Miracle-dz/UniFAR-FTUs huggingface dataset:
Terahertz frequency range band-stop filters

We report the operation of band-stop filters in the terahertz (THz) frequency range, working at a center frequency of 600GHz. The filters were characterized by embedding them in a microstrip line attached to photoconductive switches which act as THz emitters and detectors. The filters have applications in sensing and detection. The chosen filter design allows cascading of several filters along the same microstrip line, which is of particular importance for a proposed molecular sensing array.
Changes in cell surface properties of Pseudomonas fluorescens by adaptation to NaCl induced hypertonic stress

Abstract Determination of the effect of water stress on the surface properties of bacteria is crucial to study bacterial induced soil water repellency. Changes in the environmental conditions may affect several properties of bacteria such as the cell hydrophobicity and morphology. Here, we study the influence of adaptation to hypertonic stress on cell wettability, shape, adhesion, and surface chemical composition of Pseudomonas fluorescens. From this we aim to discover possible relations between the changes in wettability of bacterial films studied by contact angle and single cells studied by atomic and chemical force microscopy (AFM, CFM), which is still lacking. We show that by stress the adhesion forces of the cell surfaces towards hydrophobic functionalized probes increase while they decrease towards hydrophilic functionalized tips. This is consistent with the contact angle results. Further, cell size shrunk and protein content increased upon stress. The results suggest two possible mechanisms: Cell shrinkage is accompanied by the release of outer membrane vesicles by which the protein to lipid ratio increases. The higher protein content increases the rigidity and the number of hydrophobic nano-domains per surface area.
Design and performance analysis of a tunable and self-pulsation diode pumped double-clad D-shaped Yb3+-doped silica fiber laser

Ytterbium doped silica fibers exhibits very broad absorption and emission band, from ~800 nm to ~1064 nm for absorption and ~970 nm to ~1200 nm for emission according to the cavity length. A wide range of applications for tunable ytterbium fiber laser like development of single-frequency sources for spectroscopic applications, pumping source of Pr: ZBLAN amplifier and Tm: ZBLAN up conversion laser, material processing and military applications. In this paper, a 976 nm high power fiber coupled diode laser of up to 5 W end pumped ytterbium doped multimode D-shaped fiber laser using Fabry-Perot cavity with different regime of operation with the output coupler reflectivities of 80%, 60%, and Fresnel reflection of 4%. The output laser wavelength ranges from 1041 nm to 1094 nm for a cavity length from 1 m to 10 m, respectively. The optical to optical slope efficiency of 45% at 1 m and increased to be 60% at 4 m cavity length were measured. The maximum slope efficiency of 82.12% at cavity length of 2m were investigated with Fresnel reflection output coupler, and the measured lowest threshold pump power for this configuration was 130 mW. Also, the self-pulsation phenomena were observed just at higher pumping power of more than 4W and its threshold pumping power were (4.3W, 4.5W and 4.7W) with output coupler reflectivities of (80%, 60%, and Fresnel reflection of 4%), respectively at 10 m fiber length.
Mean and Turbulence Characteristics of Three-Dimensional Wall Jet on Convex Cylindrical Surfaces

The influence of convex curvature on the mean and turbulent characteristics of three-dimensional wall jet generated from a circular orifice geometry is reported in this paper. Mild, moderate, and strong curvature are considered. Detailed results on a plane surface are also obtained for comparison purposes. Among the mean properties, the decay rate of maximum velocity and the growth of length scales are significantly altered due to curvature effects. The turbulent components, both turbulent normal and shear stresses, show an increase with curvature parameter in a direction normal to the curved surfaces; however, there is very little change in the spanwise direction.
An Fe-Ni Bubble in the Small Magellanic Cloud Supernova Remnant B0049–73.6

We present observations with the Chandra X-Ray Observatory of the supernova remnant (SNR) B0049-73.6 in the Small Magellanic Cloud (SMC). The remnant shows outer emission from swept-up SMC gas and a bright ejecta-dominated ring in the interior. The X-ray spectrum of the outer shell shows normal SMC abundances and allows us to estimate the current blast wave speed at 570 km s-1 from Sedov models. The swept-up mass is equal to 170 M⊙, the SNR age is 14,000 yr, and the explosion energy is 8.1 × 1050 ergs. The brightest parts of the inner ring are dominated by O- and Ne-rich heavy-element ejecta. B0049-73.6 is thus a remnant of a core-collapse explosion. More diffuse interior ejecta emission shows less prominent O and Ne lines. The total mass of O within the heavy-element ejecta is about 0.3 M⊙. The filling fraction of the O-rich gas is less than 1%, and its average ionization timescale of 5 × 1010 cm-3 s suggests that the observed emission is dominated by relatively dense (ne ∼ 0.2 cm-3) ejecta. The bright inner ring most likely is composed of the innermost ejecta swept up by a central "nickel bubble" resulting from radioactive energy input from freshly synthesized 56Ni. This is in a qualitative agreement with theoretical predictions of such centrally located Fe-Ni bubbles, and it confirms the important role of the Ni bubble effect in determining the innermost ejecta structure in core-collapse supernovae.
Aspects of guaranteed error control in computations for partial differential equations

This thesis studies guaranteed error control for elliptic partial differential equations on the basis of the Poisson model problem, the Stokes equations and the obstacle problem. The error control derives guaranteed upper bounds for the energy error between the exact solution and different finite element discretisations, namely conforming and nonconforming first-order approximations. The unified approach expresses the energy error by dual norms of one or more residuals plus computable extra terms, such as oscillations of the given data, with explicit constants. There exist various techniques for the estimation of the dual norms of such residuals. This thesis focuses on equilibration error estimators based on Raviart-Thomas finite elements, which permit efficient guaranteed upper bounds. The proposed postprocessing in this thesis considerably increases their efficiency at almost no additional computational costs. Nonconforming finite element methods also give rise to a nonconsistency residual that permits alternative treatment by conforming interpolations. A side aspect concerns the explicit residual-based error estimator that usually yields cheap and optimal refinement indicators for adaptive mesh refinement but not very sharp guaranteed upper bounds. A novel variant of the residual-based error estimator, based on the Luce-Wohlmuth equilibration design, leads to highly improved reliability constants. A large number of numerical experiments compares all implemented error estimators and provides evidence that efficient and guaranteed error control in the energy norm is indeed possible in all model problems under consideration. Particularly, one model problem demonstrates how to extend the error estimators for guaranteed error control on domains with curved boundary.
On the unimodality of the likelihood for the Cauchy distribution: Some comments

Copas (1975) shows that under regularity conditions the joint likelihood for both location and scale parameters for independent, identical Cauchy variables has exactly one maximum point, and at most one stationary point. However, the proof is not complete; Copas shows that the joint likelihood for both location and scale parameters, L say, has the property that any stationary point of L is a local maximum, and concludes that, in fact, L possesses only one such point, which is then a global maximum. Under fairly weak conditions this argument is correct and it seems to be widely accepted in the statistical literature although I know of no rigorously established general theorems of this kind. The analytic result on global maximization which forms the basis of the argument is as follows.
The topographic torque associated with a tangentially geostrophic motion at the core surface and inferences on the flow inside the core

Abstract In the last few years seismologists have proposed core-mantle topographies. At the same time much effort has been devoted by geomagneticians to calculate the fluid flow (and the related pressure field) at the top of the core, based on the observation of the secular variation of the geomagnetic field. A ‘‘topographic torque'', which results from the action of the pressure field at the core surface, has long been invoked to allow for exchanges of angular momentum between the core and the mantle. In this paper, we show that this torque can be computed if forces at the top of the core are in geostrophic balance. The deep nature of this topographic torque can be understood only if one goes beyond the case of a pseudo-static equilibrium and considers explicitly the acceleration term in the equation of motion. We show that the pressure field acts in such a way as to accelerate a zonal flow consisting of cylindrical annuli. These annuli rotate like rigid bodies, with an angular velocity which depends on .
Erbium-doped fiber laser with distributed Rayleigh output mirror

An erbium-doped fiber laser based on random distributed feedback through Rayleigh scattering in a long-distance (5–30 km) single-mode fiber (SMF) is demonstrated for the first time. Under the pump of a 1480 nm laser diode, typical random laser radiation is achieved with an obvious threshold behavior as a function of pump power. Thanks to the fiber Bragg grating (FBG)-based half-opened cavity design and the efficient gain from the pumped erbium-doped fiber, a low threshold power of 10 mW is achieved, which is approximately two orders lower in magnitude than that of previously reported conventional random fiber lasers amplified through distributed Raman effects. Dual-wavelength lasing operation is also achieved by using two FBGs with different reflection wavelengths to collaborate with the distributed Rayleigh output mirror.
Tunneling entity in different injection regimes of InGaN light emitting diodes

The forward I-V characteristics of InGaN-based light emitting diodes heteroepitaxially grown have previously been shown to be dominated by tunneling over a wide range of bias, as indicated by unrealistic values for the ideality factor. Comparison of the electrical characteristics in different bias regimes for InGaN light emitting diodes (LEDs) to expressions for the tunneling current enables one to achieve an understanding of the tunneling entities involved. At low bias for LEDs grown on sapphire, data are consistent with electron tunneling to deep levels in the vicinity of mixed/screw dislocations and are characterized by an energy near 200meV. This component is absent for those devices homoepitaxially grown. In the intermediate bias regime, LEDs both heteroepitaxially and homoepitaxially grown exhibit a tunneling component that is proposed to be associated with the heavy hole tunneling via intermediate states and to have a characteristic energy near 80meV.
Imaging of electron density troughs by tomographic techniques

Troughs in the latitudinal distribution of electron density are a well‐known feature of the ionosphere from subauroral to polar latitudes. The location and depth of the trough minimum, the width of the feature, and the horizontal gradients in electron density associated with the trough walls are all quantities of interest or concern to practical applications of radio systems involving the ionosphere. In practice, the precise characteristics of trough‐like structures have been difficult to monitor using ground‐based methods. Ionospheric tomography represents a new development that is maturing into a technique ideally suited to the study of electron density troughs. Results are presented from a variety of observations made during tomographic campaigns in northern Europe. A long‐term investigation has been made of the main trough from a network of stations in the United Kingdom. The position of the trough minimum and the wall gradients have been studied on a diurnal basis using tomographic images reconstructed from measurements for a succession of passes of Navy Navigation Satellite System satellites. With stations deployed for more than 6 months, the average behavior has also been studied. Examples are shown of extreme behavior of the trough under very disturbed geomagnetic conditions, during which tomography continues to yield images while the limitations of ionosondes are exposed. Studies of narrow troughs with very steep gradients seen at auroral latitudes have been used to investigate some of the successes and limitations of the tomographic method. Measurements made in the polar cap show the depleted densities of the polar hole in the center of the dawn convection cell and illustrate the power of the tomographic method at high latitudes. Finally, the dayside trough at the high‐latitude boundary between corotating and counterstreaming flux tubes in the afternoon sector has been revealed in a tomographic image extending over some 30° latitude, made using a chain of six stations in Scandinavia.
Semigroup Kernels, Poisson Bounds, and Holomorphic Functional Calculus

LetLbe the generator of a continuous holomorphic semigroupSwhose action is determined by an integral kernelKon a scale of spacesLp(X; ρ). Under mild geometric assumptions on (X, ρ), we prove that ifLhas a boundedH∞-functional calculus onL2(X; ρ) andKsatisfies bounds typical for the Poisson kernel, thenLhas a boundedH∞-functional calculus onLp(X; ρ) for eachp∈⦠1, ∞⦔. Moreover, if (X, ρ) is of polynomial type andKsatisfies second-order Gaussian bounds, we establish criteria forLto have a bounded Hormander functional calculus or a bounded Davies–Helffer–Sjostrand functional calculus.
AGILIS: Restoring Functional Grasping in Individuals with Tetraplegia using Epineural Electrodes

 Abstract — We propose a novel approach to restore grasping in individuals with complete tetraplegia using epineural stimulation. Two multi-contact cuff electrodes were positioned around radial and median nerves in 2 volunteers during a surgery. The electrodes were maintained for 28 days. A user interface allowed triggering pre-programmed stimulation sequences on demand by executing stereotyped movements or by contracting voluntarily muscle on the contralateral shoulder. The stimulation selectivity obtained with the epineural electrodes was sufficient to obtain functional palmar and key pinch grip.
Leveraging maternity waiting homes to increase the uptake of immediate postpartum family planning in primary health care facilities in Ethiopia

Background: Maternity waiting homes within primary health care facilities are ideal platforms to reach women with family planning education and counselling. Maternity waiting home users interact with health care providers on a regular basis throughout their waiting period and can prepare to initiate the family planning method of their choice immediately after childbirth. To date, there has been no clear evidence about the use of maternity waiting homes to increase the uptake of immediate postpartum family planning. The aim of this study is to assess the contribution of maternity waiting homes to increase the uptake of immediate postpartum family planning among women who deliver in primary health care facilities in Ethiopia. Methods: A comparative cross-sectional study design was conducted to collect quantitative data from women who gave birth within 12 months prior to the study. Multi-stage random sampling procedures were employed to select 884 women. Descriptive summaries and logistic regressions with 95% confidence intervals were conducted using Stata version14 to analyze the data. Results: The prevalence of immediate postpartum family planning use among women who used maternity waiting homes was 44%, while among those who did not use maternity waiting homes it was 36%. The use of maternity waiting homes significantly contributed to an increase in the immediate uptake of postpartum family planning (OR = 0.69, 95% CI = 0.51-0.95, p<0.022). Conclusions and recommendations: This study showed that maternity waiting homes significantly contributed to improved uptake of immediate postpartum family planning within 10 minute or 48 hours after delivery. Developing a comprehensive package of maternal care services in maternity waiting homes has the potential to improve the uptake of family planning among postpartum women. [Ethiop. J. Health Dev. 2021; 35(1):9-17]
Infinitely wide limits for deep Stable neural networks: sub-linear, linear and super-linear activation functions

There is a growing literature on the study of large-width properties of deep Gaussian neural networks (NNs), i.e. deep NNs with Gaussian-distributed parameters or weights, and Gaussian stochastic processes. Motivated by some empirical and theoretical studies showing the potential of replacing Gaussian distributions with Stable distributions, namely distributions with heavy tails, in this paper we investigate large-width properties of deep Stable NNs, i.e. deep NNs with Stable-distributed parameters. For sub-linear activation functions, a recent work has characterized the infinitely wide limit of a suitable rescaled deep Stable NN in terms of a Stable stochastic process, both under the assumption of a ``joint growth"and under the assumption of a ``sequential growth"of the width over the NN's layers. Here, assuming a ``sequential growth"of the width, we extend such a characterization to a general class of activation functions, which includes sub-linear, asymptotically linear and super-linear functions. As a novelty with respect to previous works, our results rely on the use of a generalized central limit theorem for heavy tails distributions, which allows for an interesting unified treatment of infinitely wide limits for deep Stable NNs. Our study shows that the scaling of Stable NNs and the stability of their infinitely wide limits may depend on the choice of the activation function, bringing out a critical difference with respect to the Gaussian setting.
The Role of Social Media in Promoting Reading Attitudes among Undergraduate Students in UCSI University

================================================================== Abstract In recent years, technological advancements in social media such as Facebook, Instagram, Twitter and YouTube have raised concern to how reading and reading attitude is perceived and acted on among students in institutions of higher education. This study was conducted to investigate the relationship between time spent on social media and reading attitude among undergraduate students in UCSI University. The study also intended to find out which social media platforms such as Facebook, Instagram, Twitter and YouTube affected students’ reading attitude the most. To answer these questions, the present study adopted the correlational research design to identify the relationship and degree of association between social media use and reading attitude.
The full-spectrum correlated k method for longwave atmospheric radiative transfer: treatment of gaseous overlap

The correlated k-distribution (CKD) method is widely used in the radiative transfer schemes of atmospheric models, and involves dividing the spectrum into a number of bands and then reordering the gaseous absorption coefficients within each one. The fluxes and heating rates for each band may then be computed by discretizing the reordered spectrum into of order 10 quadrature points per major gas, and performing a pseudo-monochromatic radiation calculation for each point. In this paper it is firs t argued that for clear-sky longwave calculations, sufficient accuracy for most applications can be achieved without the need for bands: reordering may be performed on the entire longwave spectrum. The resulting full-spectrum correlated k (FSCK) method requires significantly fewer pseudo-monochromatic calculations than standard CKD to achieve a given accuracy. The concept is first demonstrated by comparing with line-by-line calculations for an atmosphere containing only water vapor, in which it is shown that the accuracy of heating-rate calculations improves approximately in proportion to the square of the number of quadrature points. For more than around 20 points, the root-mean-squared error flattens out at around 0.015 K d −1 due to the imperfect rank correlation of absorption spectra at different pressures in the profile. The spectral overlap of m different gases is treated by considering an m-dimensional hypercube where each axis corresponds to the reordered spectrum of one of the gases. This hypercube is then divided up into a number of volumes, each approximated by a single quadrature point, such that the total number of quadrature points is slightly fewer than the sum of the number that would be required to treat each of the gases separately. The gaseous absorptions for each quadrature point are optimized such they minimize a cost function expressing the deviation of the heating rates and fluxes calculated by the FSCK method from line-by-line calculations for a number of training profiles. This approach is validated for atmospheres containing water vapor, carbon dioxide and ozone, in which it is found that in the troposphere and most of the stratosphere, heating-rate errors of less than 0.2 K d −1 can be achieved using a total of 23 quadrature points, decreasing to less than 0.1 K d −1 for 32 quadrature points. It would be relatively straightforward to extend the method to include other gases. (See also Hogan, R. J., 2010, J. Atmos. Sci., 67, 2086‐2100.)
Microsoft Word-Inequality and Monetary Policy Book.docx

Interest rates have declined over the last forty years, a period of increasing inequality. The steady decline in interest rates has been interpreted by and large as resulting from a decline of the natural rate of interest. This paper surveys the main explanations associated with the notion of a decline in the natural rate of interest, including the savings glut and the secular stagnation hypothesis. It analyzes the views according to which demographic forces were behind the decline, and might perhaps be associated to a future rise of the same natural rate. It also discusses the view according to which the role of inequality has been also to affect the natural rate of interest. Finally, views that discuss the role of monetary and financial factors, including the so-called global financial cycle literature, are discussed. It is argued that the conventional view suffers from logical and empirical problems that are ultimately unsurmountable. A brief critique of the notion of a natural rate of interest, and alternative monetary theory of the decline of interest rates, as determined exogenously by the monetary authority of the hegemonic country, the United States, is proposed.
Two-Stage Model of Silicate Glass Transition

After several decades of study, the nature of the glass state and glass transition remains controversial. This work describes a newly proposed two-stage model for silicate glass transition. The model recognizes that there is a cooling rate independent critical temperature Tc, separating two temperature regions. The coherent structures in the two regions change along different paths. All observed dynamic features in the glass transition result from structural rearrangements in the process. According to the proposed model, the silicate glass transition can be recognized as a second-order phase transition following an incomplete first-order phase transition. This work will first describe the two-stage model, and then apply the model to silica glass, as well as binary and ternary silicate glass transitions.