Miracle-dz/UniFAR-FTUs huggingface dataset:
Graviton Creation by Small Scale Factor Oscillations in an Expanding Universe

We treat quantum creation of gravitons by small scale factor oscillations around the average of an expanding universe. Such oscillations are predicted both by modied gravity theories with a term proportional to the square of the Ricci scalar in the gravitational action, and by semiclassical gravity in which a renormalized expectation value of a quantum matter stress tensor is the source of gravity. A perturbative method due to Birrell and Davies involving an expansion in a conformal coupling parameter is used to calculate the number density and energy density of the created gravitons. Cosmological constraints on the present graviton energy density are discussed, which indicate an upper bound of the order of 4% of the total mass-energy density of the universe. This constraint leads to an upper bound on the dimensionless amplitude of the oscillations. We also discuss decoherence of quantum systems produced by the spacetime geometry uctuations due to such a graviton bath, and nd a lower bound on the decoherence time resulting from this process.
The Effect of Fasting Period and Low-Fat Diet on The Testosterone and Follicle Stimulating Hormone of Male Rats

Nourishment is essential for the continuity of life in all animals’ kinds. Fasting is one of the world's most widespread fitness and health fads for enhancing their health and simplifying their lives. The low-fat diet is one of the most used applications to maintain the levels of different hormones and therefore decreased the risk of diseases such as cardiovascular disease. Thus, the current study was designed to investigate the effect of a low-Fat Diet in tow period strategy of fasting in 14 hours and 20 hours by using 36 healthy young male albino rats on testosterone and follicle stimulation hormone.
Preliminary investigation on the energy harvesting of vortex-induced vibration with the use of magnet

The utilization of natural resources as renewable energy is thriving as its innovation brings clean energy, environmentally friendly and also cut down costs. Hence, the purpose of this study is to propose a technique to enhance the output voltage of piezoelectric as an energy harvesting device by applying nonlinear magnetic forces from a phenomenon called vortex induced vibration (VIV). This harvester device is designed with a presence of two magnets that placed at the bottom of a circular cylinder and on the lower base. The mechanical conversion energy that is studied is the vibration from circular cylinder’s oscillation through a phenomenon called Vortex Induced Vibration by using piezoelectric transducer. A VIV-based energy harvester has been fabricated and carried out in water flow to observe the optimum output voltage that can be generated. Three different lengths of piezoelectric cantilever plates and two magnet distances are tested to investigate the influence of system’s stiffness and the repulsive force to the harvested energy. From the experiment, it is observed that a lower stiffness of the system provides higher harvested voltage. In addition, the presence of magnets shows a greater output voltage due to the action of nonlinear magnetic forces where the position between two magnets able to shift the synchronization region thus, showing a greatly wider synchronization region and increasing the performance of VIV-based energy harvesting system.
Stability analysis of tunnels driven in jointed rocks by means of a homogenized limit analysis approach

Conceived as a potential alternative to the classical design methods employed for analyzing the stability of underground structures driven in jointed rocks, the homogenization approach stems from the heuristic idea that, from a macroscopic point of view, a rock mass cut by a network of joints may be perceived as a homogenized continuum. The strength properties of the latter can be theoretically obtained from the failure conditions of its individual constituents: rock matrix and joint interfaces.
An introduction to homogenization

Homogenization theory is a powerful method for modeling the microstructure of composite materials, including superconductors and optical fibers. This book is a complete introduction to the theory. It includes background material on partial differential equations and chapters devoted to the steady and non-steady heat equations, the wave equation, and the linearized system of elasticity.
The Hamiltonian Brain

A venerable history of models have shown that simple and complex cell responses in the primary visual cortex (V1) are adapted to the statistics of natural images. These models are based, either explicitly or implicitly, on the assumption that neural responses represent maximum likelihood or a posteriori inferences in a generative model trained on natural images and thus provide a normative account of steady-state neural responses in V1. However, such models have very different structural and dynamical properties to the brain. In particular, these models violate Dale's law, have gradient ascent, rather than oscillatory dynamics, and approach a single fixed point in response to fixed input. We give a solution to all of these problems, by suggesting that the brain samples possible explanations of incoming data using a mechanism inspired by Hamiltonian Monte Carlo. Our sampler has recurrent connections that obey Dale's law, gives rise to oscillatory dynamics, and continues sampling in response to fixed input, rather than reaching a single fixed point. These properties of our model allow it to match three key aspects of neural responses in V1. First, the oscillation frequency increases with stimulus contrast. Second, there are large transient increases in firing rate upon stimulus onset. Third, excitation and inhibition are balanced, and inhibition lags excitation.
A tunable few electron triple quantum dot

In this paper we report on a tuneable few electron lateral triple quantum dot design. The quantum dot potentials are arranged in series. The device is aimed at studies of triple quantum dot properties where knowing the exact number of electrons is important as well as quantum information applications involving electron spin qubits. We demonstrate tuning strategies for achieving required resonant conditions such as quadruple points where all three quantum dots are on resonance. We find that in such a device resonant conditions at specific configurations are accompanied by novel charge transfer behaviour.
Effect of the Richardson Number on Flow and Heat Transfer in a Cylinder Filled with Cu-Water Nano-fluid at Different Nanoparticle Concentrations

Fluid circulation and thermal exchange properties via integrated natural and artificial convection within a container have attracted considerable interest due to its many industrial uses. This present work concentrates on determining the effect of the Richardson number on flow and heat transfer in a cylinder filled with Cu-Water nanofluid at different nanoparticle concentrations. The governing equations: continuity and Navier Stoke fields were discretized using the finite difference approach and simulated in C++ programming language. In this work, the Richardson parameter ranged from 2.6*104 to 2.8*104, while the concentration of Cu nanoparticles ranged from 1% to 10%, and the results are presented as Nusselt number, vorticity, and stream function profiles. The results reveal that the maximum Richardson value is 2.76 x 104 at the nanoparticle volume of 0.04, resulting in a considerable increase in the convective heat transfer rate. Furthermore, as the Richardson parameters increase, the Nusselt number in the nanofluid increases exponentially while the local drag coefficient decreases. The stream function, longitudinal velocity and circulation increase as the Richardson parameters grow. The technical design for air turbulence prediction involves an understanding of the Richardson-driven connection as a mix of wind speed and convective stability variables.
Information theory of open fragmenting systems

An information theory description of finite systems explicitly evolving in time is presented. We impose a MaxEnt variational principle on the Shannon entropy at a given time while the constraints are set at a former time. The resulting density matrix contains explicit time odd components in the form of collective flows. As a specific application we consider the dynamics of the expansion in connection with heavy ion experiments. Lattice gas and classical molecular dynamics simulations are shown.
Connecting Perceived Service Quality, Value and Shopping Behavior: An Analysis on Chinese College Students Traveling Overseas

In recent years, tourist destinations around the world have witnessed an exponential growth in the number of Chinese tourists. With a view of understanding the consequences of their shopping activity in terms of behavioral response, this study inspects Chinese college students traveling overseas by analyzing 180 questionnaires. The reasoned action theory is applied to examine the impact of a number of factors influencing shopping behavior. The inquiry at hand makes use of methods, including factor analysis, regression analysis, and moderation analysis, to explore the relationship among perceived service quality, perceived value and shopping behavioral intention of tourists. The results show, inter alia, that service quality is a relevant dimension influencing the likelihood of tourists to share their shopping experience with friends and relatives, encouraging them to shop in the same destination, and to continue to shop in the same destination themselves in the future, regardless of the costs of visiting. Therefore, improving service quality may increase college students’ consumption during travel as well as their word of mouth after returning home. The outcomes of this study may contribute to the existing tourism economics and management scholarship and the tourism industry.
Job-Related Performance and Quality of Life Benefits in First Responders Given Access to H-Wave® Device Stimulation: A Retrospective Cohort Study

Current chronic pain treatments primarily target symptoms and are often associated with harmful side-effects and complications, while safer non-invasive electrotherapies like H-Wave® device stimulation (HWDS) have been less explored. The goal of this study is to evaluate first responder-reported effects of HWDS on job-related and quality-of-life measures. This is a retrospective cohort study where first responders were surveyed following voluntary use of HWDS regarding participant experience, frequency of use, job-related performance, and quality-of-life. Responses were analyzed using means comparison tests, while bivariate analysis assessed responses associated with HWDS usage. Overall, 92.9% of first responder HWDS users (26/28) reported a positive experience (p < 0.0001), with 82.1% citing pain reduction (p = 0.0013), while 78.6% indicated it would be beneficial to have future device access (p = 0.0046). Participants using H-Wave® were at least six times more likely to report higher rates of benefit (100% vs. 0%, p = 0.022), including pain reduction (91.3% vs. 8.7%, p = 0.021) and improved range-of-motion (93.3% vs. 69.2%, p = 0.044). Spending more time with family was associated with better job performance following frequent HWDS use (50% vs. 8.3%, p = 0.032). Repetitive first responder H-Wave® use, with minimal side effects and easy utilization, resulted in significant pain reduction, improvements in job performance and range-of-motion, and increased time spent with family, resulting in overall positive experiences and health benefits. Level of Evidence: III.
FIRST QUINTUPLET FREQUENCY SOLUTION OF A BLAZHKO VARIABLE: LIGHT CURVE ANALYSIS OF RV UMa

RV UMa is one of the RRab stars showing regular large-amplitude light-curve modulation. Extended photoelectric observations of RV UMa obtained at the Konkoly Observatory were published by Kanyó, and the data were analysed by Kovács. After detecting an error in the reduction procedure of the published Konkoly data, corrected photometric data are presented with additional, previously unpublished measurements. The re-analysis of the combination of the corrected Konkoly data supplemented by Preston & Spinrad's observations has led to the discovery that the appropriate mathematical model of the light curve is, in fact, a quintuplet frequency solution, rather than, a triplet. This finding has crucial importance in the interpretation of the Blazhko phenomenon, as a triplet (doublet) is the preferred structure in resonance models, quintuplet in magnetic models. Period changes of both the pulsation and modulation light variations of RV UMa have been detected based on its century-long photometric observations. An overall anticorrelation between the pulsation and modulation period changes can be defined by dPBl/dP0 = −8.6 × 104 gradient, i.e., the modulation period is longer if the pulsation period is shorter. Between 1946 and 1975 the pulsation and modulation periods showed, however, parallel changes, which points to the fact that there is no strict relation between the changes in the periods of the pulsation and modulation.
Rapid Quantitative Detection of Live Escherichia coli Based on Chronoamperometry

The rapid quantitative detection of Escherichia coli (E. coli) is of great significance for evaluating water and food safety. At present, the conventional bacteria detection methods cannot meet the requirements of rapid detection in water environments. Herein, we report a method based on chronoamperometry to rapidly and quantitatively detect live E. coli. In this study, the current indicator i0 and the electricity indicator A were used to record the cumulative effect of bacteria on an unmodified glassy carbon electrode (GCE) surface during chronoamperometric detection. Through the analysis of influencing factors and morphological characterization, it was proved that the changes of the two set electrochemical indicator signals had a good correlation with the concentration of E. coli; detection time was less than 5 min, the detection range of E. coli was 104–108 CFU/mL, and the error range was <30%. The results of parallel experiments and spiking experiments showed that this method had good repeatability, stability, and sensitivity. Humic acid and dead cells did not affect the detection results. This study not only developed a rapid quantitative detection method for E. coli in the laboratory, but also realized a bacterial detection scheme based on the theory of bacterial dissolution and adsorption for the first time, providing a new direction and theoretical basis for the development of electrochemical biosensors in the future.
The sunspot observations by Samuel Heinrich Schwabe

A long time-series of sunspot observations is preserved from Samuel Heinrich Schwabe who made notes and drawings of sunspots from 1825-1867. Schwabe's observing records are preserved in the manuscript archives of the Royal Astronomical Society, London. The drawings have now been digitized for future measurements of sunspot positions and sizes. The present work gives an inventory and evaluation of the images obtained from the log books of Schwabe. The total number of full-disk drawings of the sun with spots is 8486, the number of additional verbal reports on sunspots is 3699. There are also 31 reports about possible aurorae.
Proper Motions and Shock Wave Dynamics in the HH 7-11 Stellar Jet

We have used the Hubble Space Telescope (HST) to acquire new broadband and narrowband images of the optical line emission and red continuum associated with the HH 7-11 stellar jet in the NGC 1333 star formation region. Combining the new narrowband images of Hα, [O i] λ6300, and [S ii] λ6716 allows us to measure electron densities and excitations at each point in the outflow with the spatial resolution of HST, while the I-band image traces out the boundary of the cavity evacuated by the outflow. Comparing these images with those taken ∼20 yr ago yields high-precision proper motions for all the HH objects in the outflow. HH 11 is a bullet-like clump and emerges from the exciting source SVS 13A toward the Earth at 24° to the line of sight. In contrast, HH 8 and HH 10 consist of two rings of shocked gas that show no bulk proper motions, even though the emitting gas is blueshifted. The HH 8 rings are expanding with time. These shocks mark places where ambient material located along the path of the jet redirects the outflow. HH 7 consists of multiple shells and emits strongly in H2 in what appears to be a terminal bow shock for the outflow, implying that the jet has yet to fully break out of its nascent cloud core. The jet largely fragments into clumps by the time it reaches HH 7. As in the case of HH 110, deflection from ambient material plays a key role in producing observable shock waves in the HH 7-11 outflow.
Investigation of POWER8 processors for astronomical adaptive optics real-time control.

The forthcoming Extremely Large Telescopes (ELTs) all require adaptive optics systems for their successful operation. The real-time control for these systems becomes computationally challenging, in part limited by the memory bandwidths required for wavefront reconstruction. We investigate new POWER8 processor technologies applied to the problem of real-time control for adaptive optics. These processors have a large memory bandwidth, and we show that they are suitable for operation of first-light ELT instrumentation, and propose some potential real-time control system designs. A central processing unit (CPU)-based real-time control system significantly reduces complexity, improves maintainability, and leads to increased longevity for the real-time control system.
B $\to$ $\pi$ form factor with 2 flavours of $O(a)$ improved Wilson quarks

The determinations of $|V_{\rm ub}|$ from the exclusive branching ratios of $B\to \tau \nu$ and $B \to \pi l \nu$ tend to show a tension at the level of $3\sigma$ \cite{Beringer:1900zz}. On the theoretical side they depend on the lattice computation of the hadronic matrix elements $f_{\rm B}$ and the $B\to \pi$ form factor $f_+(q^2)$. To understand the tension, improved precision and a careful analysis of the systematics involved are necessary. Working towards this goal, we present preliminary lattice results of the ALPHA collaboration for the $B\to \pi$ form factor $f_+(q^2)$ with $N_{\rm f}=2$ flavours of $O(a)$-improved Wilson fermions. Our computation uses HQET in the static limit, pion masses ranging down to $\sim250$ MeV, large volumes with $m_\pi L >4$, three lattice spacings, and non-perturbative renormalization. We describe the techniques adopted to reduce the statistical noise (stochastic all-to-all with full time dilution) and the contamination from excited states (smearing for the B and the pion). We estimate the size of the chiral and continuum extrapolations. We discuss the impact our result could have to clarify the above mentioned discrepancy in the determination of $|V_{\rm ub}|$.
Arrhythmia Classification and Diagnosis Based on ECG Signal: A Multi-Domain Collaborative Analysis and Decision Approach

Electrocardiogram (ECG) signal plays a key role in the diagnosis of arrhythmia, which will pose a great threat to human health. As an effective feature extraction method, deep learning has shown excellent results in processing ECG signals. However, most of these methods neglect the cooperation between the multi-lead ECG series correlation and intra-series temporal patterns. In this work, a multi-domain collaborative analysis and decision approach is proposed, which makes the classification and diagnosis of arrhythmia more accurate. With this decision, we can realize the transition from the spatial domain to the spectral domain, and from the time domain to the frequency domain, and make it possible that ECG signals can be more clearly detected by convolution and sequential learning modules. Moreover, instead of the prior method, the self-attention mechanism is used to learn the relation matrix between the sequences automatically in this paper. We conduct extensive experiments on eight advanced models in the same field to demonstrate the effectiveness of our method.
Torsion in almost Kaehler geometry

We study almost K\"ahler manifolds whose curvature tensor satisfies the second curvature condition of Gray (shortly ${\cal{AK}}_2$). This condition is interpreted in terms of the first canonical Hermitian connection. It turns out that this condition forces the torsion of this connection to be parallel in directions orthogonal to the K\"ahler nullity of the almost complex structure. We prove a local structure result for ${\cal{AK}}_2$ manifolds, showing that the basic pieces are manifolds with parallel torsion and special almost K\"ahler manifolds, a class generalizing, to some algebraic extent, the class of 4-dimensional ${\cal{AK}}_2$-manifolds. In the case of parallel torsion, the Einstein condition and the reducibility of the canonical Hermitian connection is studied.
NOMA Enhanced Hybrid RIS-UAV-Assisted Full-Duplex Communication System With Imperfect SIC and CSI

In this work, we consider a hybrid aerial full-duplex (FD) relaying protocol consisting of a reconfigurable intelligent surface (RIS) mounted over an FD unmanned aerial vehicle (UAV) relay operating in the decode and forward mode to assist the information transfer between the base station and multiple users. For better spectral efficiency, we investigate the use of non-orthogonal multiple access (NOMA) in such networks and focus on both the performance analysis and design optimization of the considered RIS-NOMA network under imperfect channel state information (CSI) and successive interference cancellation (SIC) at each user, and residual-self interference (RSI) at UAV. We first formulate the sum rate maximization problem and adopt the block coordinate descent method to deal with the non-convex nature of the problem. Thereafter, we propose an algorithm based on the Riemannian conjugate gradient method to get the optimal phase shifts at the RIS, an iterative algorithm to obtain the optimal UAV/RIS position and the exhaustive method to obtain the optimum power allocation coefficients. Next, with obtained optimal position, phase shift and power coefficients, we further analyze the performance of the network and derive the closed-form expressions of outage probability, achievable throughput and ergodic capacity. We present Monte Carlo simulation-based results to validate the accuracy of the proposed algorithms and derived expressions and demonstrate the superiority of NOMA over OMA.
Long-distance entanglement in one-dimensional quantum systems under sinusoidal deformation

We investigate entanglement generation in one-dimensional quantum spin systems with the sinusoidal deformation. In the system, the energy scale of each local term in the Hamiltonian is modified according to a position-dependent function \sin^\alpha[\frac{\pi}{N} (x - \frac{1}{2})], where x is the position of the local term and N is the length of the system. We show that at zero temperature the system with \alpha \ge 2 is able to generate a sizable entanglement between two spins at open edges even when the two spins are infinitely far apart. This long-distance entanglement is rather robust against thermal fluctuations and survives up to a temperature that decays with the system size slowly, in an algebraic form.