Miracle-dz/UniFAR-FTUs huggingface dataset:
A finite volume method for large strain analysis of incompressible hyperelastic materials

This paper describes development of a displacement–pressure based finite volume formulation for modelling of large strain problems involving incompressible hyperelastic materials. The method is based on the solution of the integral conservation equations governing momentum balance in total Lagrangian description. The incompressibility constraint is enforced by employing the integral form of the mass conservation equation in deformed configurations of the body. A Mooney–Rivlin incompressible material model is used for material description. A collocated variable arrangement is used and the spatial domain is discretized using finite volumes of an arbitrary polyhedral shape. A segregated approach is employed to solve resulting set of coupled non‐linear algebraic equations, utilizing a SIMPLE based algorithm for displacement–pressure coupling. Comparisons of numerical and analytical results show a very good agreement. For the limited range of cell topologies tested the developed method appears to be locking free. Copyright © 2005 John Wiley & Sons, Ltd.
The Stokes force on a droplet in an unbounded fluid medium due to capillary effects

The Stokes force on a fluid droplet is obtained when the droplet is placed in an unbounded fluid medium and motion ensues due to an arbitrary interfacial-tension gradient on the droplet surface. The force, derived here for a spherical droplet, is proportional to the integral of the interfacial-tension gradient over the droplet surface. It may be calculated without solving the complete governing equations from a knowledge of this integral and the ratio of the viscosity of the droplet phase to that of the continuous phase, as shown in the principal result displayed in (29). When the interfacial-tension gradients are caused by temperature or concentration variations, the result for the force may be further specialized when convective transport effects are negligible. In this case, it is possible to express the force in terms of the gradient of the undisturbed temperature (or concentration) field evaluated at the location of the droplet centre in a form analogous to Faxén's force law.
An experimental study on the behaviours of circular synthetic jets at low Reynolds numbers

In the work presented in this article, the behaviour of circular synthetic jets issuing into quiescent surrounding fluid at low Reynolds numbers is experimentally studied for potential mixing applications of synthetic jets at micro-scales or in highly viscous fluids. Sugar solutions and silicone oil are used as the flow media in order to achieve the required low Reynolds numbers. The conditions for jet instability, vortex rollup and synthetic jet formation are investigated using both flow visualisation techniques and particle image velocimetry, and the typical behaviour of synthetic jets at a Reynolds number around unity is also illustrated. The roles of Reynolds number, dimensionless stroke length and Stokes number in determining the characteristics of synthetic jets are examined and found to be largely consistent with the finding obtained at higher Reynolds numbers. Finally, a parameter map of synthetic jet flow patterns is produced based on the results from this study, which can be used to aid the choice of synthetic jet operating conditions for specific applications or anticipate if a desired vortex structure can be obtained at a given synthetic jet operating condition.
Direct numerical simulation of vortex synchronization due to small perturbations

Direct numerical simulation (DNS) is performed to investigate the vortex synchronization phenomena in the wake behind a circular cylinder at the Reynolds numbers, Re = 220 (mode-A regime) and 360 (mode-B regime). To generate vortex synchronization, a sinusoidal streamwise velocity perturbation, the frequency of which is about twice the natural shedding frequency, is superimposed on the free stream velocity. At Re = 360, vortex synchronization occurs when the perturbation frequency is exactly twice the natural shedding frequency. However, at Re = 220, it does not occur when the same perturbation frequency condition is imposed. Instead, it occurs when the perturbation frequency is near twice the hypothetical two-dimensional laminar vortex shedding frequency as if there were no wake transition at Re = 220. It is elucidated that, as a result of vortex synchronization, the trajectory of the Kármán vortices and the vortex structure are changed. The Kármán vortices are formed along the mean separating streamline slightly inside the mean wake bubble at Re = 220, but slightly outside at Re = 360. Thus, the Reynolds shear stress force has different contribution to the streamwise force balance of the mean wake bubble depending on the Reynolds numbers: its magnitude is negligible at Re = 220, compared to other force components, while it reverses its sign at Re = 360. More importantly, at Re = 220, the mode-A instability is suppressed into two-dimensional laminar flow with strong Kármań vortices. At Re = 360, the dominant instability mode changes from mode B to mode A.
Proton radiation testing of digital micromirror devices for space applications

Abstract. Scientists are interested in using digital micromirror devices (DMD) as slit-masks in multiobject spectrometers on future space missions. A favored orbit is at the second Lagrangian point (L2). A requirement for mission planning is to determine how long such microelectrical mechanical systems devices would remain operational given the L2 radiation environment, which is primarily composed of solar protons and cosmic rays. To this end, we initiated DMD proton testing. Three DMDs were irradiated with high-energy protons (35 to 50 MeV) at the Lawrence Berkeley National Laboratory 88 in. Cyclotron. Assuming a typical spacecraft shielding of 100 mils of aluminum, our tests imply that DMDs remain fully operable in a five-year mission at L2 with a margin of safety of 4.5.
Low-κ′ dielectric properties of UV-treated bi-axially oriented polypropylene films

A 40 µm multilayer bi-axially oriented polypropylene (BOPP) film, was fabricated by the tenter process and its dielectric response was investigated after applying combined action of UV, humidity and heat. Dissipation factor (tan δ) and relative dielectric constant measurements were performed via the capacitance method for frequencies 20Hz–1 GHz. These results show that the relative dielectric constant (κ′) reduces towards ultra low values (1.8) with an increasing number of applied UV–condensation cycles without any subsequent increase in the dielectric loss. Having no added physical porosity and absence of fluorine atoms, the irradiated BOPP structures offer significant advantages over poly(tetrafluoroethylene) PTFE due to reduced polarization effects, lower dielectric constant values and chemical stability to the adjacent copper or aluminium conductors. Possible application fields are dry type high-voltage capacitors and insulation within electronic components.
Luteolin protects DYT-PRKRA cells from apoptosis by suppressing PKR activation

DYT-PRKRA is a movement disorder caused by mutations in the PRKRA gene, which encodes for PACT, the protein activator of interferon-induced, double-stranded RNA (dsRNA)-activated protein kinase PKR. PACT brings about PKR’s catalytic activation by a direct binding in response to stress signals and activated PKR phosphorylates the translation initiation factor eIF2α. Phosphorylation of eIF2α is the central regulatory event that is part of the integrated stress response (ISR), an evolutionarily conserved intracellular signaling network essential for adapting to environmental stresses to maintain healthy cells. A dysregulation of either the level or the duration of eIF2α phosphorylation in response to stress signals causes the normally pro-survival ISR to become pro-apoptotic. Our research has established that the PRKRA mutations reported to cause DYT-PRKRA lead to enhanced PACT-PKR interactions causing a dysregulation of ISR and an increased sensitivity to apoptosis. We have previously identified luteolin, a plant flavonoid, as an inhibitor of the PACT-PKR interaction using high-throughput screening of chemical libraries. Our results presented in this study indicate that luteolin is markedly effective in disrupting the pathological PACT-PKR interactions to protect DYT-PRKRA cells against apoptosis, thus suggesting a therapeutic option for using luteolin to treat DYT-PRKRA and possibly other diseases resulting from enhanced PACT-PKR interactions.
The stability of shearing motion in a rotating fluid

This paper is concerned with the stability of a parallel shear flow in an inviscid homogeneous unbounded rotating fluid. A sufficient condition for stability is obtained in terms of the dimensionless parameter N = (cosϕ)/S, where ϕ is the angle between the wave-number K of the disturbance and the axis of rotation, and S is the Rossby number based on the thickness of the shear layer and the change in velocity across the layer. The condition is that infinitesimal disturbances are stable if either $N \ge \frac{1}{2}(1-sin\; \theta)\; \; or\; \; N \le -\frac {1}{2}(1+sin\; \theta)$ Where θ is the angle between k and the direction of streaming. For a shear layer profile of the type U = tanh z, the neutral curves are calculated for various Rossby numbers. These are compared to the stability of a shear layer in a stratified non-rotating fluid. The stability criterion for the large wave-numbers in a cylindrical shear layer is inferred from these results.
A Combined Three-Phase Signal Extraction of the Sudbury Neutrino Observatory Data Using Markov Chain Monte Carlo Technique

Neutrino physics has entered an era of precision, after proving that the Standard Solar Model is a viable theory and going beyond the current Standard Model of particle physics by proving that neutrinos possess nonzero masses. The Sudbury Neutrino Observatory (SNO) experiment, along with other experiments, has restricted neutrino mixing angle (θ12) and the mass square difference (∆m21) to lie within the large mixing solution area. SNO, located 2 km underground in Sudbury, Canada, was an ultraclean heavy-water (D2O) imaging detector for observing neutrinos produced by fusion reactions in the Sun. Neutrino interactions with heavy water resulted in flashes of light called C̆erenkov radiation which was detected by an array of photomultiplier tubes. SNO took data from November 1999 to November 2006, totalling 1082 days of data taking. This work describes an improved measurement of the mixing parameters from a combined fit of all the data. For the signal extraction fit on the data consisting of 4 observable of an event – radial position, recoil electron energy, direction relative to the Sun and event isotropy – Markov Chain Monte Carlo (MCMC) method based on Metropolis algorithm was employed. The nuisance parameters (systematics), weighted by external constraints, were allowed to vary in the fit. The goal of the thesis was to extract the survival probabilities of electron neutrinos and determine the total flux of active-flavour neutrinos from B decay in the Sun measured through the neutral current interactions of neutrinos on deuterium. The B flux from the fit is (5.24 ± 0.02) × 10 cm−2 s−1; uncertainty from statistics and systematics is 3.56%. Along with B flux, the fit extracted energy spectra of charged current interactions of neutrinos on deuterium and elastic scattering interactions of neutrinos on electrons. The fit described the energy-dependent day survival probability of solar neutrinos as a quadratic equation and asymmetry on the day survival probability as a linear equation. Four polynomial coefficients of the survival probability were extracted from the fit: constant coefficient as 0.3206± 0.0197, linear coefficient as 0.005± 0.008 and quadratic coefficient as −0.0014± 0.0033. There are two coefficients on the day-night asymmetry: constant coefficient as 0.0496 ± 0.0347 and the linear coefficient as −0.018 ± 0.028. The day-night asymmetry (0.0496) observed is 1. 4σ away from zero. Using these findings, the oscillation space in terms of ∆m21 and θ12 will be further constrained. Compared to the previous published SNO results, the uncertainty on B went down from 3.83% to 3.56% and average B νe survival probability (p0) went down from 6.57% to 6.14%. If the data were analysed with the same assumptions, the decrease in uncertainties would have been approximately twice as big; however, more conservative systematic uncertainties were assigned in some cases.
Output-feedback control of stochastic strict-feedback systems under an exponential cost criterion

We consider a class of single-input single-output stochastic nonlinear systems in strict-feedback form with a risk sensitive cost criterion and with only the output of the system being available for feedback. We design an output-feedback controller under which the closed-loop signals maintain an arbitrarily small average risk-sensitive cost. Moreover, all closed-loop signals remain bounded in probability, and under certain conditions we obtain asymptotic stability in probability.
Effects of Plyometric Training on Rock’n’Roll Performance

Objectives: The aim of the study was to analyse if plyometric training increases the sport specific performance in rock’n’roll dancers. Design: Fifteen semi-professional rock’n’roll dancers participated in a plyometric training study. Pre- and posttests were conducted to document alterations of sport specific performance, reactive strength as well as maximal isokinetic torque. Method: The participants (n=15) accomplished two training sessions weekly for a training period of 6 weeks. The training program consisted of different of jumps. Pre- and posttests included a rock’n’roll specific performance test examining the maximal number of kicks within 30 s. Moreover, jumping height and ground contact time (GCT) during drop jump were determined to calculate reactive strength (RSI). Maximal dynamic torque and work were determined during maximal isokinetic contractions of the plantar flexors. Results: The number of kicks increased from 46.5 ± 2.6 to 49.4 ± 2.7 (p=0.00, d Z =1.83). The RSI increased significantly from 2.57 ± 0.29 to 2.72 ± 0.44 (p=0.05, d Z =0.55). The gains of RSI are based on increases in jumping height (pretest: 24.6 ± 4.0 cm, posttest 26.5 ± 4.7 cm, p=0.01, d Z =0.71), whereas the GCT remained unaltered (p=0.53). The work during maximal isokinetic plantar flexions increased significantly in both legs (jumping leg: p = 0.04, d Z =0.58; kicking leg: p=0.05, d Z =0.55). Conclusions: Plyometric training increases the kicking frequency during rock’n’roll dance. This might be attributed to the observed increase in reactive strength. Training induced changes in muscle activity or structure were discussed. It is suggested to implement plyometric training into the training program of rock’n’roll dancers. Keywords: Rock’n’roll, plyometric training, reactive strength, plantar flexors
Laboratory Detection of the Ring-Chain Molecule C7H2

Following the recent laboratory detection of the ring-chain carbene C5H2, we have now detected C7H2, the next longer member of the sequence formed by substituting a carbon chain for one of the hydrogen atoms of cyclic C3H2. The strongest lines, again obtained with a diacetylene-neon discharge, were roughly 15 times weaker than those of C5H2. Enough rotational lines were detected in both the normal and doubly deuterated isotopic species to be certain of the identification and to obtain the rotational and leading centrifugal distortion constants accurately enough for calculation of the entire rotational spectrum below 300 GHz to a fraction of 1 km s-1 in equivalent radial velocity. The ring chain here is calculated to be the most stable isomer of C7H2 and extremely polar, so it is of considerable astronomical interest. Several other isomers of C7H2 may be detectable in the laboratory and in space with present techniques.
Differential COVID-19 Vaccination Uptake and Associated Factors among the Slum and Estate Communities in Uganda: A Cross-Sectional Population-Based Survey

Vaccination against COVID-19 remains one of the ultimate solutions to the ongoing pandemic. This study examined and compared the completion of primary COVID-19 vaccination series and associated factors in the slum and estate communities of Uganda. This was a cross-sectional survey conducted among 1025 slum and estate residents. Logistic regression models were fitted. Of the 1025 participants, 511 were slum residents and 514 were estate residents. Completion of COVID-19 vaccination was 43.8% in the slum community and 39.9% in the estate community (p = 0.03). Having more knowledge about COVID-19 was positively associated with completing COVID-19 vaccination in both communities. Perceived benefits and cues to action also had a positive association, but only among the slum residents. However, perceiving people infected with COVID-19 as having a high death rate, perceived barriers such as serious side effects and long distances, and depressive symptoms had negative associations with vaccine uptake among the slum community, but not in the estate community. Addressing barriers to vaccination, strengthening and utilizing the various cues to action, engagement of religious and cultural leaders, and continued community education and sensitization tailored to the needs of each community are potentially vital strategies in raising vaccination rates. Consideration of socioeconomic impact-alleviation strategies, especially among the urban poor, would also be beneficial.
Time-harmonic acoustic wave scattering in an ocean with depth-dependent sound speed

Time-harmonic acoustic wave propagation in an inhomogeneous ocean with depth-dependent sound speed can be modeled by the Helmholtz equation in an infinite, three-dimensional (3D) waveguide of finite height. Using variational theory in Sobolev spaces we prove well posedness of the corresponding scattering problem from a bounded inhomogeneity inside such an ocean. To this end, we introduce an exterior Dirichlet-to-Neumann operator for depth-dependent sound speed and prove boundedness, coercivity, and holomorphic dependence of this operator in function spaces adapted to our weak solution theory. Analytic Fredholm theory then yields existence and uniqueness of solution for the scattering problem for all but a countable sequence of frequencies. The latter result generalizes corresponding theory for waveguide scattering with constant sound speed and easily extends to various related scattering problems, e.g. to scattering from impenetrable obstacles.
The Effects of Peripubertal THC Exposure in Neurodevelopmental Rat Models of Psychopathology

Adolescent exposure to cannabinoids as a postnatal environmental insult may increase the risk of psychosis in subjects exposed to perinatal insult, as suggested by the two-hit hypothesis of schizophrenia. Here, we hypothesized that peripubertal Δ9-tetrahydrocannabinol (aTHC) may affect the impact of prenatal methylazoxymethanol acetate (MAM) or perinatal THC (pTHC) exposure in adult rats. We found that MAM and pTHC-exposed rats, when compared to the control group (CNT), were characterized by adult phenotype relevant to schizophrenia, including social withdrawal and cognitive impairment, as revealed by social interaction test and novel object recognition test, respectively. At the molecular level, we observed an increase in cannabinoid CB1 receptor (Cnr1) and/or dopamine D2/D3 receptor (Drd2, Drd3) gene expression in the prefrontal cortex of adult MAM or pTHC-exposed rats, which we attributed to changes in DNA methylation at key regulatory gene regions. Interestingly, aTHC treatment significantly impaired social behavior, but not cognitive performance in CNT groups. In pTHC rats, aTHC did not exacerbate the altered phenotype nor dopaminergic signaling, while it reversed cognitive deficit in MAM rats by modulating Drd2 and Drd3 gene expression. In conclusion, our results suggest that the effects of peripubertal THC exposure may depend on individual differences related to dopaminergic neurotransmission.
A review of digital storytelling in language learning in children: methods, design and reliability

Digital storytelling (DS) is an innovative approach to language learning and teaching. Generally, DS refers to the form of storytelling that utilizes digital technology for expression. Scholars have established the value of DS in both traditional and non-traditional (online) classrooms as a tool to teach and learn languages. However, the research methods and standards of such studies continue to be overlooked even though the robustness of these studies needs to be established for the implementation of DS into the language curriculum for children. Thus, the present research conducted a systematic investigation of research methods, design and reliability in DS studies on children’s language learning. We identified and extracted 50 documents from the Scopus database that satisfied the criteria of inclusion. In the initial evaluation, we coded every paper for (a) the research method applied, (b) research design and (c) reliability investigation of the instruments. We observed that most studies in the dataset used qualitative methods (n = 24, 48%) and most examined the effect of DS on children’s written abilities (n = 25, 50%). The abilities of children to speak (n = 15, 30%) and read a specific language (n = 10, 20%) were investigated to a lesser extent. Yet, none of these studies investigated listening skills. Notably, more than 92% of DS studies on children language learning provided no evidence of reliability investigation. While we coded for eight reliability statistics in the DS dataset, only two of the indexes were identified. Among these methods, Cronbach’s α was most often used to examine internal reliability, whereas correlation coefficient was applied to establish external reliability. Based on these findings, we offer some suggestions and guidelines for future DS research.
Static and dynamic properties of injection-locked semiconductor lasers

The static and dynamic properties of injection-locked semiconductor lasers considering the influence of nonlinear gain are presented systematically. Depending on locking conditions, the modulation bandwidth of a semiconductor laser may be increased or decreased by external light injection. However, the relaxation resonance frequency and the damping rate as defined for a solitary Fabry-Perot (FP) laser are always enhanced by injection locking. That is, contrary to that in a solitary FP laser, the modulation bandwidth in an injection-locked laser is not determined solely by the relaxation resonance frequency, because an injection-locked laser is a third-order system. Therefore, a new definition of the modulation bandwidth is presented for such a laser. The performances of injection-locked distributed feedback (DFB) lasers are also discussed. The theory is in good agreement with the experiments. >
On pointwise laws of iterated logarithm for estimators of certain conditional functionals

We study the estimation of certain functionals of the conditional distribution function with two classes of nonparametric estimators—the rank nearest neighbour (RNN) type estimators and the Nadaraya-Watson (NW) kernel type estimators. We obtain sharp pointwise rates of strong consistency by establishing laws of the iterated logarithm for these two classes of estimators. The results parallel those of Hall [Hall, P., 1981, Laws of the iterated logarithm for nonparametric density estimators. Zeitschrift Fur Wahrscheinlichkeitstheorie Und Verwandte Gebiete, 56, 47–61] and Härdle [Härdle, W. , 1984, A law of the iterated logarithm for nonparametric regression function estimators. The Annals of Statistics, 12, 624–635] for certain density and regression function estimators respectively, and extend those of Mehra et al. [Mehra, K.L. , Rama Krishnaiah, Y.S. and Rao, S.M. , 1992a, Asymptotic properties of smoothed vs. unsmoothed conditional distribution function estimators, Bulletin of Informatics and Cybernetics, 25, 71–97] on the strong consistency of smooth conditional distribution function estimators.