the energetic magnetospheric particles as well as evidence for its movement with speeds from approx.30 to more than 80 km/sec in association with the intensification of the westward auroral electrojet during a magnetic bay at the station closest to the local time of the spacecraft (also local midnight). The size of the source was estimated to be degreeXapprox. =500 km. The observations indicate that in this case energetic particles are accelerated to >1.85 MeV in a moving and localized region in the geomagnetotail. (AIP)
First fabrication of full 3D-detectors at SINTEF

3D-detectors, with electrodes penetrating through the entire substrates have drawn great interests for high energy physics and medical imaging applications. Since its introduction by C. Kenney et al in 1995, many laboratories have begun research on different 3D-detector structures to simplify and industrialise the fabrication process. SINTEF MiNaLab joined the 3D collaboration in 2006 and started the first 3D fabrication run in 2007. This is the first step in an effort to fabricate affordable 3D-detectors in small to medium size production volumes. The first run was fully completed in February 2008 and preliminary results are promising. Good p-n junction characteristics have been shown on selected devices at the chip level with a leakage current of less than 0.5 nA per pixel. Thus SINTEF is the second laboratory in the world after the Stanford Nanofabrication Facility that has succeeded in demonstrating full 3D-detectors with active edge. A full 3D-stacked detector system were formed by bump-bonding the detectors to the ATLAS readout electronics, and successful particle hit maps using an Am-241 source were recorded. Most modules, however, showed largely increased leakage currents after assembly, which is due to the active edge and p-spray acting as part of the total chip pn-junction and not as a depletion stop. This paper describes the first fabrication and the encountered processing issues. The preliminary measurements on both the individual detector chips and the integrated 3D-stacked modules are discussed. A new lot has now been started on p-type wafers, which offers a more robust configuration with the active edge acting as depletion stop instead of part of the pn-junction.
A Mother‐daughter‐granddaughter mechanism of shear dominated intersonic crack motion along interfaces of dissimilar materials

Abstract In this paper we report recent progress in large‐scale atomistic studies of crack propagation along interfaces of dissimilar materials. We consider two linear‐elastic material blocks bound together with a weak potential whose bonds snap early upon a critical atomic separation. This approach confines crack motion along the interface. In the two blocks, atoms interact with harmonic potentials with different spring constants adjacent to the interface. An initial crack is introduced along the interface and subjected to shear dominated displacement loading along the upper and lower boundaries of the sample. Upon initiation of the crack, we observe that it quickly approaches a velocity close to the Rayleigh‐wave speed of the soft material. After cruising at this speed for some time, a secondary crack is nucleated at a few atomic spacings ahead of the crack. This secondary crack, also referred to as the daughter crack, propagates at the longitudinal‐wave speed of the soft material. Shortly after that, a tertiary crack, referred to as the granddaughter crack, is nucleated and begins to move at the longitudinal wave speed of the stiff material. The granddaughter crack is supersonic with respect to the soft material and is clearly identifiable by two Mach cones in the soft material. Our results indicate that the limiting speed of shear dominated cracks along a bi‐material interface is the longitudinal wave speed of the stiff material, and that there are two intermediate limiting speeds (Rayleigh and longitudinal wave speeds of the soft material) which can be overcome by the mother‐daughter‐granddaughter mechanism.
Numerical Approach for The Evaluation of Hemodynamic Behaviour in Peripheral Arterial Disease: A Systematic Review

Reduced blood flow to the lower extremities causes peripheral arterial disease (PAD), which is caused by atherosclerotic plaque in the arterial wall. If this impairment is not treated, it will result in severe vascular diseases like ulceration and gangrene. Previous research has shown that while evaluating the pathology of the peripheral artery, the assumption of the model geometry significantly impacts the uncertainty of the stenosis area. However, more work needs to be done to understand the interaction between mechanical better and flow conditions in the peripheral artery using a separate computer model of the cardiovascular system. This paper reviews the numerical approach on pre- and post-treatment of hemodynamic behavior in peripheral arterial disease (PAD). The goal of this study was to thoroughly examine the most recent developments with the application of computational studies in PAD from 2017 to 2022. While FSI investigation highlights the behavior of both the fluid and structure domains (blood and artery) during the numerical analysis of blood flow, CFD simulations primarily focus on the fluid domain (blood) behavior. Out of 92 research publications, 19 were appropriate for this assignment. This thorough study divides the publications into the categories of CFD, and FSI approaches. The results were then reviewed in accordance with the wall characteristic, analytical method, geometry, viscosity models, and validation. This paper summarizes the parameters of geometrical construction, viscosity models, analysis methods, and wall characteristics taken into consideration by the researchers to identify and simulate the blood flood flow in the stenosis area. These parameters are summarised in this study. Additionally, it could offer systematic data to help future studies produce better computational analyses.
Anarchy Meets Hierarchy: Sociopolitical Implications of Diachronic Variation in Exchange Indices from Central California’s Pecho Coast

ABSTRACT For decades, it has been recognized that Chumash-speaking peoples of the Santa Barbara Channel had a highly complex society that featured sedentism, high population density, craft specialization, and chiefdom-like political authority. Among the material evidence indicating complexity are shell bead production centers on the Channel Islands and sewn-plank canoes. Chumash speakers to the north, including the yak tityu tityu yak tilhini, in what is now known as the San Luis Obispo area, lacked plank canoes and major bead-making workshops, so there has long been certain ambiguity about the nature of their sociopolitical organization and its origins. Here we briefly review the historic evidence for traits of complexity north of Point Conception. Then we evaluate the cumulative archaeological record of obsidian and shell beads from the Pecho coast, including new findings from CA-SLO-585. Patterns in the relative abundance of these commodities show striking differences over time, as obsidian disappears during the Late Period at the same time that beads increase. These trends raise the possibility that territoriality arose during or slightly before the Late Period at Pecho in tandem with hierarchical political authority.
Biomass production and biochemical composition of Chlorella vulgaris grown in Net-House Photobioreactor (NHPBR) using sugarcane press mud waste

The present Net-House Photobioreactor (NHPBR), which has a final capacity of 500 liters, was developed for the purpose of cultivating the Chlorella vulgaris by employing vinasse waste as a source of organic carbon and certain minerals in an effort to lower the cost of production. The growth unit consisted of one reservoir tank carrying 4 Plexi-glass ponds. For each plate, growth and biochemical composition were routinely evaluated to assess the precipitation and growth. Our data revealed no differences in the biomass and chemical constituents in the running algal slurry. However, differences were observed in the precipitated algal biomass for each plate, with the reservoir (CR) and the lower plate (P1) forming the greatest precipitation in terms of dry weight and mat thickness, respectively. The biochemical composition of the harvested biomass was 51.0% crude protein, 13.4% total carbohydrates, 12.1% lipids, and 7.2% ash.
The Interplay of Weakly Coordinating Anions and the Mechanical Bond: A Systematic Study of the Explicit Influence of Counterions on the Properties of (Pseudo)rotaxanes

Weakly coordinating anions (WCAs) have attracted much attention in recent years due to their ability to stabilise highly reactive cations. It may well be argued, however, that a profound understanding of what truly defines a WCA is still lacking, and systematic studies to unravel counterion effects are scarce. In this work, we investigate a supramolecular pseudorotaxane formation reaction, subject to a selection of anions, ranging from strongly to weakly coordinating, which not only aids in fostering our knowledge about anion coordination properties, but also provides valuable theoretical insight into the nature of the mechanical bond. We employ state-of-the-art DFT-based methods and tools, combined with isothermal calorimetry and 1H NMR experiments, to compute anion-dependent Gibbs free association energies ΔGa, as well as to evaluate intermolecular interactions. We find correlations between ΔGa and the anions’ solvation energies, which are exploited to calculate physico-chemical reaction parameters in the context of coordinating anions. Furthermore, we show that the binding situation within the (pseudo)rotaxanes can be mostly understood by straight-forward electrostatic considerations. However, quantum-chemical effects such as dispersion and charge-transfer interactions become more and more relevant when WCAs are employed.
The swimming of minute organisms

Some of the processes relevant to the propulsion of small organisms are investigated using the simple mathematical model of two-dimensional waves passing through a sheet immersed in a viscous fluid. This model was first used by Taylor, who considered an inextensible sheet moving in an unbounded fluid of negligible inertia. Here the effects of fluid inertia, of straining of the wave-bearing surface, and of nearby walls are included in the study. The applicability of the results is restricted both by the unrealistic geometry of the model and by the method of analysis which gives results valid for small Reynolds numbers and for small wave amplitudes only. However, the following general results may have counterparts in nature. The effect of fluid inertia is to increase the propulsive speed for a particular wave amplitude. Straining of the waving surface will probably reduce the propulsive velocity for a given amplitude, although there exist modes of surface straining that give augmented propulsion. If the wave celerity and the energy output in swimming remain constant in the presence of a solid wall, the amplitude of the wave is reduced as the wall is approached while the propulsive speed first rises slightly and then drops. It appears further that an organism swimming near a wall may induce a shear pattern which directs it away from the wall.
Deep-Learning-Enabled Computer-Aided Diagnosis in the Classification of Pancreatic Cystic Lesions on Confocal Laser Endomicroscopy

Accurate classification of pancreatic cystic lesions (PCLs) is important to facilitate proper treatment and to improve patient outcomes. We utilized the convolutional neural network (CNN) of VGG19 to develop a computer-aided diagnosis (CAD) system in the classification of subtypes of PCLs in endoscopic ultrasound-guided needle-based confocal laser endomicroscopy (nCLE). From a retrospectively collected 22,424 nCLE video frames (50 videos) as the training/validation set and 11,047 nCLE video frames (18 videos) as the test set, we developed and compared the diagnostic performance of three CNNs with distinct methods of designating the region of interest. The diagnostic accuracy for subtypes of PCLs by CNNs with manual, maximal rectangular, and U-Net algorithm-designated ROIs was 100%, 38.9%, and 66.7% on a per-video basis and 88.99%, 73.94%, and 76.12% on a per-frame basis, respectively. Our per-frame analysis suggested differential levels of diagnostic accuracy among the five subtypes of PCLs, where non-mucinous PCLs (serous cystic neoplasm: 93.11%, cystic neuroendocrine tumor: 84.31%, and pseudocyst: 98%) had higher diagnostic accuracy than mucinous PCLs (intraductal papillary mucinous neoplasm: 84.43% and mucinous cystic neoplasm: 86.1%). Our CNN demonstrated superior specificity compared to the state-of-the-art for the classification of mucinous PCLs (IPMN and MCN), with high specificity (94.3% and 92.8%, respectively) but low sensitivity (46% and 45.2%, respectively). This suggests the complimentary role of CNN-enabled CAD systems, especially for clinically suspected mucinous PCLs.
Neuroprotective Nanoparticles Targeting the Retina: A Polymeric Platform for Ocular Drug Delivery Applications

Neuroprotective drug delivery to the posterior segment of the eye represents a major challenge to counteract vision loss. This work focuses on the development of a polymer-based nanocarrier, specifically designed for targeting the posterior eye. Polyacrylamide nanoparticles (ANPs) were synthesised and characterised, and their high binding efficiency was exploited to gain both ocular targeting and neuroprotective capabilities, through conjugation with peanut agglutinin (ANP:PNA) and neurotrophin nerve growth factor (ANP:PNA:NGF). The neuroprotective activity of ANP:PNA:NGF was assessed in an oxidative stress-induced retinal degeneration model using the teleost zebrafish. Upon nanoformulation, NGF improved the visual function of zebrafish larvae after the intravitreal injection of hydrogen peroxide, accompanied by a reduction in the number of apoptotic cells in the retina. Additionally, ANP:PNA:NGF counteracted the impairment of visual behaviour in zebrafish larvae exposed to cigarette smoke extract (CSE). Collectively, these data suggest that our polymeric drug delivery system represents a promising strategy for implementing targeted treatment against retinal degeneration.
The k-Domination and k-Stability Problems on Sun-Free Chordal Graphs

The k-domination problem is to find a minimum cardinality vertex set D of a graph such that every vertex of the graph is within distance k from some vertex of D, where k is a positive integer. The k-stability problem is to find a maximum cardinality vertex set S such that the distance between any two distinct vertices of S is greater than k. For sun-free chordal graphs, $2k$-stability and k-domination are dual problems. In particular, a minimum cardinality set of vertices D such that every vertex is within distance k of D has the same cardinality as a maximum cardinality set of vertices S such that the distance between every pair of vertices in S is greater than $2k$. To obtain this result we establish some theorems about the powers and radius of chordal graphs. Efficient algorithms for both problems on sun-free chordal graphs are obtained by transforming them to solvable cases of the clique covering and vertex packing problems. We also prove the NP-completeness of both problems on bipartite and chordal g.
Structure and behavior of the high-speed deflagration generated by a detonation wave passing through a perforated plate

An experimental investigation on the high-speed deflagration in the acetylene-oxygen mixture was carried out in a smooth straight tube.The deflagration was generated by putting a perforated plate in the way of a self-sustained detonation wave and interrupting it.Streak schlieren photos were taken to illustrate the averaged structure of the initially transmitted deflagrations near the plate,and pressure transducers were used to trace the further development of the wave front.The high-speed deflagration wave was found to be a complex of precursor shock and flame.With the increase of the initial pressure,it varies from a laminar structure to a turbulent one,and the onset of the latter seems corresponding to the smaller or comparable cellular width of incident detonation to the disturbance scale of perforated plate.This study reveals that deflagrations with laminar structure can not stand the attenuation of background rarefaction and keeps on slowing down,whereas the turbulent one is capable of running up and transiting to a detonation wave.There is an unstable critical case between the mentioned two situations,where the deflagration can propagate for a relatively long distance at a 0.5~0.6 times CJ detonation speed.This critical case matches the constant-volume combustion solution of the Rankine-Hugoniont relations across dual discontinuities.
The NOAO-XCS survey & the optical to X-ray scaling relations of galaxy clusters

In this thesis we present the NOAO-XMM Cluster Survey (NXS). NXS has provided optical follow-up of X-ray cluster candidates serendipitously detected by the XMM Cluster Survey (XCS). We report details on the execution, data reduction and analysis of 154 wide-field MOSAIC images containing 630 XCS cluster candidates. We present a redshift algorithm, based on the ‘red-sequence technique’, designed to confirm cluster identifications and extract photometric cluster redshifts from NXS data. This algorithm exploits the homogeneity of elliptical cluster galaxies to provide simultaneous redshift and optical richness estimates. In addition, we apply this redshift algorithm to the Sloan Digital Sky Survey public data releases SDSS DR7 and SDSS Stripe 82. The resulting catalogue of ~500 optically confirmed XCS clusters with red-sequence redshifts is presented, spanning the redshift range 0.1<z<1.0. This sample will enable a future XCS measurement of the cosmological parameters Ωm and σ8, as well as a selfconsistent measure of the cluster X-ray luminosity to temperature scaling relation. Furthermore, for clusters with measured X-ray temperatures or luminosities, we measure the optical richness of red-sequence galaxies within the cluster virial radius (R200). Using these measurements, we investigate the optical halo-mass scaling relation. Understanding cluster optical scaling relations, in particular the optical-light to halo-mass relation, is key for surveys hoping to measure cosmological parameters using optically detected clusters alone. By combining the optical NXS and SDSS data sets with X-ray information from XCS, this thesis provides much needed optical to X-ray scaling relations for future optical cluster surveys.
A CONCRETE EXAMPLE OF THE EXISTENCE OF FOUR LIMIT CYCLES FOR PLANE QUADRATIC SYSTEMS

This paper gives a positive answer to an unknown problem as to whether a plane vector field, given by two polynomials of 2nd degree, can have more than 3 limit cycles. This problem was put forward at the symposium on the mathematical consequences of the Hilbert problems, sponsored by the American Mahematical Society in May, 1974.
Traveling wave analysis of semiconductor lasers: modulation responses, mode stability and quantum mechanical treatment of noise spectra

We present a traveling wave analysis of a general class of semiconductor lasers, which includes multisection DFB/DBR lasers and gain-coupled DFB lasers. The analysis leads to new semianalytic expressions for the small-signal IM and FM modulation responses, the intensity and FM noise spectra, and the linewidth. The expressions are given in terms of solutions to four coupled linear homogeneous differential equations and can easily be evaluated numerically. We also derive a stability parameter /spl sigma/, for which /spl sigma/ >
The mesa problem: diffusion patterns for ut=⊇. (um⊇u) as m→+∞

In this paper we consider the limit m→+∞ of solutions of the porous-medium equation ut = ∇•(um∇u)(xeRN), with N > 1. We conjecture that, for initial data with a unique maximum, the evolution is characterized by the onset of a ‘mesa’ region, in which the solution is nearly spatially independent, surrounded by a region in which u is nearly equal to its initial value. The transition between these regions occurs near a surface which is identified with the free boundary in a certain Stefan problem which can be studied using variational inequalities. Moreover, singular-perturbation theory can be used to describe the structure of the transition region.